Lattice 2024

Session

Tests of fundamental symmetries

1 Aug 2024, 09:00

Conveners

Tests of fundamental symmetries: TR7

• Thomas Blum (UConn)

17. Update on the lattice calculation of K->pipi decays with G-parity boundary conditions on a second lattice spacing

Christopher Kelly (Brookhaven National Laboratory)

01/08/2024, 09:00

Tests of Fundamental Symmetries

Talk

We present preliminary results of a second, finer-lattice-spacing calculation of the I=0 K->pi pi decay amplitude in the 3 flavor theory with physical kinematics and G-parity boundary conditions, performed by the RBC & UKQCD collaborations. This new calculation will enable a continuum limit extrapolation, reducing/eliminating the significant finite-lattice spacing systematic error on our...

66. Gradient Flow of the Weinberg Operator

Tanmoy Bhattacharya (Los Alamos National Laboratory)

01/08/2024, 09:20

Tests of Fundamental Symmetries

Talk

We will present latest results on the gradient flow of our Weinberg three-gluon operator and its mixing with the topological term. This will allow us to combine our calculation of neutron electric dipole moments (nEDM) due to the lattice Weinberg operator with our previous results on the nEDM due to the topological term to constrain beyond-the-standard model contributions to the Weinberg operator.

163. Unitarity triangles and the lattice

Amarjit Soni (BNL)

01/08/2024, 09:40

Tests of Fundamental Symmetries

Talk

First, in brief historically important role of the lattice in the confirmation
of the KM theory of CP violation via the (Standard or B) unitarity triangle(UT) is recapitulated.
We then briefly remark on the current tensions between inclusive
and exclusive (i.e. lattice) determinations of Vxb that are important for the BUT. Wrt the KUT,
special role of eps’ is discussed. Furthermore,...

171. Study of symmetry of $N_f=2$ QCD near the critical temperature using Mobius Domain Wall Fermions

David Ward (Osaka University)

01/08/2024, 10:00

Tests of Fundamental Symmetries

Talk

We report on the ongoing study of symmetry of $N_f=2$ QCD around the critical temperature. Our simulations of $N_f=2$ QCD employ the Mobius domain-wall fermion action with residual mass $\sim 1\mbox{MeV}$ or less, maintaining a good chiral symmetry. Using the screening masses from the two point spatial correlators we compare the mass difference between channels connected through symmetry...

187. Lattice techniques to investigate the strong CP problem: lessons from a toy model

David Albandea (IFIC - University of Valencia)

01/08/2024, 10:20

Tests of Fundamental Symmetries

Talk

Recent studies have claimed that the strong CP problem does not occur in QCD, proposing a new order of limits in volume and topological sectors when studying observables on the lattice. In this talk I will study the effect of the topological $θ$-term on a simple quantum mechanical rotor that allows a lattice description. I will particularly focus on recent proposals to face the challenging...

478. Subtleties and systematics in obtaining a sub-percent determination of gA

Andre Walker-Loud (LBNL)

01/08/2024, 10:40

Tests of Fundamental Symmetries

Talk

The nucleon axial charge has evolved from being a critical benchmark quantity to one that can be used to provide a competitive constraint on BSM right handed currents. In order to achieve this goal, we must be able to determine $g_A$ with sub-percent precision which presents us with several systematic uncertainties that must be addressed. The most glaring issue is the need to provide a...