Isolating the Roper Resonance in Lattice QCD

Abstract

We present results for the first positive parity excited state of the nucleon, namely, the Roper resonance ($N^{{1/2}^{+}}$=1440 MeV) from a variational analysis technique. The analysis is performed for pion masses as low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of smeared-smeared correlation functions are used to construct correlation matrices. This is done in order to find a suitable basis of operators for the variational analysis such that eigenstates of the QCD Hamiltonian may be isolated. A lower lying Roper state is observed that approaches the physical Roper state. To the best of our knowledge, the first time this state has been identified at light quark masses using a variational approach.

7pp, 4 figures; minor typos corrected and one Ref. added

References in corpus (35)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• A New Way to Set the Energy Scale in Lattice Gauge Theories and its Application to the Static Force and ${\alpha }_s$ in SU(2) Yang--Mills Theory
• Analytic Smearing of SU(3) Link Variables in Lattice QCD
• On the generalized eigenvalue method for energies and matrix elements in lattice field theory
• What is the structure of the Roper resonance?
• Gauge-Invariant Smearing and Matrix Correlators using Wilson Fermions at beta=6.2
• A Lattice Study of the Nucleon Excited States with Domain Wall Fermions
• Hadron Masses From Novel Fat-Link Fermion Actions
• Renormalization group flow of SU(3) lattice gauge theory - Numerical studies in a two coupling space
• Mixing of scalar glueballs and flavour-singlet scalar mesons
• Excited Baryons in Lattice QCD
• Excited hadrons on the lattice: Baryons
• Roper Resonance and S_{11}(1535) from Lattice QCD
• Lattice QCD determination of patterns of excited baryon states
• Nucleon Properties from Unconventional Interpolating Fields
• Excited hadrons on the lattice: Mesons
• Spectral Analysis of Excited Nucleons in Lattice QCD with Maximum Entropy Method
• Spatially improved operators for excited hadrons on the lattice
• Negative-parity Baryon Masses using an O(a)-improved Fermion Action
• Negative-Parity Baryon Spectroscopy
• Isolating Excited States of the Nucleon in Lattice QCD
• Excited nucleons with chirally improved fermions
• Extracting excited states from lattice QCD: the Roper resonance
• Scaling of FLIC Fermions
• Search for the pentaquark resonance signature in lattice QCD
• Excited baryons from Bayesian priors and overlap fermions
• Latest results from lattice QCD for the Roper resonance
• Variational method for lattice spectroscopy with ghosts
• Even parity excitations of the nucleon in lattice QCD
• Spin 3/2 Pentaquark Resonance Signature in Lattice QCD
• Masses of excited baryons from chirally improved quenched lattice QCD
• Excited hadrons from improved interpolating fields
• Baryon Operators and Baryon Spectroscopy
• Hybrid Meson Spectrum from the FLIC action

Cited by in corpus (19)

• Baryon spectroscopy
• Light Hadron Masses from Lattice QCD
• Pion-nucleon scattering in the Roper channel from lattice QCD
• Roper Resonance in 2+1 Flavor QCD
• Structure and Flow of the Nucleon Eigenstates in Lattice QCD
• Search for low-lying lattice QCD eigenstates in the Roper regime
• Lattice baryon spectroscopy with multi-particle interpolators
• Pion momentum distributions in the nucleon in chiral effective theory
• Isolating Excited States of the Nucleon in Lattice QCD
• Low-lying Odd-parity States of the Nucleon in Lattice QCD
• Positive-parity Excited-states of the Nucleon in Quenched Lattice QCD
• Nucleon Excited States in N${}_f$=2 lattice QCD
• Ordering of Spin-$\frac{1}{2}$ Excitations of the Nucleon in Lattice QCD
• Nucleon matrix elements from lattice QCD with all-mode-averaging and a domain-decomposed solver: an exploratory study
• Electromagnetic transition form factors of the Roper resonance in effective field theory
• Accessing High Momentum States In Lattice QCD
• On the nature of the Roper resonance
• Excited States of the Nucleon in 2+1 Flavor QCD
• Understanding the structure of nucleon excitations from their wavefunctions