Observation of Double <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>φ</mi></math></span>-Meson Production in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mi>p</mi></math></span> Interactions

A. Etkin; K. J. Foley; J. H. Goldman; W. A. Love; T. W. Morris; S. Ozaki; E. D. Platner; A. C. Saulys; C. D. Wheeler; E. H. Willen; S. J. Lindenbaum; M. A. Kramer; U. Mallik

doi:10.1103/PhysRevLett.40.422

Observation of Double $φ$ -Meson Production in $π^{-} p$ Interactions

A. Etkin, K. J. Foley, J. H. Goldman, W. A. Love, T. W. Morris, S. Ozaki, E. D. Platner, A. C. Saulys, C. D. Wheeler, E. H. Willen, S. J. Lindenbaum, M. A. Kramer, and U. Mallik

Phys. Rev. Lett. 40, 422 – Published 13 February 1978

Abstract

We report a measurement of the reaction $π^{-} p \to ϕ ϕ n$ at 22.6 GeV/c. The $ϕ ϕ$ effectivemass spectrum shows a concentration of events from threshold to about 2.4 GeV/ $c^{2}$ . From the data near 2.8 GeV/ $c^{2}$ effective mass, we place an upper limit on $σ$ times the branching ratio of 2 nb (90% confidence level) for the production of $η_{c}$ and its decay into $ϕ ϕ$ .