The Qcd Perspective on Lifetimes of Heavy-flavour Hadrons
نویسنده
چکیده
Over the last few years a theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology is described as it applies to total lifetimes, and the underlying theoretical issues are discussed. Theoretical expectations are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than predicted. The ramifications of those findings are analyzed in detail, and future refinements are described.
منابع مشابه
Lifetimes of Heavy-flavour Hadrons – Whence and Whither?
A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than expected. The ramifications of those fi...
متن کامل4 v 2 2 7 Ju l 1 99 5 UND - HEP - 95 - BIG 06 June 1995 LIFETIMES OF HEAVY - FLAVOUR HADRONS – WHENCE AND WHITHER ?
A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than expected. The ramifications of those fi...
متن کاملQCD predictions for lepton spectra in inclusive heavy flavor decays.
We derive the lepton spectrum in semileptonic beauty decays from a nonperturbative treatment of QCD; it is based on an expansion in 1/mQ with mQ being the heavy flavour quark mass. The leading corrections arising on the 1/mQ level are completely expressed in terms of the difference in the mass of the heavy hadron and the quark. Nontrivial effects appear in 1/m2Q terms affecting mainly the endpo...
متن کاملSe p 20 00 SPECTATOR EFFECTS AND QUARK - HADRON DUALITY IN INCLUSIVE BEAUTY DECAYS
5 Quark-hadron duality 51 6 Conclusion 55 ii 0.1 Preface This Thesis is a review of the inclusive decays of heavy hadron. It is based on the author's study of two issues which are important in the description of the inclusive beauty decays given by the heavy quark expansion. • Evaluation of the expectation values of the four-quark operators in the heavy quark expansion, • Study on the validity ...
متن کاملForm Factors for Semileptonic Decays of Heavy-Light Hadrons
In the quark mass M → ∞ limit, QCD has an exact SU(2Nf) spin-flavour symmetry. This symmetry relates many matrix elements and form factors of hadrons containing heavy quarks [2,3]. In particular, the semileptonic weak decay form factors of s−wave hadrons containing a single infinitely heavy quark can be reduced to two unknown functions, one for mesons (ξ) and another for baryons (ζ). The knowle...
متن کامل