arXiv subjects

Parvin Eslami

Publications and source records attributed to Parvin Eslami.

5 recordsLinked to original sources

arXiv2020

Constraining the top quark effective field theory using the top quark pair production in association with a jet at future lepton colliders

Our main aim in this paper is to constrain the effective field theory describing the top quark couplings through the $e^{-} e^{+} \rightarrow t \bar{t}+$jet process. The analysis is carried out considering two different center-of-mass energies of 500 and 3000 GeV including a realistic simulation of the detector response and the main sources of background processes. The expected limits at 95\% CL are derived on the new physics couplings such as $t \bar t γ$, $t \bar t Z$, and $t \bar t g$ for each benchmark scenario using the dileptonic $t \bar{t}$ final state. We show that the 95\% CL limits on dimensionless Wilson coefficients $\bar{c}_i$ considered in this analysis could be probed down to $10^{-4}$.

hep-ph↗

arXiv2017

Analytical solutions of the QCD$\otimes$QED DGLAP evolution equations based on the Mellin transform technique in NLO approximation

In this paper we present a new and efficient analytical solutions for evolving the QED$\otimes$QCD DGLAP evolution equations in mellin space and obtain the parton distribution functions (PDFs) in perturbative QCD including the QED corrections. The validity of our analytical solutions, which have done in the next to leading order QCD and the leading order QED approximations, are checked with the initial parton distributions from newly released CT14QED global analysis code (Phys. Rev.D93,114015(2016)). The evolved parton distributions are in good agreement with CT14QED code and also with those from APFEL (Computer Physics Communications 185, 1647 (2014)) program.

hep-ph↗

arXiv2017

Parton distribution functions with QED corrections in the valon model

Parton distribution functions (PDFs) with QED corrections extracted from the QED$\otimes$QCD DGLAP evolution equations in the framework of "valon" model. Our results for the PDFs with QED corrections in this phenomenological model are in good agreement with the newly related CT14QED global fit code [Phys. Rev. D93, 114015 (2016)] and APFEL (NNPDF2.3QED) [Computer Physics Communications 185, 1647 (2014)] program in a wide range of $x=[10^{-5}, 1]$ and $Q^2=[0.283, 10^8] \, {\rm GeV}^2$. The model calculations agree rather well with those codes. We also proposed the new method for studying the symmetry breaking of the sea quarks distribution functions inside proton. Then these PDFs set can be used to explore the proton-proton scattering at the LHC era.

hep-ph↗

arXiv2017

Decoupling the NLO coupled QED $\otimes$ QCD, DGLAP evolution equations,Using Laplace Transform Method

We analytically solved the QED $\otimes$ QCD coupled DGLAP evolution equations at leading order (LO) quantum electrodynamics (QED) and next to leading order (NLO) quantum chromodynamics (QCD) approximations, using the Laplace transform method and then computed the proton structure function in terms of the unpolarized parton distributions functions. Our analyitical solutions for parton densities are in good agreement with those from APFEL (A PDF Evolution Library) (Computer Physics Communications 185, 1647-1668 (2014)) and CT14QED (Phys. Rev. D 93, 114015 (2016)) global parameterizations. We also compared the proton structure function, $F_{2}^{p}(x,Q^{2})$, with experimental data released by the ZEUS and H1 collaborations at HERA. There is a nice agreement between them in the range of low and high x and $Q^{2}$.

hep-ph↗

arXiv2016

Acceleration in a nonplanar time-dependent billiard

We study the dynamical properties of a particle in a non-planar square billiard. The plane of the billiard has a sinusoidal shape. We consider both the static and time-dependent plane. We study the affect of different parameters that control the geometry of the billiard in this model. We consider variations of different parameters of the model and describe how the particle trajectory is affected by these parameters. We also investigate the dynamical behavior of the system in the static condition using its reduced phase plot and show that the dynamics of the particle inside the billiard may be regular, mixed or chaotic. Finally, the problem of the particle energy growth is studied in the billiard with the time-dependent plane. We show that when in the static case, the billiard is chaotic, then the particle energy in the time-dependent billiard grows for small number of collisions, and then it starts to saturate. But when the dynamics of the static case is regular, then the particle average energy in the time-dependent situation stays constant.

physics.comp-ph↗