Eur. Phys. J. A (2005) 26: 79-88
https://doi.org/10.1140/epja/i2005-10150-y

Original Article

Search for higher flavor multiplets in partial-wave analyses

¹ Petersburg Nuclear Physics Institute, 188300, St. Petersburg, Russia
² Thomas Jefferson National Accelerator Facility, VA 23606, Newport News, USA
³ Center for Nuclear Studies, Physics Department, The George Washington University, DC 20052, Washington, USA
⁴ Institute for Theoretical Physics II, Ruhr University, 44801, Bochum, Germany

^* e-mail: azimov@thd.pnpi.spb.ru

Received: 22 August 2005
Accepted: 1 September 2005
Published online: 25 October 2005

Abstract

The possible existence of higher multi-quark flavor multiplets of baryons is investigated. We argue that the S-matrix should have poles with any quantum numbers, including those which are exotic. This argument provides a novel justification for the existence of hadrons with arbitrary exotic structure. Though it does not constitute a proof, there are still no theoretical arguments against exotics. We then consider KN and πN scattering. Conventional and modified partial-wave analyses provide several sets of candidates for correlated pairs (Θ₁,Δ), each of which could label a related 27-plet. Properties of the pairs (masses, mass orderings, spin-parity quantum numbers) do not quite correspond to the current theoretical expectations. Decay widths of the candidates are either wider or narrower than expected. Possible reasons for such disagreements are briefly discussed.