Comprehensive search for the {theta}{sup +} pentaquark on the lattice

Journal Article · Wed Feb 01 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.73.034506· OSTI ID:20776678

Csikor, F; Katz, S D; Toth, B C ^[1]; Fodor, Z ^[1]; Kovacs, T G ^[2]

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1. Institute for Theoretical Physics, Eoetvoes University (Hungary)
2. Department of Theoretical Physics, University of Pecs (Hungary)

We study spin 1/2 isoscalar and isovector, even and odd parity candidates for the {theta}{sup +}(1540) pentaquark particle using large scale lattice QCD simulations. Previous lattice works led to inconclusive results because so far it has not been possible to unambiguously identify the known scattering spectrum and tell whether additionally a genuine pentaquark state also exists. Here we carry out this analysis using several possible wave functions (operators). Linear combinations of those have a good chance of spanning both the scattering and pentaquark states. Our operator basis is the largest in the literature, and it also includes spatially nontrivial ones with unit orbital angular momentum. The cross correlator we compute is 14x14 with 60 nonvanishing elements. We can clearly distinguish the lowest scattering state(s) in both parity channels up to above the expected location of the pentaquark, but we find no trace of the latter. Based on that we conclude that there are most probably ({approx_equal}2{sigma}/6{sigma} levels in the negative/positive parity channels) no pentaquark bound states at our quark masses, corresponding to m{sub {pi}}=400-630 MeV. However, we cannot rule out the existence of a pentaquark state at the physical quark mass corresponding to m{sub {pi}}=135 MeV or pentaquarks with a more exotic wave function.

• OSTI ID: 20776678
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 73; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOUND STATE
COMPUTERIZED SIMULATION
HYPERONS
ISOVECTORS
LATTICE FIELD THEORY
MEV RANGE
ORBITAL ANGULAR MOMENTUM
PARITY
PARTICLE IDENTIFICATION
QUANTUM CHROMODYNAMICS
QUARKS
REST MASS
SCATTERING
SPIN
WAVE FUNCTIONS