Proposte Tesi - Particle, Astroparticle Physics and Advanced Technologies
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Titolo | Abstract | Contatto |
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Advanced Technologies
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Characterization of first prototypes of ultra-thin bent silicon pixel sensors for
Inner Tracking System 3 in the ALICE-LHC experiment |
The ALICE experiment at the Large Hadron Collider (LHC) at CERN has planned an upgrade of the Inner Tracking System (ITS), named ITS3, to be installed during the LHC Long Shutdown 3 (2026-2029). This upgrade will implement a new 65 nm CMOS pixel chip, fabricated using Monolithic Active Pixel Sensor (MAPS) and the stitching technology to use wafer scale chip up to 26 cm long. These chips will be bent to replace the three innermost layers of the existing detector with new ultra-light, truly cylindrical layers.
This thesis will focus on characterization of the first prototypes of ultra-thin bent silicon pixel sensors fabricated using the TowerJazz 65 nm CMOS process. The investigation will cover the timing performance, signal chain response and spatial resolution across various parameter settings. Furthermore, to deeply explore the analog behavior of the sensors, the analysis of signal response from a low-energy X-ray source will be carried out. The student will have the opportunity to collaborate with a group of researchers and postdocs involved in the proposed research activities. The activities take place in the High Technology Laboratory of the University of Bari Aldo Moro & INFN Section of Bari and CERN. |
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Advanced Technologies
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Study on the performance of bent ALPIDE in test beam environments
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Over the last decades, silicon-based vertexing detectors have become the main tracking devices close to the interaction point in essentially all high energy and nuclear physics experiments. In order to minimise the distance of the sensors to the primary vertex and to reduce the material
budget of the overall detector to a minimum, the usage of truly cylindrical, bent, wafer-size monolithic active pixel sensors (MAPS) presents an almost ideal solution. The ALICE Collaboration has planned an extensive test beam campaign to explore the performance of these sensors after the bending procedure. The test beam, which involved bent ALPIDE chips with a thickness of 50 μm, was conducted at the CERN SPS. This thesis will focus on analyzing the data collected during the test beam to demonstrate the performance of these bent sensors in terms of efficiency, cluster size, and spatial resolution. |
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Advanced Technologies
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Modeling parameters of interest in radiobiology (LET, RBE) using a Monte Carlo approach at both macro and micro-dosimetric scale.
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A reliable prediction of the spatial Linear Energy Transfer (LET) distribution in biological tissue is a crucial point for the estimation of the radiobiological parameters on which are based the current treatment planning. Nowadays, the accuracy and approach for the LET calculation can significantly affect the reliability of the calculated Relative Biological Effectiveness (RBE).
Monte Carlo (MC) technique is considered the most accurate method to account for complex radiation transport effects and energy losses in a medium. However, as a computation method, the accuracy and precision of the MC calculation result strongly depend on the physics interaction cross sections applied as well as the simulation algorithms used and the transport parameters chosen. In this framework, the goal of the project consists on the development, study and validation of a completely new open source tool based on Geant4 code for the calculation of the LET-track, LET-dose and RBE distributions of therapeutic proton and ion beams completely independent to transport parameters. The thesis work on this topic could also include experimental measurements.
** This is a thesis work envisaging a collaboration with INFN Laboratori Nazionali del Sud (LNS) **
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Advanced Technologies
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PRAGUE: Proton Range Measure Using Silicon Carbide
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Measuring and verifying the reliability and stability of the dosimetric properties of a radiotherapeutic beam, is the most important task of any external-beam radiotherapy quality assurance program. The beam characteristics can be assessed in terms of several different parameters, such as the percentage depth-dose distribution, flatness, symmetry, and absolute dose output. The depth-dose-distribution measure is today performed, adopting commercial systems whose main advantage is the short operational time. The aim of PRAGUE (Proton RAnGe measure Using silicon carbidE) project is to design and construct a detector, based on a new generation of Silicon Carbide (SiC) devices, to measure proton depth dose distributions in real-time and with high spatial resolution (10 μm). The extreme radiation hardness of such devices and the independence of their response with the proton beam energy, makes them capable to operate with clinical hadrontherapy beams and flash proton beams, where extremely high dose rates are delivered. The detector will be composed by a stack of new generation, large area SiC devices with an active thickness of 10 μm. A first detector protype was already designed and tested. The obtained results indicate the SiC detector as a suitable detector for relative dosimetry with charged particles. It showed, in fact, a stable and reproducible response and an extremely good behavior in terms of linearity as respect to absorbed dose was found. The negligible dependence of its response against energy and dose-rate and the high radiation hardness, represent advantageous features as respect other commercial solid-state detectors for ion beams dosimetry. A thesis work on this topic can include more than one of the following aspects:
- Geant4 simulation of the entire system;
- experimental runs in different facilities (the detector will be tested with conventional and laser-driven proton beams);
- electrical characterization of Silicon Carbides.
** This is a thesis work envisaging a collaboration with INFN Laboratori Nazionali del Sud (LNS) **
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Advanced Technologies
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Reconstruction of Bragg peak for clinical ions
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Particle beam radiotherapy provides compelling evidence about its superior efficacy in cancer treatment. The therapeutic use of protons and heavy ions, such as helium, carbon, and oxygen has gained significant interest due to advantageous physical and radiobiologic properties compared to photon-based therapy. Cancer cells are targeted more effectively as the dose is deposited in a localised region due to the so-called Bragg peak, with a smaller chance of cancer recurring. Compared to protons, heavy ion beams show a steeper dose gradient at the end of the ion range in matter. The sharper Bragg peak makes ion beam therapy particularly sensitive to range uncertainties that can lead to severe over-dosage of healthy tissue.
Scintillators are indispensable for radiation detection in various fields. This technology has been successfully transferred to clinical applications where these detectors are employed in particle therapy instrumentation for beam profile monitoring and depth-dose profile measurements. To reconstruct the Bragg peak, an analytical model for the quenched depth-light curve is derived by combining Bortfeld’s analytical approximation of a proton Bragg curve with Birks’ formula for light quenching. Despite its extraordinary performance with protons, the model shows some limitations when applied to clinical ions. Such ion beams have a significant dose contribution from projectile fragmentation and undergo a strong quenching at the Bragg peak. In order to exploit the full potential of ion-beam radiotherapy, improved methods for range measurements are compelling.
The goal of this thesis work is to develop and test new models for the range measurement of He and Carbon beams. Real data will be analysed. We propose to explore the numerical model for depth-dose deposition developed by Kramer et al.[doi:10.1088/0031-9155/45/11/313]
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anna.colaleo@uniba.it |
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Advanced Technologies
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Simulation of a Quality Assurance Range Calorimeter for particle therapy
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Proton radiotherapy provides significant benefits over conventional X-ray radiotherapy targeting cancer cells more effectively with a smaller chance of cancer recurring and requires sophisticated instrumentation in order to ensure that treatment is carried out safely. Range uncertainties is one of the largest sources of uncertainty in proton therapy and prevent taking full advantage of its superior dose conformity. To ensure optimal patient safety, quality assurance (QA) procedures are carried out each day before treatment begins, which are often time-consuming.
A new device named Quality Assurance Range Calorimeter (QuARC) is currently under development to provide fast, accurate, water-equivalent proton range measurements for daily QA. The detector consists of a series of optically isolated plastic scintillator sheets that sample the proton energy deposition along its path. Light from each sheet is measured by a series of photodiodes: this light output is proportional to the deposited energy. An analytical depth-light model is used to fit the data and measure the proton range to sub-mm precision. The student will perform an accurate simulation of the detector using Geant4. The simulated response of the detector with different configurations will support and guide the system R&D. The results will be validated against experimental data.
