The tiny neutrino masses are most naturally explained by the seesaw mechanism through singlet right-handed neutrinos, which can further explain the matter-antimatter asymmetry in the universe. We propose a new approach to study cosmological signatures of neutrino seesaw through the interaction between inflaton and right-handed neutrinos. After inflation the inflaton predominantly decays into right-handed neutrinos and its decay rate is modulated by the fluctuations of Higgs field which act as the source of curvature perturbations. We demonstrate that this modulation produces primordial non-Gaussian signatures, which can be measured by the forthcoming large-scale structure surveys. We find that these surveys have the potential to probe a large portion of the neutrino seesaw parameter space, opening up a new window for testing the high scale seesaw mechanism.

报告人简介

韩成成，中山大学物理学院副教授、博士生导师。他2014年在理论物理所取得博士学位，之后分别在亚太理论物理中心(APCTP)、东京大学卡弗里数物连携宇宙研究机构(Kavli IPMU)、韩国高等研究院(KIAS)从事博士后研究。2020年入职中山大学任现职，并入选中山大学中青年杰出人才计划。2023年起受聘为亚太理论物理中心的协联研究员(APCTP fellow)。已在PRL, JHEP等杂志发表论文五十余篇，总引用两千余次。主要研究兴趣包括LHC上的新物理、粒子宇宙学、暗物质模型等。

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皮石 研究员