Pion-pion scattering amplitude. IV. Improved analysis with once subtracted Roy-like equations up to 1100 MeV

Journal Article · Fri Apr 01 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.83.074004· OSTI ID:21537707

Garcia-Martin, R; Pelaez, J R; Ruiz de Elvira, J ^[1]; Kaminski, R ^[2]; Yndurain, F J ^[3]

---

1. Departamento de Fisica Teorica II, Universidad Complutense de Madrid, 28040 Madrid (Spain)
2. Department of Theoretical Physics, Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342, Krakow (Poland)
3. Departamento de Fisica Teorica, C-XI Universidad Autonoma de Madrid, Canto Blanco, E-28049, Madrid (Spain)

We improve our description of {pi}{pi} scattering data by imposing additional requirements on our previous fits, in the form of once-subtracted Roy-like equations, while extending our analysis up to 1100 MeV. We provide simple and ready to use parametrizations of the amplitude. In addition, we present a detailed description and derivation of these once-subtracted dispersion relations that, in the 450 to 1100 MeV region, provide an additional constraint which is much stronger than our previous requirements of forward dispersion relations and standard Roy equations. The ensuing constrained amplitudes describe the existing data with rather small uncertainties in the whole region from threshold up to 1100 MeV, while satisfying very stringent dispersive constraints. For the S0 wave, this requires an improved matching of the low and high energy parametrizations. Also for this wave we have considered the latest low energy K{sub l4} decay results, including their isospin violation correction, and we have removed some controversial data points. These changes on the data translate into better determinations of threshold and subthreshold parameters which remove almost all disagreement with previous chiral perturbation theory and Roy equation calculations below 800 MeV. Finally, our results favor the dip structure of the S0 inelasticity around the controversial 1000 MeV region.

• OSTI ID: 21537707
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 83; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
CHIRALITY
CORRECTIONS
DECAY
DISPERSION RELATIONS
ENERGY RANGE
GEV RANGE
GEV RANGE 01-10
HADRON-HADRON INTERACTIONS
INTERACTIONS
ISOSPIN
MESON-MESON INTERACTIONS
MEV RANGE
MEV RANGE 100-1000
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PERTURBATION THEORY
PION-PION INTERACTIONS
SIMULATION