Conservation of B, S, and Q charges in relativistic viscous hydrodynamics solved with smoothed particle hydrodynamics
Christopher Plumberg, Dekrayat Almaalol, Travis Dore, Débora Mroczek, Jordi Salinas, Willian Matioli Serenone, Lydia Spychalla, Patrick Carzon, Matthew D. Sievert, Fernando G. Gardim, Jacquelyn Noronha-Hostler
Abstract
Conservation laws play a crucial role in the modeling of heavy-ion collisions, including those for charges such as baryon number (B), strangeness (S), and electric charge (Q) (hereafter referred to as BSQ charges). In this study, we present a new (2+1)-dimensional relativistic viscous hydrodynamic code called ccake which uses the smoothed particle hydrodynamics formalism to locally conserve BSQ charges, together with an extended description of the multidimensional equation of state obtained from lattice quantum chromodynamics. Initial BSQ charge distributions for ccake are supplied by iccing, an algorithm which samples gluon splittings into quark-antiquark pairs from a background energy distribution from the TRENTo model. We study correlations between the BSQ charges and find that local BSQ fluctuations remain finite during the evolution, with corresponding chemical potentials of $\ensuremath{\approx}100--200\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ at freeze-out. We find that our framework produces reasonable multiplicities of identified particles and that iccing has no significant effect on the collective flow of all charged particles nor of identified particles when only one particle of interest is considered. However, we show specifically for Pb $+$ Pb collisions at the LHC $\sqrt{{s}_{NN}}=5.02$ TeV that iccing does have an effect on collective flow of identified particles if two particles of interest are considered.