0000000000680302
AUTHOR
Joaquim Prades Hernández
Constraints on the W-R mass and CP violation in left-right models
We update the constraints on the right-handed WR gauge boson mass, mixing angle ζ with the left-handed WL gauge boson, and other parameters in general left-right symmetric models with different mechanisms of CP violation. Constraints mostly independent of any assumption on the quark sector are obtained from a re-analysis of muon decay data. Estimates of the left-right hadronic matrix elements in the neutral kaon system and their uncertainties are revised using large Nc and Chiral Perturbation Theory arguments. With explicitly given assumptions on the long-distance (ΔS=1)2 contributions to the KL−KS mass difference, lower bounds on MWR are obtained. With the same assumptions, one also gets s…
Determination of m(s) and vertical bar V-us vertical bar from hadronic tau decays
The mass of the strange quark is determined from SU(3)-breaking effects in the tau hadronic width. Compared to previous analyses, the contributions from scalar and pseudoscalar spectral functions, which suffer from large perturbative corrections, are replaced by phenomenological parametrisations. This leads to a sizeable reduction of the uncertainties in the strange mass from tau decays. Nevertheless, the resulting m(s) value is still rather sensitive to the moment of the invariant mass distribution which is used for the determination, as well as the size of the quark-mixing matrix element \V-us\. Imposing the unitarity fit for the CKM matrix, we obtain m(s)(2 GeV) = 117 +/- 17 MeV, whereas…