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| Advanced Technologies | Study and development of machine learning and deep learning algorithms for biometric applications on secure storage devices |
The aim of this Master’s thesis is to develop advanced solutions for security applications. The thesis will be carried out at a company , in a dynamic environment and in close contact with experts in cutting-edge security technologies. Skills: Students will gain knowledge and practical experience in a company on advanced biometric security applications and algorithm design. |
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| Advanced Technologies | A pioneering Compton Camera for hadrontherapy with a 3D silicon Pixel Chamber |
Compton Cameras were originally developed in astrophysics to determine the origin (i.e. direction) of gamma rays from a few hundred keV to several MeV, an energy range where Compton scattering is the dominating interaction process. A Compton camera consists of two position- and energy-sensitive sub-detectors: scatterer and absorber. A single gamma that undergoes a Compton scattering in the first detector and is then fully absorbed in the second detector does not allow to determine univocally its direction, but only a continuous cone of possible directions. Therefore, several gammas from the same source point are needed to reconstruct the source position, the larger the number of gammas, the better the pointing resolution. The hadron (proton or ion) therapy for treating cancer has been widely used over the past decades, because of the peculiarity of the energy release of the hadron beam. The sharp Bragg peak provides a unique benefit for cancer therapy, allowing for dose escalation to the tumor and a reduction of exposure for the surrounding healthy tissues. However, the uncertainties in the position of the distal falloff restrict our ability to exploit the steep dose gradients at the distal edge of the Bragg peak, reducing the full clinical potential of hadrontherapy. Therefore, in vivo beam monitoring is essential to guarantee the treatment effect of hadrontherapy. Compton Cameras can perform this task, but present detectors do not yet allow an on-line monitoring of the treatment, which requires high-resolution imaging of direct gamma sources to be performed over a time of a few seconds. The main limitation is the large number of gammas required to determine the source with sufficient precision. The student will develop a new concept of Compton Camera that exploits a Pixel Chamber as the scatterer. The Pixel Chamber offers the extraordinary possibility to also reconstruct the direction of the emitted electron, thus closing the kinematics and allowing one to determine the direction with a single photon. The focus of the thesis could be either on Monte Carlo simulations to optimize the design or hardware-oriented for the construction of the first Pixel Chamber prototypes |
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| Advanced Technologies |
Development of an innovative silicon pixel detector for imaging applications in radioguided surgery |
Radioguided surgery (RGS) is a widely utilized technique in oncology. Its primary objective is to enable surgeons to locate tumor masses in real-time, eliminating the need for pre-surgical diagnostic images or histological tissue sample examinations during surgery, that would prolong the procedure and introduce additional risks. Prior to surgery, a radiotracer, preferably absorbed by tumor cells rather than healthy tissue, is administered to the patient. By detecting the emissions of the radiotracer using a specialized probe, both the primary tumor and possible residual tumor foci can be identified. The use of a probe with imaging capabilities further enables surgeons to precisely delineate tumor boundaries, minimizing the amount of healthy tissue removal and reducing the risk of incomplete tumor excision. The student will actively participate to the development of an innovative intraoperative probe designed for radio-guided surgery (RGS). This probe will employ the ALPIDE pixel detector, originally developed for High Energy Physics, as the sensitive element. The tasks will include performing measurements with phantoms soaked with beta+ radiotracers and conducting comprehensive simulation studies to assess the probe's performance under realistic clinical scenarios. |
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| Astroparticle Physics |
Advanced multi-instrument analysis of energetic Gamma-Ray Bursts observed by the Fermi Gamma-Ray Space Telescope | The Fermi mission has been a very prolific Gamma-Ray Burst (GRB) hunter over the past 13 years. The Gamma-Ray Burst Monitor (GBM, 8 keV - 40 MeV) triggered on more than 3200 GRBs, with a rate of almost 240 bursts per year. About 8% of all GBM-detected events has been observed at higher (>100 MeV) energies with the Large Area Telescope (LAT, 100 MeV - 300 GeV) onboard Fermi, unveiling very interesting high-energy properties of these events both regarding the prompt as well as the afterglow emission. Some super bright GRBs have also been seen at TeV energies with Cherenkov telescopes of the MAGIC and the H.E.S.S. experiments. The goal of the project is the temporal and spectral analysis of a subset of energetic events, to be analyzed with a “multi-instrument” approach over a very wide energy range. In particular, the project will focus on the joint study of a few interesting GBM+LAT events reported in the Second Fermi-LAT catalog, using the recently developed gbmtools software and the multimission-analysis software package 3ML. |
elisabetta.bissaldi@ba.infn.it serena.loporchio@ba.infn.it |
| Astroparticle Physics |
Exploring the short Gamma-Ray Bursts class using 13 years of data collected by the Fermi Gamma-Ray Space Telescope |
The Fermi mission has been a very prolific Gamma-Ray Burst (GRB) hunter over the past 13 years. The Gamma-Ray Burst Monitor (GBM, 8 keV - 40 MeV) triggered on more than 3200 GRBs, of which ~80% are long and ~20% are short duration events. Short GRBs are particularly interesting, since they have been firmly associated with neutron star merger events, thanks to the joint detection of GRB 170817A both in gamma rays with Fermi-GBM and in gravitational waves (GW) with the LIGO-Virgo interferometers. The goal of the project is to analyze the spectral properties of GBM-detected GRBs belonging to the short-duration class, and to deeper investigate their differences and similarities to the long GRB class. This will be done by means of the newly developed gbmtools software. |
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| Astroparticle Physics |
Probing Cosmic Ray Acceleration using young Supernova Remnants observed by the Fermi Gamma-Ray Space Telescope | The origin of Galactic Cosmic Rays is still unknown. In particular, it is widely debated which are the Galactic sources able to accelerate particles up to the PeV energies measured at the Earth’s surface. Supernova Remnants (SNRs) are the best candidate to be acceleration sites, since their shock wave is able to accelerate particles and explain the cosmic ray energy density. The Fermi Large Area Telescope has widely studied a number of SNRs, looking for signatures of accelerated particles in the gamma-ray energy range. In particular, young SNRs, which are less than 1000 years old, are still in the initial phase of their evolution and are the best candidate to detect freshly accelerated protons. In this project, the known young SNRs will be systematically studied with 13 years of Fermi-LAT data, taking advantage of the large dataset to disentangle the hadronic from the leptonic origin of the gamma-ray emission. | |
| Astroparticle Physics |
Development of deep learning algorithms for the event reconstruction of the Schwarzschild-Couder Telescope proposed for CTA | The Cherenkov Telescope Array Observatory (CTAO) is a project aimed to detect very high energy gamma rays of astrophysical origin between 20 GeV and 200 TeV, in order to unveil the most mysterious phenomena in our Universe. The Schwarzschild-Couder telescope is a medium sized telescope proposed for CTAO with innovative dual mirror optics and an advanced camera based on Silicon Photomultipliers (SiPM). At present, the event reconstruction algorithms are based on the so-called Hillas parameters, obtained from the typical elliptical shape of the gamma-ray images in the Cherenkov telescope cameras. In order to exploit the very high resolution of the SCT camera, new algorithms based on Convolutional Neural Networks (CNN) are being developed. The goal of this project is the study and development of these new algorithms, with a full study of the event reconstruction. | |
| Astroparticle Physics |
Indirect dark matter searches with Fermi-LAT |
The existence of dark matter is supported by many experimental results, but its nature is still unknown. The Weakly Interacting Massive Particles (WIMPs), whose existence is predicted in the framework of several theoretical supersymmetry models, are among the most credited dark matter candidates.
The data collected by the Fermi Large Area Telescope (LAT) can be used to perform indirect dark matter searches by looking at possible excesses of gamma rays (or cosmic-ray electrons and positrons) from possible dark matter sources. WIMPs could in fact annihilate or decay into final states with pairs of Standard Model particles (including gamma rays, electrons and positrons). An excess of these particles from a dark matter rich astrophysical site (“target”) would therefore represent a proof of the WIMP nature of dark matter. Conversely, a non-detection would allow to set upper limits on the WIMP annihilation cross sections and decay rates.
