Student projects

  • Simulations of a setup for AMBER Drell-Yan measurement

    | bachelor thesis | diploma thesis | Supervisor: Jan Matoušek, Zoë Earnshaw, Vendula Benešová |
    AMBER is a new experiment at CERN aiming to access the pion sea quark PDF by studying the Drell-Yan production of muon pairs in pion-nucleon scattering. Moreover, AMBER may be able to access the kaon PDFs as the first experiment since NA3 in 1980 if we achieve to tag kaons in the hadron beam. The experiment will use a new streaming data acquisition, which will require upgrades of front-end electronics of many detectors. In addition, some of them are ageing, and the need for bandwidth in streaming readout is much larger than in the old-fashioned triggered mode. Optimisation is therefore necessary to define a minimal yet effective spectrometer for muon detection, determine the required resolutions, active areas, occupancies, and estimate data rates using a Monte Carlo simulation.

  • Design and construction of a cosmic ray muon detector

    | project/SFG | Supervisor: Mehran Dehpour |
    Space is full of high-energy particles called cosmic rays. When they hit Earth's atmosphere, they create new particles called muons. These muons are all around us and can pass through walls and buildings. The goal of this project is to build a functional detector to study these muons. You will use a plastic scintillator (a material that glows when a particle hits it) and a modern light sensor called a SiPM. You will also use an Arduino to count the particles and save the data. We will measure how many muons arrive from different directions and see how the numbers change behind different materials. Then, we will compare our results with physics simulations. This setup will also give us a strong foundation for future upgrades, such as measuring the muon lifetime. This project is a perfect way to learn the actual technology used in large-scale experiments, e.g., at CERN.

  • Radiative Corrections for SIDIS off isoscalar target at COMPASS

    | project/SFG | Supervisor: Vendula Benešová |
    COMPASS experiment collected a large dataset of SIDIS events using both proton and deuteron targets. These measurements provide important input for extracting transverse-momentum–dependent parton distribution and fragmentation functions (TMDs), which describe the transverse structure of the nucleon and the hadronisation process. The observables are typically analysed using the leading-order (tree-level) SIDIS cross section. However, radiative effects and higher-order contributions can bias such leading-order analyses. While radiative corrections are well understood for inclusive measurements, they do not fully account for dependencies on hadronic variables. Recently, a new method has been developed within the COMPASS collaboration to include these effects consistently. This approach is now being applied to proton data, whereas earlier results for deuteron targets did not include such corrections. This project aims at correcting the 2004 data on the isoscalar target, which have already been published by the COMPASS collaboration.

  • Monte Carlo studies of hadron production in deep inelastic scattering

    | project/SFG | bachelor thesis | Supervisor: Jan Matoušek |
    Our group is studying the distributions of charged hadrons in deep inelastic scattering to learn about the quarks within the nucleon (see Talks). However, the distributions of final state hadrons depend not only on the nucleon structure, but also on the fragmentation (hadronization) process in which the interaction between the struck quark and the spectator quarks give rise to the final state hadrons. In addition, some of the hadrons decay soon afer, so part of the hadrons reaching the detectors are secondary. These effects can be studied in Monte Carlo simulations. Recently, a first plugin for fragmentation of polarised quarks has been developed for the Pythia event generator by our Trieste colleague [StringSpinner]. As we are interested in correlations within the nucleon involving quark spins, we would like to test and start using this model to better understand our experimental observations.

  • Development of software tools for detector efficiency simulation

    | project/SFG | Supervisor: Jan Matoušek |
    Detector efficiency may vary across the detector plane. There may be broken readout cards serving a group of wires or strips, less efficient photomultipliers at certain sctintillating hodoscope slabs, effects of space charge or ageing in high-occupancy central regions of wire chambers etc. These effects have impact on the experimental acceptance for particles. Therefore, 2D detector efficiencies were measured and are being used in Monte Carlo simulations for the acceptance determination at COMPASS. However, unbiased measurement of the efficiency is computationally very intensive. To take into account variation of the efficiency in time, corrections could be determined based on the so-called pseudo-efficiency, which is biased, but much less demanding to obtain. The goal of this project would be to develop a tool for the application of such corrections and in general for easy 2D efficiency comparison and manipulation.

  • K0 and Λ production in deep inelastic scattering

    | bachelor thesis | diploma thesis | Supervisor: Jan Matoušek |
    Our group is studying the distributions of charged hadrons in deep inelastic scattering to learn about the quarks within the nucleon (see Talks). The hadrons are mainly a mix of charged pions and kaons. This needs to be taken into account in the interpretation of the measurements. Identification of the hadrons would make the interpretation easier, allowing better quark flavour separation. One way is identifying the charged hadrons using Cherenkov effect, another way is looking at the so-called V0 particles K0 and Λ via their decay products.

  • ρ0 and φ production in deep inelastic scattering

    | bachelor thesis | diploma thesis | Supervisor: Jan Matoušek |
    Our group is studying the distributions of charged hadrons in deep inelastic scattering to learn about the quarks within the nucleon (see Talks). The hadrons are mainly a mix of charged pions and kaons. This needs to be taken into account in the interpretation of the measurements. Identification of the hadrons would make the interpretation easier, allowing better quark flavour separation. One way is identifying the charged hadrons using Cherenkov effect, another way is looking at ρ0 and φ resonances via their decay products. It is also desirable to understand to what extent the hadrons from these decays enter the standard charged hadrons sample (clearly significantly in the case of ρ0) and how they influence it.

  • π0 production in deep inelastic scattering

    | diploma thesis | Supervisor: Jan Matoušek | assigned | Investigator: Jakub Tatárik |
    Our group is studying the distributions of charged hadrons in deep inelastic scattering to learn about the quarks within the nucleon (see Talks). About 70% of the hadrons are charged pions. It may be interesting to expand this studies to neutral pions, which decay into two photons immediately after being born. As COMPASS experiment is equipped with electromagnetic calorimeters, the π0 can be reconstructed.

  • RICH detector performance studies

    | project/SFG | Supervisor: Patrizio Pucci | assigned | Investigator: David Slaný |
    RICH detector uses the Cherenkov effect to identify charged particles by determining their mass. In fact, it measures their velocity, which is then combined with the momentum measured in a magnetic spectrometer. The particle identification is important for correct interpretation of measurements of hadron production in deep inelastic scattering at COMPASS and it is vital for the measurement of antiproton production cross section at AMBER. Knowing the efficiency and purity of the particle identification as a function of relevant kinematic variables is necessary for such measurements.