| Autor: |
H. M. Asatrian, A. Hovhannisyan, U. Nierste, A. Yeghiazaryan |
| Jazyk: |
angličtina |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Journal of High Energy Physics, Vol 2017, Iss 10, Pp 1-30 (2017) |
| Druh dokumentu: |
article |
| ISSN: |
1029-8479 |
| DOI: |
10.1007/JHEP10(2017)191 |
| Popis: |
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 ΔΓ s in the B s − B ¯ s $$ {B}_s-{\overline{B}}_s $$ system. The considered diagrams contain a closed fermion loop in a gluon propagator and constitute the order α s 2 N f , where N f is the number of light quarks. Our results entail a considerable correction in that order, if ΔΓ s is expressed in terms of the pole mass of the bottom quark. If the M S ¯ $$ \overline{\mathrm{MS}} $$ 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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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