Neutron-skin effect in direct-photon and charged-hadron production in Pb+Pb collisions at the LHC
Helenius, I., Paukkunen, H., & Eskola, K. (2017). Neutron-skin effect in direct-photon and charged-hadron production in Pb+Pb collisions at the LHC. European Physical Journal C, 77 (3), 148. doi:10.1140/epjc/s10052-017-4709-9
Published inEuropean Physical Journal C
© The Author(s) 2017. This article is published with open access at Springerlink.com and distributed under the terms of the Creative Commons Attribution 4.0 International License. Funded by SCOAP3.
A well-established observation in nuclear physics is that in neutron-rich spherical nuclei the distribution of neutrons extends farther than the distribution of protons. In this work, we scrutinize the influence of this so called neutronskin effect on the centrality dependence of high-pT directphoton and charged-hadron production. We find that due to the estimated spatial dependence of the nuclear parton distribution functions, it will be demanding to unambiguously expose the neutron-skin effect with direct photons. However, when taking a ratio between the cross sections for negatively and positively charged high-pT hadrons, even centrality-dependent nuclear-PDF effects cancel, making this observable a better handle on the neutron skin. Up to 10% effects can be expected for the most peripheral collisions in the measurable region.