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Pion-nucleon scattering in the Roper channel from lattice QCD

Journal Article · · Physical Review D
 [1];  [2];  [3];  [4]
  1. Univ. of Graz, Graz (Austria)
  2. Univ. of Arizona, Tucson, AZ (United States)
  3. Univ. of Graz, Graz (Austria); Univ. Regensburg, Regensburg (Germany)
  4. Univ. of Ljubljana, Ljubljana (Slovenia); Jozef Stefan Institute, Ljubljana (Slovenia); Univ. Regensburg, Regensburg (Germany); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

We present a lattice QCD study of $$N\pi$$ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance $N^*(1440)$ resides in experiment. The study is based on the PACS-CS ensemble of gauge configurations with $$N_f=2+1$$ Wilson-clover dynamical fermions, $$m_\pi \simeq 156~$$MeV and $$L\simeq 2.9~$$fm. In addition to a number of $qqq$ interpolating fields, we implement operators for $$N\pi$$ in $$p$$-wave and $$N\sigma$$ in $$s$$-wave. In the center-of-momentum frame we find three eigenstates below 1.65 GeV. They are dominated by $N(0)$, $$N(0)\pi(0)\pi(0)$$ (mixed with $$N(0)\sigma(0)$$) and $$N(p)\pi(-p)$$ with $$p\simeq 2\pi/L$$, where momenta are given in parentheses. This is the first simulation where the expected multi-hadron states are found in this channel. The experimental $$N\pi$$ phase-shift would -- in the approximation of purely elastic $$N\pi$$ scattering -- imply an additional eigenstate near the Roper mass $$m_R\simeq 1.43~$$GeV for our lattice size. We do not observe any such additional eigenstate, which indicates that $$N\pi$$ elastic scattering alone does not render a low-lying Roper. Coupling with other channels, most notably with $$N\pi\pi$$, seems to be important for generating the Roper resonance, reinforcing the notion that this state could be a dynamically generated resonance. Our results are in line with most of previous lattice studies based just on $qqq$ interpolators, that did not find a Roper eigenstate below $1.65~$GeV. As a result, the study of the coupled-channel scattering including a three-particle decay $$N\pi\pi$$ remains a challenge.

Research Organization:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-06OR23177
OSTI ID:
1398393
Alternate ID(s):
OSTI ID: 1341928
Report Number(s):
JLAB-THY--16-2330; DOE/OR/23177--3953; arXiv:1610.01422
Journal Information:
Physical Review D, Journal Name: Physical Review D Journal Issue: 1 Vol. 95; ISSN PRVDAQ; ISSN 2470-0010
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (81)

