Observation of a JPC=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- Into π-π -π+.

Abstract

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the pi- pi- pi+ final state using a 190 GeV/c pion beam hitting a lead target. A partial wave analysis of the data has been performed.

The well-known resonances a1(1260), a2(1320), and pi2(1670) are clearly observed. In addition, the data show a significant natural parity exchange production of a resonance with spin-exotic quantum numbers J^PC = 1-+ at 1.66 GeV/c^2 decaying to rho pi.

Keywords

• Hadron spectroscopy
• Light meson spectrum
• Gluonic excitations
• Exotic mesons
• Hybrids