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مرکز اطلاعات علمی SID1
اسکوپوس
دانشگاه غیر انتفاعی مهر اروند
ریسرچگیت
strs
Author(s): 

Heshmatian Sara | Naji Jalil

Issue Info: 
  • Year: 

    2017
  • Volume: 

    7
  • Issue: 

    13
  • Pages: 

    51-59
Measures: 
  • Citations: 

    0
  • Views: 

    525
  • Downloads: 

    196
Abstract: 

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.

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Issue Info: 
  • Year: 

    2018
  • Volume: 

    8
  • Issue: 

    18
  • Pages: 

    137-142
Measures: 
  • Citations: 

    0
  • Views: 

    489
  • Downloads: 

    186
Abstract: 

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.

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Author(s): 

Saneapour Maryam | Sadeghi Amir

Issue Info: 
  • Year: 

    2018
  • Volume: 

    18
  • Issue: 

    7 (59)
  • Pages: 

    159-180
Measures: 
  • Citations: 

    0
  • Views: 

    422
  • Downloads: 

    169
Abstract: 

This article introduces, analyzes, and criticizes the work of Lawrence M. Hinman, Ethics: A Pluralistic Approach to Moral Theory. Hinman is a Philosopher of Ethics in the multimedia learning. He believes that multiculturalism is important factor of nowadays so the most important responsibility of philosophers of Ethics is prevention of moral conflict. The global communication and information in 21st century needs global tolerance and respect of various nations, cultures, and moralities together because different people and societies have a common human nature and common natural rights that obligate to justice and moral relationship between different people and various societies’ beliefs throughout the world. Moral communication in multiculturalism approach is against racial, gender, national, and ethnic prejudice. Hinman believes in moral dialogue and global learning across different cultures. The book of Ethics: A Pluralistic Approach to Moral Theory has a proper category of new ethical problems, and the candid standpoint of author is considerable. He has a logical method, and in the end of every part of book there are some questions for evaluation of students learning. So this book is proper for the philosophy of ethics in universities.

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گارگاه ها آموزشی
Author(s): 

MEHRBAN H. | SAYAHI M.

Issue Info: 
  • Year: 

    2010
  • Volume: 

    34
  • Issue: 

    A4
  • Pages: 

    285-303
Measures: 
  • Citations: 

    0
  • Views: 

    761
  • Downloads: 

    168
Abstract: 

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.

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Author(s): 

MEHRABAN HOSSEIN

Issue Info: 
  • Year: 

    2011
  • Volume: 

    11
  • Issue: 

    3
  • Pages: 

    157-176
Measures: 
  • Citations: 

    0
  • Views: 

    734
  • Downloads: 

    230
Abstract: 

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.

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Author(s): 

MEHRABAN H. | MOHAMMADI B.

Issue Info: 
  • Year: 

    2011
  • Volume: 

    10
  • Issue: 

    4
  • Pages: 

    0-0
Measures: 
  • Citations: 

    0
  • Views: 

    63876
  • Downloads: 

    28312
Abstract: 

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.

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strs
Issue Info: 
  • Year: 

    2019
  • Volume: 

    8
  • Issue: 

    19
  • Pages: 

    139-152
Measures: 
  • Citations: 

    0
  • Views: 

    511
  • Downloads: 

    217
Abstract: 

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.

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Issue Info: 
  • Year: 

    2011
  • Volume: 

    5
  • Issue: 

    3
  • Pages: 

    127-134
Measures: 
  • Citations: 

    0
  • Views: 

    89426
  • Downloads: 

    50078
Abstract: 

The electromagnetic form factors of the K* meson are investigated in the framework of light cone QCD sum rules. The values of magnetic and quadrupole moments are calculated with the help of a suitable fit function. Comparing the results with the predictions of other approaches especially DSE based models reveals the difference between the values. Deciding which technique gives the better result in absence of experimental data is hard, so precise data on K* meson form factor is needed.

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Author(s): 

AL JAMEL A.

Issue Info: 
  • Year: 

    2011
  • Volume: 

    5
  • Issue: 

    1
  • Pages: 

    21-24
Measures: 
  • Citations: 

    0
  • Views: 

    125180
  • Downloads: 

    99684
Abstract: 

The effect of noncommutative space, to the second order in q, on heavy quarkonium spectra is studied within the framework of the nonrelativistic Schrodinger equation with the static Cornell potential. Due to this effect, a singular term 1/r3 appears in the potential, which is remedied using a regularization scheme by introducing a cut-off radius on the lower limit of the integrals needed for the perturbation computations. The results are applied to the 1S states of c`c, and it is found that the energy shifts are quadratic in the noncommutative parameter q. By comparing the results with those from experimental 1S-hyperfine splitting of c`c, we infer an upper limit on q.

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Author(s): 

MEHRBAN H. | SAYAHI M.

Issue Info: 
  • Year: 

    2010
  • Volume: 

    21
  • Issue: 

    4
  • Pages: 

    353-367
Measures: 
  • Citations: 

    0
  • Views: 

    1110
  • Downloads: 

    106
Abstract: 

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.

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