γ-hadron spectra in p plus Pb collisions at √sNN=5.02 TeV

Under the assumption that a quark-gluon plasma (QGP) droplet is produced and its evolution can be described by hydrodynamics in p + A collisions, gamma-triggered hadron spectra are studied within a next-to-leading-order perturbative QCD parton model with the medium-modified parton fragmentation functions. The initial conditions and space-time evolution of the small QGP droplet are provided by the superSONIC hydrodynamic model simulations and parton energy loss in such a medium is described by the high-twist (HT) approach. The range of scaled jet transport coefficient (q) over cap (0)/T-0(3) in this HT approach is extracted from single hadron suppression in A + A collisions with similar initial medium temperature as in p + A collisions. Numerical results for this scenario show that gamma-hadron spectra at p(T)(gamma) = 12-40 GeV/c are suppressed by 5-15% in the most central 0-10% p + Pb collisions at root s(NN) = 5.02 TeV. The suppression becomes weaker at higher transverse momentum of the gamma trigger. As a comparison, gamma-hadron suppression in Pb+Pb collisions at root s(NN) = 2.76 and 5.02 TeV is also predicted.

Automated summary

This study investigates the evolution of a QGP droplet produced in p + A collisions and analyzes gamma-triggered hadron spectra using medium-modified parton fragmentation functions. The initial conditions and space-time evolution of the small QGP droplet were provided by simulations using the superSONIC hydrodynamic model, with parton energy loss described by the high-twist approach in this medium. Numerical results show suppression of gamma-hadron spectra at high transverse momentum in p + Pb collisions at root s(NN) = 5.02 TeV.