Nucleon excited states in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>N</mml:mi></mml:mrow><mml:mrow><mml:mi>f</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math>lattice QCD

Alexandrou, C.; Korzec, Tomasz; Koutsou, Giannis; Leontiou, Theodoros

doi:10.1103/physrevd.89.034502

Cited by 35 publications

(59 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consequently, also here the errors are substantial and the results by far do not have the quality of the positive-parity ground state calculations. Nevertheless, within error bars there is agreement between different groups that the N (1535) is seen although the extracted mass is still larger than the experimental one, see [264,279,416,417,425,427] and references therein. The structure of this state has been investigated in Ref.…”

Section: Octet and Decuplet Baryonsmentioning

confidence: 84%

“…[419,426] the authors verified that the wave function of the Roper has indeed a single node, thus suggesting the identification of the observed state with the first radial excitation of the nucleon. Furthermore, it has been recently argued [427] that the differences of the mass evolution results from the Jefferson Lab HSC [281], CSSM [423,424] and Cyprus groups [264,425] can be accounted for and brought to consensus with each other. It is, however, not clear from an outsider's perspective where the results from the χQCD group [420] fit in and therefore it seems fair to state that there may not be an overall agreement in the lattice community concerning the status of the Roper and the last word is by far not spoken.…”

Section: Octet and Decuplet Baryonsmentioning

confidence: 99%

See 1 more Smart Citation

Baryons as relativistic three-quark bound states

Eichmann

Sanchis-Alepuz

Williams

et al. 2016

Progress in Particle and Nuclear Physics

438

530

View full text Add to dashboard Cite

We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon processes and Compton scattering determined in the DysonSchwinger framework with those of lattice QCD and the available experimental data. The general aim is to identify the underlying physical mechanisms behind the plethora of observable phenomena in terms of the underlying quark and gluon degrees of freedom.

show abstract

Section: Octet and Decuplet Baryonsmentioning

confidence: 84%

Section: Octet and Decuplet Baryonsmentioning

confidence: 99%

Baryons as relativistic three-quark bound states

Eichmann

Sanchis-Alepuz

Williams

et al. 2016

Progress in Particle and Nuclear Physics

438

530

View full text Add to dashboard Cite

show abstract

“…Correlation matrices composed of traditional three-quark operators have been very successful in revealing a dense spectrum of baryon excited states in lattice QCD [1][2][3][4][5][6][7][8][9][10][11][12]. However the lowest lying multi-particle scattering state thresholds are often absent in the observed spectra.…”

Section: Introductionmentioning

confidence: 99%

Searching for low-lying multi-particle thresholds in lattice spectroscopy

Mahbub¹,

Kamleh²,

Leinweber³

et al. 2014

Annals of Physics

View full text Add to dashboard Cite

We explore the Euclidean-time tails of odd-parity nucleon correlation functions in a search for the S -wave pionnucleon scattering-state threshold contribution. The analysis is performed using 2 + 1 flavor 32 3 × 64 PACS-CS gauge configurations available via the ILDG. Correlation matrices composed with various levels of fermion source/sink smearing are used to project low-lying states. The consideration of 25,600 fermion propagators reveals the presence of more than one state in what would normally be regarded as an eigenstate-projected correlation function. This observation is in accord with the scenario where the eigenstates contain a strong mixing of single and multi-particle states but only the single particle component has a strong coupling to the interpolating field. Employing a twoexponential fit to the eigenvector-projected correlation function, we are able to confirm the presence of two eigenstates. The lower-lying eigenstate is consistent with a Nπ scattering threshold and has a relatively small coupling to the three-quark interpolating field. We discuss the impact of this small scattering-state contamination in the eigenvector projected correlation function on previous results presented in the literature.

show abstract

“…Other recent progress in calculating excited-state energies in lattice QCD can be found in Refs. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Extended hadron and two-hadron operators of definite momentum for spectrum calculations in lattice QCD

et al. 2013

View full text Add to dashboard Cite

Multi-hadron operators are crucial for reliably extracting the masses of excited states lying above multi-hadron thresholds in lattice QCD Monte Carlo calculations. The construction of multi-hadron operators with significant coupling to the lowest-lying multi-hadron states of interest involves combining single hadron operators of various momenta. The design and implementation of large sets of spatially-extended single-hadron operators of definite momentum and their combinations into two-hadron operators are described. The single hadron operators are all assemblages of gaugecovariantly-displaced, smeared quark fields. Group-theoretical projections onto the irreducible representations of the symmetry group of a cubic spatial lattice are used in all isospin channels. Tests of these operators on 24 3 × 128 and 32 3 × 256 anisotropic lattices using a stochastic method of treating the low-lying modes of quark propagation which exploits Laplacian Heaviside quark-field smearing are presented. The method provides reliable estimates of all needed correlations, even those that are particularly difficult to compute, such as ηη → ηη in the scalar channel, which involves the subtraction of a large vacuum expectation value. A new glueball operator is introduced, and the evaluation of the mixing of this glueball operator with a quark-antiquark operator, ππ, and ηη operators is shown to be feasible.

show abstract

Nucleon excited states inNf=2lattice QCD

Cited by 35 publications

References 24 publications

Baryons as relativistic three-quark bound states

Baryons as relativistic three-quark bound states

Searching for low-lying multi-particle thresholds in lattice spectroscopy

Extended hadron and two-hadron operators of definite momentum for spectrum calculations in lattice QCD

Contact Info

Product

Resources

About