New effects observed in central production by experiment WA102 at the CERN Omega Spectrometer

A partial wave analysis of the centrally produced KK and pipi systems shows that the fJ(1710) has J = 0. In addition, a study of central meson production as a function of the difference in transverse momentum (dPT) of the exchanged particles shows that undisputed qqbar mesons are suppressed at small dPT whereas the glueball candidates are enhanced and that the production cross section for different resonances depends strongly on the azimuthal angle between the two outgoing protons.Comment: 5 pages, Latex, 3 Figures to appear in the proceeding of PANIC 99, Uppsala, Sweden, June 199

Resonance production in central pp collisions at the CERN Omega Spectrometer

A study of resonance production in central pp collisions is presented as a function of several kinematical variables. In particular the difference in the transverse momentum (dPT) of the exchanged particles shows that undisputed qqbar mesons are suppressed at small dPT whereas glueball candidates are enhanced and in addition, the azimuthal angle phi gives information on the nature of the Pomeron.Comment: 14 pages, Latex, 5 Figure

A study of the pi^0pi^0 system produced in charge exchange and central collisions

A study of the $\pi^0\pi^0$ system produced in charge exchange $\pi^-p$ collisions at 38 and 100 GeV/c and in central $pp$ interactions at 450 GeV/c has been carried out. The $S$ wave has rather a complicated structure in both processes indicating the existence of several scalar resonances. The $f_0(980)$ and $f_0(1500)$ appear as dips at 1 and 1.5 GeV in the $S$ wave for charge exchange reaction, and as shoulders at these masses in the $S$ wave for central production. The production of the $f_0(980)$, $f_0(1300)$ and $f_0(1500)$ in the reaction $pp \to p_f\pi^0\pi^0p_s$ as a function of the $dP_{T}$ kinematical filter shows the behaviour differed from what has been observed for the undisputed $q\bar{q}$ mesons. An extra $f_0(2000)$ state is seen in the $S$ wave for charge exchange reaction as a dip at 2 GeV. Resonances with higher spins, $f_2(1270)$, $f_4(2050)$ and $f_6(2510)$, have also been studied. All the three mesons are produced in the reaction $\pi^-p\to\pi^0\pi^0{n}$ mainly via an one-pion exchange for small $-t$, whereas a natural-parity exchange domimates for large $-t$. The behaviour of the centrally produced $f_2(1270)$ as a function of the $dP_{T}$ is consistent with what has been observed for other $q\bar{q}$ states.Comment: 6 pages, 6 figures, use file stwol.sty, presented at International High-Energy Physics Euroconference in Quantum Chromodynamics, 2-8 July 1998, Montpellier, France on behalf of the GAMS and WA102 Collaboration

A study of the f0(1370), f0(1500), f0(2000) and f2(1950) observed in the centrally produced 4pi final states

The production and decay properties of the f0(1370), f0(1500), f0(2000) and f2(1950) have been studied in central pp interactions at 450 GeV/c. The dPT, phi and |t| distributions of these resonances are presented. For the J = 0 states, the f0(1370) and f0(2000) have similar dPT and phi dependences. These are different to the dPT and phi dependences of the f0(980), f0(1500) and f0(1710). For the J = 2 states the f2(1950) has different dependences to the f2(1270) and f2'(1520). This shows that the dPT and phi dependences are not just J phenomena.Comment: 14 pages, Latex, 4 Figure

Experimental evidence for a vector-like behaviour of Pomeron exchange

Evidence is presented that the Pomeron act as a non-conserved vector current. A study has been made of the azimuthal angle phi, which is defined as the angle between the pT vectors of the two outgoing protons, in the reaction pp -> pp(X0) for those resonances (X0) 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 pi-Pomeron exchange, the phi distribution is flat.Comment: 13 pages, Latex, 4 Figure

A coupled channel analysis of the centrally produced K+K- and pi+pi- 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.Comment: 16 pages, Latex, 5 Figure