3 papers
hep-ph2003
S-wave pi-pi scattering lengths
N. Nasrallah
An old calculation of the s-wave pi-pi scattering lengths is updated and supplemented with experimental data on the pi-pi s-wave phase shift. The results ma0 = .215 and ma2 = -.039…
hep-ph2002
Charged pion pair production by two photons from a chiral sum rule
N. F. Nasrallah, K. Schilcher
The cross-section for a charged pion pair production by two photons is evaluated by using the low energy expression previously obtained from current algebra and PCAC which involves…
hep-ph1999
On QCD and mixing
N. F. Nasrallah
The evaluation of sum rules and vacuum condensates used in the calculation of the mixing parameters of the system involve dangerous cancellations of large numbers. In this no…