VIRTUAL

 

Thursday, December 9th    2021

3:45 – 4:45 pm (MT)

WEBEX


Speaker:  Rajan Gupta

Fellow of Los Alamos National Laboratory, 2006

T-2: NUC & PARTICLE PHYS, ASTROPHYS & COSMOL

 

 

“Simulations of lattice quantum chromodynamics come of age”

 

 

Abstract: 

The standard model (SM) is the synthesis of three of the four forces of nature–weak, electromagnetic and strong–and a classification of all the elementary particles. Its elegant mathematical formulation, quantum field theory, describes all observed phenomena in terms of 26 parameters. After a brief history of its development, successes and open questions, I will focus on the strong interactions between quarks and gluons described by quantum chromodynamics (QCD). It exhibits many fascinating properties but continues to defy an analytical solution to how properties of the observed bound states, called hadrons, arise from the properties of the constituents, quarks and gluons. Its formulation on a finite Euclidean space-time lattice (lattice QCD) made it amenable to numerical simulations, and the growth in numerical algorithms and computing power is now allowing us to calculate the properties of hadrons with sufficient precision to confront theoretical predictions with experiments. I will provide examples of how this exhausting tango between theory and experiment, in which each side is continually increasing precision, is one of two ways in which physicists are searching for physics beyond the SM (BSM). At the same time, these large scale simulations of lattice QCD are providing quantitative insight into the rich structure of protons and neutrons (their mass, spin, electric dipole moment, …) and, furthermore, the connection between the tiny corrections to their properties that new BSM physics will induce that are being looked for in experiments and constraining the possible landscape of BSM theories. In conclusion, I will highlight examples of this interplay between calculations and experiments, and the search for BSM physics taking place at LosAlamos through measurements of neutron electric dipole moment and lifetime, neutrinolessdouble beta decay, sterile neutrinos, and CP violation in neutrino flavor mixing.

 

Bio:

https://cnls.lanl.gov/~rajan/rg.pdf

https://cnls.lanl.gov/~rajan/