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arXiv 0812.4320hep-ph
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Tevatron和LHC对B -->轻子轻子的完全单圈MSSM预言

Complete One-Loop MSSM Predictions for B --> lepton lepton' at the Tevatron and LHC

Athanasios Dedes, Janusz Rosiek, Philip Tanedo

摘要:

在过去的几年中,Tevatron极大地改善了稀有B介子衰变为两个轻子的边界。在B_s --> mu+ mu-的情况下,当前边界仅比标准模型期望值大10倍。对这种衰变的敏感性是LHCb性能和物理的基准目标之一。希格斯企鹅在MSSM的大tan(β)区域中占主导地位。在低tan(β)区域,情况不一定如此,因为箱形图和Z-企鹅图的贡献率可能相当。在这篇文章中,我们计算了完整的单循环MSSM对B -> l+ l '-的贡献,其中l,l' = e,mu。我们研究的预测与任意风味混合参数的一般值的tan(β)。我们讨论了增强和抑制相对于其标准模型预期的分支比的可能性。特别是,我们发现,有“取消区域”的参数空间中的分支比被抑制远低于标准模型的期望,使其有效地无形的大型强子对撞机。

英文摘要:

During the last few years the Tevatron has dramatically improved the bounds on rare B-meson decays into two leptons. In the case of B_s --> mu+ mu-, the current bound is only ten times greater than the Standard Model expectation. Sensitivity to this decay is one of the benchmark goals for LHCb performance and physics. The Higgs penguin dominates this rate in the region of large tan(beta) of the MSSM. This is not necessarily the case in the region of low tan(beta), since box and Z-penguin diagrams may contribute at a comparable rate. In this article, we compute the complete one-loop MSSM contribution to B --> l+l'- for l,l' = e, mu. We study the predictions for general values of tan(beta) with arbitrary flavour mixing parameters. We discuss the possibility of both enhancing and suppressing the branching ratios relative to their Standard Model expectations. In particular, we find that there are "cancellation regions" in parameter space where the branching ratio is suppressed well below the Standard Model expectation, making it effectively invisible to the LHC.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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