共查询到20条相似文献,搜索用时 109 毫秒
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回顾了最近关于手征平滑过渡温度和手征相变温度的研究结果。首先给出了在零重子化学势能下的手征平滑过渡温度为156.5(1.5) MeV,其次,给出了在非零重子化学势能下手征相转变曲线的二阶及四阶曲率分别为0.012(4)和0.000(4)。接着讨论了在格点QCD中第一次得到的量子色动力学的手征相变温度。在热力学极限、连续极限及手征极限下,我们得到手征相变温度为132$^{+3}_{-6}$ MeV。 相似文献
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本文综述量子色动力学在有限温度密度区间的相结构,包括高密条件下的色超导态和在高温条件下相对论重离子碰撞实验中产生的强耦合夸克-胶子等离子体。我们简要地介绍在相对论重离子碰撞实验中发现强耦合夸克-胶子等离子体的历史,并且讨论用体粘滞系数与熵的比值确定QCD临界点的可能性。对于在高密区域的相结构,我们着重讨论错位配对情况下的非标准色超导态,解释无能隙色超导态的色磁不稳定性、Sarma不稳定性和Higgs不稳定性. 相似文献
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作为一种定性的指导,本文用近似方法考察了具有动力学破缺的模型的手征对称性恢复相变.建立了模型的自洽方程;给出了费米子的凝聚和质量以及系统的能量密度和比热对温度和密度的依赖关系.结果表明在零化学势和有限温度情况,手征相变是二级相变,而在有限温度和密度及零温有限密度情况,手征相变是一级相变且从破缺相到正常相的转变温度或密度不同于从正常相到破缺相的转变温度或密度. 相似文献
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本文综述量子色动力学在有限温度密度区间的相结构,包括高密条件下的色超导态和在高温条件下相对论重离子碰撞实验中产生的强耦合夸克-胶子等离子体。我们简要地介绍在相对论重离子碰撞实验中发现强耦合夸克-胶子等离子体的历史,并且讨论用体粘滞系数与熵的比值确定QCD临界点的可能性。对于在高密区域的相结构,我们着重讨论错位配对情况下的非标准色超导态,解释无能隙色超导态的色磁不稳定性、Sarma不稳定性和Higgs不稳定性. 相似文献
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S. A. Gottlieb J. Kuti D. Toussaint A. D. Kennedy S. Meyer B. J. Pendleton R. L. Sugar 《Journal of statistical physics》1986,43(5-6):1105-1115
We present a large-scale Monte Carlo calculation of the deconfining phase transition temperature in lattice quantum chromodynamics
without fermions. Using the Wilson action, the transition temperature as a function of the lattice couplingg is consistent with scaling behavior dictated by the perturbativeα function for 6/g2>6.15.
Speaker at the conference; on leave from CRIP, Budapest. 相似文献
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The talk summarizes some new results of lattice investigations of QCD at finite temperature. The topics discussed cover the
flavor dependence of the critical temperature and the equation-of-state as well as hadronic correlation functions. 相似文献
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The hyperon form factors obtained by using lattice quantum chromodynamics have been used in the Chou-Yang model in conjunction
with the proton form factor obtained by parametrization of the experimental data including the most recent results to obtain
differential cross-sections of hyperon-proton elastic reactions. The agreement with available experimental data verifies lattice
QCD results at low momentum transfers. 相似文献
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Chiral phase transition in thermal QCD is studied by using the Dyson-Schwinger (DS) equation in the real time hard thermal
loop approximation. Our results on the critical temperature and the critical coupling are significantly different from those
in the preceding analyses in the ladder DS equation, showing the importance of properly taking into account the essential
thermal effects, namely the Landau damping and the unstable nature of thermal quasiparticles. 相似文献
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We investigate the behavior of the chiral condensate in lattice QCD at finite temperature and finite chemical potential. The study was done using two flavors of light quarks and with a series of β and ma at the lattice size 24×122×6. The calculation was done in the Taylor expansion formalism. We are able to calculate the first and second order derivatives of <ψψ> in both isoscalar and isovector channels. With the first derivatives being small, we find that the second derivatives are sizable close to the phase transition and that the magnitude of ψψ decreases under the influence of finite chemical potential in both channels. 相似文献
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Existence of a phase transition is proved for a one-dimensional lattice gas with long-range interaction and nearest neighbor exclusion. 相似文献
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Kosterlitz-Thouless transition for the finite-temperatured=2+1,U(1) Hamiltonian lattice gauge theory
We prove that in thed=2+1,U(1) Hamiltonian (continuous time) lattice gauge theory the confining potential between two static external charges grows logarithmically with their distance, at sufficiently high temperatures. As it is known that for zero or low temperatures and large coupling constant the model confines linearly, we have therefore established the existence of a Kosterlitz-Thouless transition. Our results are based on a Mermin-Wagner type of argument combined with correlation inequalities and known results for the two-dimensional (spin) Villain model. 相似文献
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Ai-Yuan Hu Lin Wen Guo-Pin Qin Zhi-Min Wu Peng Yu Yu-Ting Cui 《Frontiers of Physics》2019,14(5):53601
The frustrated spin-1/2 J1a–J1b–J2 antiferromagnet with anisotropy on the two-dimensional square lattice was investigated, where the parameters J1aand J1b represent the nearest neighbor exchanges and along the x and y directions, respectively. J2 represents the next-nearest neighbor exchange. The anisotropy includes the spatial and exchange anisotropies. Using the double-time Green’s function method, the effects of the interplay of exchanges and anisotropy on the possible phase transition of the Néel state and stripe state were discussed. Our results indicated that, in the case of anisotropic parameter 0≤η<1, the Néel and stripe states can exist and have the same critical temperature as long as J2 = J1b/2. Under such parameters, a first-order phase transformation between the Néel and stripe states can occur below the critical point. For J2 ≠J1b/2, our results indicate that the Néel and stripe states can also exist, while their critical temperatures differ. When J2>J1b/2, a first-order phase transformation between the two states may also occur. However, for J2<J1b/2, the Néel state is always more stable than the stripe state. 相似文献
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We study the vacuum structure in QCD in a nonperturbative manner using a variational approach with gluon condensates. We show
that in Coulomb gauge as the coupling becomes moderately strong, the perturbative vacuum of QCD becomes unstable leading to
gluon condensates and a gauge dependent effective mass for the gluons related to the gauge independent value of 〈vac‖G
μν
a
G
aμν‖vac〉 of Shifmanet al. 相似文献
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We prove a form of reflection positivity in planes containing sites for a class of quantum lattice systems. As an application, a proof is given of a phase transition for the Fisher-stabilized Ising antiferromagnet in an external magnetic field with parallel and transverse components, both by the method of infrared bounds and by a suitable version of the Peierls argument. We also discuss the spherical model in an appendix. 相似文献