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

Journal Article · Wed Dec 01 00:00:00 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, Vol. 82, Issue 11; Other Information: DOI: 10.1103/PhysRevD.82.114002; (c) 2010 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

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