arXiv subjects

S. K. Singh

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

139 records · Page 8Linked to original sources

arXiv2006

Nuclear cross sections in $^{16}\text{O}$ for $β$ beam neutrinos at intermediate energies

The nuclear cross sections for charged lepton production induced by $β$ beam neutrinos (anti-neutrinos) in $^{16}$O have been presented at intermediate energies corresponding to the Lorentz boost factor $γ<250 (150)$. The calculations for quasi-elastic lepton production includes the effect of Pauli blocking, Fermi motion and renormalization of weak transition strengths in the nuclear medium. The calculations for the inelastic lepton production is done in the $Δ$ dominance model. The renormalization of $Δ$ properties in a nuclear medium and final state interactions of pions with the final nucleus are taken into account. The results may be useful in performing feasibility studies for the future CERN-FREJUS base line neutrino oscillation experiments.

nucl-th↗

arXiv2006

Neutrino Induced Charged Current 1$π^+$ Production At Intermediate Energies

The charged current one pion production induced by $ν_μ$ from nucleons and nuclei like $^{12}$C and $^{16}$O nuclei has been studied. The calculations have been done for the incoherent and the coherent processes from nuclear targets assuming 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 has been taken into account. The theoretical uncertainty in the total cross sections due to various parameterizations of the weak transition form factors used in literature has been studied. The numerical results for the total cross sections are compared with the recent preliminary results from the MiniBooNE collaboration on $^{12}$C and could be useful in analyzing future data from the K2K collaboration.

nucl-th↗

arXiv2006

Weak Quasi-elastic Production of Hyperons

The quasielastic weak production of $Λ$ and $Σ$ hyperons from nucleons and nuclei induced by antineutrinos is studied in the energy region of some ongoing neutrino oscillation experiments in the intermediate energy region. The hyperon nucleon transition form factors determined from neutrino nucleon scattering and an analysis of high precision data on semileptonic decays of neutron and hyperons using SU(3) symmetry have been used. The nuclear effects due to Fermi motion and final state interaction effects due to hyperon nucleon scattering have also been studied. The numerical results for differential and total cross sections have been presented.

hep-ph↗

arXiv2006

Nuclear Effects in Neutrino Induced Coherent Pion Production at K2K and MiniBooNE Neutrino Energies

The coherent pion production induced by neutrinos in nuclei is studied using a delta hole model in local density approximation taking into account the renormalization of $Δ$ properties in a nuclear medium. The pion absorption effects have been included in an eikonal approximation. These effects give a large reduction in the total cross section. The numerical results for the total cross section are found to be consistent with recent experimental results from K2K and MiniBooNE collaborations and other older experiments in the intermediate energy region.

nucl-th↗

arXiv2005

Weak Pion Production From Nuclei

The charged current pion production induced by neutrinos in $^{12}{C}$, $^{16}{O}$ and $^{56}{Fe}$ nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming $Δ$ dominance and take into account the effect of Pauli blocking, Fermi motion and the renormalization of $Δ$ in the nuclear medium. The pion absorption effects have also been taken into account.

nucl-th↗

arXiv2005

Charged Lepton Production from Iron Induced by Atmospheric Neutrinos

The charged current lepton production induced by neutrinos in $^{56}Fe$ nuclei has been studied. The calculations have been done for the quasielastic as well as the inelastic reactions assuming $Δ$ dominance and take into account the effect of Pauli blocking, Fermi motion and the renormalization of weak transition strengths in the nuclear medium. The quasielastic production cross section for lepton production are found to be strongly reduced due to nuclear effects while there is about 10% reduction in the inelastic cross sections in the absence of the final state interactions of the pions. The numerical results for the momentum and angular distributions of the leptons averaged over the various atmospheric neutrino spectra at the Soudan and Gransasso sites have been presented. The effect of nuclear model dependence and the atmospheric flux dependence on the relative yield of $μ$ to e has been studied and discussed.

