Relationship between Oxygen Chemical Potential and Steel Cleanliness

To investigate inclusion formation in each step during steel making process, several samples were taken in different steps of the production of steel at Mobarakeh Steel Co of Esfahan to measure the oxygen chemical potential of the molten steel in each stage. The chemical compositions of the inclusions in samples were investigated by scanning electron microscope. The chemical composition of the slag was analyzed. With the use of thermodnamic calculations and chemical analysis of the melt, at the working temperature, the relationship between dissolved oxygen and other elements were determined. Finally, it was found that there is a close relationship between inclusions formed in each step with the oxygen partial pressure.

A Modified Approach for Calculating Dressed Quark Propagator at Finite Chemical Potential

Based on the rainbow approximation of Dyson-Schwinger equation and the assumption that the full inverse quark propagator at finite chemical potential is analytic in the neighborhood of μ = 1, it is proved that the dressed quark propagator at finite chemical potential μ can be written as G0^-1 [μ] =iγ·p↑-A（p↑-^2） ＋B（p↑-^2） with p↑-μ= （p↑-p4 ＋iμ）. From the dressed quark propagator at finite chemical potential in Munczek model the bag constant of a baryon and the scalar quark condensate are evaluated. A comparison with previous results is given.

Shear Viscosity of Hot QED at Finite Chemical Potential from Kubo Formula

Within the framework of finite temperature field theory this paper discusses the shear viscosity of hot QED plasma through Kubo formula at one-loop skeleton diagram level with a finite chemical potential The effective widths (damping rates) are introduced to regulate the pinch singularities and then gives a reliable estimation of the shear viscous coefficient.The finite chemical potential contributes positively compared to the pure temperature case. The result agrees with that from the kinetics theory qualitatively.

Effect of strong magnetic field on chemical potential and electron capture in magnetar

The chemical potential of electrons in a strong magnetic field is investigated. It is shown that the magnetic field has only a slight effect on electron chemical potential when B 〈 10^11 T, but electron chemical potential will decrease greatly when B 〉 10^11 T. The effects of a strong magnetic field on electron capture rates for ^60Fe are discussed, and the result shows that the electron capture sharply decreases because of the strong magnetic field.

Influence of Finite Chemical Potential on Critical Boson Mass in QED3

Using the coupled Dyson-Schwinger equation for the fermion propagator at finite chemical potential μ, we investigate the fermion chiral condensate when the gauge boson mass is nonzero in QED3. We show that the chiral symmetry restores when the boson mass is large enough, and the critical boson mass depends little on μ.

Analytic Method to Study Influence of Finite Chemical Potential in QED_3~*

Adopting the approximation to the first order of chemical potential μ, we resolve rigidly the influence on fermion condensate from μ in QED3. We show that this condensate does not respond linear expression to μ. Moreover, the influence on fermion chiral condensate from chemieal potential is investigated.

Renormalization of the chemical potential due to multiphonon effects at the surface of metals

We study the relation between renormalization of the chemical potential due to multiphonon effects at the surface of Be（0001） and doping by solving the strong-coupling self-consistent equations of a two-dimensional（2D） electron-phonon interaction system.We present the quasiparticle dispersions and inverse lifetimes of a 2D electron system interacting with Einstein phonons under the different dopings（corresponding to chemical potentials）.We find that the effect of electron-phonon interaction on electron structure is strongest at the half filling,but it has no effect on the chemical potential.However,the chemical potential shows distinct renormalization effects away from half filling due to the electron-phonon interaction.

Fermion-Boson Vertex at Finite Chemical Potential

Based on the Ward-Takahashi identity at finite chemical potential and Lorentz structure analyms, we generalize the Ball-Chiu vertex to the case of nonzero chemical potential and obtain the general form of the frmionboson vertex in QED at finite chemical potential.

