The parity-violating asymmetry in the 3He(n,p)3H reaction

Abstract

The longitudinal asymmetry induced by parity-violating (PV) components in the nucleon-nucleon potential is studied in the charge-exchange reaction 3He(n,p)3H at vanishing incident neutron energies. An expression for the PV observable is derived in terms of T-matrix elements for transitions from the {2S+1}L_J=1S_0 and 3S_1 states in the incoming n-3He channel to states with J=0 and 1 in the outgoing p-3H channel. The T-matrix elements involving PV transitions are obtained in first-order perturbation theory in the hadronic weak-interaction potential, while those connecting states of the same parity are derived from solutions of the strong-interaction Hamiltonian with the hyperspherical-harmonics method. The coupled-channel nature of the scattering problem is fully accounted for. Results are obtained corresponding to realistic or chiral two- and three-nucleon strong-interaction potentials in combination with either the DDH or pionless EFT model for the weak-interaction potential. The asymmetries, predicted with PV pion and vector-meson coupling constants corresponding (essentially) to the DDH "best values" set, range from -9.44 to -2.48 in units of 10^{-8}, depending on the input strong-interaction Hamiltonian. This large model dependence is a consequence of cancellations between long-range (pion) and short-range (vector-meson) contributions, and is of course sensitive to the assumed values for the PV coupling constants.

19 pages, 15 tables, revtex4

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Cited by in corpus (8)

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• The parity-violating nucleon-nucleon force in the 1/N_c expansion
• A chiral effective field theory study of hadronic parity violation in few-nucleon systems
• Deuteron-deuteron scattering above four-nucleon breakup threshold
• First Precision Measurement of the Parity Violating Asymmetry in Cold Neutron Capture on ${}^3$He
• Towards a unified treatment of $\Delta S=0$ parity violation in low-energy nuclear processes
• Parity violation in $n{+}^{3}He{\to }^{3}H+p$ reaction: resonance approach
• $\Delta S=0$ Hadronic Parity Violation in Next-to-Leading Order QCD: Anomalous Dimension Matrices and Their Implications