arXiv subjects

Yuan-Fang Wu

Publications and source records attributed to Yuan-Fang Wu.

8 recordsLinked to original sources

arXiv2021

The sixth order cumulant of net-proton number in Binomial distribution at $\sqrt{s_{NN}} = $ 200 GeV

It is proposed that ratios of the sixth order to the second order cumulant ($C_6/C_2$) of conserved quantities are sensitive to the chiral crossover transition. Recently, the negative $C_6/C_2$ was obtained both in theoretical Lattice QCD and experiments at $\sqrt{s_{NN}} = $ 200 GeV. In this study, we investigate the behavior of net-proton $C_6/C_2$ in statistical Binomial distribution (BD) at $\sqrt{s_{NN}} = $ 200 GeV in Au + Au collisions. With the BD parameters extracted from RHIC/STAR, it is found that $C_6/C_2$ can be negative. Furthermore, the obtained $C_6/C_2$ becomes smaller when applying the same magnitude of experimental statistics and calculation method to simulations. In 0-10\% centrality, there is a significant difference between the simulated result and theoretical expectation. Based on the extracted parameters and experimentally collected statistics, the baseline of net-proton $C_6/C_2$ in BD is presented.

nucl-th↗

arXiv2021

The suppressions of dijet azimuthal correlations in the future EIC

Quark-antiquark pair (or dijet) production at the electron-ion collider (EIC) has been argued to be one of most important processes that allowing to access the Weizsäcker-Williams (WW) gluon distributions at small $x$ limit. Within the framework of Color Glass Condensate (CGC) effective field theory (EFT), we calculated the dijet cross sections and the azimuthal correlations by including the Sudakov resummations, numerical results shown that the back-to-back correlations are significantly suppressed when the Sudakov resummations are taken into account. In addition, by using the solutions of running-coupling Balitsky-Kovchegov (rcBK) equation, the unpolarized and linearly polarized WW gluon distributions both in coordinate and momentum space are presented.

hep-ph↗

arXiv2018

How to locate the QCD phase boundary by scanning observable in the phase plane

For small volume of the quark-gluon plasma formed in heavy ion collisions, the observable near criticality must obey finite-size scaling. According to the finite-size scaling, there exists a fixed point at the critical temperature, where scaled susceptibility at different system sizes intersect. It also exists at the transitional temperature of a first order phase transition and can be generalized to the region of the crossover. In order to quantify the feature of the fixed point, we introduce {\it the width of a set of points}. When all points in the set are in their mean position within error, the width reaches its minimum, and all points merge into the fixed point. Using the observable produced by the Potts model, we demonstrate that the contour plot of the width defined in this study clearly indicates the temperatures and exponent ratios of fixed point, which could correspond to either the critical point, the points on the transition line, or the crossover region. This method is therefore instructive to the determination of QCD phase boundary by beam energy scan in relativistic heavy ion collisions.

hep-ph↗

arXiv2017

Sub-leading correction of two-gluon rapidity correlations of strong colour field

In the framework of Color Glass Condensate (CGC) effective field theory (EFT), we calculate two-gluon rapidity correlations in the leading and sub-leading orders of $p_\perp/Q_s$. In the leading order, both short- and long-range rapidity correlations are enhanced. In contrast, the contribution of sub-leading order is mainly short range quantum correlations. It is much smaller than that of the leading one, but is not negligible. Transverse momentum dependence of rapidity correlation shows that the leading order is sensitive to the saturation momentum of two incident particles, but the sub-leading one is not.

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arXiv2017

High cumulants of conserved charges and their statistical uncertainties

We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million.

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arXiv2016

Behavior and finite-size effects of the sixth order cumulant in the three-dimensional Ising universality class

The high-order cumulants of conserved charges are suggested to be sensitive observables to search for the critical point of Quantum Chromodynamics (QCD). This has been calculated to the sixth order in experiments. Corresponding theoretical studies on the sixth order cumulant are necessary. Based on the universality of the critical behavior, we study the temperature dependence of the sixth order cumulant of the order parameter using the parametric representation of the three-dimensional Ising model, which is expected to be in the same universality class as QCD. The density plot of the sign of the sixth order cumulant is shown on the temperature and external magnetic field plane. We found that at non-zero external magnetic field, when the critical point is approached from the crossover side, the sixth order cumulant has a negative valley. The width of the negative valley narrows with decreasing external field. Qualitatively, the trend is similar to the result of Monte Carlo simulation on a finite-size system. Quantitatively, the temperature of the sign change is different. Through Monte Carlo simulation of the Ising model, we calculated the sixth order cumulant of different sizes of systems. We discuss the finite-size effects on the temperature at which the cumulant changes sign.

hep-lat↗

arXiv2016

Two-gluon rapidity correlations of strong colour field in $pp$, $pA$ and $AA$ collisions

Using the CGC formalism, we calculate the two-gluon rapidity correlations of strong colour fields in $pp$, $pA$ and $AA$ collisions, respectively. If one trigger gluon is fixed at central rapidity, a ridge-like correlation pattern is obtained in symmetry $pp$ and $AA$ collisions, and a huge bump-like correlation pattern is presented in asymmetry $pA$ collisions. It is demonstrated that the ridge-like correlation patterns are caused by the stronger correlation with the gluon of colour source. The transverse momentum and incident energy dependence of the ridge-like correlation pattern is also systematically studied. The ridge is more likely observed at higher incident energy and lower transverse momentum of trigger gluon.

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arXiv2016

Rapidity bin multiplicity correlations from a multi-phase transport model

The central-arbitrary bin and forward-backward bin multiplicity correlation patterns for Au+Au collisions at $\sqrt{s_{NN}} $= $7.7-62.4$ GeV are investigated within a multi-phase transport (AMPT) model. An interesting observation is that for $\sqrt{s_{NN}} <19.6$ GeV Au+Au collisions, these two correlation patterns both have an increase with the pseudorapidity gap, while for $\sqrt{s_{NN}} >19.6$ GeV Au+Au collisions, they decrease. We mainly discuss the influence of different evolution stages of collision system on the central-arbitrary bin correlations, such as the initial conditions, partonic scatterings, hadronization scheme and hadronic scatterings. Our results show that the central-arbitrary bin multiplicity correlations have different responses to partonic phase and hadronic phase, which can be suggested as a good probe to explore the dynamical evolution mechanism of the hot dense matter in high-energy heavy-ion collisions.

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