arXiv subjects

S. Tahery

Publications and source records attributed to S. Tahery.

5 recordsLinked to original sources

arXiv2020

Thermal width and entropic force of a moving quarkonia with charged deformed AdS background

The entropic force and the imaginary part of potential experienced by a moving quarkonia in a plasma, are computed in a charged deformed AdS background by holography approaches. In that case, the axis of the moving quarkonia has an arbitrary angle with wind. We show that the charge in deformed AdS background deeply effect on the increasing entropic force and decreasing thermal width. So, the dissociation length of the meson becomes short when charge is increasing. In addition, the entropic force and thermal width are increased by the deformation of the space. Therefore the deformation parameter in such background leads us to find process with arbitrary dissociation length of quark- anti quark.

hep-th↗

arXiv2018

Quark anti-quark entropic force and diffusion constant in a Yang-Mills like theory

The entropic force experienced by a moving quarkonia in a plasma, is computed in a hyperscaling violation background by holography approach. In that case, the axis of the moving quarkonia has an arbitrary angle with wind. We use the results for HSV parameters which obtained in our paper [1] as appropriate values satisfying condition $ImV_{Q\bar{Q}}< 0$. We will show that, in this background the entropic force of the meson shows a decreasing behaviour corresponds to increasing dissociation length. Results of this paper are in agreement with our mentioned work. In addition we will find diffusion constant in an exact case and by an exact approach [2] which satisfies the mentioned condition in there.

hep-th↗

arXiv2017

The investigation of quark - antiquark potential in plasma with hyperscaling violation background

In this paper, we investigate imaginary part of the potential for a moving quarkonia in plasma. In order to verify the validity of imaginary part of the potential we employ hyperscaling violation metric background. In QCD system the imaginary part of potential shows the decay behaviour and the corresponding potential should be negative. The corresponding potential always appears in QCD as an exponential function. We find general constraints for Im$V_{Q\bar{Q}}$ at the near horizon limit and apply them for some known cases. Finally, we find the suitable spatial dimension d, z and $θ$ also rapidity $η$ for two interesting cases. Our calculation with AdS/CFT guarantees the dynamical parameter as a $θ$ in hyperscaling violation metric background. We also present the hyperscaling violationg metric in this context very close to YM theory with finite temperature.

hep-th↗

arXiv2016

Holographic Schwinger effect with a deformed AdS background

In this paper, we consider a deformed AdS background and study effect of deformation parameter on the pair production rate of the Schwinger effect. The electrostatic potential is important for the pair production in the holographic Schwinger effect. In this paper, we analyze the electrostatic potential in a deformed AdS background and investigate the effect of deformation parameter which may be useful to test of AdS/QCD. In the case of zero temperature we find that larger value of the deformation parameter leads to a smaller value of separation length of the test particles on the probe. Also we find a finite maximum of separation length in presence of modification parameter.

hep-th↗

arXiv2015

The effects of deformation parameter on thermal width of moving quarkonia in plasma

In general we can say that the thermal width of quarkonia corresponds to imaginary part of its potential. Gravity dual of theories give explicit form of potential as $V_{Q\bar{Q}}$ . Since there is an explicit formula for $Im V_{Q\bar{Q}}$ one can consider different gravity duals and study the results of contribution of various parameters. Variable gravity duals of moving pair in plasma have different results for potential. Our paper shows that deformation parameter c in warp factor leads to new results that we present them for arbitrary angles of the pair with respect to its velocity. We compare our results with the case that no deformation parameter is in metric background. We will see that the thermal width of the pair increases with increasing deformation parameter. Also, for nonzero values of deformation parameter the pair feels moving plasma in all distances. In addition our results indicate that contribution of deformation parameter leads to larger dissociation length for the moving pair reverse to the effect of the pairs velocity in the plasma.

hep-th↗