Meson and baryon spectrum for QCD with two light dynamical quarks

Journal Article · Sun Aug 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.034505· OSTI ID:21432881

Engel, Georg P; Lang, C B; Limmer, Markus ^[1]; Mohler, Daniel ^[1]; Schaefer, Andreas ^[2]

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1. Institut fuer Physik, FB Theoretische Physik, Universitaet Graz, A-8010 Graz (Austria)
2. Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg (Germany)

We present results of meson and baryon spectroscopy using the Chirally Improved Dirac operator on lattices of size 16{sup 3}x32 with two mass-degenerate light sea quarks. Three ensembles with pion masses of 322(5), 470(4), and 525(7) MeV and lattice spacings close to 0.15 fm are investigated. Results for ground and excited states for several channels are given, including spin two mesons and hadrons with strange valence quarks. The analysis of the states is done with the variational method, including two kinds of Gaussian sources and derivative sources. We obtain several ground states fairly precisely and find radial excitations in various channels. Excited baryon results seem to suffer from finite size effects, in particular, at small pion masses. We discuss the possible appearance of scattering states, considering masses and eigenvectors. Partially quenched results in the scalar channel suggest the presence of a 2-particle state, however, in most channels we cannot identify them. Where available, we compare our results to results of quenched simulations using the same action.

• OSTI ID: 21432881
• Journal Information: Physical Review. D, Particles Fields, Vol. 82, Issue 3; Other Information: DOI: 10.1103/PhysRevD.82.034505; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON SPECTROSCOPY
BARYONS
COMPARATIVE EVALUATIONS
DIRAC OPERATORS
EIGENVECTORS
EXCITATION
EXCITED STATES
GROUND STATES
MASS
MEV RANGE 100-1000
PIONS
QUANTUM CHROMODYNAMICS
QUARKS
SCATTERING
SIMULATION
SPECTRA
SPIN
VARIATIONAL METHODS
ANGULAR MOMENTUM
BOSONS
CALCULATION METHODS
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVALUATION
FERMIONS
FIELD THEORIES
HADRONS
MATHEMATICAL OPERATORS
MESONS
MEV RANGE
PARTICLE PROPERTIES
PSEUDOSCALAR MESONS
QUANTUM FIELD THEORY
QUANTUM OPERATORS
SPECTROSCOPY