Standard Model parameters and observables from gradient flow

Lattice Study of the Pion Vector Form Factor in the Instanton Liquid Model Using Gradient Flow

15 May 2026, 10:00

30m

Lecture theatre B, 3rd Floor (James Clerk Maxwell Building)

Submitted Talk

Speaker

Vaibhav Chahar (Jagiellonian University)

Description

Instanton liquid model is believed to capture the main features of vacuum QCD dynamics. Recently, multiple predictions for hadron structure functions have been derived and compared with experimental measurements and lattice QCD calculations, finding a general agreement. In order to explore the precision of the instanton liquid model, one has to compare its predictions with non-perturbative simulations in a regime dominated by instanton dynamics.
This has been performed for two gluon-sensitive observables: the gluon Green's function and the strong running coupling constant [1]. In this contribution, we propose to study a fermionic observable, the pion vector form factor, for which instanton liquid model predictions have been discussed in [1]. We use the gradient flow to single out the dominant contribution from the instantons out of a lattice QCD configuration ensemble. We describe the details of our numerical setup, and some first, preliminary results.

References:
1. Wei-Yang Liu, Edward Shuryak, and Ismail Zahed, Phys. Rev. D 109,
074029 (2024). doi:10.1103/PhysRevD.109.074029