Title: Overcoming Dark Matter Detection Thresholds and its Astrophysical Consequences

Speaker: 葛韶锋

Institute: 上海交通大学李政道研究所

Host: 武剑锋/罗舒

Time: 2024.4.15 周一 16:10

Location: 物理楼 552

Abstract: 

The existence of dark matter (DM) has received tremendous amount of evidences from astrophysical and cosmological observations. However, its nature and properties still await experimental probe. It is of great importance to overcome the detection thresholds in order to expand the scope of detectable DM scenarios. Threshold issue exists not just in the direct detection of DM with nuclei or electron recoil, but also in astrophysical observations. I would introduce two scenarios, the absorption DM and forbidden DM, for illustration. The fermionic absorption DM can release & convert its mass to the kinetic energy of recoil electron to overcome the detection threshold in the direct detection. An important consequence is that it can decay in space which can be observed with X-ray telescopes such as HXMT-Insight. For the second scenario, the DM pair annihilation is typically forbidden & hence cannot be probed by the indirect detection with cosmic ray or photon observations. However, the supermassive black hole can serve as DM accelerator to reactivate its annihilation such that gamma-ray observations with Fermi-LAT becomes possible.

Bio：

葛韶锋，上海交通大学李政道研究所副教授、李政道学者。2002-2006年清华物理系本科，2006-2012年清华高能物理中心博士，期间2009年在美国德克萨斯州立大学奥斯汀分校联合培养。2012-2014年获得日本学术振兴会（JSPS）学者在日本高能加速器研究机构（KEK）、2014-2017年在德国海德堡马普所MPIK、2017-2019年受日本东京大学Kavli IPMU和美国加州大学伯克利分校联合聘请任博士后；2017年获美国费米加速器国家实验室（Fermilab）中微子中心（NPC）学者奖、并受邀于2018年夏天访问研究三个月。2019年加入上海交通大学李政道研究所，任李政道学者、副教授；IPMU连携研究员。入选上海市科委浦江人才计划、国家海外高层次青年人才、中科院粒子物理前沿卓越创新中心青年拔尖人才。主要研究领域为中微子和暗物质相关的粒子物理、天体和宇宙学理论和唯象研究。共发表文章50多篇，其中6篇发表在物理学顶级专业期刊PRL上。目前担任Physics Letters A编辑。

References:

[1] Shao-Feng Ge, Xiao-Gang He, Xiao-Dong Ma, Jie Sheng, Revisiting the Fermionic Dark Matter Absorption on Electron Target, JHEP 05 (2022) 191 [arXiv:2201.11497 [hep-ph]]

[2] Yu Cheng, Shao-Feng Ge, Xiao-Gang He, Jie Sheng, Forbidden Dark Matter Combusted Around Supermassive Black Hole, Phys.Lett.B 847 (2023) 138294 [2211.05643 [hep-ph]]

[3] Yu Cheng, Shao-Feng Ge, Jie Sheng, Tsutomu T. Yanagida, Right-Handed Neutrino Dark Matter with Forbidden Annihilation, Phys.Rev.D 107 (2023) 12, 123013 [2304.02997 [hep-ph]]

[4] Yu Cheng, Shao-Feng Ge, Jie Sheng, Tsutomu T. Yanagida, Dark Matter Annihilation via Breit-Wigner Enhancement with Heavier Mediator, [2309.12043 [hep-ph]]