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相关论文: Nucleon Excited States in N$_f$=2 lattice QCD

200 篇论文

We study the pion-nucleon system in s-wave in the framework of lattice QCD in order to gain new information on the nucleon excited states. We perform simulations for $n_f =2$ mass degenerate light quarks at a pion mass of 266 MeV. The…

高能物理 - 格点 · 物理学 2013-04-19 C. B. Lang , V. Verduci

We discuss the extraction of negative-parity baryon masses from lattice QCD calculations. The mass of the lowest-lying negative-parity $J = 1/2^{-}$ state is computed in quenched lattice QCD using an ${\cal O}(a)$-improved clover fermion…

We present results of our numerical calculation of the mass spectrum for isospin one-half and spin one-half non-strange baryons, i.e. the ground and excited states of the nucleon, in quenched lattice QCD. We use a new lattice discretization…

高能物理 - 格点 · 物理学 2009-11-07 Shoichi Sasaki , Tom Blum , Shigemi Ohta

The study of the spectrum of excited states of the nucleon is vital to our understanding of how QCD is realized in the baryon spectrum. Using a simultaneous analysis of the pion nucleon scattering data up to 2 GeV as well as the results of…

高能物理 - 唯象学 · 物理学 2025-03-14 Shiryo Owa , Derek B. Leinweber , Anthony W. Thomas

Results on the electromagnetic form factors of the nucleon using twisted mass fermion configurations are presented. These include a gauge field ensemble simulated with two degenerate light quarks yielding a pion mass of around 130 MeV, as…

We present lattice QCD calculations of nucleon electromagnetic form factors using pion masses $m_\pi$ = 149, 202, and 254 MeV and an action with clover-improved Wilson quarks coupled to smeared gauge fields, as used by the…

高能物理 - 格点 · 物理学 2014-11-20 J. R. Green , J. W. Negele , A. V. Pochinsky , S. N. Syritsyn , M. Engelhardt , S. Krieg

We present results for excited meson spectra from $N_f=2$ clover-Wilson configurations provided by the CP-PACS Collaboration. In our study we investigate both low and high spin mesons. For spin-0 and spin-1 mesons, we are especially…

高能物理 - 格点 · 物理学 2009-08-03 Tommy Burch , Christian Hagen , Martin Hetzenegger , Andreas Schäfer

The energies of the excited states of the Nucleon, Delta and Omega are computed in lattice QCD, using two light quarks and one strange quark on anisotropic lattices. The calculations are performed at three values of the pion mass: 392(4),…

We employ a novel method to analyze Euclidean correlation functions entering the calculation of hadron energies in lattice QCD. The method is based on the sampling of all possible solutions allowed by the spectral decomposition of the…

高能物理 - 格点 · 物理学 2015-06-23 C. Alexandrou , T. Leontiou , C. N. Papanicolas , E. Stiliaris

We present results on the light, strange and charm nucleon scalar and tensor charges from lattice QCD, using simulations with $N_f=2$ flavors of twisted mass Clover-improved fermions with a physical value of the pion mass. Both connected…

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…

高能物理 - 格点 · 物理学 2009-09-28 M. S. Mahbub , Alan Ò Cais , Waseem Kamleh , Ben G. Lasscock , Derek B. Leinweber , Anthony G. Williams

The energies of the excited states of the Nucleon, $\Delta$ and $\Omega$ are computed in lattice QCD, using two light quarks and one strange quark on anisotropic lattices. The calculation is performed at three values of the light quark…

高能物理 - 格点 · 物理学 2015-03-17 J. Bulava , R. G. Edwards , E. Engelson , B. Joó , H-W. Lin , C. Morningstar , D. G. Richards , S. J. Wallace

In this paper, we study the nucleon energy spectrum in the ground-state (with orbital momentum L=0) and the first excited state (L=1). The aim of this study is to find the mass and mixing angles of excited nucleons using a potential model…

高能物理 - 唯象学 · 物理学 2007-05-23 I. K. Bensafa , F. Iddir , L. Semlala

We present results on the nucleon electromagnetic form factors from Lattice QCD at momentum transfer up to about $12$~GeV$^2$. We analyze two gauge ensembles with the Wilson-clover fermion action, a lattice spacing of $a\approx 0.09$~fm and…

Highly excited states for isospin 1/2 baryons are calculated for the first time using lattice QCD with two flavors of dynamical quarks. Anisotropic lattices are used with two pion masses: 416(36) MeV and 578(29) MeV. The lowest four…

Masses of positive and negative parity excited nucleons and hyperons are calculated in quenched lattice QCD using an O(a^2) improved gluon action and a fat-link clover fermion action in which only the irrelevant operators are constructed…

高能物理 - 格点 · 物理学 2010-03-04 W. Melnitchouk , J. N. Hedditch , D. B. Leinweber , A. G. Williams , J. M. Zanotti , J. B. Zhang

We present a dedicated analysis of the influence of excited states on the calculation of nucleon matrix elements. This calculation is performed at a fixed value of the lattice spacing, volume and pion mass that are typical of contemporary…

高能物理 - 格点 · 物理学 2015-05-30 Simon Dinter , Constantia Alexandrou , Martha Constantinou , Vincent Drach , Karl Jansen , Dru B. Renner

The chirally improved (CI) fermion action allows us to obtain results for pion masses down to 320 MeV on (in lattice units) comparatively small lattices with physical extent of 2.4 fm. We use differently smeared quarks sources to build sets…

高能物理 - 格点 · 物理学 2010-11-05 G. Engel , C. Gattringer , C. B. Lang , M. Limmer , D. Mohler , A. Schäfer

We present an update of our analysis [1] which includes additional ensembles at different quark masses, lattice spacings and volumes, all with high statistics. We use $N_f=2$ mass-degenerate quark flavours, employing the non-perturbatively…

In this contribution, results from $N_f=2$ lattice QCD simulations at one lattice spacing using twisted mass fermions with a clover term at the physical pion mass are presented. The mass splitting between charged and neutral pions…

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