Thermal photons from U+U collisions at RHIC

U+U collisions at √s_NN=193 GeV at RHIC have gained a lot of attention in the relativistic heavy ion collision physics community in recent years. The uranium nuclei (²³⁸U) have a prolate shape and as a result, even the most central U+U collisions lead to different collision geometries and consequently different values of observables produced in heavy ion collisions. We calculate spectra and elliptic flow parameter υ₂ of thermal photons from tip-tip and body-body configurations (which are the limiting cases of particle multiplicity) of full-overlap U+U collisions and compare the results with that obtained from Au+Au collisions at RHIC energies. The major axes of the two incoming uranium nuclei are perpendicular to the beam axis in body-body collisions, whereas, for tip-tip collisions the major axes are along the beam direction. The overlapping zone in tip-tip collisions is circular in shape and produces larger initial temperature and higher particle multiplicity. On the other hand, the body-body collisions lead to an elliptical shape with larger volume of the overlapping zone and non-zero anisotropic flow parameters