منابع مشابه
Relativistic Effects in S-wave Quarkonium Decays
The decay widths of S-wave quarkonia (ηc, ηb → γγ and J/ψ,Υ → ee) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via quarkonium wave function. It is shown that relativistic corrections may be large (10-50 %) and comparable with QCD corrections.
متن کاملProspects of Probing New Physics in Bottomonium Decays and Spectroscopy *
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breaking in Upsilon leptonic decays. Moreover, mixing between such a pseu-doscalar Higgs boson and η b states might shift their mass levels, thereby modifying the values of the M Υ(nS) − M η b (nS) hyperfine splittings predicted in the standard model. Besides, η b resonances could be broader than ...
متن کاملNew predictions for inclusive heavy-quarkonium P-wave decays.
We show that some nonrelativistic quantum chromodynamics color-octet matrix elements can be written in terms of (derivatives of) wave functions at the origin and of nonperturbative universal constants once the factorization between the soft and ultrasoft scales is achieved by using an effective field theory where only ultrasoft degrees of freedom are kept as dynamical entities. This allows us t...
متن کاملRigorous QCD predictions for decays of P-wave quarkonia.
Rigorous QCD predictions for decay rates of the P-wave states of heavy quarkonia are presented. They are based on a new factorization theorem which is valid to leading order in the heavy quark velocity and to all orders in the running coupling constant of QCD. The decay rates for all four P states into light hadronic or electromagnetic final states are expressed in terms of two phenomenological...
متن کاملS to P wave form factors in semi - leptonic B decays
We apply HQET to semi-leptonic B and Bs meson decays into the observed charmed P wave states. In order to examine the sensitivity of the results to the choice of a specific model, we perform all calculations using several different meson models, and find that uncertainty introduced by the choice of a particular model is about 30%. Specifically, assuming τB = 1.50ps and Vcb = 0.040, we obtain br...
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ژورنال
عنوان ژورنال: Nuclear Physics B - Proceedings Supplements
سال: 1995
ISSN: 0920-5632
DOI: 10.1016/0920-5632(95)00234-z