Critical Number of Fermion Flavors at Finite Chemical Potential in QED3

We propose a new method for calculating the dressed fermion propagator at finite chemical potential in QED3 under the rainbow approximation of Dyson-Schwinger equation. In the above approximation, we show that the dressed fermion propagator at finite chemical potential # has the form S（p） = iγ.p^-A（p^-2） ＋ B（ p^-2） with p^-μ= （p^-1p3 ＋ iμ）. Using this form of fermion propagator at nonzero chemical potential, we investigate the Dyson-Schwinger equation for the dressed fermion propagator at finite chemical potential and study the effects of the chemical potential on the critical number of the fermion flavors.

Linear Chemical Potential Dependence of Two-Quark Condensate

By differentiating the inverse dressed quark propagator at finite chemical potential μ with respect to μ, the linear response of the dressed quark propagato r to the chemical potential can be obtained, From this we extract a modelindependent formula for the linear chemical potential dependence of the in-medium two-quark condensate and show by two independent methods （explicit calculation and Lorentz covariance arguments） that the first-order contribution in μ to the in-medium two-quark condensate vanishes identically. Therefore if one wants to study the in-medium two-quark condensate one should expand to at/east the second order in the chemical potential μ.

Dyson-Schwinger Equations of Chiral Chemical Potential

We discuss the chiral phase transition of quantum chromodynamics （QCD） with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson-Schwinger equations, we focus particularly on the behavior of the widely accepted as well as interesting critical end point （CEP）, using a separable gluon propagator and a Gaussian gluon propagator. We find that there may be no CEP5 in the T-μ5 plane, and the phase transition in the T μ5 plane might be totally crossover. Our results have apparent consistency with the Lattice QCD calculation. On the other hand, our study may also provide some useful hints to some other studies related to μ5.

A Model-Independent Discussion of Quark Number Density and Quark Condensate at Zero Temperature and Finite Quark Chemical Potential

Generally speaking, the quark propagator is dependent on the quark chemical potential in the dense quantum chromodynamics （QCD）. By means of the generating functional method, we prove that the quark propagator actually depends on p4 ＋ iμ from the first principle of QCD. The relation between quark number density and quark condensate is discussed by analyzing their singularities. It is concluded that the quark number density has some singularities at certain # when T = 0, and the variations of the quark number density as well as the quark condensate are located at the same point. In other words, at a certain # the quark number density turns to nonzero, while the quark condensate begins to decrease from its vacuum value.

Chemical Potential Dependence of Vertices

Based on the rainbow-ladder approximation of the Dyson-Schwinger equations and the assumption of the analyticity of the fermion-boson vertex in the neighborhood of zero chemical potential （μ = 0） and neglecting the #-dependence of the dressed gluon propagator, we apply the method in [Phys. Rev. C 71 （2005） 015205] of studying the dressed quark propagator at finite chemical potential to prove that the general fermion-boson vertex at finite μ can also be obtained from the one at μ = 0 by a simple shift of variables. Using this result we extend the results of [Phys. Lett. B 420 （1998） 267] to the situation of finite chemical potential and show that under the approximations we have taken, the Gell-Mann Oakes-Renner relation also holds at finite chemical potential

A stepwise simulation approach to the chemical potential of fluids

A new approach to the computation of the chemical potential of fluids is presented. In this method the particle-insertion operation in the conventional test particle method is replaced by the growth of a specific particle. Application of the new technique to hard sphere and Lennard-Jones fluids shows that it is capable of providing reliable estimates of the chemical potential, even at high density where the conventional test particle methods are difficult to apply.

Nonextensive effects on QCD chiral phase transition with a chiral chemical potential

In this study,we investigate the QCD chiral phase diagram in the presence of a chiral chemical potential μ based on nonextensive statistical mechanics.A feature of this new statistic is a dimensionless nonextensivity parameter q,which summarizes all possible effects violating the assumptions of Boltzmann-Gibbs(BG)statistics(when q→1,it returns to the BG case).Within the nonextensive Polyakov-Nambu-Jona-Lasinio model,we find that as μ increases,the critical end point(CEP)in the T-μ plane continues to CEP_(5)in the T-μ plane,and nonextensive effects have a significant impact on the evolution from the CEP to CEP_(5).Generally,with an increase in q,both the CEP and CEP_(5)move in the direction of a lower temperature T and larger chemical potentialμ(μ_(5)).In addition,we find that chiral charge density ngenerally increases with T,μ,μ_(5),and q.Our study may provide useful hints about lattice QCD and relativistic heavy-ion collision experiments.