The possible targets for dark matter searches include the Galactic Center, the Milky Way Dwarf Spheroidal Galaxies, the Galactic Halo, and also celestial bodies such as our Sun. Thesis are available, focused on the study of the flux of gamma rays (or cosmic-ray electrons and positrons) from any of these sources, aimed at the search of a possible excess correlated to dark matter. |
marionicola.mazziotta@ba.infn.it
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| Astroparticle Physics |
Galactic cosmic ray propagation |
Galactic cosmic rays (CR) are subject to diffusion due to collisionless interactions with plasma, interactions with the interstellar gas, magnetic drifts, continuous energy losses and other processes during their propagation. Current measurements of CR fluxes have reached unprecedented accuracy thanks to the new generation of facilities studying this phenomenon. This work is aimed at analyzing those experimental data to obtain the posterior probabilities of the relevant diffusion parameters in the propagation of cosmic rays in the Galaxy. |
marionicola.mazziotta@ba.infn.it
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| Astroparticle Physics |
Interactions of cosmic rays with interstellar medium and solar bodies |
Gamma rays are produced in the hadronic interactions of cosmic-ray nuclei with the celestial bodies in the solar system, including the Sun, the Earth, the Moon, the planets, the asteroids and the small bodies like comets. The Moon is one of the brightest sources of gamma rays in the sky. Gamma rays are produced by cosmic-ray nuclei impinging on the regolith of the lunar surface. Lunar gamma rays are therefore a valuable tool to study the mechanisms of the high-energy hadronic interactions of cosmic rays. The gamma-ray flux from the Moon also exhibits a time dependence, correlated to the solar activity. A possible thesis will be focused on the analysis of the gamma-ray data collected by the LAT to measure the flux from the Moon and to study its time evolution. The process of gamma-ray emission from the planets is similar to that from the Moon. Due to the large distances from the Earth, their emission has not yet been detected. A possible thesis will be aimed at the measurement of the gamma-ray flux from the planets closer to the Earth (Mars, Venus, Jupiter) or from small bodies passing close to the Earth with the Fermi LAT data. In case of non-detection, upper limits will be set and their interpretation will be provided. Finally, gamma rays are produced in the interactions of cosmic rays with the upper layers of the Earth’s atmosphere (Earth’s limb). Their fluxes are related to the composition and density of the atmosphere, and are affected by the geomagnetic field and by the interplanetary magnetic field. A possible thesis will be focused on the measurement of the gamma-ray fluxes from the atmosphere using the Fermi LAT data. |
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| Astroparticle Physics |
Extragalactic source analysis in the very high energy gamma-rays with the Fermi-LAT and MAGIC telescopes | Active Galactic Nuclei (AGN) constitute the widest population of extragalactic gamma-ray sources. These sources often show variable fluxes due to flaring events. A dedicated study is necessary to detect variable sources and study their emission in their flaring state. In this project, a selection of AGN will be studied with the Fermi-LAT data in the GeV range and the MAGIC data at the TeV energies. In particular, the flaring state of these objects will be analysed and their emission mechanisms will be investigated. |
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| Astroparticle Physics |
Study of the quiescent gamma-ray emission from the Sun with Fermi-LAT |
The Sun is a very special and bright gamma-ray source, whose emission is due to the interactions of cosmic ray (CR) protons and electrons with matter and photons in the solar environment. The nuclear interactions of CR protons and nuclei in the solar atmosphere leads to a point-like disk emission (disk component), while the Inverse Compton (IC) scattering of CR electrons off solar photons in the whole heliosphere is responsible for a space-extended emission (IC component). The Fermi-Large Area Telescope (Fermi-LAT) has observed the Sun since its launch in orbit in 2008, entirely covering the last 11-years Solar Cycle. We propose a detailed study of the two gamma-ray emission components from the Sun in order to reconstruct their energy spectrum in the energy range from 100 MeV to 300 GeV covered by Fermi-LAT and compare them with the known theoretical predictions. |
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| Astroparticle Physics |
Study of the solar modulation in gamma-rays during Solar Cycle 24 with Fermi-LAT data |
The Sun is among the brightest gamma-ray sources in the sky. The high energy gamma-ray emission from the Sun is due to the interactions of cosmic ray (CR) protons and electrons with matter and photons in the solar environment. Such interactions lead to two component gamma-ray emission: a pointlike emission due to the nuclear interactions of CR protons and nuclei in the solar atmosphere and a space-extended emission due to the inverse Compton (IC) scattering of CR electrons off solar photons in the whole heliosphere. The Fermi-Large Area Telescope (Fermi-LAT), in orbit since 2008, has observed the Sun during the whole 11-years Solar Cycle 24, Therefore, we propose to perform a dedicated study of the Fermi-LAT data from the Sun in order to show the anti-correlation between solar activity and gamma-ray emission and show for the first time the time trend of the two high-energy emission components from the Sun at energies above 100 MeV. |
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| Astroparticle Physics and Advanced Technologies | Characterization and testing of the read-out chain for the upgrade camera of the prototype Schwarzschild-Couder telescope for CTA |
The Cherenkov Telescope Array Observatory (CTAO) is a project aimed to detect very high energy gamma rays of astrophysical origin between 20 GeV and 200 TeV, in order to unveil the most mysterious phenomena in our Universe. The Schwarzschild-Couder telescope is a medium sized telescope proposed for CTAO with innovative dual mirror optics and an advanced camera based on Silicon Photomultipliers (SiPM). The frontend electronics (FEE) readout chain is based on two ASICs, the SMART to amplify analog signals and the TARGET to digitize the waveforms and generate physical triggers. The goal of this project is the characterization and test of the readout chain from the sensor to the FEE electronics, with a particular focus on the development of the low level calibration procedures. |
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| Astroparticle Physics and Advanced Technologies |
Characterization and test of prototypes of the Plastic Scintillator Detector of the HERD experiment onboard the Chinese Space Station |
The High Energy cosmic-Radiation Detection (HERD) facility has been proposed as one of several space astronomy payloads onboard the future China's Space Station (CSS), planned for operation starting around 2027 for about 10 years. The primary scientific objectives of HERD are: Indirect dark matter search with unprecedented sensitivity; precise cosmic ray spectrum and composition measurements up to the knee energy; Gamma-ray monitoring and full sky survey. The Plastic Scintillator Detector (PSD) is the one devoted to the nuclei and gamma-ray identification. The thesis will be focused on different aspects of the R&D activities related to the detector (front-end electronics test and characterization, detector performance studies, simulation and data analysis.) Keywords: HERD experiment, Cosmic-rays, gamma-rays, detector physics, frontend electronics, data analysis |
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| Astroparticle Physics and Advanced Technologies |
Performances studies of the HERD experiment onboard the Chinese Space Station |
The High Energy cosmic-Radiation Detection (HERD) facility has been proposed as one of several space astronomy payloads onboard the future China's Space Station (CSS), planned for operation starting around 2027 for about 10 years. The primary scientific objectives of HERD are: Indirect dark matter search with unprecedented sensitivity; precise cosmic ray spectrum and composition measurements up to the knee energy; Gamma-ray monitoring and full sky survey. The thesis will be focused on the studies of the performances of the experiment with the simulation tool GEANT4. Different aspects will be studied related both to the performances of each sub-detector and to the overall capability of the experiment to measure cosmic-rays and gamma-rays in a wide energy range. |
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| Astroparticle Physics and Advanced Technologies |
Development of a fiber tracker |
The current generation of satellite-borne cosmic-ray detectors for high-energy astrophysics mainly consists of multi-layer tracker-converters, based on silicon strip sensors. The typical tracker layer is usually segmented in different modules, called “ladders”, each composed of a few AC-coupled single-sided silicon micro-strip detectors (SSDs), daisy-chained via micro-wire bonding. A tracker module consists of many layers mounted on support trays, with the strips of each layer oriented perpendicularly to those of the adjacent layers, thus providing coordinate measurements along two orthogonal directions, both perpendicular to the detector pointing axis. With the evolution of the sensor technologies, trackers based on scintillating fiber readout with silicon photomultipliers (SiPMs) array now represent a promising alternative to silicon detectors. The achievable spatial resolution is correlated with the fiber diameter, and can be improved with staggered multi-layer fiber configurations. The goal of this work is to study the performance of a small-scale prototype equipped with novel SiPM multi-channel counters together with dedicated front-end and read-out boards. |
