Shanghai Jiao Tong University Physics and Astronomy Academic Innovation Forum for Doctoral Students

Session

Nuclear&Particle Session I

11 Dec 2021, 14:00

Tsung-Dao Lee Institute

10. Flavor-changing Majoron interactions with leptons

Mr Jin Sun (TDLI, SJTU)

11/12/2021, 14:00

When the Standard Model Higgs sector is extended with a complex singlet that breaks global lepton number symmetry spontaneously, a massless Goldstone boson called the Majoron $J$ arises. In addition to increasing Higgs invisible decay through mixing, the Majoron can generally have flavor-changing interactions with fermions.
We find that type-III seesaw model poses such interesting properties...

13. Dissecting Axion and Dark Photon with A Network of Vector Sensors

Yanjie Zeng (Institute of Theoretical Physics, Chinese Academy of Sciences)

11/12/2021, 14:20

We explore the applications of a network of vector sensors, sensitive to certain spatial components of the signals, in identifying the property of light axion or dark photon background. These bosonic fields contribute to vector-like signals in the detectors, including effective magnetic fields triggering the spin precession, effective electric currents in a shielded room, and forces on the...

14. Overview of PandaX-4T recent results

Mr Zhou Huang (Shanghai Jiao Tong University)

11/12/2021, 14:40

The PandaX-4T experiment will utilize a two-phase liquid/gas xenon time projection chamber to search dark matter. The PandaX-4T is located in the Hall B2 of the Jinping Underground Laboratory with 2400 m overburden. In the commissioning run, 1058 candidate events are identified with 3.7-tonne of liquid xenon target and an exposure of 0.63 tonne·year. A stringent limit to the dark...

29. 费米实验室缪子反常磁矩实验

bingzhi li

11/12/2021, 15:00

费米实验室的缪子g-2实验对缪子的反常磁矩进行了精确的测量，首批物理结果现已公布。最新的实验结果表明缪子反常磁矩的理论预言与实验测量之间存在4.2σ的偏差，为新物理的存在提供了强有力的证据，预示着世界上可能存在新的未知粒子或者作用力。

缪子反常磁矩由两个角频率的精确测量确定。实验中，缪子受强磁场束缚在储存环内运动，通过统计缪子衰变产生的高能电子数目得到缪子的反常进动频率ω_a。利用脉冲核磁共振技术，测量质子的自旋进动频率ω_p表征强磁场的大小。结合上述两个频率以及缪子在储存环中的分布函数和其他已知常数可以精确的测量缪子的反常磁矩。首批物理结果的测量精度达到了0.46ppm，后继测量结果的精度将进一步提高，预计于2022年发布。