共查询到19条相似文献,搜索用时 62 毫秒
1.
讨论了磁场中夸克物质的非轻子弱作用过程. 改进了在弱磁场情况下的近似计算方法, 分别给出了强弱磁场下非轻子过程的反应率的表达式, 以及一定条件下的近似表达式. 结果显示, 强磁场极大的抑制反应率的大小, 进而影响奇异夸克物质的粘滞性. 相似文献
2.
3.
利用与奇异夸克质量相关的非轻子弱过程u+s←→d+u的反应速率, 在考虑了夸克之间的相互作用并做了热力学自恰处理后, 重新推导、计算了奇异夸克物质的体黏滞系数. 由于热力学自恰的需要引入一项压力附加项, 使得奇异星的体黏滞系数比前人计算的有了很大的增加. 通过计算振动衰减时间我们发现, 虽然体黏滞系数增大了很多, 但以前对于奇异星观测的结论仍然成立. 相似文献
4.
5.
6.
7.
8.
9.
10.
11.
12.
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 相似文献
13.
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 Ac ~ 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 Ac~ 105. The stable radius, electric charge, and quark flavor fractions of magnetized strangelets are shown. 相似文献
14.
Starting from the Kubo formula and the QCD low energy theorem, we study the the bulk viscosity of hot dense quark matter in the PNJL model from the equation of state. We show that the bulk viscosity has a sharp peak near the chiral phase transition, and that the ratio of bulk viscosity over entropy rises dramatically in the vicinity of the phase transition. These results agree with those from the lattice and other model calculations. In addition, we show that the increase of chemical potential raises the bulk viscosity. 相似文献
15.
We investigate the equation of state of the strong interaction matter in a background magnetic field via the two flavor Nambu-Jona-Lasinio model. Starting from the mean-field thermodynamical potential density Ω, we calculate the pressure density p, the entropy density s, the energy density ε, and the interaction measure (ε-3p)=T4 of the strong interaction matter at finite temperature and finite magnetic field. The results manifest that the chiral phase transition is just a crossover but not a low order phase transition. Moreover there may exist magnetic catalysis effect, and its mechanism is just the effective dimension reduction induced by the magnetic field. 相似文献
16.
17.
18.
WANGXing-Xiang 《理论物理通讯》2004,42(3):361-364
The Bianchi type Ⅲ cosmological model for a cloud string with bulk viscosity are presented. To obtain a determinate model, an equation of state ρ=kλ and a relation between metric potentials B = C^n are assumed. The physical and geometric aspects of the model are also discussed. The model describes a shearing non-rotating continuously expanding universe with a big-bang start, and the relation between the coefficient of bulk viscosity and the energy density is ζ∝ρ^1/2. 相似文献
19.
In this paper bulk viscosity is introduced to describe the effects of cosmic non-perfect fluid on the cosmos evolution and to build the unified dark energy (DE) with (dark) matter models. Also we derive a general relation between the bulk viscosity form and Hubble parameter that can provide a procedure for the viscosity DE model building. Especially, a redshift dependent viscosity parameterζ∝λ0 +λ1(1+z)n proposed in the previous work [X.H. Meng and X. Dou, Commun. Theor. Phys. 52 (2009) 377] is investigated extensively in this present work. Further more we use the recently released supernova dataset
(the Constitution dataset) to constrain the model parameters. In order to differentiate the proposed concrete dark energy models from the well known $\Lambda$CDM model, statefinder diagnostic method is applied to this bulk viscosity model, as a complementary to the Om parameter diagnostic and the deceleration parameter analysis performed by us before. The DE model evolution behavior and tendency are shown in the plane of the statefinder diagnostic parameter pair {r,s} as axes where the fixed point represents theΛCDM model. The possible singularity property in this bulk viscosity
cosmology is also discussed to which we can conclude that in the different parameter regions chosen properly, this concrete viscosity DE model can have various late evolution behaviors and the late time singularity could be avoided. We also calculate the cosmic entropy in the bulk viscosity dark energy frame, and find that the total entropy in the viscosity DE model increases monotonously with respect to the scale factor evolution, thus this monotonous
increasing property can indicate an arrow of time in the universe evolution, though the quantum version of the arrow of time is still very puzzling. 相似文献