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DOI: 10.5445/IR/1000077127

Towards next-to-next-to-leading-log accuracy for the width difference in the Bs−B¯s system: fermionic contributions to order (mc/mb)⁰ and (mc/mb)¹

Asatrian, H. M.; Hovhannisyan, A.; Nierste, U.; Yeghiazaryan, A.

Abstract:
We calculate a class of three-loop Feynman diagrams which contribute to the next-to-next-to-leading logarithmic approximation for the width difference ΔΓs in the B s −B ¯ s system. The considered diagrams contain a closed fermion loop in a gluon propagator and constitute the order αs2Nf, where Nf is the number of light quarks. Our results entail a considerable correction in that order, if ΔΓs is expressed in terms of the pole mass of the bottom quark. If the MS ¯ scheme is used instead, the correction is much smaller. As a result, we find a decrease of the scheme dependence. Our result also indicates that the usually quoted value of the NLO renormalization scale dependence underestimates the perturbative error.


Zugehörige Institution(en) am KIT Institut für Theoretische Teilchenphysik (TTP)
Publikationstyp Zeitschriftenaufsatz
Jahr 2017
Sprache Englisch
Identifikator ISSN: 1029-8479, 1126-6708
URN: urn:nbn:de:swb:90-771270
KITopen ID: 1000077127
Erschienen in Journal of high energy physics
Band 2017
Heft 10
Seiten 191
Bemerkung zur Veröffentlichung Gefördert durch SCOAP3
Schlagworte NLO Computations
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