SU(6), triquark states, and the pentaquark

Journal Article · Tue Apr 01 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.074016· OSTI ID:21249941

Majee, Swarup Kumar; Raychaudhuri, Amitava ^[1]

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1. Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India) and Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700 009 (India)

The purported observation of a state {theta}{sup +} with strangeness S=+1 led to its quark model interpretation in terms of a pentaquark combination involving a triquark-diquark structure--the Karliner-Lipkin model. In this work, the proper color-spin symmetry properties for the qqq triquark are elucidated by calculating the SU(6) unitary scalar factors and Racah coefficients. Using these results, the color-spin hyperfine interactions, including flavor symmetry breaking therein, become straightforward to incorporate and the pentaquark masses are readily obtained. We examine the effect on the pentaquark mass of (a) deviations from the flavor symmetric limit and (b) different strengths of the doublet and triplet hyperfine interactions. Reference values of these parameters yield a {theta}{sup +} mass prediction of 1601 MeV but it can comfortably accommodate 1540 MeV for alternate choices. In the same framework, other pentaquark states {xi}(S=-2) and {theta}{sup c} (with charm C=-1) are expected at 1783 MeV and 2757 MeV, respectively.

• OSTI ID: 21249941
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COLOR MODEL
FLAVOR MODEL
FORECASTING
GEV RANGE 01-10
INTERACTIONS
MASS
QUARKS
RACAH COEFFICIENTS
SPIN
STRANGENESS
SU-6 GROUPS
SYMMETRY
SYMMETRY BREAKING
TRIPLETS