Higher Dimensional Cosmological Model with Quark and Strange Quark Matter

We study higher dimensional homogeneous cosmological model in the presence of quark and strange quark matter. The dynamical behavior of the model for the strange quark matter equation of state of the form p = \frac13 (r- 4 B_c)p= \frac{1}{3} (\rho- 4 B_{c}) are studied.     

Quark Condensate in the Strange Matter

In a nonlinear chiral SU(3) framework, we investigate the quark condensate in the strange matter including N, Σ, Ξ, and Λ, making use of chiral symmetry spontaneous breaking Lagrangian and mean-field approximation. The results show that the chiral symmetry is restored partially when the strange matter density increases and that 〈π→2〉 plays a very important role in the strange matter which may approach the constituents of the neutron stars. In addition, we can find that the strange matter density where the π-condensate emerges leads to the ratio of the nucleon number to baryon number.     

奇异夸克物质的夸克质量密度温度相关模型(英文)

在夸克质量密度相关模型处理奇异夸克物质滴时 ,会发现其半径随温度增加而变小 .为克服这一困难 ,我们通过使口袋常数 B温度参数化 ,引入了夸克质量密度温度相关模型 .在这一模型中 ,B=B0 [1 - a(T/Tc) +b(T/Tc) 2 ],文章中讨论了参数 a,b的取法. It is found that the radius for a stable strangelet is a decreasing function of temperature in quark mass density- dependent model. To overcome this difficulty, we extend this model to quark mass density- and temperature- dependent model in which the vacuum energy density at zero baryon density limit B depends on temperature. An ansatz B=B 0[1-a(T/T c )+b(T/T c ) 2] is introduced and the regions for the best choice of the parameters are studied.     

关于奇异夸克物质的性质

基于以前的工作,导出了新的奇异夸克质量公式,并用于研究奇异夸克物质的性质,得到与MIT袋模型类似的结果.而且发现,新公式导致与以前有所不同的结果,即声速随能量密度的增加而趋向于极端相对论情况的速度减慢.     

Non-Spherical Gravitational Collapse of Strange Quark Matter

We study the non-spherical gravitational collapse of the strange quark null fluid. The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole. We extend the earlier work of Harko and Cheng [Phys. Lett. A 266 （2000） 249] to the non-spherical case.     

Geometry of Quark and Strange Quark Matter in Higher Dimensional General Relativity

In this paper we study quark matter and strange quark matter in higher-dimensional spherical symmetric space-times. We analyze strange quark matter for the different equations of state and obtain the space-time geometry of quark and strange quark matter. We also discuss the features of the obtained solutions in the context of higher-dimensional general theory of relativity.     

Propagation of Strange Quark Matter in the atmosphere

We propose a model of propagation of lumps of Strange Quark Matter (strangelets) through the atmosphere, which accounts for their apparent strong penetrability and normal nuclear-type sizes at the same time. The mass spectrum of strangelets reaching the Earth predicted by this model agrees very well with the existing data on the abundance of different elemets in the Universe.     

Strange Quark Matter and Strangelets in a Strong Magnetic Field

We study the stability properties of magnetized strange quark matter and strangelets under a strong magnetic field in the MIT bag model. The free energy per baryon of strange quark matter feels a great influence from the magnetic field. At the field strength about 10¹⁷G, the magnetized strange quark matter becomes more stable. Considering the finite size effect, the magnetic influence on strangelets becomes complicated. For a given magnetic field, there exists a critical baryon number, below which the magnetized strangelets have lower energy than the non-magnetized strangelets. For the field strength of 5× 10¹⁷G, the critical baryon number is A_c ～ 100. Generally, the critical baryon number increases with the decreasing external magnetic field. When the field strength is smaller than 10¹⁷G, the critical baryon number goes up to A_c～ 10⁵. The stable radius, electric charge, and quark flavor fractions of magnetized strangelets are shown.     

Strange Quark Matter Attached to String Cosmology in FRW Space-Time

We have obtained FRW cosmological model with strange quark matter attached to the string cloud in general relativity. The model is obtained with the help of special law of variation for Hubble parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983). Also, some physical and kinematics properties of the model are discussed. The results are analogous to results obtained by Yilmaz (Gen. Relativ. Gravit. 38:1397–1406, 2006).     

