121754937
A MODEL STUDY OF QUARK NUMBER SUSCEPTIBILITY AT FINITE CHEMICAL POTENTIAL AND ZERO TEMPERATURE
In this paper, we try to provide a direct method for calculating quark number susceptibility at finite chemical potential and zero temperature. In our approach, quark number susceptibility is totally determined by G[mu](p) (the dressed quark propagator at finite chemical potential mu). By applying the general result given in Phys. Rev. C 71, 015205 (2005), G[mu](p) is calculated from the model quark propagator proposed in Phys. Rev. D 67, 054019 (2003). From this the full analytic expression of quark number susceptibility at finite mu and zero T is obtained.
121809939
The Wigner solution of quark gap equation and chiral phase transition of QCD at finite temperature and nonzero chemical potential
By employing some modification to the normal NJL model, we discuss the Wigner solution of quark gap equation at finite temperature and chemical potential when the current quark mass m is nonzero. The discovery of the coexistence of the Nambu solution and the Wigner solution at finite temperature and chemical potential beyond the chiral limit is of great importance in the study of the chiral phase transition of QCD. Using the pressure difference between Nambu phase and Wigner phase (or in other words, the bag constant) as an order parameter for chiral phase transition, we draw a possible phase diagram based on our calculations.
120263943
Quark-meson vertices and pion properties at finite chemical potential
Based on the rainbow-ladder approximation of the Dyson-Schwinger equations and the assumption of the analyticity of the quark-meson vertex in the neighborhood of zero chemical potential ({mu}=0) and neglecting the {mu}-dependence of the dressed gluon propagator, we use the method of studying the dressed quark propagator at finite chemical potential given in [H. S. Zong, L. Chang, F.Y. Hou, W. M. Sun, and Y. X. Liu, Phys. Rev. C 71, 015205 (2005)] to show that the axial-vector quark-meson vertex at finite {mu} can be obtained from the corresponding one at {mu}=0 by a shift of variable: {gamma}{sub 5{nu}}{sup j}[{mu}](k, p)={gamma}{sub 5{nu}}{sup j}(k{approx}, p), where k and p are the relative and total momentum of the quark-antiquark pair, respectively, and k{approx}=(k-vector, k{sub 4}+i{mu}). Similar relations hold for any other type of quark-meson vertex. This feature would facilitate the numerical calculations of the quark-meson vertex function at finite {mu} considerably. Based on these results and using the dressed quark propagator at {mu}=0 proposed in [R. Alkofer, W. Detmold, C. S. Fischer, and P. Maris, Phys. Rev. D 70, 014014 (2004)], we calculate the pion decay constant f{sub {pi}} and the pion mass m{sub {pi}} at finite {mu} and a comparison of ourmore » results with those in the literature is made.« less
121136055
The equation of state of QCD under hard-dense-loop approximation
Based on the method proposed by Zong et al., we calculate the equation of state (EOS) of QCD at zero temperature and finite quark chemical potential under the hard-dense-loop (HDL) approximation. A comparison between the EOS under HDL approximation and the cold, perturbative EOS of QCD proposed by Fraga, Pisarski and Schaffner-Bielich is made. It is found that when µ is less than 4.7 GeV, the pressure density calculated using HDL approximation is much larger than that calculated using perturbation theory. This enhancement of the obtained pressure density with respect to that of perturbation theory can be regarded as a possible explanation for the strong coupled QGP. It is also expected that the obtained EOS can be applied in the study of neutron stars.
124327174
The Renormalized Equation of State and Quark Star
By means of the EOS of QCD at zero temperature and finite quark chemical potential we proposed [Phys. Rev. D 78(2008)054001] in the framework of rainbow-ladder approximation of Dyson-Schwinger approach, we investigate the structure of quark star and its property. It is found that the mass-radius relation in our model is very different from that of usual quark star models, but similar to neutron star models. The obtained mass of quark star is about 1.75M⊙ ~ 2.2M⊙. The obtained radius of quark star is 22 ~ 26 km, which is obviously larger than the results in other models. The reason for this discrepancy is analyzed.
53688784
Locate QCD critical end point in a continuum model study
A bstractWith a modified chemical potential dependent effective model for the gluon propagator, we try to locate the critical end point (CEP) of strongly interacting matter in the framework of Dyson-Schwinger equations (DSE). Beyond the chiral limit, we find that Nambu solution and Wigner solution could coexist in some area. Using the CornwallJackiw-Tomboulis (CJT) effective action, we show that these two phases are connected by a first order phase transition. We then locate CEP as the end point of the first order phase transition line. Meanwhile, based on CJT effective action, we give a direct calculation for the chiral susceptibility and thereby study the crossover.
45741338
Diagnosing degenerate Higgs bosons at 125 GeV.
We develop diagnostic tools that would provide incontrovertible evidence for the presence of more than one Higgs boson near 125 GeV in the LHC data.
124816809
Toric sheaves on weighted projective planes
We give an explicit description of toric sheaves on the weighted projective plane P(a, b, c) viewed as a toric Deligne-Mumford stack. The stack P(a, b, c) has an action of the torus T = C and by a toric sheaf we mean a coherent sheaf together with a lift of the torus action. The integers (a, b, c) are not necessarily chosen coprime or mutually coprime allowing for gerbe and root stack structures. This is a first step in an attempt to give an explicit description of toric sheaves on any smooth toric Deligne-Mumford stack. Specializing the description to torsion free sheaves gives a combinatorial picture with various new features, which do not appear in the case of smooth toric varieties. As an application, we describe the fixed point locus of the moduli scheme of stable rank 1 and 2 torsion free sheaves on P(a, b, c) with fixed K-group class. Summing over all K-group classes, we obtain formulae for generating functions of the topological Euler characteristics of these moduli schemes.
123025416
Bc DECAYS TO HEAVY-LIGHT ORBITALLY EXCITED MESONS
We calculate the exclusive semileptonic and nonleptonic decays of Bc meson to heavy-light orbitally excited states in the framework of the improved Bethe–Salpeter method. The hadronic matrix elements are calculated and expressed as overlap integrals of the relativistic Salpeter wave functions of corresponding mesons, decay rates of the semileptonic and nonleptonic Bc decays to , and are obtained. Some channels provide us sizable ratios, for examples, and , with such ratios, the missing scalar Bs0 may be detected though its cascade strong decays in the forthcoming LHC experiment.
119925663
A general derivation of the Hall conductivity on the noncommutative plane
By algebraic approach, Hall conductivity on the noncommutative plane is derived exactly. The calculations are carried out in noncommutative phase spaces without any representations or perturbation expansions of the coordinate and momentum operators.
118172840
Search for the electron electric dipole moment
Extensions to the Standard Model (SM) typically include new heavy particles and new mechanisms for CP violation. These underlying phenomena can give rise to electric dipole moments of the electron and other particles. Tabletop‐scale experiments used to search for these effects are described. Present experiments are already sensitive to new physics at the TeV scale, and new methods could extend this range dramatically. Such experiments could be among the first to show evidence for physics beyond the SM.