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

Abstract

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 amore » more exotic wave function.« less

Authors:
; ;  [1];  [1];  [2];  [3]
  1. Institute for Theoretical Physics, Eoetvoes University (Hungary)
  2. (Germany)
  3. Department of Theoretical Physics, University of Pecs (Hungary)
Publication Date:
OSTI Identifier:
20776678
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevD.73.034506; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Csikor, F., Katz, S.D., Toth, B.C., Fodor, Z., Department of Physics, University of Wuppertal, and Kovacs, T.G.. Comprehensive search for the {theta}{sup +} pentaquark on the lattice. United States: N. p., 2006. Web. doi:10.1103/PhysRevD.73.034506.
Csikor, F., Katz, S.D., Toth, B.C., Fodor, Z., Department of Physics, University of Wuppertal, & Kovacs, T.G.. Comprehensive search for the {theta}{sup +} pentaquark on the lattice. United States. doi:10.1103/PhysRevD.73.034506.
Csikor, F., Katz, S.D., Toth, B.C., Fodor, Z., Department of Physics, University of Wuppertal, and Kovacs, T.G.. Wed . "Comprehensive search for the {theta}{sup +} pentaquark on the lattice". United States. doi:10.1103/PhysRevD.73.034506.
@article{osti_20776678,
title = {Comprehensive search for the {theta}{sup +} pentaquark on the lattice},
author = {Csikor, F. and Katz, S.D. and Toth, B.C. and Fodor, Z. and Department of Physics, University of Wuppertal and Kovacs, T.G.},
abstractNote = {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.},
doi = {10.1103/PhysRevD.73.034506},
journal = {Physical Review. D, Particles Fields},
number = 3,
volume = 73,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2006},
month = {Wed Feb 01 00:00:00 EST 2006}
}