2018 Impact factor 4.843
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.



© Società Italiana di Fisica, Springer-Verlag 2001