Constituent quarks, chiral symmetry, and chiral point of the constituent quark model

Journal Article · Fri Sep 01 04:00:00 EDT 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.74.054004· OSTI ID:20871092

Lucha, Wolfgang ^[1]; Melikhov, Dmitri ^[1]; Simula, Silvano ^[2]

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1. Institute for High Energy Physics, Austrian Academy of Sciences, Nikolsdorfergasse 18, A-1050, Vienna (Austria)
2. INFN, Sezione di Roma 3, Via della Vasca Navale 84, I-00146, Rome (Italy)

We construct the full axial current of the constituent quarks by a summation of the infinite number of diagrams describing constituent quark soft interactions. By requiring that the conservation of this current is violated only by terms of order O(M{sub {pi}}{sup 2}), where M{sub {pi}} is the mass of the lowest pseudoscalar QQ bound state, we derive important constraints on (i) the axial coupling g{sub A} of the constituent quark and (ii) the QQ potential at large distances. We define the chiral point of the constituent quark model as those values of the parameters, such as the masses of the constituent quarks and the couplings in the QQ potential, for which M{sub {pi}} vanishes. At the chiral point the main signatures of the spontaneously broken chiral symmetry are shown to be present, namely: the axial current of the constituent quarks is conserved, the leptonic decay constants of the excited pseudoscalar bound states vanish, and the pion decay constant has a nonzero value.

• OSTI ID: 20871092
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 5 Vol. 74; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALGEBRAIC CURRENTS
BOUND STATE
CHIRAL SYMMETRY
CHIRALITY
COUPLING
DISTANCE
FEYNMAN DIAGRAM
LEPTONIC DECAY
PIONS
POTENTIALS
QUARK MODEL
QUARKS
REST MASS