F E. Close

A coupled channel analysis of the centrally produced K+ K- and π+ π- final states in pp interactions at 450 GeV/c

A coupled channel analysis of the centrally produced K+K- and pi+pi- final states has been performed in pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ratios to pipi and KK of the f0(980), f0(1370), f0(1500) and f0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the pi+pi- and K+K- channels has been performed.Abstract A coupled channel analysis of the centrally produced K+K−and π+π−final states has been performed in pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ratios to ππ and K K of the f0(980), f0(1370), f0(1500) and f0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the π+π−and K+K−channels has been performed.

A study of the ηπ+π− channel produced in central pp interactions at 450 GeV/c

The reaction pp ->pf (eta eta) ps has been studied at 450 GeV/c. For the first time a partial wave analysis of the centrally produced eta eta system has been performed. Signals for the f0(1500), f0(1710) and f2(2150) are observed and the decay branching fractions of these states are determined.

A spin analysis of the 4π channels produced in central pp interactions at 450 GeV/c

The reactions pp ! pf(X 0 )ps ,w here X 0 is observed decaying to 0000 , + + and + 00 , have been studied at 450 GeV/c. There is evidence for an a2(1320) decay mode of the 2(1645) and 2(1870) in the + 00 and + + nal states. The f2(1950) is consistent with being a single resonance with a dominant f2(1270) decay mode. The f0(1370) is found to decay dominantly to while the f0(1500) is found to decay to and .

A partial wave analysis of the centrally produced

A partial wave analysis of the centrally produced K+K- and K0K0 channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found in each channel. The striking feature is the observation of peaks in the S-wave corresponding to the f0(1500) and fJ(1710) with J = 0. The D-wave shows evidence for the f2(1270)/a2(1320), the f2(1525) and the f2(2150) but there is no evidence for a statistically significant contribution in the D-wave in the 1.7 GeV mass region.A partial wave analysis of the centrally produced K+K- and K0K0 channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found in each channel. The striking feature is the observation of peaks in the S-wave corresponding to the f0(1500) and fJ(1710) with J = 0. The D-wave shows evidence for the f2(1270)/a2(1320), the f2(1525) and the f2(2150) but there is no evidence for a statistically significant contribution in the D-wave in the 1.7 GeV mass region.

K^{+}K^{-}

Abstract A study of the f 1 (1285) and f 1 (1420) produced in central pp interactions has been performed. For the first time in a single experiment the branching fractions of both mesons in all major decay modes have been determined. Both the f 1 (1285) and f 1 (1420) are consistent with being produced by double Pomeron exchange.A study of the f1(1285) and f1(1420) produced in central pp interactions has been performed. For the first time in a single experiment the branching fractions of both mesons in all major decay modes have been determined. Both the f1(1285) and f1(1420) are consistent with being produced by double Pomeron exchange.

and

Abstract The production and decay properties of the f 0 (1370), f 0 (1500), f 0 (2000) and f 2 (1950) have been studied in central pp interactions at 450 GeV/c. The dP T , φ and | t | distributions of these resonances are presented. For the J =0 states, the f 0 (1370) and f 0 (2000) have similar dP T and φ dependences. These are different to the dP T and φ dependences of the f 0 (980), f 0 (1500) and f 0 (1710). For the J =2 states the f 2 (1950) has different dependences to the f 2 (1270) and f 2 ′ (1520). This shows that the dP T and φ dependences are not just J phenomena.

K^{0}_{s}K^{0}_{s}

Abstract Evidence is presented that the Pomeron acts as a non-conserved vector current. A study has been made of the azimuthal angle φ , which is defined as the angle between the p T vectors of the two outgoing protons, in the reaction pp → pp ( X 0 ) for those resonances ( X 0 ) which are compatible with being produced by double Pomeron exchange. These distributions have been compared with a model which describes the Pomeron as a non-conserved vector current and a qualitative agreement is found. In addition, when one of the particles exchanged is known to have spin 0, namely π –Pomeron exchange, the φ distribution is flat.

systems in pp interactions at 450 GeV/c and new information on the spin of the

The reaction pp ! pfps(K + K K + K ) in which the K + K K + K system is centrally produced has been studied at 450 GeV/c. production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the system favours J PC =2 ++ and its dPT dependence is similar to that observed for glueball candidates.The reaction pp to pfps(K+K-K+K-) in which the K+K-K+K- system is centrally produced has been studied at 450 GeV/c. Phi phi production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the phi phi system favours JPC = 2++ and its dPT dependence is similar to that observed for glueball candidates.

f_{1}

Abstract A partial wave analysis of the centrally produced ηπ 0 and ηπ − channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. Clear a 0 (980) and a 2 (1320) signals have been observed in S and D + waves respectively. The dP T , φ and | t | distributions of these resonances are presented.

(1710)

The reaction pp ! pf(!!)ps has been studied at 450 GeV/c and a spin analysis of the !! channel has been performed for the rst time in central production. Evidence is found for the f2(1910) in the J PC =2 ++ wave with spin projection JZ = 2. This is the only state observed in central production with spin projection JZ =2 . ItsdPT and dependencies are similar to those observed for other glueball candidates. In addition, evidence is found for a state with J PC =4 ++ consistent with the f4(2300). The f0(2000), previously observed in the