marionicola.mazziotta@ba.infn.it
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| Astroparticle Physics and Advanced Technologies | Characterization of a prototype active converter module for gamma-ray detection in the MeV energy range |
The astrophysical community is focusing its efforts in the development of a new generation of gamma-ray telescopes for detecting low-energy photons, in the sub-GeV region. Among the several proposed designs, the Astroparticle Telescope (APT) has been proposed to study the MeV sky. Its core detector is based on active converter modules made of thin scintillator crystals, coupled to WLS fibers readout by SiPMs. This design allows both the interaction of the incoming gamma-rays through Compton scattering and the measurement of the energy and position of the recoil electron. The possible theses will be focused on the characterization of detector prototypes and on the Monte Carlo simulations of full scale instruments. |
marionicola.mazziotta@ba.infn.it
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| Astroparticle Physics and Advanced Technologies | Development of a novel Silicon Pixel Detector for MeV astroparticle physics in space |
The astrophysical community is focusing its efforts in the development of a new generation of gamma-ray telescopes for detecting low-energy photons, in the MeV region. These detectors will be equipped with an active low density pixel detector for tracking the Compton electron in photon scattering events. Geant based simulation will be developed for the optimization of the detector design in terms of performance, power consumption and layout. |
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| Particle, Astroparticle Physics and Advanced technologies | Hunt to the strangest baryons at LHCb |
The "Eightfold way", a forerunner of the modern quark model, successed to classify hadrons into flavor SU(3) multiplets. A neat prediction was the existence of a baryon made of three strange quarks. Such baryon, named \Omega, was discovered in 1964 with a mass close to the predicted value. However, unlike other baryons, only few excited \Omega baryons have been observed so far, despite several states are expected by the quark model.
The student will look for new excited \Omega baryons using data collected by the LHCb experiment at CERN. Such states could be produced promptly at the proton-proton interaction point or from decays of the \Omega_c baryon (made of 1 charm +2 strange quarks). Both production processes will be explored. The project demands good analytical and programming skills (C++, root, Python, or similar). Further readings: https://physicstoday.scitation.org/doi/pdf/10.1063/1.3051535
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marco.pappagallo@cern.ch Dipartimento di Fisica, office R53 |
| Particle, Astroparticle Physics and Advanced technologies | Search for excited \Xi_cc^++ baryons at LHCb | In 2017 the LHCb collaboration claimed the observation of the \Xi_cc^++ baryon, the first hadron ever with two charm quarks. To investigate the internal quantum numbers of this unique system, the observation of excited \Xi_cc^*++ states is required. The student will look for the first excited \Xi_cc^++ baryon using data collected by the LHCb experiment at CERN. The search will be carried out by selecting candidates produced promptly at the proton-proton interaction point. The project demands good analytical and programming skills (C++, root, Python, or similar). Further readings: https://arxiv.org/abs/1707.01621 |
marco.pappagallo@cern.ch Dipartimento di Fisica, office R53 |
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Elementary Particle Physics
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Jet Reconstruction at a Muon Collider
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In the high energy physics community, there is an increased interest for a future multi-TeV muon collider, as one of the main tools to investigate the Standard Model with unprecedented precision after the LHC. In this context, the physics with jets will play a crucial role, both to measure the Higgs boson self coupling (e.g in the H-->HH—>4b as the greatest branching ratio) and the coupling with second quark generation (e.g. H—>ccbar)
Nevertheless, in a multi-TeV muon collider, the muon beam decay products can contaminate the interaction region. The physics reaches can be properly evaluated only when the detector performance is determined. Strategies to minimise the effect of the beam-induced background need to be implemented for jet reconstruction and flavour-tagging.
Machine learning techniques will be exploited to this purpose, and the jet identification performance will be taken as a benchmark for an optimized calorimeter design.
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Raffaella Radogna:
Rosamaria Venditti:rosamaria.venditti@uniba.it) |
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Elementary Particle Physics
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Low-energy muon reconstruction at the CMS experiment
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The search for rare decays of D and B mesons will be an excellent tool to probe new physics in next runs of the CERN Large Hadron Collider, as the increased integrated luminosity will result in high precision measurement. The excellent muon reconstruction capability of the Compact Muon Solenoid (CMS) experiment makes rare decays with muons in the final state the ideal playground for this kind of research.
Nevertheless, muons produced in such rare decays ($B_s\to\mu\mu$, $D_s\to\tau(3\mu)\nu$) typically have low transverse momenta thus being detected in the forward region of the CMS muon system.
The proton-proton collisions at high luminosity will also produce high levels of background particles produced forwardly, and the muon reconstruction and identification will be a challenging task for the analysers.
Multi-variate analysis (MVA) techniques have become established in high energy physics and can also be used for improving the existing muon identification algorithms.
In this thesis, MVA algorithms like “Boosted Decision Tree” and “Deep Neural Network” combining the low-level information from the tracker and muon detectors into physics object discriminators will be developed and studied, aimed at identifying low-energy muons with high efficiency and low fake rates in the context of the rare decays searches, even in a high background environment.
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Rosamaria Venditti:rosamaria.venditti@uniba.it
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Elementary Particle Physics
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The Higgs boson mass is one of the most important free parameters of the Standard Model. It is crucial to properly determine its value since it determines all the other Higgs boson properties (e.g cross section, branching ratio). Since its discovery in 2012, it has reached a precision of 0.1%, making it one of the best mass measurements in the world. H -> ZZ ->4 leptons decay is a golden channel to perform this measurement thanks to its clear signature and large signal-to-background ratio due to the complete reconstruction of the final state decay products.The student will perform the Higgs boson mass measurement in the H -> ZZ -> 4 leptons channel using data collected by the CMS experiment during Run 2 at LHC at centre-of-mass energy of 13 TeV. Key activities will be signal shape extraction, background estimation (either from simulation or from data), systematic uncertainties treatment and statistical interpretations of the results.
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Advanced technologies: instrumentation for medical technologies
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Simulation of a fast timing micro pattern gas detector for TOF-PET
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Positron Emission Tomography (PET) is an imaging technique used to visualise organ and tissue functions. It is based on electron-positron annihilation with the production of two back-to-back photons with energy of 511 keV. The detection of two coincident photons allows reconstructing a straight line (line of response, LOR), along which the annihilation took place. The measurement of several hundreds of thousands of LORs allows reconstructing the target. The quality of the reconstructed images can be improved using time-of-flight (TOF) information, reducing background from mismatched photons. Current TOF-PET time resolution is less than nano-second but a novel detector technology can be investigated in order to reduce it.
Simulation is a powerful tool for designing new detectors and guiding the construction of new prototypes. A new detector layout, named Fast Timing Micro Pattern Gas Detector (FTM), has been recently proposed that would feature high spatial resolution, high rate capability and fast timing. This thesis investigates the use of the FTM technology for an innovative TOF-PET imaging detector and emphases the importance of full detector simulation to guide the design of the detector geometry and performance. Geant4 will be used for the simulation of the passage of particles through the detector material.
