发表机构
University of Oklahoma; University of Wisconsin, Madison（俄克拉荷马大学; 威斯康星大学麦迪逊分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在特定超对称模型中，通过RPV WIMP衰变及相关级联衰变机制，改善宇宙学模问题，允许质量约130 TeV的轻弦状模存在，协调了自然性与弦状模的存在。
AI 中文摘要
我们在使用离散R对称性来抑制μ项、且μ项通过Kim-Nilles超势算子再生的超对称模型框架下，研究宇宙学模问题（CMP）。这类理论中会出现作为偶然近似对称性的整体U(1)_{PQ}，它可解决强CP问题；R宇称也会作为偶然近似对称性产生，其中R宇称破坏（RPV）算子会受到(f_a/m_P)^n的抑制。当n=1时，早期宇宙中热产生的最轻超对称粒子（LSPs）可能在原初核合成（BBN）前衰变，仅留下SUSY DFSZ型的轴子暗物质。此前，轻弦状模的主要宇宙学约束来自模诱导的WIMP过量产生问题；如今，RPV WIMP衰变改善了WIMP过量产生问题，但模诱导的BBN约束可能因长寿命模衰变与长寿命RPV WIMP衰变的耦合（即长寿命粒子（LLP）级联衰变）而加剧。在该背景下，质量低至m_φ≈130 TeV的模是允许存在的，这可协调自然性与早期宇宙中弦状模的存在。
英文摘要
We investigate the cosmological moduli problem (CMP) in the context of supersymmetric models where discrete R-symmetries are used to suppress the mu term, and where mu is regenerated via Kim--Nilles superpotential operators. In such theories, a global U(1)_{PQ} emerges as an accidental, approximate symmetry which solves the strong CP problem. R-parity is also generated as accidental but approximate, where RPV operators gain a (f_a/m_P)^n suppression. When n=1, the thermally-produced LSPs may decay before BBN in the early universe, leaving axion-only dark matter of the SUSY DFSZ type. Meanwhile, the dominant cosmological constraint on light stringy moduli previously came from the modulus-induced WIMP overproduction problem. WIMP overproduction is now ameliorated by the RPV WIMP decays, but the moduli-induced BBN bound may be exacerbated by convolving long-lived modulus decay with long-lived RPV WIMP decay: long-lived particle (LLP) cascade decays. In this context, moduli as light as m_ϕ~ 130 TeV may be allowed which can reconcile naturalness with the presence of stringy moduli in the early universe.
Comments24 pages including 17 frames of .png figures
