Studies of Exclusive e+e- -> hadrons Reactions with Baryons and Strange Particles Using Initial State Radiation at Babar

TL;DR

This paper reports on measurements of exclusive e+e- annihilation into hadrons with baryons and strange particles at low energies using initial state radiation at BaBar, revealing new states and providing detailed cross sections and form factors.

Contribution

It presents new experimental results on exclusive hadronic final states involving baryons and strange mesons, including the observation of a new Y(2175) resonance.

Findings

Measured cross sections for e+e- -> baryon-antibaryon and strange meson pairs.

Derived effective baryon form factors and compared with theoretical predictions.

Observed the new Y(2175) resonance in e+e- -> K+K-f0(980).

Abstract

New Babar results on exclusive e+e- -> hadrons reactions at low c.m. energy with a baryon-antibaryon or K\bar{K} pair in the final state are presented. Cross sections are measured using the initial state radiation technique from the threshold up to 4--5 GeV. From the measured e+e- -> proton\antiproton, Lambda\Lbar, Sigma0\Sigbar0, Lambda\Sigbar0(Sigma0\Lbar) cross sections we derive effective baryon form factors and compare them with predictions. We measure the K\bar{K}\pi(\eta), K+K-\pi\pi, K+K-3\pi, K+K-4\pi, K+K-K+K- final states and also study their internal structure. A new Y(2175) state is observed in e+e- -> K+K-f0(980), with f0\to\pi\pi. The total measured e+e- annihilation cross section into final states including strange baryons or strange mesons is estimated to be 10% of the full hadronic cross section.