Journal Article

FZJ-2021-02538

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png $P$-wave nucleon-pion scattering amplitude in the $\Delta(1232)$ channel from lattice QCD

Silvi, G. (Corresponding author)FZJ* ; Paul, S. ; Alexandrou, C. ; Krieg, S.FZJ* ; Leskovec, L. ; Meinel, S. ; Negele, J. ; Petschlies, M. ; Pochinsky, A. ; Rendon, G. ; Syritsyn, S. ; Todaro, A.

2021
Inst. Melville, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/27916  doi:10.1103/PhysRevD.103.094508

Abstract: We determine the $\Delta(1232)$ resonance parameters using lattice QCD and the L{\"u}scher method. The resonance occurs in elastic pion-nucleon scattering with $J^P=3/2^+$ in the isospin $I = 3/2$, $P$-wave channel. Our calculation is performed with $N_f=2+1$ flavors of clover fermions on a lattice with $L\approx 2.8$ fm. The pion and nucleon masses are $m_\pi =255.4(1.6)$ MeV and $m_N=1073(5)$ MeV, respectively, and the strong decay channel $\Delta \rightarrow \pi N$ is found to be above the threshold. To thoroughly map out the energy-dependence of the nucleon-pion scattering amplitude, we compute the spectra in all relevant irreducible representations of the lattice symmetry groups for total momenta up to $\vec{P}=\frac{2\pi}{L}(1,1,1)$, including irreps that mix $S$ and $P$ waves. We perform global fits of the amplitude parameters to up to 21 energy levels, using a Breit-Wigner model for the $P$-wave phase shift and the effective-range expansion for the $S$-wave phase shift. From the location of the pole in the $P$-wave scattering amplitude, we obtain the resonance mass $m_\Delta=1378(7)(9)$ MeV and the coupling $g_{\Delta\text{-}\pi N}=23.8(2.7)(0.9)$.

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Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 511 - Enabling Computational- & Data-Intensive Science and Engineering (POF4-511) (POF4-511)

Appears in the scientific report 2021

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Database coverage:
; ; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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