Lattice QCD study of a five-quark hadronic molecule

Journal Article · Sat Sep 01 00:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.054507· OSTI ID:21027700

Cook, M S ^[1]; Fiebig, H R ^[1]

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1. Physics Department, FIU-University Park, Miami, Florida 33199 (United States)

We compute the ground-state energies of a heavy-light K-{lambda} like system as a function of the relative distance r of the hadrons. The heavy quarks, one in each hadron, are treated as static. Then, the energies give rise to an adiabatic potential V{sub a}(r) which we use to study the structure of the five-quark system. The simulation is based on an anisotropic and asymmetric lattice with Wilson fermions. Energies are extracted from spectral density functions obtained with the maximum entropy method. Our results are meant to give qualitative insight: Using the resulting adiabatic potential in a Schroedinger equation produces bound-state wave functions which indicate that the ground state of the five-quark system resembles a hadronic molecule, whereas the first excited state, having a very small root-mean-square (rms) radius, is probably better described as a five-quark cluster, or a pentaquark. We hypothesize that an all light-quark pentaquark may not exist, but in the heavy-quark sector it might, albeit only as an excited state.

• OSTI ID: 21027700
• Journal Information: Physical Review. D, Particles Fields, Vol. 76, Issue 5; Other Information: DOI: 10.1103/PhysRevD.76.054507; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANISOTROPY
ASYMMETRY
B QUARKS
BOUND STATE
C QUARKS
CALCULATION METHODS
ENTROPY
EXCITED STATES
GROUND STATES
HADRONS
KAONS
LAMBDA BARYONS
LATTICE FIELD THEORY
MOLECULES
POTENTIALS
QUANTUM CHROMODYNAMICS
SCHROEDINGER EQUATION
SPECTRAL DENSITY
WAVE FUNCTIONS