Search results for "Muon capture"
showing 10 items of 52 documents
Radiative muon capture and the value of gP in nuclei
1990
Abstract Radiative muon capture by nuclei is analyzed by means of sum rule techniques, providing a total photon yield calculated with RPA precision. The measured yields relative to the ordinary muon capture rate are well reproduced for the nuclei 12C, 16O and 40Ca using a value of the pseudoscalar weak coupling constant gP enhanced by only 25% with respect to its canonical value. Therefore, the large renormalization of gP claimed up to now must be reconsidered.
Muon capture revisited
1990
Abstract The problem of inclusive muon capture in nuclei is studied by calculating the capture rate in asymmetric infinite nuclear matter and using the local density approximation to evaluate the capture rates in nuclei. It is shown that the method is rather reliable and allows one to improve on approximations used in the past. The need for a strong nuclear renormalization is shown, reducing the capture rates by about a factor two in medium and heavy nuclei. By using standard effective interactions in the spin-isospin channel one can account for this renormalization and one finds a remarkable overall agreement with the measured capture rates for a large list of nuclei through the periodic t…
Shell-Model Effective Operators for Muon Capture in ^{20}Ne
1999
It has been proposed that the discrepancy between the partially-conserved axial-current prediction and the nuclear shell-model calculations of the ratio $C_P/C_A$ in the muon-capture reactions can be solved in the case of ^{28}Si by introducing effective transition operators. Recently there has been experimental interest in measuring the needed angular correlations also in ^{20}Ne. Inspired by this, we have performed a shell-model analysis employing effective transition operators in the shell-model formalism for the transition $^{20}Ne(0^+_{g.s.})+\mu^- \to ^{20}F(1^+; 1.057 MeV) + \nu_\mu$. Comparison of the calculated capture rates with existing data supports the use of effective transiti…
Pinning down the strength function for ordinary muon capture on 100Mo
2019
Ordinary muon capture (OMC) on 100Mo is studied both experimentally and theoretically in order to access the weak responses in wide energy and momentum regions. The OMC populates states in 100Nb up to some 50 MeV in excitation energy. For the first time the associated OMC strength function has been computed and compared with the obtained data. The present computations are performed using the Morita-Fujii formalism of OMC by extending the original formalism beyond the leading order. The participant nuclear wave functions are obtained in extended no-core single-particle model space using the spherical version of proton-neutron quasiparticle random-phase approximation (pnQRPA) with two-nucleon…
Exact relativistic beta decay endpoint spectrum
2007
5 pages, 3 figures.-- PACS nrs.: 14.60.Pq; 13.30.-a; 23.40.-s; 23.40.Bw.-- ISI Article Identifier: 000250620900070.-- ArXiv pre-print available at: http://arxiv.org/abs/0706.0897
Double-βtransformations in isobaric triplets with mass numbersA=124, 130, and 136
2012
The Q values of double-electron capture in ${}^{124}$Xe, ${}^{130}$Ba, and ${}^{136}$Ce and double-beta decay of ${}^{124}$Sn and ${}^{130}$Te have been determined with the Penning-trap mass spectrometer SHIPTRAP with a few hundred eV uncertainty. These nuclides are members of three isobaric triplets with common daughter nuclides. The main goal of this work was to investigate the existence of the resonant enhancement of the neutrinoless double-electron-capture rates in ${}^{124}$Xe and ${}^{130}$Ba in order to assess their suitability for the search for neutrinoless double-electron capture. Based on our results, in neither of these cases is the resonance condition fulfilled.
Shell-model study of partial muon-capture rates in light nuclei
1998
Abstract The nuclear shell model is used to study ordinary muon capture of light nuclei in the p, sd and p-sd shell-model spaces. Several well-established two-body interactions are applied to calculate the involved nuclear matrix elements and the emerging results are compared with each other. The resulting theoretical partial muon-capture rates are compared with experimental data and their stability against different model spaces and interactions studied. The effects of the induced-pseudoscalar strength, C p , on the capture rates is discussed. The relation between the allowed partial muon capture rates and the Gamow-Teller strength function is stressed.
Analysis of the 2νββ decay and muon capture reactions for the mass A = 46 and A = 48 nuclei using the nuclear shell model
2005
We discuss the two-neutrino double-beta decays of 46Ca and 48Ca by using the nuclear shell model with well-tested two-body interactions. We also discuss the ordinary muon-capture (OMC) reaction on the final nuclei, 46Ti and 48Ti, of these decays. The OMC leads to the virtual states of the intermediate nuclei, 46Sc and 48Sc, in these double-beta decays.
Total muon-capture rate. Application to11B
1972
A study of the total muon-capture rate in nuclei is presented, with the aid of the impulse and closure approximations and under the assumption that the initial nucleus can be described by a mixing of states in theJ-scheme. The theory is applied to the process of muon capture in11B, with a discussion on the value of the average neutrino momentum.
Radiative muon capture on 12C and 16O
1979
Abstract We study exclusive radiative muon capture on 12 C(g.s.) leading to 12 B(g.s.), and on 16 O(g.s.) leading to 16 N(0 − , 120 keV). Our investigation, which is based on impulse approximation, puts special emphasis on elementary particle aspects of radiative capture, such as tests of magnitude and momentum transfer dependence of the induced pseudoscalar, and possible contributions of axial currents of second kind (weak electricity). We calculate several correlation observables which are sensitive to the nucleonic currents but depend very little on the structure of the nuclear initial and final states. In particular, it is shown that in capture on 12 C the polarization and alignment of …