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A. B. Shokouhi

Publications and source records attributed to A. B. Shokouhi.

3 recordsLinked to original sources

NNLO compatibility between pQCD theory and phenomenology in determination of the $b$-quark pole and \MSbar running masses

This contribution attempts to determine the $b$-quark pole mass $M_b$ and \MSbar running mass $\overline{m}_b$ with two different approaches at the next-to-next-to-leading order (NNLO) corrections. At the first approach, we derive a relation between the $b$-quark pole mass $M_b$ and its \MSbar running mass $\overline{m}_b$ at the NNLO corrections based on the perturbative Quantum Chromo Dynamics (pQCD) predictions. At the second approach, we extract numerical values of the $b$-quark pole and \MSbar running masses based on the NNLO phenomenology of H1 and ZEUS Collaborations combined beauty vertex production experimental data. Then we discuss about the compatibility between the pQCD theory results and phenomenology approach in determination of the $b$-quark pole and \MSbar running masses at the NNLO corrections. Also, we investigate the role and influence of the $b$-quark mass as an extra degree of freedom added to the input parameters of the Standard Model Lagrangian, on the improvement of the uncertainty band of the proton parton distribution functions (PDFs) and particularly on the gluon distribution.

hep-ph↗

The effect of LHC ATLAS jet production cross sections data at $ \sqrt{s} = 7$ TeV on the proton PDFs up to N3LO

The effect of full $7$ sets of LHC ATLAS jet cross sections data at $ \sqrt{s} = 7$ TeV on the proton parton distribution functions (PDFs) up to next-to-next-to-next-to-leading order (NNNLO or N3LO) corrections is investigated for the first time. Phenomenologically, the proton central PDFs in this perturbative Quantum Chromo Dynamics (pQCD) analysis are defined based on the full seven data sets from HERA I and II combined. It is shown that, the LHC ATLAS jet cross sections data at $ \sqrt{s} = 7$ TeV on the HERA I and II combined data reduces the error band of proton PDFs. Particularly, the uncertainties of the gluon $xg(x,Q^2)$ and charm $xc(x,Q^2)$ distributions decrease dramatically. Adding the LHC ATLAS jet cross sections data at $ \sqrt{s} = 7$ TeV on the central proton PDFs improves the quality of the fit up to $\sim 1.53$ \%, $\sim 2.72$ \% and $\sim 2.80$ \% corresponding to next-to-leading order (NLO), next-to-next-to leading order (N2LO) and N3LO, respectively.

hep-ph↗

The pQCD analysis to extract PDFs and $α_s^{\rm NLO}(M^2_Z)$ from inclusive jet-hadron production data

This perturbative Quantum Chromo Dynamics (pQCD) analysis attempts to present a simultaneous determination of parton distribution functions (PDFs) and the strong coupling $α_s(M^2_Z)$ from inclusion of inclusive H1 and ZEUS jet, DiJets and TriJets production cross sections data on the HERA I and II combined data, as the central data sets for probing the internal structure of proton. To present an accurate pQCD analysis, we separate the role and influence of inclusion jet production cross sections data from inclusion of the strong coupling $α_s(M^2_Z)$ as an extra fit parameter parameter on the gluon distribution. We show inclusion of jet, DiJets and TriJets production cross sections data improves the consistency between experiment and theory of cross sections for neutral current (NC) and charged current (CC) interactions of deep inelastic ${e^\pm}p$ scattering on proton up to $\sim 2.8$~\%. In addition, we show inclusion of jet production cross section data and considering $α_s(M^2_Z)$ as a pQCD free parameter not only reduce dramatically the uncertainty band of gluon distribution but also improve the consistency between experiment and theory of NC and CC deep inelastic ${e^\pm}p$ scattering cross sections up to $\sim 3.6$~\%. Our simultaneous determination of PDFs and the strong coupling $α_s(M^2_Z)$ with inclusion of jet production cross sections data leads to $α_s^{\rm NLO}(M^2_Z) = 0.12041 \pm 0.00086$, which is in a good agreement with world average and other individual measurements.

hep-ph↗