Hoạt động khoa học
Seminar
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Seminar Trung tâm Vật lý quốc tế: | |
| Tên báo cáo | The Dark Hypercharge Symmetry |
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| Người trình bày | TS. Hemant Kumar Prajapati |
| Cơ quan | Viện Giáo dục và Nghiên cứu Khoa học Ấn Độ (ISER), Bhopal, Ấn Độ. |
| Ngày | Thứ Tư, 30-07-2025 |
| Giờ | 14:00 PM |
| Địa điểm | Phòng 315, 10 Đào Tấn, Ba Đình, Hà Nội |
| Tóm tắt | In this talk, I present a new class of $U(1)_X$ symmetries where all Standard Model fermions are chiral, i.e., the left- and right-handed components have different charges under the $U(1)_X$ symmetry. Gauge anomaly cancellation is achieved by introducing three Standard Model gauge singlet dark fermions ($f_i; i = 1, 2, 3$) charged under this symmetry. We systematically present chiral solutions for cases in which (a) one, (b) two, or (c) all three generations of Standard Model fermions are charged under the $U(1)_X$ symmetry. The $U(1)_X$ charges of these dark fermions are uniquely determined by anomaly cancellation conditions. These new fermions belong to the dark sector, with the lightest of them serving as a viable dark matter candidate. Additionally, the $Z'$ gauge boson mediates interactions between the dark and visible sectors, and we refer to this $U(1)_X$ symmetry as the \textbf{Dark Hypercharge} symmetry. Using a benchmark model, we explore the phenomenological implications in the heavy $Z'$ case ($M_{Z'} > M_Z$), analyzing collider constraints and examining the viability of the lightest dark fermion as dark matter. Our analysis shows that it satisfies all current dark matter constraints over a wide range of dark matter masses. In the case of $M_{Z'} < M_Z$, coherent elastic neutrino-nucleus scattering (CEvNS) and elastic neutrino-electron scattering (EvES) data are utilized to constrain chiral $U(1)_X$ gauged models. |
| Người chủ trì | Đỗ Thị Hương |