论文标题
宇宙模量问题和自然性
The cosmological moduli problem and naturalness
论文作者
论文摘要
宇宙学模量问题（CMP）分为三个部分：1。潜在的违反了后期衰减的模量田地的BBN约束，2。模量引起的Gravitino问题，其中graveritinos被过度生产，而模量诱导的最轻的SUSY粒子（LSP）（LSP）过量生产问题。我们检查了宇宙模量问题及其与Electroweak自然性的联系。我们将光模量场的各种两体衰减宽度计算为一般超对称模型中的MSSM颗粒和Gravitinos。我们包括相位空间和混合效应。我们检查了对重力诺（Case 1＆2）和/或Gauginos（案例A＆B）的模量衰减的无螺旋性抑制案例。对于情况B1，我们评估了由BBN限制的Gravitino质量M_ {3/2}与模量质量M_DACARAMETER限制，通过过度生产重力和过量的Neutilino Dark Matter，以及与自然性的连接。在这种情况下，除非M_D> 〜2.5 \ times 10^3 tev tev，tev tev带有m_ϕ <2m_ {3/2}，否则所有参数空间本质上都被排除在外。对于可能是最有利的情况B2，带有ϕ -decay到Higgs并关闭物质，然后将模量分支到SUSY和GRAVITINOS上，在大M_D上被高度抑制。但是，由于模量数密度的增加速度快于分支部分的降低，因此中inino暗物质的总生产过多。我们还表明，在这种情况下，热产生的重力问题是通过巨大的熵稀释固定的，但是除非M_D <2m_ {3/2}在运动学上抑制它，否则Moduli衰减产生的非热重力杆菌仍然是一个巨大的问题。在教学附录中，我们介绍了模量场两体衰减宽度的详细计算。
The cosmological moduli problem (CMP) comes in three parts: 1. potential violation of BBN constraints from late decaying moduli fields, 2. the moduli-induced gravitino problem wherein gravitinos are overproduced and 3. the moduli-induced lightest SUSY particle (LSP) overproduction problem. We examine the cosmological moduli problem and its connection to electroweak naturalness. We calculate the various two-body decay widths of a light modulus field into MSSM particles and gravitinos within general supersymmetric models. We include both phase space and mixing effects. We examine cases without and with helicity suppression of modulus decays to gravitinos (cases 1 & 2) and/or gauginos (cases A & B). For case B1, we evaluate regions of gravitino mass m_{3/2} vs. modulus mass m_ϕparameter space constrained by BBN, by overproduction of gravitinos and by overproduction of neutralino dark matter, along with connections to naturalness. For this case, essentially all of parameter space is excluded unless m_ϕ>~ 2.5\times 10^3 TeV with m_ϕ<2m_{3/2}. For a potentially most propitious case B2 with ϕdecay to Higgs and matter turned off, then modulus branching fractions to SUSY and to gravitinos become highly suppressed at large m_ϕ. But since the modulus number density increases faster than the branching fractions decrease, there is still gross overproduction of neutralino dark matter. We also show that in this scenario the thermally produced gravitino problem is fixed by huge entropy dilution, but non-thermal gravitino production from moduli decay remains a huge problem unless it is kinematically suppressed with m_ϕ< 2m_{3/2}. In a pedagogical appendix, we present detailed calculations of modulus field two-body decay widths.