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Raffaella Radogna |
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Nuclear physics
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The use of Machine Learning techniques for analysis of nuclear data at n_TOF (CERN)
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Machine Learning (ML) techniques are now well establish within the global scientific community, e.g. with convolutional neural networks (CNNs) for image and signal analysis or autoencoders for noise elimination. Since a few years these techniques are also being applied to the analysis of a variety of data collected in Nuclear and Particle Physics experiments, thanks to superior performances of ML in signal reconstruction or pattern recognition, relative to standard techniques.The thesis here proposed will focus on the application of some of these techniques to nuclear data for Astrophysics and applications collected at the neutron time-of-flight facility n_TOF at CERN. Different ML strategies and techniques will be investigated, and their performance compared, with the intent to identify the optimal solution for signal processing and data analysis of complex detection systems. The advantages of the ML techniques relative to traditional techniques will finally be discussed. |
Domenico Diacono (INFN-Bari)
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| Nuclear physics |
Feasibility study of nuclear reactions of astrophysical interest within the LUNA experiment |
The LUNA experiment (Laboratory for Underground Nuclear Astrophysics) deals with reproducing in the laboratory the nuclear reactions that generate most of the energy produced by stars and that have allowed the synthesis of elements within the stars and in the early Universe. These reactions are characterized by a very small probability (cross section) at energies of astrophysical interest and are very difficult to measure in laboratories at the Earth's surface where the cosmic background would mask the weak signal expected. In the last 25 years, the LUNA collaboration has installed two accelerators in the underground laboratories of the LNGS where the cosmic background is reduced by 6 orders of magnitude compared to the Earth's surface and measured some key reactions of the hydrogen burning cycle and primordial nucleosynthesis. Soon a new accelerator will be installed that will allow to measure also reactions of the helium and carbon combustion cycles. |
Giovanni Francesco Ciani (Uniba and INFN-Bari)giovanni.ciani@ba.infn.it |
| Nuclear physics | Development of detection techniques for nuclear astrophysics experiments (LUNA) |
The LUNA experiment (Laboratory for Underground Nuclear Astrophysics) deals with reproducing in the laboratory the nuclear reactions that generate most of the energy produced by stars and that have allowed the synthesis of elements within the stars and in the |
Giovanni Francesco Ciani (Uniba and INFN-Bari)giovanni.ciani@ba.infn.it |
| Nuclear physics | Nucleosintesi degli elementi oltre al Fe: I processi nucleari nelle stelle AGB |
While most of the light isotopes are produced in the stars via charged particle reactions, the Coulomb barrier becomes prohibitively high above the Fe abundances peak ( Z ≥ 26 ) for charged particle reactions to play any significant role at energies attainable in a stellar environment. Beyond iron, the only method of production is via neutron induced reactions. |
Giuseppe Tagliente (INFN-Bari) giuseppe.tagliente@ba.infn.it |
| Nuclear physics |
The neutron damage in structural materials of future fusion reactors: measurements at |
One of the problems on the route to energy production from fusion is related to the radiation damage in the structural materials of future reactors. In particular, the extremely high neutron flux generated in the plasma is expected to lead to a degradation of the thermo-mechanical properties of some fundamental reactor components, such as the mantle and the divertor, severely limiting their lifetime. In order to estimate and mitigate the radiation damage in future fusion reactors it is necessary to study neutron-induced reactions, in a wide energy range. A dedicated research program on this topic is being carried out at CERN with the neutron beam of the n_TOF facility (neutron Time-Of-Flight). The characteristics of the beam, in particular the high neutron flux and the wide energy spectrum (from meV to GeV), make n_TOF unique for such studies. |
Nicola Colonna (INFN-Bari) nicola.colonna@ba.infn.it |
| Nuclear physics |
Measurement of neutron capture reactions at n_TOF (CERN) for medical applications |
Neutron capture reactions play an important role in several fields of Physics, such as in Nuclear Astrophysics for the understanding of the nucleosynthesis of heavy elements (beyond iron) in stars via the s- and r-processes, in neutrino detector developments and in nuclear technology. |
Mario Mastromarco (Uniba and INFN-Bari) mario.mastromarco@ba.infn.it |
| Nuclear physics |
Study of the absorbed dose distribution in radiation therapy using the GATE/Geant4 |
The treatment planning in radiation therapy (RT) requires an accurate assessment of the absorbed dose distribution throughout the organs and tissues, whatever the RT approach (e.g. using photons, electrons, protons, carbon beams, radioisotopes), and the different delivery conditions (broad beam, pencil beam, scanning, rotational, brachytherapy, and targeted radionuclide therapy). |
Annamaria Mazzone (CNR and INFN – Bari) annamaria.mazzone@ic.cnr.it |
| Nuclear physics |
A Monte Carlo Study of the DNA Damage Induced by Ionizing Radiation: the Geant4- |
Emerging oncological radiotherapy modalities, such as targeted particle therapy, hadron therapy or radio-sensitisation of cells by high-Z nanoparticles, would greatly benefit from the theoretical determination of radiation track structure at the nanoscale level in order to evaluate radiation-induced damage at the cellular and DNA level and subsequent biological response. In this thesis, we propose the use of the GEANT4-DNA code in conjunction with a DNA atomic resolution model for studying the chemical damage induced by ionizing radiations. The thesis will focus on possible applications of the code for the assessment of the DNA damage after proton irradiation or for the estimate of radon induced cellular damage. |
Annamaria Mazzone (CNR and INFN – Bari) annamaria.mazzone@ic.cnr.it Nicola Colonna (INFN-Bari) nicola.colonna@ba.infn.it |
| Particle physics |
Study of strange particle production with ALICE at LHC |
While the ALICE experiment at CERN is re-starting data taking during the upcoming LHC Run 3 phase in 2022, large statistics samples are already available from Run 1 and Run 2 (2009- 2018) for a variety of colliding systems (pp, p-Pb, Pb-Pb and Xe-Xe) and at different center-ofmass energies. The measurement of particles containing strange quarks (like Lambda, Xi and Omega hyperons) is a key tool to investigate the properties of the strongly interacting matter created by ultra-relativistic heavy-ion collisions. Candidate decay selection, transverse momentum spectra reconstruction and production yield estimation as well as comparisons between different colliding systems and energies and with physics models provide several thesis themes, to be developed in close collaboration with the ALICE Collaboration activities at CERN. |
Domenico Di Bari (Uniba and INFN-Bari) domenico.dibari@ba.infn.it
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| Particle physics |
Silicon vertex performance study for future detectors at EIC and ALICE |
The Electron Ion Collider (EIC) at BNL is planned to start its activities in the early 2030s. The accelerator will be able to collide polarised electrons with a large variety of heavy and light polarized nuclei. The EIC central tracking system will be a combination of a silicon vertex detector and an outermost gas tracker. The CMOS Monolithic Active Pixel Sensors (MAPS) in 65 nm technology would fullfill all performance requirements for the EIC vertex tracker. This novel technology is currently targeted by the R&D activities for the upgrade of the ALICE inner tracking system (ITS3), to be installed before the LHC Run 4 (2027). The thesis activity will focus on the basic performance study for the EIC vertex detector and the consequent impact on the measurement of golden physics channels. This exercise will be done in close collaboration with CERN and synergistically with similar studies performed for the development of the ALICE ITS3. Keywords: ALICE experiment at LHC, heavy-ion physics, Monte Carlo simulation, detector performance, Experiments at the US EIC |
Domenico Di Bari (Uniba and INFN-Bari) domenico.dibari@ba.infn.it
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| Particle physics | Charm and multi-charm baryon measurements with the upgraded ALICE detectors |
A fundamental ingredient of the ALICE physics programme for the new decade is a comprehensive study of the charm and multi-charm baryon production: since charm is exclusively produced in initial hard scatterings, such measurements may indeed provide unique insight into the Quark Gluon Plasma medium as well as hadronization from protonproton to lead-lead collisions. Thesis themes will focus on the study of the achievable performance of such strangeness tracking method, also using ML, starting from the ALICE inner tracking detector in Run 3 and investigating its potential in a future experiment with an extensive silicon tracking detector having a first layer very close to the interaction point. Keywords: ALICE experiment at LHC, heavy-ion physics, machine learning, detector performance |
Domenico Di Bari (Uniba and INFN-Bari) domenico.dibari@ba.infn.it
