Exploring a new approach to hadronic parity violation from lattice QCD

Marcus Petschlies; Nikolas Schlage; Aniket Sen; Carsten Urbach

doi:10.1140/epja/s10050-023-01208-z

2024 Impact factor 2.8

Hadrons and Nuclei

Open Access

Eur. Phys. J. A (2024) 60: 9
https://doi.org/10.1140/epja/s10050-023-01208-z

Regular Article - Theoretical Physics

Exploring a new approach to hadronic parity violation from lattice QCD

Marcus Petschlies¹^,2^a, Nikolas Schlage¹^,2, Aniket Sen¹^,2 and Carsten Urbach¹^,2

¹ Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115, Bonn, Germany
² Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115, Bonn, Germany

^a marcus.petschlies@hiskp.uni-bonn.de

Received: 21 July 2023
Accepted: 27 November 2023
Published online: 17 January 2024

Abstract

The long-range, parity-odd nucleon interaction generated by single-pion exchange is captured in the parity-odd pion–nucleon coupling $h_{π}^{1}$ $h^{1}_{\pi }$ . Its calculation in lattice QCD requires the evaluation of four-quark operator nucleon three-point functions. We investigate a new numerical approach to compute $h_{π}^{1}$ $h^{1}_{\pi }$ based on nucleon matrix elements of parity-even four-quark operators and related to the parity-violating electroweak theory by partial conservation of axial current (PCAC) and chiral perturbation theory. This study is performed with 2+1+1 dynamical flavors of twisted mass fermions at pion mass $m_{π} \approx 260 MeV$ $m_{\pi } \approx 260 \,\text {MeV}$ in a lattice box of $L \approx 3 fm$ $L \approx 3 \,\text {fm}$ and with lattice spacing of $a \approx 0.091 fm$ $a \approx 0.091 \,\text {fm}$ . From a calculation excluding fermion loop diagrams we find a bare coupling of $h_{π}^{1} = 8.08 (98) \cdot 10^{- 7}$ $h^{1}_{\pi }= 8.08 \,(98) \cdot 10^{-7}$ .

© The Author(s) 2024

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