Parity-violating asymmetry in the ${}^3\mathrm{He}$ ( $\mathrm{n⃗},p$ ) ${}^3\mathrm{H}$ reaction

Journal Article · Fri Oct 01 00:00:00 EDT 2010 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.82.044001· OSTI ID:1259281

Viviani, M.; Schiavilla, R.; Girlanda, L.; Kievsky, A.; Marcucci, L. E.

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+1LJ = 1S0 and 3S1 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.

• Research Organization: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1259281
• Report Number(s): JLAB-THY-10-1184; DOE/OR/23177-1222; arXiv:1007.2052; PRVCAN
• Journal Information: Physical Review C, Vol. 82, Issue 4; ISSN 0556-2813
• Country of Publication: United States
• Language: English