Perturbative corrections to Λ <sub>b</sub> → Λ form factors from QCD light-cone sum rules
- Author(s)
- Yu-Ming Wang, Yue-Long Shen
- Abstract
Abstract: We compute radiative corrections to Λ
b → Λ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with Λ
b-baryon distribution amplitudes. Employing the diagrammatic approach factorization of the vacuum-to-Λ
b-baryon correlation function is justified at leading power in Λ/m
b, with the aid of the method of regions. Hard functions entering the factorization formulae are identical to the corresponding matching coefficients of heavy-to-light currents from QCD onto soft-collinear effective theory. The universal jet function from integrating out the hard-collinear fluctuations exhibits richer structures compared with the one involved in the factorization expressions of the vacuum-to-B-meson correlation function. Based upon the QCD resummation improved sum rules we observe that the perturbative corrections at (Formula presented.) shift the Λ
b → Λ from factors at large recoil significantly and the dominant contribution originates from the next-to-leading order jet function instead of the hard coefficient functions. Having at hand the sum rule predictions for the Λ
b → Λ from factors we further investigate several decay observables in the electro-weak penguin Λ
b → Λ ℓ
+ℓ
− transitions in the factorization limit (i.e., ignoring the “non-factorizable” hadronic effects which cannot be expressed in terms of the Λ
b → Λ from factors), including the invariant mass distribution of the lepton pair, the forward-backward asymmetry in the dilepton system and the longitudinal polarization fraction of the leptonic sector.
- Organisation(s)
- Particle Physics
- External organisation(s)
- Technische Universität München, Ocean University of China
- Journal
- Journal of High Energy Physics
- Volume
- 2016
- No. of pages
- 51
- ISSN
- 1029-8479
- DOI
- https://doi.org/10.1007/JHEP02(2016)179
- Publication date
- 02-2016
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103012 High energy physics
- Keywords
- ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/perturbative-corrections-to--b---form-factors-from-qcd-lightcone-sum-rules(2774af40-d88c-48ce-97ec-8f6132314fd1).html