Produção de mésons por interações γγ em colisões de alvo fixo no LHC

Abstract

The production cross sections of mesons and the number of events per year are calculated considering photon-photon (γγ) interactions in fixed-target collisions at the energies of the Large Hadron Collider (LHC) at CERN. We use the equivalent photon approximation method with a photon flux that depends on the impact parameter, ensuring an appropriate realistic description of ultraperipheral collisions. Different exotic hadronic states were analyzed, including tetraquark candidates, hadronic molecules, and glueballs, whose partial decay widths into two photons are well established experimentally. The results indicate that the production of these states is experimentally feasible for low-mass particles (m < 2 GeV), with cross sections of 10 2 –10 4 nb and rates of up to 10 events per year at the LHC. In contrast, massive states (m > 2 GeV) exhibit reduced cross sections of 10 5 0 to 10 nb, limiting their event rates in current experimental configurations to 10 −3 −5 events per year. The analysis of the rapidity distribution Y revealed that the region 2 < Y < 4.5 (where LHCb operates) concentrates the largest contribution to the cross section. This study demonstrates that fixed-target collisions are effective for probing light exotic states.