arXiv subjects

S. K. Singh

Publications and source records attributed to S. K. Singh.

At least 127 records · Page 7Linked to original sources

arXiv2012

The effect of isoscalar-isovector coupling in infinite nuclear matter

Working on the framework of Relativistic Mean Field theory, we exposed the effect of nonlinear isoscalar-isovector coupling on G2 parameter set on the density dependence of nuclear symmetry energy in infinite nuclear matter. The observables like symmetric energy and few related coefficients are studied systematically. We presented the results of stiff symmetry energy at sub-saturation densities and a soft variation at normal densities. Correlation between the symmetric energy and the isoscalar-isovector coupling parameter fully demonstrated for wide range of density. The work further extended to the octet system and showed the effect of coupling over the equation of state.

nucl-th↗

arXiv2011

Neutral Current $ν$ Induced Reactions in Nuclei at Supernova Neutrino Energies

We calculate cross sections for the neutral current induced neutrino/antineutrino reaction from $^{208}Pb$ target and applied it to study Supernova neutrino event rates. The calculations are done in local density approximation taking into account Pauli blocking, Fermi motion effects and renormalization of weak transition strengths in the nuclear medium. The numerical results for the neutrino nucleus total cross sections have been averaged over the various Supernova neutrino/antineutrino fluxes available in literature.

nucl-th↗

arXiv2011

Raman-assisted Rabi resonances in two-mode cavity QED

The dynamics of a vibronic system in a lossy two-mode cavity is studied, with the first mode being resonant to the electronic transition and the second one being nearly resonant due to Raman transitions. We derive analytical solutions for the dynamics of this system. For a properly chosen detuning of the second mode from the exact Raman resonance, we obtain conditions that are closely related to the phenomenon of Rabi resonance as it is well known in laser physics. Such resonances can be observed in the spontaneous emission spectra, where the spectrum of the second mode in the case of weak Raman coupling is enhanced substantially.

quant-ph↗

arXiv2009

CC1$π^+$ to CCQE cross sections ratio at accelerator energies

MiniBooNE and K2K collaborations have recently reported the ratio for the $ν_μ$ induced charge current 1$π^+$ production cross section to the charged current induced quasielastic lepton production cross section i.e. $R(E)=\frac{σ^{CC1π^+}}{σ^{CCQE}}$. In this paper we study, theoretically, in a local density approximation the effect of nuclear medium in charged current quasielastic(CCQE) and charged current one pion production(CC1$π^+$) processes for the $ν_μ$ induced reaction in nuclei. The theoretical results have been compared with the results of experimental observations by the MiniBooNE and K2K collaborations. The ratio R(E) for $ν_μ$ induced reaction in water for the proposed T2K experiment is also presented.

nucl-th↗

arXiv2009

A study of nuclear effect in $F_3$ structure function in the deep inelastic $ν(\barν)$ reactions in nuclei

We study nuclear effect in the $F^A_3(x)$ structure function in the deep inelastic neutrino reactions on iron by taking into account Fermi motion, binding, target mass correction, shadowing and anti-shadowing corrections. Calculations have been done in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations for nuclear matter. Results for $F^A_3(x)$ have been compared with the results reported at NuTeV and also with some of the older experiments reported in the literature.

nucl-th↗

arXiv2009

Theoretical study of lepton events in the atmospheric neutrino experiments at SuperK

Super-Kamiokande has reported the results for the lepton events in the atmospheric neutrino experiment. These results have been presented for a 22.5kT water fiducial mass on an exposure of 1489 days, and the events are divided into sub-GeV, multi-GeV and PC events. We present a study of nuclear medium effects in the sub-GeV energy region of atmospheric neutrino events for the quasielastic scattering, incoherent and coherent pion production processes, as they give the most dominant contribution to the lepton events in this energy region. We have used the atmospheric neutrino flux given by Honda et al. These calculations have been done in the local density approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reactions. The inelastic reactions leading to production of leptons along with pions is calculated in a $Δ$- dominance model by taking into account the renormalization of $Δ$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We present the results for the lepton events obtained in our model with and without nuclear medium effects, and compare them with the Monte Carlo predictions used in the simulation and the experimentally observed events reported by the Super-Kamiokande collaboration.

