We present the results of a recent simultaneous study of the muon capture reactions (2)H(mu (-), nu (mu) )nn and (3)He(mu (-), nu (mu) )(3)H. The initial and final A = 2 and 3 nuclear wave functions are obtained from the Argonne v (18) or chiral N3LO two-nucleon potential, in combination with, respectively, the Urbana IX or chiral N2LO three-nucleon potential in the case of A = 3. The weak current consists of polar- and axial-vector components. The former are related to the isovector piece of the electromagnetic current via the conserved-vector-current hypothesis. These and the axial currents are derived either in a meson-exchange or in a chiral effective field theory (chi EFT) framework. In the first case, there is one parameter which is fixed by reproducing the Gamow-Teller matrix element in tritium beta-decay (GT(EXP)). In the second case, the low-energy constants, two in the polar and one in the axial-vector current, are fixed, respectively, by reproducing the A = 3 magnetic moments and GT(EXP). The total rates are found to be 392.0 +/- 2.3 s(-1) for A = 2, and 1484 +/- 13 s(-1) for A = 3, where the spread accounts for the model dependence relative to the adopted interactions and currents (and cutoff sensitivity in the chi EFT currents).
Muon Capture on Deuteron and (3)He
MARCUCCI, LAURA ELISA;
2011-01-01
Abstract
We present the results of a recent simultaneous study of the muon capture reactions (2)H(mu (-), nu (mu) )nn and (3)He(mu (-), nu (mu) )(3)H. The initial and final A = 2 and 3 nuclear wave functions are obtained from the Argonne v (18) or chiral N3LO two-nucleon potential, in combination with, respectively, the Urbana IX or chiral N2LO three-nucleon potential in the case of A = 3. The weak current consists of polar- and axial-vector components. The former are related to the isovector piece of the electromagnetic current via the conserved-vector-current hypothesis. These and the axial currents are derived either in a meson-exchange or in a chiral effective field theory (chi EFT) framework. In the first case, there is one parameter which is fixed by reproducing the Gamow-Teller matrix element in tritium beta-decay (GT(EXP)). In the second case, the low-energy constants, two in the polar and one in the axial-vector current, are fixed, respectively, by reproducing the A = 3 magnetic moments and GT(EXP). The total rates are found to be 392.0 +/- 2.3 s(-1) for A = 2, and 1484 +/- 13 s(-1) for A = 3, where the spread accounts for the model dependence relative to the adopted interactions and currents (and cutoff sensitivity in the chi EFT currents).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
