Estimating the production of dark photons with η decay in high-energy collisions

We propose searching for dark photon signals in the decay channel of η mesons,specifically through the leptonic decay(A'→e^(+)e^(-)(μ^(+)μ^(-)))observable in photon-photon interactions during ultra-peripheral heavy-ion collisions.We estimate the total cross-section for dark photon production in ultra-peripheral PbPb collisions at current and future hadron colliders.Our findings support the potential for detecting dark photon signals at the LHC,HighLuminosity LHC,High-Energy LHC,and Future Circular Collider.

Investigating color screening in proton-nucleus collisions with complex potentials

Color screening and parton inelastic scattering modify the heavy-quark antiquark potential in mediums consisting of particles from quantum chromodynamics(QCD),leading to the suppression of quarkonium production in relativistic heavy-ion collisions.Owing to the small charm/anti-charm(cc)pair production number in proton-nucleus(pA)collisions,the correlation between different cc pairs is negligible,which makes the Schrödinger equation viable for tracking the evolution of only one cc pair.We employ the time-dependent Schrödinger equation with an in-medium cc potential to study the evolution of charmonium wave functions in a hydrodynamic-like QCD medium produced in pA collisions.We explore different parametrizations of real and imaginary parts of the cc potential and calculate the nuclear modification factors(R_(pA))of J/ψ and ψ(2S)in √s_(NN)=5.02 TeV energy p-Pb collisions at the Large Hadron Collider(LHC).Comparing strong and weak screening scenarios with experimental data in this approach,we arrive at the conclusion that color screening is weak at temperatures close to the deconfined phase transition.Moreover,the imaginary part of the potential is crucial in describing the experimental data,which is consistent with widely studied semi-classical approaches,where dissociation rates are essential.