101 research outputs found
A study of the etapipi channel produced in central pp interactions at 450 GeV/c
The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is
clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870).
In addition, there is evidence for an a0(980)pi$ decay mode of both resonances
and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC
= 2++ a2(1320)pi wave.Comment: 15 pages, Latex, 4 Figures Branching ratio a2pi /f2 eta correcte
A study of the centrally produced pi0pi0pi0 channel in pp interactions at 450 GeV/c
The reaction pp -> pf (pi0pi0pi0) ps has been studied at 450 GeV/c. The
pi0pi0pi0 effective mass spectrum shows clear eta(547) and pi2(1670) signals.
Branching ratios for the eta(547) and pi_2(1670) are given as well as upper
limits for the decays of the omega(782), a1(1260) and a2(1320) into 3pi0.Comment: 10 pages, Latex, 4 Figure
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
A search for charmonium states produced in central pp interactions at 450 GeV/c
A search for centrally produced charmonium states has been presented. There
is no significant evidence for any charmonium production. An upper limit of 2
nb is found for the cross section of chic production using the decay chic(1P)->
J/psi gamma.Comment: 10 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
A study of the centrally produced baryon-antibaryon systems in pp interactions at 450 GeV/c
A study of the centrally produced ppbar, ppbarpi, ppbarpipi and lambda lambda
channels has been performed in pp collisions using an incident beam momentum of
450 GeV/c. No significant new structures are observed in the mass spectra,
however, important new information on the production dynamics is obtained. A
systematic study of the production properties of these systems has been
performed and it is found that these systems are not produced dominantly by
double Pomeron exchange.Comment: 13 pages, Latex, 4 Figure
A study of pseudoscalar states produced centrally in pp interactions at 450 GeV/c
A study has been made of pseudoscalar mesons produced centrally in pp
interactions. The results show that the eta and etaprime appear to have a
similar production mechanism which differs from that of the pi0. The production
properties of the eta and etaprime are not consistent with what is expected
from double Pomeron exchange. In addition the production mechanism for the eta
and etaprime is such that the production cross section are greatest when the
azimuthal angle between the pT vectors of the two protons is 90 degrees.Comment: 11 pages, Latex, 3 Figure
A measurement of the branching fractions of the f1(1285) and f1(1420) produced in central pp interactions at 450 GeV/c
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.Comment: 15 pages, Latex, 5 Figures, submitted to Physics Letters
A study of the centrally produced phiphi system in pp interactions at 450 GeV/c
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.Comment: 11 pages, Latex, 4 Figure
- …