I. Minashvili

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.

Observation of a narrow scalar meson at 1450 MeV in the reaction pp → pƒ(π+π−π+π−)ps at 450 GeV/c using the CERN Omega spectrometer

Abstract The reaction pp → pƒ(π + π − π + π − )p s has been studied at 450 GeV/c in an experiment designed to search for gluonic states. In addition to the well known ƒ 1 (1285) , the π+π−π+π− mass spectrum shows evidence for two states pre only observed by the WA76 experiment, the X(1450) and X(1900). An analysis of the X(1450) shows that it is a relatively narrow state (Γ = 56 ± 12 MeV) with I(JPC) = 0(0++) which decays to ϱ0π+π−. The X (1900) could either b single broad state (Γ = 370±70 MeV) with I(JPC) = 0(2++) or possibly separate states.

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 An analysis of the centrally produced π + π − and π + π − π + π − mass spectra from the WA76 and WA91 experiments is presented, which shows that in the π + π − π + π − channel there are two new states, the f 0 (1450) and f 2 (1900). There is another new state in the π + π − channel with M = 1497 ± 30 MeV and Γ = 199 ± 30 MeV, which is compatible with the f 0 (1520) observed by the Crystal Barrel experiment. Another interpretation is discussed, where the 1450 and 1497 GeV structures are explained as being due to an interference effect between the f 0 (1365) and f 0 (1520).

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

The reaction pp ->pf (pi+pi-pi+pi-) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. In addition to the well known f1(1285) there is evidence for two JPC=2-+ states called the eta2(1620) and eta2(1875) and a broad scalar called the f0(2000). The production of these states as a function of the dPT kinematical filter shows the behaviour expected for qqbar states. In contrast, there is evidence for two states at 1.45 GeV and at 1.9 GeV which do not show the behaviour observed for qqbar states.Abstract The reaction pp → pf(π+ π− π+ π−)ps has been studied at 450 GeV/c in an experiment designed to search for gl states. A spin analysis has been performed and the dPT filter applied. In addition to the well know f1(1285) there is evidence for two JPC = 2−+ states called the η2(1620) and η2(1875) and a broad scalar called the f0(2000). The production of these states as a function of the dPT kinematical filter shows the behaviour expected for q q states. In contrast, there is evidence for two states at 1.45 GeV and at 1.9 GeV which do not show the behaviour observed for q q states.

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

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.

f_{1}

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.