In this paper, we aim to investigate the electric conductivity of an out of equilibrium system of QCD at low temperatures. One way to study such systems is to apply a time dependent electric field and examine the out of equilibrium behavior of the system. The electric field produces pairs of quarks and antiquarks from the field theory vacuum leading to an electric current. By using the relation between the applied electric field and its relevant current, the electric conductivity of the field theory can be obtained. We use a non-critical holographic model of QCD to study the time dependent out of equilibrium solution of the system non-perturbatively and examine the effects of parameters such as electric field magnitude and frequency as well as the charge density on electric conductivity. Finally, we compare our results with those from other holographic models.

At small Bjorken scaling variable x, dominated Glouns in a hadronic process becomes a color glass condensate (CGC) and most important principle in this subject is existence of a saturation scale. Then we can describe unintegrated gluon distribution function according to the saturation scale. In this study, we want to calculate gluon distribution function with respect of AdS/CFT correspondence. By using Fourier transform of diploe scattering amplitude, we can extract an analytical formula for the unintegrated gluon distribution function that inspired from AdS/CFT correspondences. Then our results compared with does from other parameterization models. These results show that the distribution function behavior tamed at low Bjorken scaling limit.

Using QCD factorization for the hadronic matrix elements, we show that existing data, in particular the branching ratios BR (`B ® J/YK) and BR (`B ® J/Yp), can be accounted for in this approach. We analyze the decay B ® J /YK (p) within the framework of QCD factorization. The calculation of the relevant hard-scattering kernels for twist-2 and twist-3 is completed. We calculate this decay in a special scale (m=mb) and in two schemes for Wilson coefficients in NLO. We consider three functions for J/Y. The twist-3 contribution involves the logarithmically divergent integral, we consider rH=0 the canceling divergent. The obtained results are in agreement with available experimental data.

We used QCD factorization for the hadronic matrix elements to show that the existing data, in particular the branching ratios BR (B-®J/yK) and BR (B-®J/yp), can be accounted for this approach. We analyzed the decay B®J /y K (p) within the framework of QCD factorization. We have complete calculation of the relevant hard-scattering kernels for twist-2 and twist-3. We calculated this decays in a special scale (m=mb) and in two schemes for Wilson coefficients in NLO. We considered three functions for J /y. The twist-3 contribution involves logarithmically divergent integral and also we considered pH=0 canceling divergent. The obtained results are in agreement with available experimental data.

This study employs holography within a modified D3/D7 framework to explore the phase diagram of a QCD-like theory. The corresponding dual theory is characterized by a large N, $ \mathcal{N}=4 $ gauge theory, integrated with quenched $ \mathcal{N}=2 $ quark matter and a novel dilaton profile. The research focuses on how the critical point's location in the phase diagram is influenced by temperature and chemical potential. Additionally, the study examines the trajectory of these critical points in response to alterations in the dilaton profile's control parameter, revealing a trend where the critical endpoint shifts to higher temperatures and lower chemical potentials.

In this research, we are going to study of QCD penguin structure and calculated the second order approximation. The amplitude of decays related to QCD penguin in quark model up to the first and second orders calculated. We calculated the amplitude of QCD penguin on lowest order of for first order of the decay processes and for second order of the decay processes. We calculated the decay rates of the first and second order of QCD penguin for various b quark decays. We consider that, the second order of QCD penguin of b quark decays is much smaller than the first order of them. In the other hand, we can ignore the second order of QCD penguin in the b quark decays. We deduced various two and three body decays of B meson decays from various decays of b quark model. We compared the branching ratios of various decays of B meson, theoretically and experimentally and saw that the second order of QCD penguin term in b quark decays is small.

This paper studies improved factorization method, in the heavy quark limit, for B ®K p decays. Paying attention to strong interaction scale AQCD, and calculating all parameters depending on that in the particular scale (the same as µ ) show that we can obtain better and comparable results for branching ratios such as BR(B0®K0p0)=8.5+0.7-0.5×10-6 and BR(B®pk0)=2.26+0.17-0.15×10-5, and for CP-asymmetry such as, ACP(B®Kp0)=0.045 and ACP(B ®Kp0)=0.0085, which are very close to experimental values. In this framework, we fix AQCD=225Mev, and also calculate parameters such as Wilson coefficients,   aS, C8g and in this scale.

In this paper we intend to determine valence quarks distribution functions u, d in a wide range of x and Q 2 , with using experimental data groups such as CCFR, NuTeV, CHORUS and CDHSW, and determine their correlated errors using xFitter framework. We extracted the results for valence quarks distribution functions with their uncertainties and compared them with other models. Our results are in agreement with the results of other various models and recent PDG results for strong coupling constant in two approximations NLO and NNLO. The extracted results for valence-quark distributions are in good agreement with available theoretical models.