Gravitino dark matter and cosmological constraints
Gravitino dark matter and cosmological constraints
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DOI：
10.1088/1475-7516/2006/09/001
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发表时间：
2006-05
影响因子：
6.4
通讯作者：
F. Steffen
中科院分区：
文献类型：
--
作者：
F. Steffen
引力子是一个很有希望的冷暗物质候选者。我们研究了引力子是最轻的超对称粒子，而带电睡眠子是次轻的超对称粒子（NLSP）的宇宙学约束。通过计算NLSP睡眠子向引力子、相关轻子和夸克-反夸克对的四体衰变，我们得到了强子核合成界的新结果。通过考虑来自NLSP晚期衰变和早期宇宙热散射的引力子，从观测到的暗物质密度边界得到了改进。我们研究了引力子暗物质目前的自由流动速度和宇宙结构的观测和模拟的限制。假设NLSP的睡眠子在衰变前以热丰度冻结，我们得到了睡眠子和引力子质量的新界限。讨论了约束对宇宙学和对撞机现象学的影响，并概述了未来实验的潜在见解。我们提出了一组具有引力子暗物质和长寿命带电NLSP睡眠的基准情景，并描述了大型强子对撞机和国际线性对撞机的前景。
The gravitino is a promising cold dark matter candidate. We study cosmological constraints on scenarios in which the gravitino is the lightest supersymmetric particle and a charged slepton the next-to-lightest supersymmetric particle (NLSP). We obtain new results for the hadronic nucleosynthesis bounds by computing the four-body decay of the NLSP slepton into the gravitino, the associated lepton, and a quark–antiquark pair. The bounds from the observed dark matter density are refined by taking into account gravitinos from both late NLSP decays and thermal scattering in the early Universe. We examine the present free-streaming velocity of gravitino dark matter and the limits from observations and simulations of cosmic structures. Assuming that the NLSP sleptons freeze out with a thermal abundance before their decay, we derive new bounds on the slepton and gravitino masses. The implications of the constraints for cosmology and collider phenomenology are discussed and the potential insights from future experiments are outlined. We propose a set of benchmark scenarios with gravitino dark matter and long-lived charged NLSP sleptons and describe prospects for the Large Hadron Collider and the International Linear Collider.