arXiv subjects

S. Barkanova

Publications and source records attributed to S. Barkanova.

25 records · Page 2Linked to original sources

arXiv2011

One-loop electroweak corrections for polarized Moller scattering at different renormalization schemes and conditions

Using two different approaches, we perform updated and detailed calculations of the complete one-loop (Next-to-Leading Order (NLO)) set of electroweak radiative corrections to the parity violating e- e- -> e- e- (gamma) scattering asymmetry. Our first approach, more classical, relies on calculations "by hand" with reasonable approximations. Our second approach relies on program packages FeynArts, FormCalc, LoopTools, and FORM. The detailed numerical analysis of the various contributions is provided for a wide range of energies relevant for the ultra-precise 11 GeV MOLLER experiment planned at the Jefferson Laboratory, as well as future experiments at the International Linear Collider (ILC). The numerical results obtained within the on-shell renormalization scheme using two different sets of renormalization conditions are in excellent agreement. We also calculate the total NLO correction in the Constrained Differential Renormalization (CDR) scheme. Analysis of the results, along with the increasing experimental precision, shows that it is feasible that the corrections at the Next-to-Next-to-Leading Order (NNLO) level may be important for the next generation of high-precision experiments.

hep-ph↗

arXiv2010

Dynamical Polarizabilities of SU(3) Octet of Baryons

We present calculations and an analysis of the spin-independent dipole electric and magnetic dynamical polarizabilities for the lowest in mass SU(3) octet of baryons. These extensive calculations are made possible by the recent implementation of semi-automatized calculations in Chiral Perturbation Theory which allows evaluating dynamical spin-independent electromagnetic polarizabilities from Compton scattering up to next-to-the-leading order. Our results are in good agreement with calculations performed for nucleons found in the literature. The dependencies for the range of photon energies up to 1 GeV, covering the majority of the meson photo production channels, are analyzed. The separate contributions into polarizabilities from the various baryon meson clouds are studied.

nucl-th↗

arXiv2009

Lepton-nucleon interactions at the next-to-the-leading order

Next-to-Leading-Order (NLO) effects play a crucial role in tests of the Standard Model (SM), and require careful theoretical evaluation. Electroweak physics, which has just entered the precision age, is an excellent place to search for new physics, but also requires considerable theoretical input. We show how we applied computational packages such as FeynArts, FormCalc, Form and LoopTools for the evaluation of one-loop electroweak and hadronic radiative corrections.

nucl-th↗

arXiv2008

Computational Model for Electron-Nucleon Scattering and Weak Charge of the Nucleon

We show how computational symbolic packages such as FeynArts and FormCalc can be adopted for the evaluation of one-loop hadronic electroweak radiative corrections for electron-nucleon scattering and applied to calculations of the nucleon weak charge. Several numerical results are listed, and found to be in good agreement with the current experimental data.

physics.comp-ph↗

arXiv2008

Next-to-the-Leading-Order Hadronic Corrections for Standard Model and Beyond

We explore various extensions of computational packages such as Feynarts and FormCalc in application to calculation of the electron-proton scattering asymmetries relevant to the G0 and QWeak experiments. Our calculations where completed up to the Next-to-the-Leading-Order (one-loop) using the dipole form factor in hadronic vertices. We saw no significant difference between monopole and dipole type of asymmetry over the range of Q^2 = 0.1 - 1.0 GeV^2. Our results are in the good agreement with theoretical predictions by the G0 collaboration, but show discrepancy from the experiment. This discrepancy from the experimental results is due to the strange content of the proton and possibly new physics as well.

nucl-th↗

arXiv2007

Electroweak Hard Photon Bremsstrahlung in Electron-Nucleon Scattering

One way to treat the infrared divergences of the electroweak Next-to-Leading-Order (NLO) differential cross sections to parity-violating (PV) electron-proton scattering is by adding soft-photon emission contribution. Although more physical, the results are left with a logarithmic dependence on the photon detector acceptance, which can only be eliminated by considering Hard Photon Bremsstrahlung (HPB) contribution. Here we present a treatment of HPB for PV electron-proton scattering. HPB differential cross sections for electron-proton scattering have been computed using the experimental values of nucleon form factors. The final results are expressed through kinematic parameters, making it possible to apply the computed PV HPB differential cross sections for the analysis of data of a range of current and proposed experiments.

nucl-th↗

arXiv2002

Radiative corrections and parity-violating electron-nucleon scattering

Radiative corrections to the parity-violating asymmetry measured in elastic electron-proton scattering are analyzed in the framework of the Standard Model. We include the complete set of one-loop contributions to one quark current amplitudes. The contribution of soft photon emission to the asymmetry is also calculated, giving final results free of infrared divergences. The one quark radiative corrections, when combined with previous work on many quark effects and recent SAMPLE experimental data, are used to place some new constraints on electroweak form factors of the nucleon.

nucl-th↗