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| Particle physics |
Feasibility study of an aerogel RICH Cherenkov detector for the next generation heavyion program for LHC Run 5 |
The next long-term goal of QGP research is to probe the internal dynamics of the Quark Gluon Plasma with the aim of understanding how the observed abundant collective phenomena arise on (sub)fermi time scales and identifying their common dynamical origins. In this context, heavy flavour quarks, offer a direct measure of the randomisation of heavy quarks in phase space during the collision. While this field will see significant advances during High Luminosity – Large Hadron Collider (HI-LHC), based on a detector concept that addresses open challenges in tracking/vertexing and rate capabilities. A new detector concept is also needed to fully exploit the physics opportunities to quantify how the quark-gluon plasma shines electromagnetically. The long-term aim of exploiting electromagnetic radiation as a unique signature for chiral symmetry restoration in the QGP will require a novel detector concept aimed at an unprecedented level of purity of the thermal electron signal. In this context ALICE Collaboration is proposing a new apparatus (ALICE3) for the LHC Run 5 phase. Optimal hadron and electron identification capabilities are required. The Bari ALICE group, in close collaboration with CERN, is involved in R&D activities for the development of a RICH detector for ALICE3, using aerogel as Cherenkov radiator. The photon detection will be provided by a layer of Silicon Photomultiplieris (SiPM). We can offer a variety of thesis proposals including SiPM detector characterisation as well as the studies of the detector performance by means of Monte Carlo simulation, to optimize the proposed detector in term of geometry and radiator optical properties. Keywords: ALICE experiment at LHC, heavy-ion physics, Monte Carlo simulation, detector performance |
Domenico Di Bari (Uniba and INFN-Bari) domenico.dibari@ba.infn.it Giacomo Volpe (Uniba and INFN-Bari) giacomo.volpe@ba.infn.it |
| Particle physics | Study of production of beauty hadrons in Pb-Pb collisions with the ALICE experiment at the LHC |
After accomplishing its major upgrade program during the LHC Long Shutdown 2 (2019-2021) and a successful pp data taking period in Run3, ALICE could collect a large sample of Pb-Pb data in October 2023 exploiting its new Inner Tracking System (ITS) and the upgrade of the read-out of all other detectors. The new ITS represents the state-of the-art of micro-vertex pixel detector and allows one to reconstruct precisely, in the harsh environment of Pb-Pb collisions at the LHC, the exclusive decays of beauty hadrons down to very low transverse momentum. These are special probes to study the properties of the strongly interacting matter, a deconfined plasma of quarks and gluons (QGP), since the b-bbar quark pairs are created in the very first moments of the collisions and they experience the entire life of the QGP. |
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| Particle physics | Investigation of charm-quark fragmentation via angular correlations of charmed hadrons |
The study of correlations of heavy-flavour particles provides valuable insights into the production and hadronization processes of heavy quarks. Specifically, analyzing the azimuthal correlation distribution between charmed hadrons and charged particles produced in the same event offers a detailed understanding of charm quark fragmentation into a jet of final-state particles. The ALICE Collaboration has previously published results on correlations between D mesons and charged particles during the Run1 and Run2 LHC data-taking campaigns. With the ongoing collection of Run3 data samples, this study can now be conducted on significantly larger data-sets, enabling precise correlation measurements that also encompass charm baryons such as Lc and Xc. The student will conduct a data analysis focused on the reconstruction and selection of Lc particles using the new proton-proton data samples. She/he will then correlate the selected particles with other charged particles and compare the results with those obtained for D mesons, as well as with predictions from state-of-the-art models. This study will be carried out using the O2 analysis framework, which is utilized by the ALICE Collaboration and is written in C++. Therefore, a basic knowledge of the C++ programming language is required. Additional material on the subject can be found here: https://link.springer.com/article/10.1140/epjc/s10052-022-10267-3 |
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| Particle physics | Unveiling the non-universality of charm fragmentation at the LHC |
A most surprising result at the LHC have been the breaking of the charm-fragmentation universality, previously observed at lower energies among different collision systems (ee, ep, p-antip, etc.). ALICE can perform systematic and precise production measurements of charmed baryons in pp collisions, and measurements of the charm fragmentation fractions in pp and p-Pb collisions, that have revealed discrepancies between perturbative QCD models and experimental data. This unexpected finding has opened new avenues for research, particularly in the study of baryons with charm, forcing the theoretical model to hypothesize further hadronization mechanisms, to explain the charm baryon production measurements. What is still challenging is the description of the baryons with charm and strange quarks, suggesting that the process of hadronization of charm+strange quark in high-energy collisions is more complex than previously thought, and that there may be additional factors at play that are not currently accounted for in theoretical models. The student will exploit the large statistical sample collected in the LHC Run3, and the vertex capabilities of the new Inner Tracking System of the ALICE experiment to study the production of the charmed-strange baryons, Xc+, through its weak decays. Machine Learning techniques will be used to select signal from a large combinatorial background. |
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| Particle physics | Development of innovative large area ultra-thin monolithic active pixel detectors (MAPS) for the ALICE ITS3 and future ALICE 3 IRIS detectors at the LHC |
The ALICE experiment at the LHC includes in its barrel a new Inner Tracking System (ITS2), which was installed during the LHC Long Shutdown 2 (2019-2021) and represents the present state-of-the art of micro-vertex detectors at particle colliders. An intense R&D is still ongoing to further improve this system: a next upgrade will consist in the replacement of the three innermost layers of the ITS2, which is made of seven layers, with three new layers made of large-size ultra-thin pixel chips bended in a truly cylindrical shape (ITS3). A full half layer will be thus realized by bending a single large-size chip, avoiding any other material but that of the sensitive detector. Thanks to this solution, the improvement of the spatial precision of the reconstructed track will be impressive. The ITS3 detector will be installed during the LHC Long Shutdown 3 (2026-2029) and will be used during the LHC Run4 (2030-2032). The ALICE collaboration is also planning to build a completely new experiment, named ALICE 3, which will replace the ALICE apparatus and it will be installed during the LHC Long Shutdown 4 (2033-2034). The micro-vertex detector of the new experiment, referred to as the IRIS (like the flower that open and close its petals), will be based on a similar technology of the ITS3, but it will be placed much closer to the interaction point, within the beam-pipe in a secondary vacuum. The student interested in a thesis with a focus on the ITS3 detector will characterize in the laboratory and in test-beam at CERN the first large size chips realized with the 65 nm CMOS technology. She/he will improve the methods used for the bending and assembly of the chips and/or finalize the detector design with Monte Carlo simulations. The student interested in a thesis with the focus on the future ALICE 3 IRIS detector will characterize the new components and materials and their behavior in very low vacuum, she/he will optimize the design of the detector based on dedicated Monte Carlo simulations. Periods at CERN during the thesis work are foreseen. |
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| Particle physics |
Measuring the inelastic interaction between antimatter and matter nuclei with the ALICE HMPID apparatus |
The measurement of the inelastic cross section of the (anti-)deuteron and in general of the light anti-nuclei is of interest for the understanding of the anti-nucleosynthesis in the ultrarelativistic heavy ion collisions. In addition, it is of interest for the study of the anti-nuclei production in the cosmic rays. The study of the HMPID performance expected in the measurement by using specific simulation programs, and the estimate of the statistical abundances required for the requested precisions using different colliding systems (pp, p-Pb and Pb-Pb), are the main but not the exhaustive subjects of the thesis. Keywords: ALICE experiment at LHC, heavy-ion physics, Monte Carlo simulation, detector performance |
Domenico Di Bari (Uniba and INFN-Bari) domenico.dibari@ba.infn.it Giacomo Volpe (Uniba and INFN-Bari) giacomo.volpe@ba.infn.it |
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The Muon Detector for the LHCb Upgrade II |
In the HL-LHC era, the foreseen increase in luminosity up to a factor of 10 with respect to current accelerator performance will require a major upgrade of the LHCb detector in order to fully exploit the physics potential in the new running conditions.
