Jun 13 – 17, 2011
Europe/Berlin timezone
Proceedings are now available online at <a href="http://www.slac.stanford.edu/econf/C110613/">eConf</a>

Some properties of light scalar mesons in the complex plane

Jun 16, 2011, 5:30 PM
Festsaal (Künstlerhaus)



talk Light Mesons Light Mesons


Dr Bachir Moussallam (IPN Orsay)


Some properties of the scalar mesons sigma(600) and f0(980) are discussed using the Roy integral equations to control continuations in the complex energy plane. On the real axis, firstly, high precision numerical solutions of the equations are constructed for energies up to the K-Kbar threshold. Fits to the data by such solutions are performed and constrained by the recent measurements of the S-wave scattering lengths by the NA48/2 collaboration. These results are combined with recent measurements of photo-photon scattering to two pions by the Belle collaboration. From a chirally constrained analytic representation of the amplitudes, the values of the couplings of the sigma(600) and f0(980) to two photons are deduced. As a second application, the question of the gluon and q-qbar "contents" of the scalar mesons is reconsidered. These may be defined using analytic extensions to the second sheet of two-point correlators of GG and q-qbar operators. The pole residues involve pion-pion matrix elements of these operators. A numerical evaluation is made using dispersion relations and low-energy constraints.

Primary author

Dr Bachir Moussallam (IPN Orsay)

Presentation materials