Details

Autor(en) / Beteiligte

• Lovato, A.
• Rocco, N.
• Schiavilla, R.

Titel

Muon capture in nuclei: An ab initio approach based on Green's function Monte Carlo methods

Ist Teil von

• Physical review. C, 2019-09, Vol.100 (3), Article 035502

Ort / Verlag

United States: American Physical Society (APS)

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• An ab initio Green's function Monte Carlo (GFMC) method is introduced for calculating total rates of muon weak capture in light nuclei with mass number $A ≤ 12$. As a first application of the method, we perform a calculation of the rate in $^3$$\textbf{H}$ and $^4$$\textbf{He}$ in a dynamical framework based on realistic two- and three-nucleon interactions and realistic nuclear charge-changing weak currents. The currents include one- and two-body terms induced by $π$- and $ρ$-meson exchange, and $N$-to-$Δ$ excitation, and are constrained to reproduce the empirical value of the Gamow-Teller matrix element in tritium. We investigate the sensitivity of theoretical predictions to current parametrizations of the nucleon axial and induced pseudoscalar form factors as well as to two-body contributions in the weak currents. The large uncertainties in the measured $^4$$\textbf{He}$ rates obtained from bubble-chamber experiments (carried out over 50 years ago) prevent us from drawing any definite conclusions. No data exist for $^3$$\textbf{H}$, but results are compared to those of a recent Faddeev calculation as a validation of the present GFMC method.