Volume dependence of the energy spectrum in massive quantum field theories: I. Stable particle states journal June 1986
Volume dependence of the energy spectrum in massive quantum field theories: II. Scattering states journal June 1986
The spectrum of the nucleons and the strange hyperons and chiral dynamics journal April 1996
Adjoint sources in lattice gauge theory journal September 1985
How to calculate the elastic scattering matrix in two-dimensional quantum field theories by numerical simulation journal July 1990
Two-particle states on a torus and their relation to the scattering matrix journal May 1991
Signatures of unstable particles in finite volume journal October 1991
N∗ electroproduction amplitudes in a model with dynamical confinement journal December 2001
The role of components in the nucleon and the resonance journal December 2006
Roper resonance and S11(1535) from lattice QCD journal January 2005
Isolating the Roper resonance in lattice QCD journal August 2009
Wave function of the Roper from lattice QCD journal August 2013
The pentaquark candidates in the dynamical diquark picture journal October 2015
Dynamical coupled-channel model of meson production reactions in the nucleon resonance region journal February 2007
Roy–Steiner-equation analysis of pion–nucleon scattering journal April 2016
Roy–Steiner-equation analysis of pion–nucleon scattering journal January 2017
Baryons in a relativized quark model with chromodynamics conference January 1985
On the generalized eigenvalue method for energies and matrix elements in lattice field theory journal April 2009
Review of Particle Physics journal August 2014
Extended coupled channels model for π N scattering and the structure of N * ( 1440 ) and N * ( 1535 ) journal March 1998
What is the structure of the Roper resonance? journal July 2000
Parameterization dependence of T -matrix poles and eigenphases from a fit to π N elastic scattering data journal September 2012
Experimental study of the P 11 ( 1440 ) and D 13 ( 1520 ) resonances from the CLAS data on e p → e ′ π + π − p ′ journal September 2012
P -wave baryons in the quark model journal December 1978
A remnant of chiral symmetry on the lattice journal May 1982
Are there baryons which contain constituent gluons? journal July 1983
Cluster model of baryons journal July 1983
Erratum: Are there baryons which contain constituent gluons? journal February 1986
Baryons in a relativized quark model with chromodynamics journal November 1986
Electroproduction of the Roper resonance as a hybrid state journal July 1992
Hybrid baryons via QCD sum rules journal June 1995
Unified description of light- and strange-baryon spectra journal October 1998
Excited nucleons with chirally improved fermions journal May 2004
2 + 1 flavor lattice QCD toward the physical point journal February 2009
Novel quark-field creation operator construction for hadronic physics in lattice QCD journal September 2009
Improved stochastic estimation of quark propagation with Laplacian Heaviside smearing in lattice QCD journal June 2011
Coupled channel analysis of the ρ meson decay in lattice QCD journal September 2011
Excited state baryon spectroscopy from lattice QCD journal October 2011
Multiple-channel generalization of Lellouch-Lüscher formula journal July 2012
Scattering phases for meson and baryon resonances on general moving-frame lattices journal November 2012
Scattering in the π N negative parity channel in lattice QCD journal March 2013
QCD with two light dynamical chirally improved quarks: Baryons journal April 2013
Structure and flow of the nucleon eigenstates in lattice QCD journal May 2013
Nucleon excited states in N f = 2 lattice QCD journal February 2014
Nucleon excited state wave functions from lattice QCD journal March 2014
Novel analysis method for excited states in lattice QCD: The nucleon case journal January 2015
Expressing the three-particle finite-volume spectrum in terms of the three-to-three scattering amplitude journal December 2015
An a 0 resonance in strongly coupled π η , K K ¯ scattering from lattice QCD journal May 2016
Resonances in Coupled π K − η K Scattering from Quantum Chromodynamics journal October 2014
Isoscalar π π Scattering and the σ Meson Resonance from QCD journal January 2017
Evidence for a P 11 Pion-Nucleon Resonance at 556 MeV journal March 1964
Roper resonances in chiral quark models journal November 2008
Unitarized Chiral Perturbation Theory in a finite volume: Scalar meson sector journal November 2011
A perspective on pentaquarks journal February 2004
Novel quark-field creation operator construction for hadronic physics in lattice QCD text January 2009
Novel quark-field creation operator construction for hadronic physics in lattice QCD text January 2009
Isoscalar ππ Scattering and the σ Meson Resonance from QCD text January 2017
Multiple-channel generalization of Lellouch-Lüscher formula conference December 2012
Scattering phases for meson and baryon resonances on general moving-frame lattices text January 2012
Review of Particle Physics text January 2012
Review of Particle Physics text January 2018
On the generalized eigenvalue method for energies and matrix elements in lattice field theory text January 2009
Isolating the Roper Resonance in Lattice QCD text January 2009
Improved stochastic estimation of quark propagation with Laplacian Heaviside smearing in lattice QCD text January 2011
Coupled channel analysis of the rho meson decay in lattice QCD text January 2011
Scattering phases for meson and baryon resonances on general moving-frame lattices text January 2012
Structure and Flow of the Nucleon Eigenstates in Lattice QCD text January 2013
Nucleon Excited State Wave Functions from Lattice QCD text January 2013
A novel analysis method for excited states in lattice QCD - the nucleon case text January 2014
Expressing the three-particle finite-volume spectrum in terms of the three-to-three scattering amplitude text January 2015
The Pentaquark Candidates in the Dynamical Diquark Picture text January 2015
Roy-Steiner-equation analysis of pion-nucleon scattering text January 2015
N* Spectroscopy from Lattice QCD: The Roper Explained text January 2015
N^* electroproduction amplitudes in a model with dynamical confinement text January 2001
Roper Resonance and S_{11}(1535) from Lattice QCD text January 2003
Excited nucleons with chirally improved fermions text January 2003
The Spectrum of the Nucleons and the Strange Hyperons and Chiral Dynamics text January 1995
Unified description of light- and strange-baryon spectra text January 1997
What is the structure of the Roper resonance? text January 1999
Review of Particle Physics text January 2008
N * Spectroscopy from Lattice QCD: The Roper Explained conference May 2016

Cited By (28)

A Lattice QCD Study of Pion–Nucleon Scattering in the Roper Channel journal June 2018
The S- and P-Wave Low-Lying Baryons in the Chiral Quark Model journal July 2018
Developments of the Jülich–Bonn Dynamical Coupled-Channel Analysis journal October 2018
Accessing high-momentum nucleons with dilute stochastic sources journal November 2018
Dynamical generation of resonances in the P 33 partial wave journal September 2019
Analysis of the data on spin density matrix elements for γ p → K * + Λ journal January 2020
Scattering amplitudes from finite-volume spectral functions journal August 2019
Excited-state effects in nucleon structure on the lattice using hybrid interpolators journal October 2019
Three-body unitarity versus finite-volume π + π + π + spectrum from lattice QCD journal March 2020
Hamiltonian effective field theory study of the N * ( 1440 ) resonance in lattice QCD journal February 2017
Elastic I = 3 / 2 p -wave nucleon-pion scattering amplitude and the Δ ( 1232 ) resonance from N f = 2 + 1 lattice QCD journal January 2018
Valence quark contributions for the γ * N → N ( 1440 ) form factors from light-front holography journal February 2018
Three-particle N π π state contribution to the nucleon two-point function in lattice QCD journal May 2018
Structure of the Roper resonance from lattice QCD constraints journal May 2018
Variational approach to N -body interactions in finite volume journal November 2018
Beam-Recoil Polarization Measurement of π 0 Electroproduction on the Proton in the Region of the Roper Resonance journal July 2017
Finite-Volume Spectrum of π + π + and π + π + π + Systems journal February 2019
Scattering processes and resonances from lattice QCD journal April 2018
Three-body unitarity in the finite volume journal December 2017
The impact of $K^{+}\Lambda$ K + Λ photoproduction on the resonance spectrum journal June 2018
Chiral perturbation theory and nucleon–pion-state contaminations in lattice QCD journal April 2017
Excited-state effects in nucleon structure on the lattice using hybrid interpolators text January 2019
Structure of the Roper Resonance from Lattice QCD Constraints text January 2017
Three-body Unitarity in the Finite Volume text January 2017
A lattice QCD study of pion-nucleon scattering in the Roper channel text January 2018
Variational approach to $N$-body interactions in finite volume text January 2018
Scattering amplitudes from finite-volume spectral functions text January 2019
Three-body unitarity versus finite-volume $π^+π^+π^+$ spectrum from lattice QCD text January 2019

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