Feb. 10, 2026 (In person)

Prof.  Hitoshi Murayama (UC Berkeley)

Location: Room 328, Birge Hall, UC Berkeley Campus MAP

Time: 4:00pm Pacific Time

ZOOM for those who are unable to come in-person: LINK

Host: Felipe Ortega-Gama

Title: Exact Analytic Solutions to Non-Perturbative Gauge Theories

Abstract: QCD is difficult to understand. I present my recent effort to solve non-perturbative gauge theories exactly. (1) Two dimensional pure gauge theories with exact analytic expressions of partition functions with full theta dependence. I hope they can serve the purpose of testing numerical algorithms with the sign problem. I also show the electric dipole moments and deconfinement at theta=π. (2) Four-dimensional gauge theories near supersymmetric limits. I can derive chiral symmetry breaking and confinement, Witten-Veneziano formula and low-lying spectra including 0+ states.

Feb. 24, 2026 (In person)

Dr.  Ryutaro Tsuji  (KEK)

Location: Room 328, Birge Hall, UC Berkeley Campus MAP

Time: 4:00pm Pacific Time

ZOOM for those who are unable to come in-person: LINK

Host: Felipe Ortega-Gama

Title: Axial structure of the nucleon on large-volume lattice QCD at the physical point 

Abstract: The nucleon form factors are very good probes to investigate the nucleon structure. Although great theoretical and experimental efforts for the form factors have been devoted to improving our knowledge of the nucleon structure, there are several unsolved problems and tensions associated with the fundamental properties of nucleons such as the proton radius puzzle and high-precision determination of the neutrino-nucleon scattering.

In this talk, I present our resent results about the nucleon axial, induced pseudoscalar, and pseudoscalar form factors.

Based on our simulation, we also investigate the partially conserved axial-vector (PCAC) relation and the low-energy relations arising from PCAC relation by using lattice QCD data, which offers a theoretical insight into the pion-pole dominance model.

Mar. 17, 2026 (In person)

Prof. Jen-Chieh Peng  (University of Illinois at Urbana-Champaign)

Location: Swiatecki Lounge B70 annex - 228

Time: 4:00pm Pacific Time

ZOOM for those who are unable to come in-person: LINK

Host: Keh-Fei Liu

Title: Evolution of Helicity Property of Relic Neutrinos and Implications 

on Their Detection

Abstract: Neutrinos in the early Universe decoupled essentially in helicity eigenstates.

As they propagate through the Universe, their helicities could be modified via

two effects. First, neutrinos with a finite magnetic moment would rotate their

spins with respect to their momenta as they encounter cosmic magnetic fields,

modifying their helicities. Second, the bending of neutrino's spin by a

gravitational field lags the bending of its momentum, again modifying its helicity. 

We study both effects and investigate the implications of the

helicity modification on the detection of relic neutrinos using the Inverse

Tritium Beta Decay (ITBD) reaction. We find that the ITBD rate depends

sensitively on the neutrino mass hierarchy and on the Dirac or Majorana nature

of the neutrinos. This talk is based on several papers in collaboration with 

Gordon Baym.