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Author (up) Kim, C.S.; Lopez-Castro, G.; Tostado, S.L.; Vicente, A.
Title Remarks on the Standard Model predictions for R(D) and R(D*) Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 95 Issue 1 Pages 013003 - 7pp
Keywords
Abstract Semileptonic b -> c transitions, and in particular the ratios R(D-(*())) = Gamma(B -> D-(*())tau nu)/Gamma(B -> D-(*())l nu), can be used to test the universality of the weak interactions. In light of the recent discrepancies between the experimental measurements of these observables by the BABAR, Belle, and LHCb collaborations and the Standard Model predicted values, we study the robustness of the latter. Our analysis reveals that R(D) might be enhanced by lepton mass effects associated to the mostly unknown scalar form factor. In contrast, the Standard Model prediction for R(D*) is found to be more robust, because possible pollutions from B* contributions turn out to be negligibly small; this indicates that R(D) is a promising observable for searches of new physics.
Address [Kim, C. S.] Yonsei Univ, Dept Phys, Seoul 120749, South Korea, Email: cskim@yonsei.ac.kr;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000400774700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3136
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Author (up) Tostado, S.L.; Lopez Castro, G.
Title Radiative corrections of O(alpha) to B- -> V(0)l(-)(nu)over-bar(l) decays Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 9 Pages 495 - 15pp
Keywords
Abstract The O(alpha) electromagnetic radiative corrections to the B- -> V(0)l(-)(nu) over bar (l) (V is a vector meson and l a charged lepton) decay rates are evaluated using the cutoff method to regularize virtual corrections and incorporating intermediate resonance states in the real-photon amplitude to extend the region of validity of the soft-photon approximation. The electromagnetic and weak form factors of hadrons are assumed to vary smoothly over the energies of virtual and real photons under consideration. The cutoff dependence of radiative corrections upon the scale Lambda that separates the long-and short-distance regimes is found to be mild and is considered as an uncertainty of the calculation. Owing to partial cancellations of electromagnetic corrections evaluated over the three-and four-body regions of phase space, the photoninclusive corrected rates are found to be dominated by the short-distance contribution. These corrections will be relevant for a precise determination of the b quark mixing angles by testing isospin symmetrywhen measurements of semileptonic rates of charged and neutral B mesons at the fewpercent level become available. For completeness, we also provide numerical values of radiative corrections in the three-body region of the Dalitz plot distributions of these decays.
Address [Tostado, S. L.; Lopez Castro, G.] Inst Politecn Nacl, Dept Fis, Ctr Invest & Estudios Avanzados, Apdo Postal 14-740, Mexico City 07000, DF, Mexico, Email: stostado@fis.cinvestav.mx;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000389594000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2878
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