Longitudinal and transverse meson correlators in the deconfined phase from the lattice
Gert Aarts, Chris Allton, Justin Foley, Simon Hands, Seyong Kim
备注：
6 pages. Prepared for Achievements and New Directions in Subatomic Physics: Workshop in Honour of Tony Thomas' 60th Birthday, Adelaide, Australia, 15-19 Feb 2010
It has long been known that QCD undergoes a deconfining phase transition at high temperature. One of the consequent features of this new, quark-gluon phase is that hadrons become unbounded. In this talk meson correlation functions at non-zero momentum are studied in the deconfined phase using the Maximum Entropy Method.
We present continuum extrapolated results of charmonium and bottomonium correlators in the vector channel at several temperatures below and above $T_c$. The continuum extrapolation jointly performed with the interpolations to have physical values of $J/ψ$ and $Υ$ masses in the confined phase is based on calculations on several large quenched isotropic lattices using clover-improved Wilson valence fermions carrying different quark masses. The extrapolated lattice correlators are confronted with perturbation theory results incorporating resummed thermal effects around the threshold from pNRQCD a…
Considering the strong field approximation we compute the hard thermal loop pressure at finite temperature and chemical potential of hot and dense deconfined QCD matter in lowest Landau level in one-loop order. We consider the anisotropic pressure in the presence of the strong magnetic field i.e., longitudinal and transverse pressure along parallel and perpendicular to the magnetic field direction. As a first effort, we compute and discuss the anisotropic quark number susceptibility of deconfined QCD matter in lowest Landau level. The longitudinal quark number susceptibility is found to increa…
The heavy quark diffusion coefficient is encoded in the spectral functions of the chromoelectric and the chromomagnetic correlators that are calculable on the lattice. We study the chromoelectric and the chromomagnetic correlator in the deconfined phase of SU(3) gauge theory using Symanzik flow at two temperatures $1.5T_c$ and $10000 T_c$, with $T_c$ being the phase transition temperature. To control the lattice discretization errors and perform the continuum limit we use several temporal lattice extents $N_t=16,20,24$ and 28. We observe that the flow time dependence of the chromomagnetic corr…
We evaluate the longitudinal or (chromo-)electric Yang-Mills gluon propagator in the recently proposed center-symmetric Landau gauge at finite temperature [1]. To model the effect of the Gribov copies in the infrared, we use the Curci-Ferrari model which, in turn, allows us to rely on perturbative calculations. At one-loop order in the SU(2) case, the so-obtained longitudinal gluon propagator provides a clear signature for Z2 center-symmetry breaking with a singular behavior, characteristic of a continuous phase transition. This is in sharp contrast with what is found within the standard Landa…
We study charmonium correlators in pseudoscalar and vector channels at finite temperature using lattice QCD simulation in the quenched approximation. Anisotropic lattices are used in order to have sufficient numbers of degrees of freedom in the Euclidean temporal direction. We focus on the low energy structure of the spectral function, corresponding to the ground state in the hadron phase, by applying the smearing technique to enhance the contribution to the correlator from this region. We employ two analysis procedures: the maximum entropy method (MEM) for the extraction of the spectral funct…
We present results for the photon emission rate determined from the transverse channel vector correlator at fixed spatial momentum using two flavors of dynamical Wilson fermions at $T\sim$250 MeV. We estimate the transverse channel spectral function using the continuum extrapolated correlator by applying various fit ansätze with a smooth matching to the NLO perturbative result. We confront our estimate based on this channel with the latest results of our collaboration based on the difference of the transverse and longitudinal channels.
We report on recent progress in understanding confinement of colour in $QCD$ as dual superconductivity of the vacuum. A gauge invariant version of the creation operator of monopoles is constructed whose vacuum expectation value is the order parameter. This order parameter is gauge-invariant from scratch, has no infrared divergences, is finite in the confined phase and vanishes in the deconfined phase. A natural explanation also emerges of why the electric field lines in the flux tubes keep no memory of the colour orientation of the condensing monopoles. A further by-product is that the order p…
Longitudinal and transverse spectral functions in the three-dimensional O(4) model
我们在线性扩展L=120的三维晶格上对O（4）模型进行了高统计模拟。用最大熵方法分析了T =T_c时的纵、横平面自旋关联函数<T_c and T>。在横向情况下，我们发现对于所有的T和H，谱函数中有一个尖锐的峰，其位置定义了横向质量m_T，相关器是质量为m_T的自由粒子的相关器。在纵向情况下，我们发现在很高的温度区域，光谱中也有一个单一的尖峰。在从上面接近临界点时，峰有些加宽，在T_c处，对于我们所有的H值，其位置m_L都在2m_T处。在T_c以下，我们发现在ω =2m_T处仍然有一个显著的峰，在更高的ω值处，有几个较小的峰随着高度的降低而连续的状态。这一发现与Patashinskii和Pokrovskii关于纵向和横向关联函数的关系是一致的。我们在下面测试这个关系。作为副产品，我们计算临界指数和振幅，并确认我们以前的结果。
Chiral Magnetic Effect and Negative Magnetoresistance across the phase diagram of finite-density SU(2) gauge theory
University of Liverpool（利物浦大学）；Justus-Liebig-Universität（吉森大学）；Helmholtz Research Academy Hesse for FAIR (HFHF)（黑森FAIR亥姆霍兹研究院）；GSI - Helmholtzzentrum für Schwerionenforschung（GSI重离子研究中心）
