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Title: Measurement of Central Exclusive Production Rates of Chi_c using converted photons in LHCb.

Research description: Central exclusive production (CEP) of particles at the LHC is characterised by a extremely clean signature. Differently from the typical inelastic collisions where many particles are created resulting in a so-called Primary Vertex, CEP events have only the final state particles of interest. In this project the particle of interest is a pair of charmed quarks creating a chic particle. In theory this process is generated by a long range gluon exchange and can elucidate the nature of the strong force, described by the quantum chromodynamics in the the standard model. The proposed work involves generating events at the LHCb and simulating the detection efficiency in order to obtain the relative occurence rate of each chic_c species (spins 0, 1, 2), a quantity that can be easily compared to theoretical predictions. The analysis of chi_c dacying into J/psi gamma, where the photon converts into electron positron offers a clear distinction between the chi_c species and a final result with smaller systematical error.

Title: Optimization studies for Vertex detector at the High Lumi LHCb

Research description: The LHCb experiment is dedicated to measure tiny differences between matter and antimatter through the precise study of rare processes involving b and c quarks. The LHCb detector will undergo a major modification in order to dramatically increase the luminosity and be able to measure indirect effects of physics beyond the standard model. In this enviroment, over 42 simultaneous collisions are expected to happen at a time interval of 200 ps where the two proton bunches overlap. The particles of interest have a relatively long lifetime and therefore the best way to distinguish them from the background collisions is through the precise reconstruction of displaced vertices and pointing directions. The new detector considers using extremely recent or even future technologies to measure space (with resolutions below 5 um) and time (100 ps or better) to efficiently reconstruct the events of interest for physics. The project involves changing completely the LHCb Vertex Locator (VELO) geometry and determine what can be the best performance for the upgraded detector.

Title: Measurement of charge multiplication in heavily irradiated sensors

Research description: During the R&D phase for the LHCb VELO Upgrade detector a few sensor prototypes were irradiated to the extreme fluence expected to be achieved during the detector lifetime. These samples were tested using high energy particles at the SPS facility at CERN with their trajectories reconstructed by the Timepix3 telescope. A preliminary analysis revealed that at the highest irradiation levels the amount of signal observed is higher than expected, and even larger than the signal obtained at lower doses. At the Device Under Test (DUT) position inside the telecope, the spatial resolution attained by the telescope is below 2 um. This means that a detailed analysis can be performed in order to study where and how this signal amplification happens within the 55x55 um^2 pixel cell. This project involves analysing the telescope and DUT data in order to understand the charge multiplication mechanism at the microscopic level.