Neutrino Beacons: Constraining New Physics with Cosmic Messengers

by Mr Shivasankar K.A (Hokkaido University, Japan.)

Friday 12 Jun 2026, 11:00 → 12:00 Asia/Shanghai

Tsung-Dao Lee Institute/N6F-N600 - Lecture Room (Tsung-Dao Lee Institute)

Seminar abstract:

 

The origin of tiny neutrino masses remains an open question and a strong motivation for physics beyond the Standard Model. In this talk, I discuss a simple U(1) gauge extension where neutrino masses arise through a seesaw mechanism with three right-handed Majorana neutrinos. After symmetry breaking, the model is anomaly-free and predicts a new neutral gauge boson, Z', with chiral couplings to Standard Model fermions.

 

I focus on how Z' mediated neutrino interactions can play a role in extreme astrophysical environments. In particular, I study the process （p）（p）$\to e^+ e^-$ as a possible source of energy deposition in very energetic transients, such as the gamma-ray burst GRB 221009A. Estimating these rates in different backgrounds allows us to place constraints on the gauge coupling and the Z' mass.

 

Additional constraints come from neutrino–dark matter scattering through Z', using high-energy neutrino observations from sources like TXS 0506+056 and NGC 1068, together with cosmological inputs from the cosmic microwave background and Lyman-α data. I will highlight how these astrophysical and cosmological probes complement laboratory searches, including scattering experiments, beam-dump facilities, and anomalous magnetic moment measurements. Overall, this provides a unified multi-messenger picture for testing new neutrino interactions and exploring the viable parameter space of chiral Z' models.

 

Short bio/introduction of speaker:

 

Shivasankar is a second-year PhD student at Hokkaido University, Japan. His research focuses on theoretical particle physics, with particular emphasis on neutrinos and physics beyond the Standard Model in astrophysical environments. He is also interested in AI for science where he explores the physical representations learned by deep learning models and how these can be leveraged to enhance scientific discovery in physics. In this talk, he will discuss how diverse astrophysical sources can serve as powerful laboratories for probing new physics beyond the Standard Model.

Online link: https://meeting.tencent.com/dm/iWy8GU1eNXAW             Meeting ID: 787700190     Password:166774