A search for glueballs and a study of doouble pomeron exchange at the CERN intersecting storage rings

T P A Åkesson ,H Bøggild,G Damgaard,T Killian,K Kulka,B Lörstad,P Dam,E Rosso,A Rudge,P Frandsen,S Almehed,W Witzeling,G Thorstenson,E Vella,D Lissauer,L Rosselet,R Møller,S Dagan,W Frati,M Winik,I Stumer,I Dahl-Jensen,R Kroeger,Α Μάρκου ,O Benary ,J Van Der Lans ,S Frankel ,T Ludlam ,Wynne Evans ,A A Carter ,L Olsen ,W Cleland ,V Hedberg ,H J Hilke ,Murray Gibson ,H Breuker ,R Carosi ,D P Weygand ,J R Carter ,N A Mccubbin ,J Thompson ,Klavs Hansen ,U Goerlach ,T W Pritchard ,M J Goodrick ,J W Hiddleston ,Y Oren ,C Fabjan ,Richard Batley ,Volker Burkert ,J Lindsay ,M K Sullivan ,U Mjörnmark ,S U Chung ,E Dahl‐Jensen ,G Jarlskog ,P Cecil ,J Williamson ,D Cockerill ,O Botner ,M Albrow ,W Molzon ,B S Nielsen ,Anders Nilsson ,C Woody ,W Willis ,W A Zajc

doi:10.1016/0550-3213(86)90477-3

Abstract

We present results from a study of centrally produced mesons in 3 × 10 6 events with two small-angle protons at the CERN Intersecting Storage Rings. A high-statistics sample of exclusive pp → pp π + π − events at √ s = 63 GeV has been obtained, where the reaction mechanism is dominated by double pomeron exchange. Scalar or tensor glueballs may be produced by this process. The π + π − mass spectrum has a distinctive structure, and analysis shows that the data are dominantly S-wave up to 1600 MeV. The behaviour of the D-wave provides evidence for a 2 ++ resonance ( M = 1480 ± 50 MeV, Γ = 150 ± 50 MeV) in addition to the f(1270). We also show data on exclusive K + K −, p p, and π +π −π +π − production, and on the analogous reaction αα → ααπ + π − at √ s = 126 GeV. Flavour independence is suggested by the observation of approximately equal numbers of K +K − and π + π − pairs for mass above 1 GeV. The mass spectra are also apparently independent of √ s (45, 63, 126 GeV) and incident particle type (p, α).

Full Text