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SUMMARY:SEMINAR: Direct detection probe of light dark matter and heavier A
 LP from Sun
DTSTART:20260831T020000Z
DTEND:20260831T040000Z
DTSTAMP:20260908T211700Z
UID:indico-event-30512@indico.ihep.ac.cn
DESCRIPTION:Speakers: Sk Jeesun (Tsung-Dao Lee Institute\, Shanghai Jiao T
 ong University )\n\nTitle: Direct detection probe of light dark matter an
 d heavier ALP from Sun\n\nAbstract:  \n\nCurrent multiton direct-detecti
 on experiments place stringent constraints on GeV-scale Galactic dark matt
 er (DM)\, approaching the neutrino fog\, but remain largely insensitive to
  light DM. Cosmic rays can upscatter nonrelativistic halo DM\, producin
 g a relativistic subpopulation with sufficient kinetic energy to become de
 tectable in existing experiments. I will talk about this approach to dete
 ct sub-MeV electrophilic DM using the latest LZ 2025 (WS2024) data. We in
 clude attenuation of the boosted DM flux during propagation through the Ea
 rth and perform a full numerical calculation of the resulting event rate. 
 We find that\, for an energy-independent cross section\, LZ 2025 improves 
 the constraints on MeV-scale DM by roughly O(1) compared with the previous
  XENONnT limit. Despite its smaller target mass compared with neutrino d
 etectors\, LZ can also provide competitive constraints in certain mediator
  parameter regions\, particularly for light mediators\, excluding previous
 ly unexplored parameter space.\n\nI will then discuss the production and d
 etection of MeV electrophilic axion-like particles (ALPs) from the Sun. Mo
 nochromatic 5.5 MeV photons produced in solar nuclear reactions can underg
 o Compton-like scattering with ambient electrons\, generating a substantia
 l flux of MeV ALPs. Upon reaching Earth\, these ALPs can be detected throu
 gh the same electron coupling\, providing a new opportunity for direct-det
 ection experiments to probe previously unexplored parameter space. We use 
 existing data from LZ\, PandaX-4T\, and Borexino to constrain this scenari
 o.\n\n\nSpeaker information: \n\nSk Jeesun is a postdoctoral researcher a
 t the Tsung-Dao Lee Institute\, Shanghai Jiao Tong University. He obtained
  his PhD from the Indian Association for the Cultivation of Science\, Kolk
 ata\, in Aug\, 2025. His research focuses on dark matter phenomenology\, a
 stroparticle physics\, and cosmology\, with particular emphasis on light d
 ark matter\, beyond Standard-Model particles\, and their experimental/cosm
 ological signatures. His work explores connections between particle physic
 s\, astrophysical environments\, and detection strategies. Recently\, he h
 as developed  interest in reheating dynamics and its CMB probes.\n\n\n\
 nSpearker webpage: https://tdli.sjtu.edu.cn/en/people/44927/sk-jeesun\n\n
 https://indico.ihep.ac.cn/event/30512/
LOCATION:226 (多学科楼)
URL:https://indico.ihep.ac.cn/event/30512/
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