Towards $K\pi$ scattering with domain-wall fermions at the physical point using distillation

TL;DR

This paper advances the study of $K extpi$ scattering using lattice QCD with domain-wall fermions at physical pion mass, employing distillation and variational methods to extract resonance information.

Contribution

It introduces a novel application of distillation and eigenvalue analysis for $K extpi$ scattering at physical quark masses on a domain-wall fermion ensemble.

Findings

Preliminary finite-volume spectra obtained.

Eigenvalue problem solved for scattering analysis.

Methodology improvements in smearing and variational analysis.

Abstract

Resonances play an important role in Standard Model phenomenology. In particular, hadronic resonances feature in $B$ and $D$ decays, which can be central for New Physics searches. Lattice QCD simulations combined with the finite-volume method can nowadays be used to reliably study strongly coupled scattering processes such as $K\pi$ and thus the hadronic resonance $K^*$. In this work, we approach $K\pi$ scattering on a domain-wall $N_f = 2+1$ RBC-UKQCD ensemble at a physical pion mass. We use the distillation method within Grid and Hadrons software to compute sets of operator basis. That allows solving an eigenvalue problem to extract the low-energy finite-volume spectra, which are then translated into scattering information. We update the state of the calculation by reviewing the smearing process, outlining the variational analysis and concluding by showing preliminary data.