New physics upper bound on the branching ratio of B_s--> l+ l- and B_s--> l+ l- gamma
| dc.creator | Alok, Ashutosh Kumar | |
| dc.creator | Sankar, S. Uma | |
| dc.date | 2006-08-12 | |
| dc.date.accessioned | 2026-07-07T10:41:57Z | |
| dc.date.available | 2026-07-07T10:41:57Z | |
| dc.description | We consider the most general new physics effective Lagrangian for b--> s l+ l-. We derive the upper limit on the branching ratio for the processes B_s--> l^+ l- where l=e, mu, subject to the current experimental bounds on related processes, B--> (K,K*) l+ l-. If the new physics interactions are of vector/axial-vector form, the present measured rates for B--> (K,K*) l+ l- constrain B_s--> l+ l to be of the same order of magnitude as their respective Standard Model (SM) predictions. On the other hand, if the new physics interactions are of scalar/pseudoscalar form, B--> (K,K*) l+ l- rates do not impose any useful constraint on B_s--> l+ l- and the branching ratios of these decays can be as large as present experimental upper bounds. If future experiments measure B_s--> l+ l- to be > 10^{-8} then the new physics giving rise to these decays has to be of the scalar/pseudoscalar form. We also consider the effect of new physics on B_s--> l+ l- gamma subject to the present experimental constraints on B--> (K,K*) l+ l- and B--> K* gamma. New physics in form scalar/pseudoscalar, which makes a very large contribution to B_s--> l+ l-, makes no contribution at all to B_s--> l+ l- gamma due to angular momentum conservation. New Physics in the form of vector/axial-vector operators is constrained by the data on B--> (K,K*) l+ l- and new physics in the form of tensor/pseudo-tensor is constrained by the data on B--> K* gamma. In both cases, enhancement of B_s--> l+ l- gamma much beyond the SM expectation is impossible. In conclusion, present data on B-->(K,K*) transitions allow for large B(B_s--> l+ l-) but do not allow B(B_s--> l+ l- gamma) to be much larger than its SM expectation. | |
| dc.description | 3 pages, write-up for the proceedings of the '7th International Conference on Hyperons, Charm and Beauty Hadrons(BEACH 2006)', 2-8 July, Lancaster, England; to be published in Nuclear Physics B (Proceedings Supplements) | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0608144 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0608144 | |
| dc.identifier | Nucl.Phys.Proc.Suppl.167:185-187,2007 | |
| dc.identifier | doi:10.1016/j.nuclphysbps.2006.12.056 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/181785 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | New physics upper bound on the branching ratio of B_s--> l+ l- and B_s--> l+ l- gamma | |
| dc.type | text |