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Title: Chiral Perturbation Theory, the 1/N_c expansion and Regge behavior determine the structure of the lightest scalar meson

Journal Article · · Physical Review. D, Particles, Fields, Gravitation and Cosmology
 [1];  [1];  [2]
  1. Univ. Complutense Madrid (Spain)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)

The leading 1/N{sub c} behavior of Unitarized Chiral Perturbation Theory distinguishes the nature of the {rho} and the {sigma}. At one loop order the {rho} is a {bar q}q meson, while the {sigma} is not. However, semi-local duality between resonances and Regge behaviour cannot be satisfied for larger N{sub c}, if such a distinction holds. While the {sigma} at N{sub c}= 3 is inevitably dominated by its di-pion component, Unitarised Chiral Perturbation Theory beyond one loop order reveals that as N{sub c} increases above 6-8, the {sigma} has a sub-dominant {bar q}q fraction up at 1.2 GeV. Remarkably this ensures semi-local duality is fulfilled for the range of N{sub c} {approx}< 15-30, where the unitarization procedure adopted applies.

Research Organization:
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
AC05-06OR23177
OSTI ID:
1029185
Report Number(s):
JLAB-THY-10-1256; DOE/OR/23177-1315; arXiv:1009.6204; PRVDAQ; TRN: US1105655
Journal Information:
Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 84, Issue 9; ISSN 1550-7998
Country of Publication:
United States
Language:
English