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| Performance of gaseous detectors with eco-friendly gas mixtures for High Luminosity LHC |
A big effort is being carried out by the High Energy Physics community to develop gaseous detectors for the High Luminosity LHC era operated with environment-friendly gas mixtures. Keywords: RPC detector, data acquisition, data analysis, LHCb experiment at CERN |
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| Study of front-end electronics for a new generation of gaseous detectors for the LHCb experiment |
A new generation of gaseous detectors, requiring the design of new front-end electronics, is under development for HL-LHC. keywords: gaseous detectors and electronics, data acquisition, LHCb experiment at CERN |
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| Advanced Technologies | Security of Internet of Things Authentication Mechanism | The purpose of this Master’s thesis is to investigate how the communication between the consumer IoT device , the cloud and an app can be secured against hacking and data leaks. The research line is dedicated to the development and testing of encryption algorithms, certificates, secure communication methods and wireless technologies. The thesis will be carried out directly at a company or in close contact with it and will aim at realizing and testing sending telemetry and operating IoT devices remotely and secure. Duration: 6 months of industrial placement in potential combination with lab activity Skills: Students will gain knowledge and practical experience in a company on advanced IoT/cloud security. |
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| Elementary Particle Physics | Constraints on the Higgs self coupling via double Higgs production in the decay channel bbmumu with the CMS experiment at the LHC | The discovery of the Higgs boson in 2012 and the measurements of its properties has been the best achievement of the LHC experiments so far but shading light on the Higgs mechanism to give masses to the particles would require the inspection of the exact shape of the Higgs potential and in particular the measurement of the triple and quartic Higgs self coupling. A direct constraint on the trilinear self-coupling can be extracted from the production of non-resonant Higgs boson pair (HH) production. For that purpose the plan is to study the unexplored bbmumu channel, motivated by the recent evidence of the H->mumu final state of single Higgs production and the possible lower background for the double Higgs production; the expected sensitivity could be better than what obtained for the bbZZ with the Z boson decaying to a pair of charged leptons and will definitely help to reach the sensitivity to the Standard Model production cross section. The activity of the student would consist in developing a full analysis to detect a signal for HH production from the background by analyzing real data collected by the LHC for the Run 2 and the ongoing Run 3. Machine learning techniques will be used and compared w.r.t a cut-based approach. Results will be expressed in terms of upper limits on the production section, constraints on the trilinear self-coupling parameter. | Nicola DE FILIPPIS Brunella D’Anzi |
| Elementary Particle Physics | Search for a resonant production of double Higgs boson in the decay channel bbZZ with the CMS experiment at the LHC | Double Higgs production at the LHC is one of the next and more intriguing challenges at the LHC. In the Standard Model the production of double Higgs is expected to be no resonant while a new resonance decaying in tow Higgs bosons in expected in several models for physics beyond Standard Model; a Randall Sundrum graviton or a radion are possible candidate for that resonance. Several decay channel have been already explored for the double Higgs system ; for the purpose of the thesis the plan is to study the unexplored bbZZ channel with the Z boson decaying to a pair of charged leptons and/or hadrons; the candidate would work on the Monte Carlo simulation of the resonance signal and will develop a full analysis to detect a signal from the background by analyzing real data collected by the LHC for the Run2 and Run3. Machine learning techniques will be used and compared w.r.t a cut-based approach. Results will be expressed in terms of constraints of the parameters of the specific model, like the mass of the resonance of the coupling with the Standard Model Higgs. | Nicola DE FILIPPIS Walaa Elmetenawee |
| Elementary Particle Physics | Perspective studies of the double Higgs production at the HL-LHC with the CMS experiment | In order to shade light on the Higgs mechanism to give masses to the particles it is needed to inspect the exact shape of the Higgs potential and in particular the measurement of the triple and quartic Higgs self coupling. A direct measurement on the trilinear self-coupling will be done with the statistics that will be collected with the CMS experiment at the LHC in the high luminosity scenario starting in 2030. Perspective studies of the potential of the LHC in that scenario would include projections from current results of the Run2 and the incoming Run3 data, new complete simulation of signal and background with the large pileup and upgraded detectors, new algorithms. The student Is asked to work on the simulation of the HH production in the most sensitive channels bbgammagamma, bbtautau, 4b , a sign to background discrimination by using deep neural networks and a statistical analysis to combine the results of the three channels. The significance of the discovery and the precision of the measurement of the triple Higgs coupling will be derived. | Nicola DE FILIPPIS Angela Taliercio (ext.) |
| Elementary Particle Physics | Study of the Z-boson couplings to heavy fermions at the Future Circular electron - positron Collider | With the discovery of the Higgs Boson, the Standard Model (SM),describing the known elementary particles and fundamental interactions, is completed: yet it leaves several questions still open. A Future Circular Collider (FCC), a 100 km ring in the CERN area operated first as a leptonic collider(FCC-ee) and then as a ≥100 TeV proton-proton collider (FCC-hh, can answer many of them. FCC-ee will work in stages, between 90 and 365 GeV, with an unprecedented luminosity which will allow tocollect trillions of Z bosons on resonance. This “Tera-Z” run, will provide the highest-ever indirect sensitivity tonew physics via precision measurement of electroweak observables, and a rich program of flavour sectormeasurements competitive to the LHCb and Belle II plan, with expected uncertainties 10 to 100 times smaller than previous measurements. The focus of the master thesis project is to pave the way to reproduce and improve the measurement of the heavy b quark forward-backward asymmetries, possible only with this huge Z data set. With a complete study of these observables, the project aims to contribute to unravel one of the most intriguing LEP anomalies in the heavy fermions sector, and in particular the a discrepancy of almost 3 sigma on the Ab parameter entering in the measurement of the asymmetry of b-quark pair production at the Z-peak, with respect to the SM. The student Is expected to work on the simulation of the e+e- -> bb production and reconstruction and a subsequent physics analysis to derive a prediction about the Ab parameter and more in the heavy flavor sector of the SM. | Nicola DE FILIPPIS |
| Elementary Particle Physics | Precise measurement for the triple Higgs couplings at the Future Circular proton - proton Collider | In order to shade light on the Higgs mechanism to give masses to the particles it is needed to inspect the exact shape of the Higgs potential and in particular the measurement of the triple and quartic Higgs self coupling. A very precise measurement on the trilinear self-coupling will be made with a Future Circular Collider (FCC), a 100 km ring in the CERN area operated as a proton-proton collider(FCC-pp) with ≥100 TeV center of mass energy. Perspective studies of the potential of the FCC-pp in would include a complete simulation of signal and background with the large pileup and upgraded detectors, new algorithms. The student Is asked to work on the simulation of the HH production in the most sensitive channels bbgammagamma, bbtautau, 4b , a sign to background discrimination by using deep neural networks and a statistical analysis to combine the results of the three channels. Te precision of the measurement of the triple Higgs coupling will be derived. | Nicola DE FILIPPIS Angela Taliercio |
