Author: Thomas Blum

An anomalous moment for the muon

Mark Rayner/CERN

The Fermilab E989 experiment announced the first new result on the muon’s anomalous magnetic moment in almost 20 years. The new measurement, combined with Brookhaven’s E821, has increased the discrepancy with the Standard Model value to 4.2 standard deviations. UConn Professors Tom Blum and Luchang Jin explain the theory calculations in a feature story in the Cern Courier.

Professor Luchang Jin receives prestigious DOE Early Career Award

Assistant Professor of Physics Luchang Jin has been chosen to receive a prestigious Early Career Award from the US Department of Energy’s Office of High Energy Physics (HEP) for 2020. The amount of the award is $750,000 to be used over five years. The DOE Early Career Award is extremely competitive: this year only 16 scientists in HEP in the US were awarded such grants, and only 76 scientists across the entire DOE. Dr. Jin will use the grant to support his research using numerical methods to study how electromagnetic interactions affect the decays of mesons, subatomic particles composed of a quark and anti-quark pair. This study, carried out within the framework of the fundamental Standard Model of Particle Physics, is expected to improve our knowledge of the interactions between quarks and the Weak gauge bosons. With some luck, Professor Jin’s research may provide evidence of new interactions or particles yet to be discovered.

New result for part of muon anomaly


Professors Tom Blum and Luchang Jin, along with colleagues at BNL and Columbia, Nagoya, and Regensburg universities have completed a first-ever calculation of the hadronic light-by-light scattering contribution to the muon’s anomalous magnetic moment with all errors controlled. The work is published in Physical Review Letters as an Editor’s Suggestion and also appeared in Physics Magazine. A recent press release from Argonne National Lab described the calculation, which was performed on Mira, Argonne’s peta-scale supercomputer.

The team found the contribution is not sufficient to explain the longstanding difference between the Standard Model value of the anomalous magnetic moment and the BNL experiment that measured it. The discrepancy, which could indicate new physics, should be resolved soon by a new experiment at Fermilab (E989) and improved theory calculations, including the one described here, both with significantly reduced errors. E989 is set to release their first results later this year.