An alternative parametrization of the pion form factor and the mass and width of rho(770)

Details An alternative parametrization of the pion form factor and the mass and width of rho(770) An alternative parametrization of the pion form factor and the mass and width of rho(770)

2006-11-13

arxiv.org/abs/hep-ph/0611163v1

Physics

High Energy Physics

High Energy Physics - Phenomenology

Scientific paper

In order to reveal possible mass shifts of the vector mesons in a dense strongly interacting medium presumably created in high energy heavy ion collisions it is necessary to know their free masses reliably. The rho(770) mass quoted in the last two editions of the Review of Particle Physics is significantly larger than the values quoted in previous editions. The new value is mostly influenced by the results of recent experiments CMD-2 and SND at the VEPP-2M e+e- collider at Novosibirsk. We show that the values of the mass and width of the rho(770) meson measured in the e+e- -> pi+pi- annihilation depend crucially on the parametrization used for the pion form factor. We propose a parametrization of the rho(770) contribution to the pion form factor based on the running mass calculated from a single-subtracted dispersion relation and compare it with the parametrization based on the formula of Gounaris and Sakurai used recently by the CMD-2 collaboration. We show that our parametrization gives equally good or better fits when applied to the data of the CMD-2, SND, and KLOE collaborations, but yields much smaller values of the rho(770) mass, consistent with the photoproduction and hadronic reactions results. Our fit to the KLOE data becomes exceptionally excellent (confidence level of 99.88%) if an energy shift of about 2 MeV in the rho-omega region is allowed.

Affiliated with

Also associated with

No associations

Rating

An alternative parametrization of the pion form factor and the mass and width of rho(770) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with An alternative parametrization of the pion form factor and the mass and width of rho(770), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An alternative parametrization of the pion form factor and the mass and width of rho(770) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-669805