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Related papers: Excited nucleons with chirally improved fermions

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We present updated results for the nucleon axial charge and electromagnetic (EM) form factors, which include a significant increase in statistics for all ensembles (up to 4000 measurements), as well as the addition of ensembles with pion…

High Energy Physics - Lattice · Physics 2014-04-09 B. Jäger , T. D. Rae , S. Capitani , M. Della Morte , D. Djukanovic , G. von Hippel , B. Knippschild , H. B. Meyer , H. Wittig

We present a phenomenological model to investigate the chiral phase transition characterized by parity doubling in dense, beta equilibrated, cold matter. Our model incorporates effective interactions constrained by SU(3) relations and…

High Energy Physics - Phenomenology · Physics 2024-01-09 Eduardo S. Fraga , Rodrigo da Mata , Jürgen Schaffner-Bielich

We present a lattice QCD calculation of the nucleon electric polarizabilities at the physical pion mass. Our findings reveal the substantial contributions of the $N\pi$ states to these polarizabilities. Without considering these…

High Energy Physics - Lattice · Physics 2024-09-02 Xuan-He Wang , Zhao-Long Zhang , Xiong-Hui Cao , Cong-Ling Fan , Xu Feng , Yu-Sheng Gao , Lu-Chang Jin , Chuan Liu

We study the nucleon and three N* resonances' properties in an effective linear realization chiral SU_L(2) x SU_R(2) and U_A(1) symmetric Lagrangian. We place the nucleon fields into the so-called "naive" (1/2,0) + (0, 1/2) and "mirror" (0,…

High Energy Physics - Phenomenology · Physics 2010-03-24 V. Dmitrasinovic , A. Hosaka , K. Nagata

Spectral functions of the nucleon and its negative parity excited state in nuclear matter are studied using QCD sum rules and the maximum entropy method (MEM). It is found that in-medium modifications of the spectral functions are…

High Energy Physics - Phenomenology · Physics 2016-10-14 Keisuke Ohtani , Philipp Gubler , Makoto Oka

We simulate Quantum Chromodynamics (QCD) in four Euclidean dimensions with two (degenerate mass) flavors of dynamical quarks. The Dirac operator we use is the so-called chirally improved Dirac operator. We discuss the algorithm used for the…

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang , Pushan Majumdar , Wolfgang Ortner

We report a high precision calculation of the isospin vector charge $g_{S,T}$ of the nucleon using recently proposed ``blending" method which provides a high-precision stochastic estimate of the all-to-all fermion propagator. Through…

High Energy Physics - Lattice · Physics 2026-03-03 Ji-Hao Wang , Zhi-Cheng Hu , Xiangdong Ji , Xiangyu Jiang , Yushan Su , Peng Sun , Yi-Bo Yang

We study the positive parity charmed strange mesons using lattice QCD, the only reliable ab initio method to study QCD at low energies. Especially the experimentally observed $D_{s0}^*(2317)$ and $D_{s1}(2460)$ have challenged theory for…

High Energy Physics - Lattice · Physics 2016-01-06 Luka Leskovec , C. B. Lang , Daniel Mohler , Sasa Prelovsek , R. M. Woloshyn

We formulate lattice theories in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework the fermion mass term does not break chiral symmetry. This property allows us to use the Wilson term to remove the…

High Energy Physics - Lattice · Physics 2014-11-17 S. Chandrasekharan , M. Pepe , F. D. Steffen , U. -J. Wiese

We present results for the spectrum of light and strange mesons on configurations with two flavors of mass-degenerate Chirally Improved sea quarks. The calculations are performed on seven ensembles of lattice size 16^3x32 at three different…

High Energy Physics - Lattice · Physics 2015-06-03 Georg P. Engel , C. B. Lang , Markus Limmer , Daniel Mohler , Andreas Schaefer

Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large…

High Energy Physics - Lattice · Physics 2011-06-21 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , J. Noaki , T. Onogi

Several lattice collaborations performing simulations with 2+1 light dynamical quarks have experienced difficulties in fitting their data with standard Nf=3 chiral expansions at next-to-leading order, yielding low values of the quark…

High Energy Physics - Phenomenology · Physics 2011-03-03 V. Bernard , S. Descotes-Genon , G. Toucas

It is shown that experimental meson states with spins J=0,1,2,3 in the energy range 1.9 - 2.4 GeV obtained in recent partial wave analysis of proton-antiproton annihilation at LEAR remarkably confirm all predictions of chiral symmetry…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. Ya. Glozman

We study the excited baryon states for an arbitrary number of colors Nc from the perspective of the permutation group S_N of N objects. Classifying the transformation properties of states and quark-quark interaction operators under S_N…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dan Pirjol , Carlos Schat

We discuss the mass spectrum of highly-excited nucleon and $\Delta^*$ resonances. The spectrum exhibits parity doublets, pairs of resonances of identical total angular momentum J but of opposite parity. It has been proposed that the parity…

High Energy Physics - Phenomenology · Physics 2009-11-07 Eberhard Klempt

The strong decays of $\Xi$ baryons up to N=2 shell were studied in a chiral quark model. The strong decay properties of these well-established ground decuplet baryons were reasonably described. We found that (i) $\Xi(1690)$ and $\Xi(1820)$…

High Energy Physics - Phenomenology · Physics 2013-05-07 Li-Ye Xiao , Xian-Hui Zhong

In this lecture, I review progress made in the calculations of the parity-violating meson-nucleon interaction regions. The underlying framework is the topological chiral soliton model of the nucleon. Emphasis is put on the computation of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ulf-G. Meißner

Chiral effective field theory complements numerical simulations of quantum chromodynamics (QCD) on a space-time lattice. It provides a model-independent formalism for connecting lattice simulation results at finite volume and a variety of…

High Energy Physics - Lattice · Physics 2015-03-13 J. M. M. Hall , R. D. Young , D. B. Leinweber

Results for excited light and strange hadrons from the lattice with two flavors of Chirally Improved sea quarks are presented. We perform simulations at several values of the pion mass ranging from 250 to 600 MeV and extrapolate to the…

High Energy Physics - Phenomenology · Physics 2014-06-02 Georg P. Engel , C. B. Lang , Daniel Mohler , Andreas Schäfer

The effect of spontaneous breaking of chiral symmetry over the spectrum of highly excited hadrons is addressed in the framework of a microscopic chiral potential quark model (Generalised Nambu-Jona-Lasinio model) with a vectorial…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yu. S. Kalashnikova , A. V. Nefediev , J. E. F. T. Ribeiro