质量密度相关模型研究CFL奇异夸克物质性质

在质量--密度相关模型下研究了CFL奇异夸克物质, 并将结果与传统的袋模型结果进行比较. 两个模型均表明, 在合理的参数范围内, CFL相比正常核物质更稳定. 然而, 低密度时声速的行为完全相反, 这使得CFL夸克星的最大质量在质量-密度相关模型下比袋模型大.     

高温近似下奇异夸克物质的体粘滞系数

在准粒子描述下,采用自洽的热力学方法,考虑奇异夸克物质(SQM?)的介质效应,计算了高温近似下奇异夸克物质的体粘滞系数.发现介质效应对奇异夸克物质的体粘滞系数有很大影响,这使得观测数据不再排除两味色超导相奇异星的存在.     

Domain Walls Strange Quark Matter in Einstein-Rosen Space-Time with Cosmological Constant and Heat Flow

In this paper, we have studied the solutions of Einstein field equations for domain walls with cosmological constant and heat flow in Einstein-Rosen cylindrical symmetric space-time when strange quark matter and normal matter attached to the domain walls. Some physical and kinematical features of the obtained cosmological model are studied and discussed.     

一级微扰QCD耦合的夸克物质体粘滞系数

在高密情况下考虑了夸克间弱的耦合,直接应用微扰计算得到的热力学势计算了奇异夸克物质(SQM)的体粘滞系数,发现介质效应使SQM的粘滞性提高2个量级左右     

Cosmological Model with Strange Quark Matter Attached to Cosmic String for Axially Symmetric Space-Time

We have investigated cosmological model with strange quark matter attached to the string cloud in general theory of gravitation for Axially Symmetric space time. The model is obtained with the help of special law of variation for Hubble parameter proposed by Bermann (Nuovo Cimento B 74:182, 1983). Also, some physical and kinematics properties of the model are discussed.     

Axially Symmetric Space-Time with Strange Quark Matter Attached to String Cloud in Self Creation Theory and General Relativity

The Axially symmetric space times with strange quark matter attached to string cloud in Barber’s (Gen. Relativ. Gravit. 14, 117, 1982) self-creation theory and general relativity have been studied. The field equations of the two theories have been solved by using the anisotropy feature of the universe in the axially symmetric space times. Some important features of the models, thus obtained, have been discussed and it is established that the additional condition, special law of variation of Hubble parameter proposed by Bermann (Nuovo Cimento B 74, 182, 1983), taken by Katore and Shaikh (Int. J. Teor. Phys. 51, 1881, 2012) in general relativity is superfluous.     

新的质量标度下奇异夸克物质的电荷与临界密度

应用自恰的热力学方式确定夸克质量公式中的参数,并进一步证明,在新的质量标度下,适量的负电荷仍然可以降低奇异夸克物质的临界密度,从而有利于在重离子碰撞实验中寻找strangelets.当然,过量的负电荷仍将使味平衡成为不可能.     

Modeling Galactic Halos with Predominantly Quintessential Matter

This paper discusses a new model for galactic dark matter by combining an anisotropic pressure field corresponding to normal matter and a quintessence dark energy field having a characteristic parameter ω _q such that -1 < w_q < -\frac13-1<\omega_{q}< -\frac{1}{3}. Stable stellar orbits together with an attractive gravity exist only if ω _q is extremely close to -\frac13-\frac{1}{3}, a result consistent with the special case studied by Guzman et al. (Rev. Mex. Fis. 49:303, 2003). Less exceptional forms of quintessence dark energy do not yield the desired stable orbits and are therefore unsuitable for modeling dark matter.     

Higher Dimensional Strange Quark Matter Coupled to the String Cloud with Electromagnetic Field Admitting One Parameter Group of Conformal Motion

We solve Einstein＇s field equations in higher-dimensional spherically symmetric spacetime with strange quark matter attached to the string cloud, assuming one parameter group of con formal motions. The solutions match with the higher-dimensional Reissner-Nordstroem metric on the boundary at r=ro. The features of the solutions are also discussed in the framework of higher-dimensional spacetime.     

核子中奇异夸克分布不对称性与轻味夸克碎裂效应

核子中奇异－反奇异夸克分布的不对称性是核子结构研究中的重要非微扰效应, 然而至今未被实验所直接检验.为了探讨测量这种奇异分布不对称性的有效方法,考察了轻味夸克碎裂效应对测量奇异分布不对称性的影响.建议通过直接测量高能中微子和反中微子的带电流深度非弹散射中的带电和中性D介子的微分截面来测量奇异分布的不对称性.这种方法能够使奇异分布不对称性与轻味夸克碎裂的效应相分离.