The heavy quark expansion for inclusive semileptonic charm decays revisited

Fael, Matteo 1; Mannel, Thomas; Vos, K. Keri
1 Institut für Theoretische Teilchenphysik (TTP), Karlsruher Institut für Technologie (KIT)

Abstract:

The Heavy Quark Expansion (HQE) has become an extremely powerful tool in flavor physics. For charm decays, where the expansion parameters α$_{s}$(m$_{c}$) and Λ$_{QCD}$/m$_{c}$ are bigger than for bottom decays, it remains to be seen if the HQE can be applied with similar success. Nevertheless, to make optimal use of the plethora of data already available and coming in the near future, a better understanding of HQE for charm decays is crucial. This paper discusses in detail how the HQE for charm decays is set up, what is the role of four-quark (weak annihilation) operators and how this compares to the well understood bottom decays. Subtleties concerning radiative corrections and the charm mass scheme are briefly discussed. An experimental study of the relevant HQE hadronic matrix elements will then show if the HQE expansion for charm converges well enough. Besides serving as an important cross check for inclusive B decays, in the end, this study might open the road for inclusive |V$_{cs}$| and |V$_{cd}$| extractions.

 Zugehörige Institution(en) am KIT Institut für Theoretische Teilchenphysik (TTP) Publikationstyp Zeitschriftenaufsatz Publikationsmonat/-jahr 12.2019 Sprache Englisch Identifikator ISSN: 1029-8479 KITopen-ID: 1000124519 Erschienen in Journal of high energy physics Verlag Scuola Internazionale Superiore di Studi Avanzati (SISSA) Band 2019 Heft 12 Seiten Art.Nr. 67 Vorab online veröffentlicht am 09.12.2019 Nachgewiesen in DimensionsWeb of ScienceScopus
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