nucl-th↗

arXiv2009

Development of ARIES Baker-Nunn camera to a wide-field Imaging Telescope with CCD

ARIES Baker-Nunn Schmidt telescope project is converting a Baker-Nunn satellite tracking camera for Astronomical research. Original Baker-Nunn camera produces an extremely large (5X30 degree) curved focal plane at the prime focus for photographic imaging. We present here the re-designing of the camera produces a wide (4 X 4 degree) flat field of view for CCD imaging observations, which have many scientific potentials in Astronomy. Imaging performance of the CCD camera is also estimated.

astro-ph.IM↗

arXiv2008

Quasielastic and inelastic neutrino reactions in $^{12}C$ at K2K energies

In this paper, we present the results of a study made for the effect of nuclear medium in the charged current induced quasielastic lepton production(CCQE) and the incoherent and coherent one pion production (CC1$π^+$)processes from $^{12}C$ in the $ν_μ$ energy region of 0.4-3GeV. The theoretical results are compared with the recent experimental results for the ratio of charged current $ν_μ$ induced one pion production cross section to the quasielastic lepton production cross section reported by K2K collaboration. We also present the results for the angular and momentum distributions of leptons and pions produced in these processes.

nucl-th↗

arXiv2008

Nuclear effects in F_3 structure function of nucleon

We study nuclear effects in the $F^A_3(x)$ structure function in the deep inelastic neutrino reactions on iron by using a relativistic framework to describe the nucleon spectral functions in the nucleus. The results for the ratio $R(x,Q^2)=\frac{F^A_3(x,Q^2)}{AF^N_3(x, Q^2)}$ and the Gross-Llewellyn Smith(GLS) integral $G(x,Q^2)=\int_x^1 dx F^A_3(x,Q^2)$ in nuclei are discussed and compared with the recent results available in literature from theoretical and phenomenological analyses of experimental data.

nucl-th↗

arXiv2008

Parity Violating Effects in Elastic Electron Deuteron Scattering

The general expressions for parity violation observables in elastic scattering of polarized and/or unpolarized electrons from unpolarized deuterons are given and are numerically evaluated for the kinematics of SAMPLE, PVA4 and G0 experiments. The dominant contribution from the interference of $γ$ and Z exchange as well as the smaller contributions from strangeness ($s{\bar{s}}$) components of the nucleon, parity odd admixtures in the deuteron wave function, anapole moments and radiative corrections are included and discussed in the context of parity violating electron scattering experiments of present interest.

nucl-th↗

arXiv2008

Neutrino nucleus cross sections

We present the results of our calculation which has been performed to study the nuclear effects in the quasielastic, inelastic and deep inelastic scattering of neutrinos(antineutrinos) from nuclear targets. These calculations are done in the local density approximation. We take into account the effect of Pauli blocking, Fermi motion, Coulomb effect, renormalization of weak transition strengths in the nuclear medium in the case of the quasielastic reaction. The inelastic reaction leading to production of pions is calculated in a $Δ$- dominance model taking into account the renormalization of $Δ$ properties in the nuclear medium and the final state interaction effects of the outgoing pions with the residual nucleus. We discuss the nuclear effects in the $F_{3}^{A}(x)$ structure function in the deep inelastic neutrino(antineutrino) reaction using a relativistic framework to describe the nucleon spectral function in the nucleus.

nucl-th↗

arXiv2008

Neutral Current induced $π^0$ production and neutrino magnetic moment

We have studied the total cross section, $Q^2$, momentum and angular distributions for pions in the $ν$($\bar ν$) induced $π^0$ production from nucleons. The calculations have been done for the weak production induced by the neutral current in the standard model and the electromagnetic production induced by neutrino magnetic moment. It has been found that with the present experimental limits on the muon neutrino magnetic moment $μ_{ν_μ}$, the electromagnetic contribution to the cross section for the $π^0$ production is small. The neutrino induced neutral current production of $π^{0}$, while giving an alternative method to study the magnetic moment of neutrino $μ_{ν_μ}$, does not provide any improvement over the present experimental limit on $μ_{ν_μ}$ from the observation of this process in future experiments at T2K and NO$ν$A.

