ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract By combining potential models and QCD spectral sum rules (QSSR), we discuss the spectroscopy of the $$(b\bar c)$$ mesons and of the (bcq), (ccq) and (bbq) baryons (q≡d ors), the decay constant and the (semi)leptonic decay modes of theB c meson. For the masses, the best predictions come from potential models and read: $$M_{B_c } = (6255 \pm 20)$$ MeV, $$M_{B_c^* } = (6330 \pm 20)$$ MeV,M Λ(bcu) =(6.93±0.05) GeV,M Ω(bcs) =(7.00±0.05) GeV,M Σ*(ccu) =(3.63±0.05) GeV andM Σ*(bbu) =(10.21±0.05) GeV. The decay constant $$f_{B_c } = (2.94 \pm 0.21)f_\pi $$ is well determined from QSSR and leads to:Γ(B c →v ττ=(3.0±0.4)(V cb /0.037)2×1010 s−1. The uses of the vertex sum rules for the semileptonic decays of theB c show that thet-dependence of the form factors is much stronger than predicted by vector meson dominance. It also predicts the almost equal strength of about 0.30×1010 s−1 for the semileptonic ratesB c intoB s ,B s * ,η c andJ/ψ. Besides these phenomenological results, we also show explicitly how the Wilson coefficients of the 〈α s G 2〉 and 〈G 3〉 gluon condensates already contain the full heavy quark $$(\left\langle {\bar QQ} \right\rangle )$$ and mixed- $$(\left\langle {\bar QGQ} \right\rangle )$$ condensate contributions in the OPE.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01557235
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