https://doi.org/10.1140/epjc/s10052-017-4709-9
Regular Article - Theoretical Physics
Neutron-skin effect in direct-photon and charged-hadron production in Pb+Pb collisions at the LHC
1
Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 223 62, Lund, Sweden
2
Institute for Theoretical Physics, Tübingen University, Auf der Morgenstelle 14, 72076, Tübingen, Germany
3
University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014, University of Jyvaskyla, Finland
4
Helsinki Institute of Physics, P.O. Box 64, FI-00014, University of Helsinki, Finland
5
Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, E-15782, Galicia, Spain
* e-mail: ilkka.helenius@uni-tuebingen.de
Received:
19
January
2017
Accepted:
19
February
2017
Published online:
9
March
2017
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 neutron-skin effect on the centrality dependence of high-
direct-photon 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- 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.
© The Author(s), 2017
