Inclusive Semi-leptonic B Decays to order 1/m_b^4

We give a systematic way to compute higher orders in the 1/m_b expansion in inclusive semi-leptonic decays at tree level. We reproduce the known 1/m_b^3 terms and compute the 1/m_b^4 terms at tree level. The appearing non-perturbative parameters and the impact on the determination of V_{cb} are discussed.Comment: 23 pages, 3 figures, uses phystex.st

Model-independent Analysis of Lepton Flavour Violating Tau Decays

Many models for physics beyond the Standard Model predict lepton-flavour violating decays of charged leptons at a level which may become observable very soon. In the present paper we investigate the decays of a Tau into three charged leptons in a generic way, based on effective-field-theory methods, where the relevant operators are classified according to their chirality structure. We work out the decay distributions and discuss phenomenological implications.Comment: 14 pages, 10 figures, references and comments adde

Analyse "Neuer Physik" im Flavor Sektor unter Benutzung von Methoden der effektiven Feldtheorie

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Inclusive Semi-leptonic B Decays to order 1/m 4 b

We give a systematic way to compute higher orders in the 1/mb expansion in inclusive semi-leptonic decays at tree level. We reproduce the known 1/m3 b terms and compute the 1/m4 b terms at tree level. The appearing non-perturbative parameters and the impact on Inclusive semi-leptonic decays are the cleanest way to access the matrix elements of the CKM matrix. In order to achieve precision in the determination of the CKM parameters a reliable theoretical framework is needed in addition to precise data. From the off-diagonal CKM matrix elements only Vus and Vcb are known very precisely from direct measurements [1], and bot