16 research outputs found
Finite temperature properties of the Dirac operator with bag boundary conditions
We study the finite temperature free energy and fermion number for Dirac
fields in a one-dimensional spatial segment, under local boundary conditions
compatible with the presence of a spectral asymmetry. We discuss in detail the
contribution of this part of the spectrum to the determinant. We evaluate the
finite temperature properties of the theory for arbitrary values of the
chemical potential.Comment: Talk given at the Seventh International Workshop Quantum Field Theory
under the influence of External Conditions, QFEXT'05, Barcelona, Spain. Final
version, to appear in Journal of Physics A: Mathematical and Genera
On total muon capture rates and the average neutrino energy
A method of avoiding the uncertainty associated with the average neutrino energy nu in the usual closure approach to muon capture rates is discussed. Instead of neglecting the kinematic dependence on each particular channel, the partial capture rate is approximated by a first-order expansion around nu . After the sum over the final states is performed, the result is quite independent of the specific value of nu . Application to /sup 3/He, /sup 6/Li and closed-shell nuclei is given, as an effective test of the nuclear models used