QCD phase diagram at finite isospin chemical potential and temperature in an IR-improved soft-wall AdS/QCD model

We study the phase transition between the pion condensed phase and normal phase,as well as chiral phase transition in a two flavor(Nf=2)IR-improved soft-wall AdS/QCD model at finite isospin chemical potentialμI and temperature T.By self-consistently solving the equations of motion,we obtain the phase diagram in the plane ofμI and T.The pion condensation appears together with a massless Nambu-Goldstone boson mπ1(Tc,μcI)=0,which is very likely to be a second-order phase transition with mean-field critical exponents in the smallμI region.When T=0,the critical isospin chemical potential approximates to vacuum pion massμcI≈m0.The pion condensed phase exists in an arched area,and the boundary of the chiral crossover intersects the pion condensed phase at a tri-critical point.Qualitatively,the results are in good agreement with previous studies on lattice simulations and model calculations.

Influence of super-strong magnetic field on the electron chemical potential and β decay in the stellar surroundings

In this paper, considering the quantum effect of electrons in a super-strong magnetic field, the influence of a super-strong magnetic field on the chemical potential of a non-zero temperature electron is analyzed, the rates of β decay under the super-strong magnetic field are studied, and then we compare them with the case without a magnetic field. Here, the nucleus ^63Co is investigated in detail as an example. The results show that a magnetic field that is less than 1010 T has little effect on the electron chemical potential and β decay rates, but the super-strong magnetic field that is greater than 1010 T depresses the electron chemical potential and improves the β decay rates clearly.

Skyrmion stability at finite isospin chemical potential and temperature

The skyrmion stability at finite isospin chemical potentialμ_I is studied using the Skyrme Lagrangian with a finite pion mass m_π.A critical valueμ_(Ic)=■,above which a stable soliton does not exist,is found.We also explore some properties of the skyrmion as function of i.e.,the isoscalar rms radius and the isoscalar magnetic rms radius.Finally,considering the finite temperature effect on the skyrmion mass,we obtain a critical temperature T_c,using the profile function of the skyrmion,above which the skyrmion mass does not have a minimum,which can be interpreted as the occurrence of the deconfinement phase transition.

Pion properties at finite isospin chemical potential with isospin symmetry breaking

Pion properties at finite temperature, finite isospin and baryon chemical potentials are investigated within the SU（2） NJL model. In the mean field approximation for quarks and random phase approximation fpr mesons, we calculate the pion mass, the decay constant and the phase diagram with different quark masses for the u quark and d quark, related to QCD corrections, for the first time. Our results show an asymmetry between μI 〈 0 and μI 〉0 in the phase diagram, and different values for the charged pion mass（or decay constant） and neutral pion mass（or decay constant） at finite temperature and finite isospin chemical potential. This is caused by the effect of isospin symmetry breaking, which is from different quark masses.

A Dynamical Approach to the Explanation of the Upper Critical Field Data of Compressed H3S

Excellent fits were obtained by Talantsev (MPLB 33, 1950195, 2019) to the temperature (T)-dependent upper critical field (Hc2(T)) data of H3S reported by Mozaffari et al. [Nature Communications 10, 2522 (2019)] by employing four alternative phenomenological models, each of which invoked two or more properties from its sample-specific set S1 = {Tc, gap, coherence length, penetration depth, jump in sp.ht.} and a single value of the effective mass (m*) of an electron. Based on the premise that the variation of Hc2(T) is due to the variation of the chemical potential μ(T), we report here fits to the same data by employing a T-, μ- and m*-dependent equation for Hc2(T) and three models of μ(T), viz. the linear, the parabolic and the concave-upward model. For temperatures up to which the data are available, each of these provides a good fit. However, for lower values of T, their predictions differ. Notably, the predicted values of Hc2(0) are much higher than in any of the models dealt with by Talantsev. In sum, we show here that the addressed data are explicable in a framework comprising the set S2 = {μ, m*, interaction parameter λm, Landau index NL}, which is altogether different from S1.