arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1507.04467hep-phhep-th
收藏

强动力学的纯引力中介和自发B-L破缺

Pure Gravity Mediation and Spontaneous B-L Breaking from Strong Dynamics

Kaladi S. Babu, Kai Schmitz, Tsutomu T. Yanagida

摘要:

在纯引力中介(PGM)中,超对称性(SUSY)破缺到可见扇区的最小中介方案,标准模型高吉诺的软质量是在一个环中产生的,而不是通过直接耦合到超对称性破缺场。因此,在PGM的任何具体实现中,超对称破缺场都需要在某种全局或局部对称性下携带非零电荷。正如我们在本文中指出的,这种对称性的一个主要候选者可能是B-L,即与重子数B和轻子数L之差有关的阿贝尔规范对称性。超对称性破缺场的F项不仅破缺了超对称性,而且破缺了B-L,这在基本水平上联系了超对称性和B-L各自的自发破缺。作为一个特别有趣的结果,我们发现重马约拉纳中微子质量标度最终与引力子质量Lambda_N ~ m_3/2联系在一起。假设宇宙的重子不对称性是由非热的轻子生成引起的,那么这种联系就可以解释为什么超对称性必须在相当高的能量尺度上被打破,从而使m_3/2 >~ 1000 TeV符合PGM的概念。我们通过一个动力学超对称破缺的极小模型来说明我们的想法,其中B-L被确定为弱规范味对称。我们还讨论了B-L规范动力学对超粒子质量谱的影响以及由此产生的对模型参数空间的约束。特别是,我们评论的B-L D-长期的作用。

英文摘要:

In pure gravity mediation (PGM), the most minimal scheme for the mediation of supersymmetry (SUSY) breaking to the visible sector, soft masses for the standard model gauginos are generated at one loop rather than via direct couplings to the SUSY-breaking field. In any concrete implementation of PGM, the SUSY-breaking field is therefore required to carry nonzero charge under some global or local symmetry. As we point out in this note, a prime candidate for such a symmetry might be B-L, the Abelian gauge symmetry associated with the difference between baryon number B and lepton number L. The F-term of the SUSY-breaking field then not only breaks SUSY, but also B-L, which relates the respective spontaneous breaking of SUSY and B-L at a fundamental level. As a particularly interesting consequence, we find that the heavy Majorana neutrino mass scale ends up being tied to the gravitino mass, Lambda_N ~ m_3/2. Assuming nonthermal leptogenesis to be responsible for the generation of the baryon asymmetry of the universe, this connection may then explain why SUSY necessarily needs to be broken at a rather high energy scale, so that m_3/2 >~ 1000 TeV in accord with the concept of PGM. We illustrate our idea by means of a minimal model of dynamical SUSY breaking, in which B-L is identified as a weakly gauged flavor symmetry. We also discuss the effect of the B-L gauge dynamics on the superparticle mass spectrum as well as the resulting constraints on the parameter space of our model. In particular, we comment on the role of the B-L D-term.

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。

↑