Seyed Farid Taghavi
Offered Bachelor’s or Master’s Theses Topics
- How quark-gluon plasma flows in ALICE experiment
- It is predicted that in its early stage, our Universe was made of deconfined quarks and gluons, a state known as the quark-gluon plasma (QGP). Understanding its properties is therefore a crucial element in the description of the first instants after the Big Bang. In order to deepen our current knowledge of the QGP, high-energy nuclear physicists turn to the study of ultrarelativistic collisions in the Large Hadron Collider (LHC) at CERN. QGP formation is indeed a well-known stage in the evolution of the collision of two heavy ions, like lead, while signs of its possible creations have been seen in smaller system sizes, like p-Pb or even pp. The estimation of the anisotropies in the azimuthal distribution of the produced particles is one of the probes used by experimentalists to access the collective properties of the QGP. Sophisticated analysis techniques, gathered under the name of multiparticle correlation techniques, have been developed in recent years to measure the anisotropic flow phenomenon at the origin of the observed asymmetric distributions and provided great help in constraining the parametrization of the initial state and collective evolution of the system. Another important development towards this goal is the introduction of Bayesian methods, where the model parameters can be inferred from the experimental observables. This leads to a better understanding of the underlying theoretical models. Nevertheless, despite these formidable advancements in the evaluation of the QGP properties, the uncertainties remain still large, and the introduction of novel observables and new measurements is needed to fix this issue. After an introduction to the phenomenon of anisotropic flow, and its analysis techniques, the candidate students will have the possibility to work on various research topics: ● Experimental measurement of newly developed observables in Pb-Pb collisions recorded by the ALICE detector at the LHC, during Run1 and Run2, and their comparisons with the predictions from different tunings of Bayesian analyses. The determination of new tunings and consecutive generations of simulated events by the student can also be considered. ● Investigations on the dependence of the various flow observables on the collision system size. ALICE has already collected events for pp, p-Pb, Xe-Xe and Pb-Pb collisions, and O-O data are planned for the future Run3. Studying the anisotropic flow in such a wide range of system sizes helps advance our understanding of QGP formation. Moreover, such measurements would provide great insights into the supposed robustness of the parameter tuning obtained with Bayesian studies. ● Developments of new theoretical observables, complementary to the traditional techniques, and feasibility studies of their experimental measurements. Through these projects, the candidate student will be able to develop data analysis skills using some of the most used programming languages in high-energy particle physics (e.g. ROOT, bash, Mathematica, C++, ...), while experiencing the atmosphere of an international collaboration.
- suitable as
- Master’s Thesis Nuclear, Particle, and Astrophysics
- Supervisor: Laura Fabbietti