MSc thesis defense by Frederik S. K. Rømer

Probing the nuclear structure in ultra-relativistic heavy-ion collision with standardized cumulants of mean transverse momentum fluctuations

Abstract

While it has been known for decades that most atomic nuclei can exhibit intrinsic deformation, it has recently been realized, that this information also can be accessed in ultra-relativistic AA collision at LHC energies. This motivates the exploration of high and low-energy experiments to act in conjecture with each other and to probe past the strong force to precisely characterize nuclear structures. Using higher order standardized cumulants of transverse momentum correlation, a novel approach to accessing the initial conditions such as energy density and nuclear shape is presented. By analyzing ultra-relativistic heavy-ions collision of ¹²⁹Xe and ²⁰⁸Pb at LHC energies and comparing the transverse momentum p_T spectrum, it is investigated how quadrupole deformation β2 and triaxiality γ affects the final p_T spectrum. Monte Carlo models such as HIJING and AMPT are employed to interpret the experimental results and provide a deeper understanding of the observed phenomena. The results show that while it should be possible to access information about the nuclear structure using standardized cumulants, the current theoretical understanding of the probe does not allow for direct extrapolation of these quantities.