Chiral extrapolation of light resonances from one and two-loop unitarized chiral perturbation theory versus lattice results

Journal Article · Wed Dec 01 04:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.82.114002· OSTI ID:21503714

Pelaez, J R; Rios, G ^[1]

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1. Departamento de Fisica Teorica II, Universidad Complutense, 28040, Madrid (Spain)

We study the pion mass dependence of the {rho}(770) and f{sub 0}(600) masses and widths from one and two-loop unitarized chiral perturbation theory (ChPT). We show the consistency of one-loop calculations with lattice results for the M{sub {rho}}, f{sub {pi}}, and the isospin-2 scattering length a{sub 20}. Then, we develop and apply the modified inverse amplitude method formalism for two-loop ChPT. In contrast to the f{sub 0}(600), the {rho}(770) is rather sensitive to the two-loop ChPT parameters--our main source of systematic uncertainty. We thus provide two-loop unitarized fits constrained by lattice information on M{sub {rho}}, f{sub {pi}}, by the qq leading 1/N{sub c} behavior of the {rho} and by existing estimates of low-energy constants. These fits yield relatively stable predictions up to m{sub {pi}{approx_equal}3}00-350 MeV for the {rho} coupling and width as well as for all the f{sub 0}(600) parameters. We confirm, to two loops, the weak m{sub {pi}} dependence of the {rho} coupling and the Kawarabayashi-Suzuki-Riazuddin-Fayyazuddin relation, and the existence of two virtual f{sub 0}(600) poles for sufficiently high m{sub {pi}}. At two loops one of these poles becomes a bound state when m{sub {pi}} is somewhat larger than 300 MeV.

• OSTI ID: 21503714
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 11 Vol. 82; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
BOSONS
BOUND STATE
CHIRALITY
COUPLING
DIMENSIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EXTRAPOLATION
FORECASTING
HADRONS
ISOSPIN
LENGTH
MASS
MATHEMATICAL SOLUTIONS
MESONS
MEV RANGE
MEV RANGE 100-1000
NUMERICAL SOLUTION
PARTICLE PROPERTIES
PERTURBATION THEORY
PIONS
PSEUDOSCALAR MESONS
RESONANCE
RHO-770 MESONS
SCATTERING LENGTHS
VECTOR MESONS