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arXiv 1802.06803hep-ph
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MSSM中的轻子味破坏:精确对角化与质量膨胀

Lepton flavour violation in the MSSM: exact diagonalization vs mass expansion

Andreas Crivellin, Zofia Fabisiewicz, Weronika Materkowska, Ulrich Nierste, Stefan Pokorski, Janusz Rosiek

摘要:

即将到来的关于轻子味违反衰变的精确数据需要在新物理模型中进行精确和有效的计算。本文用基于味展开定理的方法计算了最小超对称标准模型(MSSM)中轻子味破坏过程,味展开定理是一种新近发展起来的对振幅进行纯代数质量插入展开的方法。本文讨论了超费米子和超对称费米子质量矩阵的非对角项的味破坏和味保持展开。用这种方法,相关过程直接用MSSM拉格朗日量的参数表示。我们还研究了振幅的解耦特性。将结果与质量本征基中的相应计算进行比较(即使用质量矩阵的精确对角化)。利用这些方法,我们考虑了以下过程:$\ell \to \ell' γ$,$\ell \to 3 \ell'$,$\ell \to 2\ell'\ell"$,$h \to \ell\ell'$以及$μ\to e$在细胞核中的转换。在数值分析中,我们更新的MSSM的味道变化参数的界限,并检查即将到来的实验结果的敏感性。我们发现,味道违反μ子衰变提供了最严格的界限超对称效应,并将继续这样做,在未来。辐射$\ell\to\ell^\primeγ$衰变和轻子三体衰变$\ell\to 3\ell^\prime$在消除参数空间中的“盲点”方面表现出有趣的互补性。在我们的分析中,我们还包括非全纯的$A$ -条款,这是重要的LFV希格斯衰变的研究的影响。

英文摘要:

The forthcoming precision data on lepton flavour violating decays require precise and efficient calculations in New Physics models. In this article lepton flavour violating processes within the Minimal Supersymmetric Standard Model (MSSM) are calculated using the method based on the Flavour Expansion Theorem, a recently developed technique performing a purely algebraic mass-insertion expansion of the amplitudes. The expansion in both flavour-violating and flavour-conserving off-diagonal terms of sfermion and supersymmetric fermion mass matrices is considered. In this way the relevant processes are expressed directly in terms of the parameters of the MSSM Lagrangian. We also study the decoupling properties of the amplitudes. The results are compared to the corresponding calculations in the mass eigenbasis (i.e. using the exact diagonalization of the mass matrices). Using these methods, we consider the following processes: $\ell \to \ell' γ$, $\ell \to 3 \ell'$, $\ell \to 2\ell'\ell"$, $h \to \ell\ell'$ as well as $μ\to e$ conversion in nuclei. In the numerical analysis we update the bounds on the flavour changing parameters of the MSSM and examine the sensitivity to the forthcoming experimental results. We find that flavour violating muon decays provide the most stringent bounds on supersymmetric effects and will continue to do so in the future. Radiative $\ell\to\ell^\primeγ$ decays and leptonic three-body decays $\ell\to 3\ell^\prime$ show an interesting complementarity in eliminating "blind spots" in the parameter space. In our analysis we also include the effects of non-holomorphic $A$-terms which are important for the study of LFV Higgs decays.

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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