2022.09.23  14:00

Speaker: Prof. Yong-Chao Zhang (Southeast U.)

Time: September 23rd Friday, 2:00-3:00pm

Title: Limits on some light particles from compact objects

Abstract: In the era of multi-messenger astrophysics, the observations of supernovae, neutron stars and other compact astrophysical objects can be used to constrain the couplings of some light beyond-standard-model particles, e.g. axion (or axion-like particles), light scalar or dark particles. In this talk, I will focus mostly on some of my recent works. For the stellar limits on light particles, the geometric effect is found to be important. For neutron-mirror-neutron mixing, the beta decay of mirror neutrons will affect significantly the neutron star limits.

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2022.08.25  14:00

Speaker: Prof. Yang Zhang (USTC)

Time: August 25th Thursday, 2pm

Title: A first look at the function space for planar 2-loop 6-particle Feynman integrals

Abstract: This talk focuses on the multiplicity frontier of multiloop Feynman integrals. Using the ideas from super-Yang-Mills theory and Baikov representation, we investigate the 2-loop 6-loop Feynman integral family. The corresponding integrals with uniform transcendental weights are found. From a finite field computation, the corresponding symbol letters on the maximal cut are obtained. This is the first step for the Next-to-Next-to-Leading-Order four-particle production precision physics study.