| Advanced Technologies | Particle identification with a cluster counting technique at the Future Circular electron - positron Collider | The large statistical fluctuations in the ionization energy loss high energy physics process by charged particles in gaseous detectors implies that many measurements are needed along the particle track to get a precise mean, and this represent a limit to the particle separation capabilities that should be overcome in the design of future colliders. The cluster counting technique (dN/dx) represents a valid alternative which takes advantage of the Poisson nature of the primary ionization process and offers a more statistically robust method to infer mass information. Simulation studies by using Garfield++ and Geant4 prove that the cluster counting allows to reach a resolution two times better than traditional dE/dx method over a wide momentum range in the use-case of a helium-based drift chamber. It consists in singling out, in ever recorded detector signal, the electron peak structures related to the arrival of the electrons belonging to a single primary ionization act (cluster) on the anode wire. However, the search for hundreds of electron peaks and the cluster recognition in real data-driven waveform signals is extremely challenging because of their superimposition in the time scale. The state-of-the-art open-source algorithms fail in finding the expected number even in low-noise conditions. The student is expected to work on a cutting-edge algorithms to search for electrons peaks and identify ionization clusters in experimental data using the latest available computing tools and physics knowledge. To validate the algorithms and show the advantages of the cluster counting technique, two beam tests has been performed at CERN/H8 facility collecting data with different helium based gas mixtures at different gas gains and angles between the wire direction and the ionizing tracks using a muon beam ranging from 40 GeV/c to 180 GeV/c on a setup made of different size drift tubes, equipped with different diameter sense wires. The student is expected to work on the data analysis results concerning the ascertainment of the Poisson nature of the cluster counting technique, the establishment of the most efficient cluster counting and electrons clustering algorithms among the various ones proposed, and the definition of the limiting effects for a fully efficient cluster counting, like the cluster dimensions, the space charge density around the sense wire and the dependence of the counting efficiency versus the beam particle impact parameter. | Nicola De Filippis Brunella D’Anzi |
| Advanced Technologies | Full simulation of the IDEA experiment at the Future Circular electron - positron Collider |
With the discovery of the Higgs Boson, the Standard Model (SM),describing the known elementary particles and fundamental interactions, is completed: yet it leaves several questions still open. A Future Circular Collider (FCC), a 100 km ring in the CERN area operated first as a leptonic collider(FCC-ee) can answer many of them. The precision physics program sets stringent requirements on the detector performance. Among these, very large solid angle coverage, excellent particle ID, very good energy and momentum resolution, efficient vertex reconstruction are critical. Indeed, as Higgs, W and Z boson factories, detectors at the future e+e− colliders have to reconstruct and identify their decay products with high efficiency, purity and precision. The IDEA experiment proposed by the INFN community would include first a pixel detector coupled with a tracking device based on a large ultra-light multiword drift chamber; then a solenoid for the magnetic filed, a dual readout calorimeter a muon chambers are arranged in a classical onion geometry. The student will be involved in the simulation of the different part of the detector with a standalone Geant4-based program and with the FCC software toolkit and will test the system by using physics events generated with standard Monte Carlo generators for e+e- physics. |
Nicola De Filippis Walaa Elmetenawee |
| Advanced Technologies | Track reconstruction with the drift chamber for the IDEA experiment at the Future Circular electron - positron Collider | : The IDEA detector concept for a future e+e− collider adopts an ultra-low mass drift chamber as central tracking system. The He based ultra-low mass drift chamber is designed to provide efficient tracking, a high precision momentum measurement, and excellent particle identification by exploiting cluster counting technique. Studies with the Garfield++ simulation confirm that the cluster counting technique allows reaching a resolution two times better than the traditional charged particles mechanism dE/dx method. To study the impact of the cluster counting technique on physics events, an algorithm, which uses the energy deposit information provided by the Geant4 simulations, has been developed to reproduce the cluster size and the cluster density distributions in a fast and convenient way. The student is expected to work on the expected tracking performance and particle identification, obtained with full simulation of physics events. | Nicola De Filippis Walaa Elmetenawee |
| Advanced Technologies | Analysis with data collected at the CERN H8 test beam facility |
Data were collected at the CERN H8 experimental area with muons with momentum ranging from 40 to 180 GeV in 2021 and 2022 by using drift tubes arranged in rectangular shape and with different cell size, different thickness of the sense wire. Different gas mixtures, operation pressure and powering scheme vere tested. The student will be involved in the technical aspects of the experimental equipment operating in the INFN laboratories in Bari and in Lecce. The student will then work with a data analysis program to study the most important observables related to the operation of the drift tubes, including the noise reduction, the signal shaping , the waveform reconstruction and the cluster counting. The student is expected to work on the ascertainment of the Poisson nature of the cluster counting technique, the establishment of the most efficient cluster counting and electrons clustering algorithms among the various ones proposed, and the definition of the limiting effects for a fully efficient cluster counting, like the cluster dimensions, the space charge density around the sense wire and the dependence of the counting efficiency versus the beam particle impact parameter. |
Nicola De Filippis
Walaa Elmetenawee
Brunella D’anzi
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| Advanced Technologies | Installation, test and operations of drift tubes and drift chamber prototypes in the INFN Bari laboratory |
A INFN laboratory is used to setup, operate drift tubes and drift chambers prototypes under different conditions of powering, gas mixture, pressure and temperature. A monitoring chamber is under development to test the dependence of the drift velocity of several parameters. Indeed % variations of the drift velocity over a distance of 5mm, affects the spatial resolution of about 50 μm. A monitoring of the drift velocity at the per mille level in few tens of nanoseconds will be used to appreciate variations of the electric filed of 2V/cm, relative variations of the isobutane content of 4.3x10-3, variations of the pressione della gas mixture of 0.8 mbar, variations of the water steam of 150 ppm. The student will operate with the technical aspects of the experimental equipment operating in the INFN laboratories in Bari and also in Lecce; the measurements of the relevant observables to monitor the drift chamber will be executed by the student.
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Nicola De Filippis
Walaa Elmetenawee
Brunella D’anzi
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| Advanced Technologies |
ML for Particle identification @ FCC-ee
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In addition to tracking and calorimetry, Particle IDentification (PID) is a crucial aspect of most particle physics experiments. PID strategies and methods used by the large LHC experiments provide outstanding examples of the state-of-the-art. Along the path defined by the European Strategy for Particle Physics an electron-positron Higgs factor is the highest priority next collider. The FCC program at CERN combine in the same 100km infrastructure a high luminosity Higgs and Electroweak factory e+e- collider, followed by a 100 TeV hadron collider. The IDEA project, as proposal for an experiment along then electron-positron collider, includes an ultralight drift chamber as the main tracking device designed to provide efficient tracking, high precision momentum measurement and excellent particle identification. The charged particle identification for pions, kaons, protons, muons and electrons, based on the sub-detectors response, is considered as a machine learning problem solved in different modes: one-vs-rest, one-vs-one and multi-classification, which affect the models training and prediction. Deep neural networks and graph neural networks could be the best tools to combine the information from various detectors effectively. Moreover, the complexity of the detector and richness of the detection techniques make PID an interesting area of research also for the computer science community. The performance of the machine learning techniques for PID are also measured in terms of signal to background discrimination in the context of physics analysis for heavy flavor measurements.
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Nicola DE FILIPPIS |
| Advanced Technologies |
Big Data for High Energy Physics: use cases from the data analysis chain for the CMS experiment
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The experimental high energy physics was pioneering the development of technologies to handle data for many decades in the recent past. By contrast currently big companies take the leadership in deployment, deployment and large scale production of data related solutions and the scientific community is making an effort to cope with the new tools, the software and development. Hundreds of physicists store, archive, analyze an increasing large data sample with different goals at the same time. The student is expected to face the challenges imposed today and in the future for data analysis and emphasize the use of “Big data” tools for data manipulation and reception, machine learning techniques and more. New directions investigated for the different purposes will be studied and comparisons between the results by using current and new tools will be performed.
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Nicola DE FILIPPIS |