hep-ph↗

arXiv2008

Neutrino induced threshold production of two pions and N^*(1440) electroweak form factors

We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon, pion and contact terms are calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account. The numerical results for the cross sections are presented and compared with the available experimental data. It has been found that in the two pion channels with $π^+π^-$ and $π^0π^0$ in the final state, the contribution of the $N^*(1440)$ is quite important and could be used to determine the $N^*(1440)$ electroweak transition form factors if experimental data with better statistics become available in the future.

hep-ph↗

arXiv2008

Production of Two Pions Induced by Neutrinos

We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon pole, pion and contact terms is calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account.

hep-ph↗

arXiv2007

Nuclear effects in Neutrino Nuclear Cross-sections

Nuclear effects in the quasielastic and inelastic scattering of neutrinos(antineutrinos) from nuclear targets have been studied. The calculations are done in the local density approximation which take into account the effect of nucleon motion as well as renormalisation of weak transition strengths in the nuclear medium. The inelastic reaction leading to production of pions is calculated in a $Δ$ dominance model taking into account the renormalization of $Δ$ properties in the nuclear medium.

nucl-th↗

arXiv2007

Single Pion production from Nuclei

We have studied charged current one pion production induced by $ν_μ(\barν_μ)$ from some nuclei. The calculations have been done for the incoherent pion production processes from these nuclear targets in the $Δ$ dominance model and take into account the effect of Pauli blocking, Fermi motion and renormalization of $Δ$ properties in the nuclear medium. The effect of final state interactions of pions has also been taken into account. The numerical results have been compared with the recent results from the MiniBooNE experiment for the charged current 1$π$ production, and also with some of the older experiments in Freon and Freon-Propane from CERN.

nucl-th↗

arXiv2007

String Cosmological Model in Cylindrically Symmetric Inhomogeneous Universe with Electromagnetic Field II

Cylindrically symmetric inhomogeneous string cosmological model of the universe in presence of electromagnetic field is investigated. We have assumed that F_{12} is the only non-vanishing component of electromagnetic field tensor F_{ij}. The Maxwell's equations show that F_{12} is the function of $x$ alone whereas the magnetic permeability is the function of x and t both. To get the deterministic solution, it has been assumed that the expansion ($θ$) in the model is proportional to the eigen value $σ^{1}_{1}$ of the shear tensor $σ^{i}_{j}$. Some physical and geometric prperties of the model are also discussed.

gr-qc↗

arXiv2007

Charged current anti-neutrino reactions from $^{12}$C at MiniBooNE energies

A study of charged current induced anti-neutrino interactions from nuclei has been done for the intermediate energy ($<2$GeV) anti-neutrinos and applied to $^{12}$C, relevant for ongoing experiment by MiniBooNE collaboration. The calculations have been done for the quasielastic and inelastic lepton production as well as for the incoherent and the coherent pion production processes. The calculations are done in local density approximation. In the case of the quasielastic reaction the effects of Pauli blocking, Fermi motion effects, renormalization of weak transition strengths in nuclear medium and the Coulomb distortion of the outgoing lepton have been taken into account. For the inelastic processes the calculations have been done in the $Δ$ dominance model and take into account the effect of Pauli blocking, Fermi motion of the nucleon and renormalization of $Δ$ properties in a nuclear medium. The effect of final state interactions of pions is also taken into account. The numerical results for the total cross sections for the charged current quasielastic scattering and incoherent pion production processes are compared with earlier experimental results available in Freon and Freon-Propane. It is found that nuclear medium effects give strong reduction in the cross sections leading to satisfactory agreement with the available data.

nucl-th↗