Baryon-strangeness correlation in quark combination models

Abstract

The baryon-strangeness correlation in the hadronization of the quark matter is studied within the quark combination mechanism. We calculate the correlation coefficient C BS = −3 BS − B S / S 2 − S 2 of initial hadrons produced from the deconfined free quark system with C (q) BS = 1. The competition of the production of baryons against that of mesons is the key dynamics that is most relevant to the change of baryon-strangeness correlation during system hadronization. Results of quark combination under the Poisson statistics agree with the statistical model predictions for a hadron resonance gas at vanishing chemical potential but differ from those at relatively large chemical potentials. Results beyond Poisson statistics are also obtained and are compared with calculations of Lattice QCD in the phase boundary, giving the best agreement at temperature T = 163 MeV. We predict the dependence of the C BS of hadron system on the baryon chemical potential and strangeness. These predictions are expected to be tested by the future Lattice QCD calculations at non-zero chemical potentials and/or by the Beam Energy Scan experiment of STAR Collaboration at RHIC.

Constituent quark number scaling from strange hadron spectra in pp collisions at TeV *

“…The parameter stands for the relative production weight of the decuplet to the octet baryons of the same flavor content. Here, is taken as 0.45 by fitting the data for the ratio in collisions at 7 TeV and -Pb collisions at 5.02 TeV [46], and is taken as 0.5 by fitting the data for and [47]. The fraction of baryons relative to mesons is for vanishing net-quarks [18,21,45].…”

Quark number scaling of $p_{T}$ spectra for $Ω$ and $ϕ$ in relativistic heavy-ion collisions

“…The parameters are all well determined by using the corresponding experimental data. The total number of quarks and antiquarks N t and the net-quark fraction z are determined by the charged hadron multiplicity and anti-hadron to hadron yield ratios (see e.g., [20][21][22]). The parameter a is determined as a = 4.86 in the light-flavor sector [23].…”

Statistical method in quark combination model *

“…Since the longitudinal phase space is easily described by the momentum rapidity, the correlation in rapidity is the basis of the QCR. This type of QCR in SDQCM has successfully explained many data of hadronic production in and pp collisions [24,25,36,37] and rapidity distributions of hadrons in heavy-ion collisions [26,27,31,38].…”

“…The quark combination model developed by the Shandong group (SDQCM) [9][10][11][22][23][24][25][26][27][28][29][30][31][32][33][34][35] is a kind of the exclusive or statistical hadronization model which is different from the Lund string model or the coa-lescence model. The SDQCM adopts a quark combination rule (QCR) to combine the quarks and antiquarks in the neighborhood of the longitudinal phase space into baryons and mesons.…”

“…The quark combination model developed by the Shandong group (SDQCM) [9][10][11][22][23][24][25][26][27][28][29][30][31][32][33][34][35] is a kind of exclusive or statistical hadronization model, which differs from the Lund string model and the coalescence model. The model first takes the constituent quark degrees of freedom as an effective description for the strongly-interacted quark gluon system at hadronization.…”