In this paper we compute the decay constant of the pseudo-scalar heavy-light mesons in the heavy quark effective theory framework of QCD sum rules. In our analysis we include the recently evaluated three-loop result of order αs for the heavy-light current correlator. The value of the bottom quark mass, which essentially limits the accuracy of the sum rules for B meson, is extracted from the non...

The singular part of Borel transform of a QCD amplitude near the infrared renormalon can be expanded in terms of higher order Wilson coefficients of the operators associated with the renormalon. In this paper we observe that this expansion gives nontrivial constraints on the Borel amplitude that can be used to improve the accuracy of the ordinary perturbative expansion of the Borel amplitude. I...

To quantitatively assay future measurements of competing observables in t → W+b decay, we consider the gV−A coupling values of the helicity decay parameters versus those for “ (V − A) + Single Additional Lorentz Structures ”. There are 2 dynamical phase-type ambiguities (S + P ) and (fM + fE). Associated with the latter (fM + fE) ambiguity, there are 3 very interesting numerical puzzles at the ...

We study the lepton-flavor-violating reaction μe → ee within two extensions of the standard model that include heavy neutrinos. The reaction is studied in the low energy limit in the form of muonium decay M → ee and in the high energy regime of a muon collider. The two theoretical models we consider are: model I, a typical see-saw model that violates lepton flavor and number by inclusion of ext...

Fig. 1 shows the comparison of the measured dielectron spectra to simulations performed with the PLUTO event generator [2] inside the geometrical acceptance of HADES. The low-mass region of the spectra is dominated by Dalitz decays of π, η, ω as well as by the Dalitz decay of the ∆(1232) resonance. The evident peak around the pole mass of the ω meson, with width of 17 ± 2 MeV, corresponds to it...