2020 Impact factor 4.590
Particles and Fields
Eur. Phys. J. C 9, 11-29
DOI 10.1007/s100529900058

Determination of radiative widths of scalar mesons from experimental results on $\gamma\gamma\to\pi\pi$

M. Boglione1 - M.R. Pennington2

1 Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
2 Centre for Particle Theory, University of Durham, Durham DH1 3LE, UK

Received: 10 Decmeber 1998 / Published online: 27 April 1999

Abstract
The scalar mesons in the 1 GeV region constitute the Higgs sector of the strong interactions. They are responsible for the masses of all light flavour hadrons. However, the composition of these scalar states is far from clear, despite decades of experimental effort. The two photon couplings of the f0's are a guide to their structure. Two photon results from Mark II, Crystal Ball and CELLO prompt a new Amplitude Analysis of $\gamma\gamma\to\pi^+\pi^-$,$\pi^0\pi^0$ cross-sections. Despite their currently limited angular coverage and lack of polarized photons, we use a methodology that provides the nearest one can presently achieve to a model-independent partial wave separation. We find two distinct classes of solutions. Both have very similar two photon couplings for the f0(980) and f0(400-1200). Hopefully these definitive results will be a spur to dynamical calculations that will bring us a better understanding of these important states.


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