nucl-th↗

arXiv2005

Neutrino nucleus cross sections for low energy neutrinos at SNS facilities

We calculate the neutrino nucleus cross sections for charged lepton production relevant for the experiments proposed with the stopped muon neutrinos using neutron spallation source facility. 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 effect of Coulomb distortion of the lepton produced in charge current reactions is taken into account by using the Fermi function as well as in a model where an effective momentum has been used for the lepton moving in the local Coulomb field of the final nucleus. The numerical results for the neutrino nucleus total cross sections averaged over Michel spectrum are presented for various nuclei.

nucl-th↗

arXiv1999

Charged current weak production of the Delta resonance

The charge changing weak production of Delta in nucleons and nuclei is studied. The reactions e^{-} p -> Delta^{0} ν_{e} and e^{+} p -> Delta^{++} \barν_{e} are considered as a possible source of information about the weak N-Delta transition form factors. The low q^2 BNL data on neutrino production of Delta are used to extract the axial vector N-Delta coupling, taking into account the deuteron structure and the Delta width. Finally, pion production induced by neutrinos in ^{16}O in the Delta region, relevant to atmospheric neutrino experiments, is investigated.

nucl-th↗

arXiv1998

Nuclear effects in the F3 structure function

By using a relativistic framework and accurate nuclear spectral functions we evaluate the ratio F_{3A}/AF_{3N} of deep inelastic neutrino scattering. Parametrizations of this ratio for different values of Q^2 are provided. These results should be useful for taking into account the nuclear effects in analyses of experimental data in neutrino reactions in nuclear targets, and test QCD predictions for the nucleon structure functions. In particular, the size of the nuclear corrections is of the same order of magnitude as the size of the QCD corrections to the Gross-Llewellyn Smith sum rule.

nucl-th↗

arXiv1998

$νd \to μ^- Δ^{++} n$ Reaction and Axial Vector $N-Δ$ Coupling

The reaction $νd \to μ^- Δ^{++} n$ is studied in the region of low $q^2$ to investigate the effect of deuteron structure and width of the $Δ$ resonance on the differential cross section. The results are used to extract the axial vector $N-Δ$ coupling $C^{A}_5$ from the experimental data on this reaction. The possibility to determine this coupling from electroweak interaction experiments with high intensity electron accelerators is discussed.

nucl-th↗

arXiv1998

Inclusive Muon Capture in Light Nuclei

We study total muon capture rates in light nuclei, taking into account renormalizations of the nuclear vector and axial vector strengths. We estimate the influence in the results of uncertainties of the spin-isospin interaction parameter and nuclear densities. A few of these reactions are theoretical benchmarks for physics involving searches for neutrino oscillations. New experiments in muon capture in several targets are suggested, in the light of some discrepancies with theory, crudeness of some experimental results and relevance to neutrino physics.

nucl-th↗

arXiv1998

Inclusive Neutrino Scattering in C-12: Implications for nu_mu to nu_e Oscillations

We study inclusive nu_e and nu_mu cross sections in C-12 in a theory that takes into account significant nuclear renormalization of strengths. Our calculation is in excellent agreement with the measured inclusive muon capture rate and the flux-averaged nu_e cross section, but overestimates the flux-averaged nu_mu inclusive cross section. These reactions are of crucial relevance to the issue of possible nu_mu to nu_e oscillations.We also calculate the flux-averaged cross sections in C-13 and Al-27, which are found to be consistent with the available experimental result.

nucl-th↗

arXiv1997

Charged current weak electroproduction of Delta resonance

We study the weak production of $Δ$ (i.e. $e^{-} + p \to Δ^{0}+ ν_{e}$ and $e^{+} + p \to Δ^{++} + \barν_{e}$) in the intermediate energy range corresponding to the Mainz and TJNAF electron accelerators. The differential cross sections $σ(θ)$ are found to be of the order of $ 10^{-39}$ cm$^2$/sr, over a range of angles which increases with energy. The possibility of observing these reactions with the high luminosities available at these accelerators, and studying the weak N-$Δ$ transition form factors through these reactions is discussed. The production cross section of N$^*(1440)$ in the kinematic region of $Δ$ production is also estimated and found to be small.

nucl-th↗