Jan 10 – 15, 2021
Weizmann Institute of Science
Asia/Jerusalem timezone
See you at IS2023 in Copenhagen in June 2023

Fixing the nuclear charge density with finite nucleons

Jan 14, 2021, 5:30 PM
Andrea's room 2 (vDLCC)

Andrea's room 2


oral The initial stages of heavy-ion collisions IS


Mauricio Hippert (University of Campinas UNICAMP (BR))


The measured charge distribution of a nucleus is often used to sample
positions of nucleons within the nucleus. However, since nucleons
have finite size, the resulting charge distribution is different from
the sampled distribution. We show that this can have significant
observable effects: Not only does it increase the size of the
nucleus, but also changes the surface diffusiveness. This in turn can
have effects as simple as an overestimate of the transverse size of
the collision system resulting in an underestimate of the final
transverse momentum, to changes in centrality determination and even
total nucleus-nucleus cross section. These differences can, for
example, add significant bias to Bayesian parameter estimation. We
then show a simple method for correcting this, so that nucleons are
sampled in a way that the average charge distribution is fixed to the
desired function, and approximately independent of the size of the
nucleon. This method can be easily implemented in existing Monte
Carlo simulations that utilize a spherical Woods-Saxon distribution.
We also discuss a more general treatment that can be used for an
arbitrary charge distribution.

Primary authors

Mauricio Hippert (University of Campinas UNICAMP (BR)) David Dobrigkeit Chinellato (University of Campinas UNICAMP (BR)) Matthew Luzum (University of Sao Paulo) Willian Matioli Serenone (University of Campinas UNICAMP (BR)) Jorge Noronha (University of Illinois at Urbana-Champaign) Prof. Tiago Jose Nunes da Silva (Universidade Federal de Santa Catarina) Jun Takahashi (University of Campinas UNICAMP (BR))

Presentation materials