Quark mass effects in B -> Xs gamma
| dc.creator | Gambino, Paolo | |
| dc.creator | Misiak, Mikolaj | |
| dc.date | 2001-04-03 | |
| dc.date | 2001-09-11 | |
| dc.date.accessioned | 2026-07-07T10:32:50Z | |
| dc.date.available | 2026-07-07T10:32:50Z | |
| dc.description | The charm-loop contribution to B -> Xs gamma is found to be numerically dominant and very stable under logarithmic QCD corrections. The strong enhancement of the branching ratio by QCD logarithms is mainly due to the b-quark mass evolution in the top-quark sector. These observations allow us to achieve better control over residual scale dependence at the next-to-leading order. Furthermore, we observe that the sensitivity of the matrix element < Xs gamma | (sc)_(V-A)(cb)_(V-A) | b > to mc/mb is the source of a sizeable uncertainty that has not been properly taken into account in previous analyses. Replacing mc^pole/mb^pole in this matrix element by the more appropriate mc(mu)/mb^pole with mc < mu < mb causes an 11% enhancement of the SM prediction for BR[B -> Xs gamma]. For E_gamma > 1.6 GeV in the B-meson rest frame, we find BR[ B -> Xs gamma]_{E_gamma > 1.6 GeV} = (3.60 +_ 0.30) * 10^-4. The difference between our result and the current experimental world average is consistent with zero at the level of 1 sigma. We also discuss the implementation of new physics effects in our calculation. The lower bound on the charged Higgs boson mass in 2HDM(II) is found the be higher than 350 GeV. | |
| dc.description | Nucl. Phys. B 611 (2001) 338. Comparison with experiment is updated in the present hep-ph version. In particular, the published results of CLEO (hep-ex/0108032) are taken into account. 30 pages, 6 figures, uses graphicx | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0104034 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0104034 | |
| dc.identifier | Nucl.Phys.B611:338-366,2001 | |
| dc.identifier | doi:10.1016/S0550-3213(01)00347-9 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/178892 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Quark mass effects in B -> Xs gamma | |
| dc.type | text |