Heavy flavor suppression: Role of hadronic matter

Abstract

The role of hadronic matter in the suppression of open heavy flavored mesons has been studied. The heavy-quarks (HQs) suppression factors have been calculated and contrasted with the experimental data obtained from nuclear collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadronic Collider (LHC) experiments. It is found that the suppression in the hadronic phase at RHIC energy is around 20% − 25% whereas at the LHC it is around 10% − 12% for the D meson. In case of B meson the hadronic suppression is around 10% − 12% and 5% − 6% at RHIC and LHC energies respectively. Present study suggests that the suppression of heavy flavor in the hadronic phase is significant at RHIC. However, the effect of hadronic suppression at LHC is marginal, this makes the characterization of QGP at LHC less complicated. 24.85.+p; 05.20.Dd; 12.38.Mh One of the primary aims of the ongoing heavy-ion collision experiments at RHIC and LHC energies is to create and study the properties of Quark Gluon Plasma (QGP). The heavy flavours (HF) play a vital role to serve this purpose [1][2][3][4][5][6][7][8][9][10][11]. In particular the depletion of high transverse momentum (p T ) hadrons (D and B) produced in Nucleus + Nucleus collisions relative to those produced in proton + proton (p+p) collisions has been considered as an indicator of QGP formation. The STAR [12], PHENIX [13] and the ALICE [14] collaborations have measured this high p T depletion. To make the characterization of the QGP reliable the role of the hadronic matter should be taken into consideration and its contribution must be disentangled from the experimental observables. In this work an attempt has been made to estimate the effect of the hadronic phase on the nuclear suppressions of HFs. PACSWe study the evolution of the HFs in the following scenario. We assume that the light quarks, anti-quarks and gluons form a thermalized matter and the nonequilibrated heavy quarks(HQs) are moving through the expanding QGP background. While the evolution of the expanding QGP is described by the relativistic hydrodynamics with initial temperature and the thermalization time constrained by the measured charged particle multiplicity, the motion of the non-equilibrated HQ is described by the Fokker-Planck equation (FP) with drag and diffusion co-efficients arising due to the interaction of HQs with the expanding QGP background. The initial conditions for the distributions of HQs have been taken from the NLO pQCD results obtained for pp collisions by using the MNR code [15].The expanding QGP converts to hadronic system when it cools down to the transition temperature, T c . The solution of the FP equation for the charm and bottom quarks at the transition point is folded with the Peterson fragmentation function [16] to obtain the momentum distributions of the heavy flavoured mesons containing the effects of the interaction of the expanding QGP back-ground. The hadronic matter evolves in space and time described by relativistic hydrodynamics till the matter gets dilute enough to fre...

Diffusion ofΛcin hot hadronic medium and its impact onΛc/Ghosh1, Das2, Greco3 et al. 2014Phys. Rev. DSelf Cite273180View full textAdd to dashboardCite

“…The ratio estimated after evolving the D [31] and Λ c in the hadronic medium through the Fokker-Planck equation is displayed in Fig. 5.…”

“…The Fokker-Planck (FP) equation has been used to study the time evolution of the D and Λ c in the hadronic bath of the equilibrated degrees of freedom. This is given by [31,43] …”

“…To make reliable characterization of the QGP, the role of the hadronic phase should be assessed and its contribution must be subtracted out from the data. Recently the diffusion coefficients of the D and B mesons have been evaluated in the hadronic phase [23][24][25][26][27][28][29][30] and their effects on R AA ðp T Þ at large transverse momentum (p T ) [31] and elliptic flow (v 2 ) [32,33] have been studied and found to be significant. Apart from the heavy mesons (D and B) the heavy baryon (Λ c ) is also significant as its enhancement [34,35] due to quark coalescence would affect the R AA ðp T Þ of nonphotonic electrons.…”

Effect of in-medium spectral density of D and mesons on the dissociation in hadronic matter

“…In summary, motivated by the non-trivial drag and diffusion coefficients of D mesons in hadronic matter seen in [9], [10] and [11] we have performed a detailed analysis of the spectral properties of heavy open charm mesons in hadronic matter at finite temperature. We use the real-time formalism of thermal field theory and extract the imaginary part of the self-energy from the discontinuities in the complex energy plane.…”

“…Recently, the drag and diffusion coefficients of a hot hadronic medium consisting of pions, kaons and eta using D [9] and B [10] mesons as well as their role in heavy flavour suppression [11] were evaluated using interactions from heavy meson chiral perturbation theory. The significant values obtained for these coefficients indicate a substantial interaction of the heavy mesons with the thermal bath (see also [12,13,14]).…”