The Search for New Interactions at Short Distance with Optomechanics and Nuclear Physics

by Prof. Giorgio Gratta (Physics Department, Stanford University)

Friday 19 Jun 2026, 14:00 → 15:00 Asia/Shanghai

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

Abstract: A number of puzzles in modern physics may be solved by introducing new interaction(s) in addition to the four known, active below a certain distance. In addition, gravity, which is anomalously weak at macroscopic scale, is usually assumed to scale with the inverse-square of the distance all the way down to the Planck scale –surely an ambitious extrapolation! It is therefore interesting to search for new forces, or modifications to the inverse square law of gravity, at progressively short distances. This is a very challenging endeavor requiring new experimental paradigms.

In this talk, I will explore a number of drastically different techniques recently developed specifically to tackle the short distance regime.  This will be a trip in optomechanics, high resolution nuclear spectroscopy and neutron scattering.  While science results are gradually appearing, I hope to convince the audience that, as is often the case with new techniques, a new and exciting array of questions and applications are also emerging!

Biography：Giorgio Gratta is an experimental physicist at Stanford university.  Since 1995, he has been a leader in several experiments searching for neutrino oscillations, culminating in the discovery of anti-neutrino oscillations with KamLAND and the first measurement of anti-neutrinos produced in the crust of the Earth.  He then led the development of neutrinoless double-beta decay experiments based on the isotope 136 and liquid-phase TPCs. The EXO-200 experiment, developed at Stanford, was, for a while, the most sensitive experiment in this area, and used 200kg of isotopically enriched Xenon, a record at the time.  Gratta and his group also developed the acoustic technique to detect ultra-high energy cosmic-ray neutrinos in sea water. In recent times, Gratta has turned his attention to the search of new forces of nature at the micron or sub-micron scale, developing new techniques involving optomechanics and optical traps, Mossbauer spectroscopy, and neutron scattering off density fluctuations in supercritical xenon. This last activity is the subject of today’s seminar. 

 

Alternative online link ：https://meeting.tencent.com/dm/PqnSHs6SwbbD

ID:872816462