Polarization observables and T-noninvariance in the weak charged current induced electron proton scattering

Abstract

In this work, we have studied the total scattering cross section (σ), differential scattering cross section (dσ/dQ 2 ) as well as the longitudinal (PL(Ee, Q 2 )), perpendicular (PP (Ee, Q 2 )), and transverse (PT (Ee, Q 2 )) components of the polarization of the final hadron (n, Λ and Σ 0 ) produced in the electron proton scattering induced by the weak charged current. We have not assumed T-invariance which allows the transverse component of the hadron polarization perpendicular to the production plane to be non-zero. The numerical results are presented for all the above observables and their dependence on the axial vector form factor and the weak electric form factor are discussed. The present study enables the determination of the axial vector nucleon-hyperon transition form factors at high Q 2 in the strangeness sector which can provide test of the symmetries of the weak hadronic currents like T-invariance and SU(3) symmetry while assuming the hypothesis of conserved vector current and partial conservation of axial vector current.

Hyperon production in quasielastic $\barν_τ-$nucleon scattering

“…The determination of all the weak form factors is based on the symmetry properties discussed above, and the details are given in Ref. [25,26]. The explicit expressions of the vector and axial vector form factors for the different N − Y transitions, assuming the SU(3) symmetry are given in Section II A 3, while the effects of SU(3) symmetry breaking on these form factors are discussed in Section II A 4.…”

“…In the energy region of ν τ (ν τ ) experiments, where the energy of the produced τ lepton is not too large compared to its rest mass m τ = 1.776 GeV, the τ leptons would not be completely longitudinally polarized, and would also have transverse component of the polarization [17][18][19][20][21][22][23][24]. Moreover, any presence of the polarization component perpendicular to the reaction plane would provide information about the T noninvariance in ν τ − N interactions [25][26][27][28]. The polarization state of the τ lepton affects the total and differential cross sections and is, therefore, an important observable in the study of ν τ − N interactions.…”

$\barν_μ$ induced quasielastic production of hyperons leading to pions

“…The symmetries of the weak hadronic current like the T-invariance, G-invariance and SU(3) symmetry can also be tested, and some information on the physics beyond the standard model may also be obtained. In the past, various calculations on the charged current induced (anti)neutrino and electron scattering from the free nucleon and nuclear targets, have been done by many authors in which both the production cross sections as well as the polarization observables of muons and baryons were studied [3][4][5][8][9][10][11][12][13][14][15][16]. With the advancement in the detection technology and the observation of the τ neutrino (ν τ ) experimentally, some calculations for the polarization observables of the τ leptons produced in the ν τ (ν τ ) induced reactions have also been performed in the weak processes [12,[17][18][19][20][21][22].…”

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The quasielastic production cross sections and polarizations of the hyperons induced by νµ on the free nucleon as well as from 40 Ar in the sub-GeV energy region has been reviewed [1][2][3][4][5]. The effects of the second class currents in the axial vector sector with and without T-invariance as well as the effect of SU(3) symmetry breaking are also studied.

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Spin asymmetry in single pion production induced by weak interactions of neutrinos with polarized nucleons

“…The investigation of the PT in the neutrino-nucleon and the neutrino-nucleus scattering has been discussed since the 1960s [34][35][36][37][38][39][40][41][42][43][44][45][46]. Recently in [33,47], we reported the results of the discussion of the impact of the NB contribution on the PT observables.…”