4$\pi$-decays of scalar and vector mesons

The CRYSTAL BARREL Collaboration A. Abele; J. Adomeit; C. Amsler; C.A. Baker; B.M. Barnett; C.J. Batty; M. Benayoun; S. Bischoff; P. Blüm; K. Braune; T. Case; V. Credé; K.M. Crowe; T. Degener; M. Doser; W. Dünnweber; D. Engelhardt; M.A. Faessler; P. Giarritta; R.P. Haddock; F.H. Heinsius; M. Heinzelmann; A. Herbstrith; N.P. Hessey; P. Hidas; C. Holtzhaußen; D. Jamnik; H. Kalinowsky; P. Kammel; J. Kisiel; E. Klempt; H. Koch; M. Kunze; U. Kurilla; M. Lakata; R. Landua; H. Matthäy; C.A. Meyer; F. Meyer-Wildhagen; L. Montanet; R. Ouared; K. Peters; B. Pick; M. Ratajczak; C. Regenfus; W. Roethel; S. Spanier; H. Stöck; U. Strohbusch; M. Suffert; J.S. Suh; U. Thoma; M. Tischhäuser; I. Uman; S. Wallis-Plachner; D. Walther; U. Wiedner; K. Wittmack

doi:doi:10.1007/s100520100735

2024 Impact factor 4.8

Particles and Fields

Eur. Phys. J. C 21, 261-269 (2001)
DOI: 10.1007/s100520100735

4 $\pi$ -decays of scalar and vector mesons

The CRYSTAL BARREL Collaboration A. Abele¹, J. Adomeit², C. Amsler³, C.A. Baker⁴, B.M. Barnett⁵, C.J. Batty⁴, M. Benayoun⁶, S. Bischoff¹, P. Blüm¹, K. Braune⁷, T. Case⁸, V. Credé⁵, K.M. Crowe⁸, T. Degener⁹, M. Doser¹⁰, W. Dünnweber⁷, D. Engelhardt¹, M.A. Faessler⁷, P. Giarritta³, R.P. Haddock¹¹, F.H. Heinsius⁸, M. Heinzelmann³, A. Herbstrith¹, N.P. Hessey⁷, P. Hidas¹², C. Holtzhaußen¹, D. Jamnik⁷, H. Kalinowsky⁵, P. Kammel⁸, J. Kisiel¹⁰, E. Klempt⁵, H. Koch⁹, M. Kunze⁹, U. Kurilla⁹, M. Lakata⁸, R. Landua¹⁰, H. Matthäy⁹, C.A. Meyer¹³, F. Meyer-Wildhagen⁷, L. Montanet¹⁰, R. Ouared¹⁰, K. Peters⁹, B. Pick⁵, M. Ratajczak⁹, C. Regenfus³, W. Roethel⁷, S. Spanier³, H. Stöck⁹, U. Strohbusch², M. Suffert¹⁴, J.S. Suh⁵, U. Thoma⁵, M. Tischhäuser¹, I. Uman⁷, S. Wallis-Plachner⁷, D. Walther⁷, U. Wiedner⁷ and K. Wittmack⁵

¹ Universität Karlsruhe, 76021 Karlsruhe, Germany
² Universität Hamburg, 22761 Hamburg, Germany
³ Universität Zürich, 8057 Zürich, Switzerland
⁴ Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
⁵ Universität Bonn, 53115 Bonn, Germany
⁶ LPNHE Paris VI, VII, 75252 Paris, France
⁷ Universität München, 80333 München, Germany
⁸ University of California, LBNL, Berkeley, CA 94720, USA
⁹ Universität Bochum, 44780 Bochum, Germany
¹⁰ CERN, 1211 Geneva 4, Switzerland
¹¹ University of California, Los Angeles, CA 90024, USA
¹² Academy of Science, 1525 Budapest, Hungary
¹³ Carnegie Mellon University, Pittsburgh, PA 15213, USA
¹⁴ Centre de Recherches Nucléaires, 67037 Strasbourg, France

(Received: 7 December 2000 / Published online: 19 July 2001 -© Springer-Verlag / Società Italiana di Fisica 2001 )

Abstract
Two different $\bar{p}n$ annihilation modes, $\bar{p}n\rightarrow\pi^{-}4\pi^{0}$ and $\bar{p}n\rightarrow 2\pi^{-}2\pi^{0}\pi^{+}$ , are used to study the 4 $\pi$ -decays of scalar and vector mesons. The data are dominated by 4 $\pi$ scalar isoscalar interactions. At least two states are needed, the f₀(1370) and the f₀(1500). The 4 $\pi$ -decay width of the f₀(1370) is more than 6 times larger than the sum of all observed partial decay widths to two pseudoscalar mesons. The state has important couplings to $(\pi\pi)_{\mathrm{S}}(\pi\pi)_{\mathrm{S}}$ and to $\rho\rho$ . The 4 $\pi$ -decays of the f₀(1500) represent about half of its total width. The $\rho(1450)$ and the $\rho(1700)$ are observed in several 4 $\pi$ decay modes. The ratio of the $4\pi$ relative to the $2\pi$ decay of the $\rho(1450)$ is in contradiction to its proposed interpretation as a pure hybrid state but it suggests that it is not a pure $2^{3}\rm S_{1}$ -state either. Our results favour the assignment of the $\rho(1700)$ as $^{3}\rm D_{1}$ state, its interpretation as $3^{3}\rm S_{1}$ -state is less plausible.