37 research outputs found
A search for J^{PC}=1^{-+} exotic mesons in the pi- pi- pi+ and pi- pi0 pi0 systems
A partial wave analysis (PWA) of the pi-pi-pi+ and pi-pi0pi0 systems produced
in the reaction pi- p -> (3pi)-p at 18 GeV/c was carried out using an isobar
model assumption. This analysis is based on 3.0M pi-pi0pi0 events and 2.6M
pi-pi-pi+ events and shows production of the a2(1320), pi2(1670) and \pi(1800)
mesons. An earlier analysis of 250K pi-pi-pi+ events from the same experiment
showed possible evidence for a J^{PC}=1^{-+}$ exotic meson with a mass of 1.6
GeV/c^2 decaying into rho pi. In this analysis of a higher statistics sample of
the (3pi)- system in two charged modes we find no evidence of an exotic meson.Comment: 4 pages, 5 figures, added comment about the negative reflectivity
exotic wave
Observation of exotic meson production in the reaction at 18 GeV/c
An amplitude analysis of an exclusive sample of 5765 events from the reaction
at 18 GeV/c is described. The
production is dominated by natural parity exchange and by
three partial waves: those with and . A
mass-dependent analysis of the partial-wave amplitudes indicates the production
of the meson as well as the meson, observed for the
first time decaying to . The dominant, exotic
(non- partial wave is shown to be resonant with a mass of
GeV/c^2 and a width of GeV/c^2 . This exotic state, the , is produced with a
dependence which is different from that of the meson, indicating
differences between the production mechanisms for the two states.Comment: 5 pages with 4 figure
Partial-wave analysis of the eta pi+ pi- system produced in the reaction pi-p --> eta pi+ pi- n at 18 GeV/c
A partial-wave analysis of 9082 eta pi+ pi- n events produced in the reaction
pi- p --> eta pi+ pi- n at 18.3 GeV/c has been carried out using data from
experiment 852 at Brookhaven National Laboratory. The data are dominated by
J^{PC} = 0^{-+} partial waves consistent with observation of the eta(1295) and
the eta(1440). The mass and width of the eta(1295) were determined to be 1282
+- 5 MeV and 66 +- 13 Mev respectively while the eta(1440) was observed with a
mass of 1404 +- 6 MeV and width of 80 +- 21 MeV. Other partial waves of
importance include the 1++ and the 1+- waves. Results of the partial wave
analysis are combined with results of other experiments to estimate f1(1285)
branching fractions. These values are considerably different from current
values determined without the aid of amplitude analyses.Comment: 22 pages, 8 figure
Evidence for Exotic J^{PC}=1^{-+} Meson Production in the Reaction pi- p --> eta pi- p at 18 GeV/c
Details of the analysis of the eta pi- system studied in the reaction pi^{-}
p --> eta pi^{-} p at 18 GeV/c are given. Separate analyses for the 2 gamma and
pi+ pi- pi0 decay modes of the eta are presented. An amplitude analysis of the
data indicates the presence of interference between the a(2)(1320)- and a
J^{PC}=1^{-+} wave between 1.2 and 1.6 GeV/c^2. The phase difference between
these waves shows phase motion not attributable solely to the a(2)(1320)-. The
data can be fitted by interference between the a(2)(1320)- and an exotic 1^{-+}
resonance with M = 1370 +-16 +50 -30} MeV/c^2 and Gamma = 385 +- 40 +65 -105
MeV/c^2. Our results are compared with those of other experiments.Comment: 50 pages of text and 34 figure
A partial wave analysis of the system produced in charge exchange collisions
A partial wave analysis of the of the system produced in the
charge exchange reaction: at an incident momentum of
is presented as a function of invariant mass,
, and momentum transfer squared, , from the incident
to the outgoing system.Comment: 24 pages total,8 pages text, 14 figures, 1 table. Submitted to Phys
Rev
Search for Exotic Mesons in pi- P Interactions at 18 GeV/c
The recent search for non mesons in interactions at
Brookhaven National Laboratory is summarized. Many final states such as , , , , , ,
which are favored decay modes of exotics, are under investigation.Comment: 9 pages, PostScript, Presented at the International School of Nuclear
Physics, Erice, Sicily, Italy, September 199
Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV
A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a
beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows
evidence for three pseudoscalar resonances, eta(1295), eta(1416), and
eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed
masses, widths and decay properties are reported. No signal was observed for
C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.Comment: 7 pages, 6 figs, to be submitted to Phys. Let
Exotic Meson Production in the System observed in the Reaction at 18 GeV/c
This letter reports results from the partial wave analysis of the
final state in collisions at 18GeV/c.
Strong evidence is observed for production of two mesons with exotic quantum
numbers of spin, parity and charge conjugation, in the decay
channel . The mass MeV/c^2 and
width MeV/c^2 of the first state are consistent
with the parameters of the previously observed . The second
resonance with mass MeV/c^2 and width MeV/c^2 agrees very well with predictions from theoretical
models. In addition, the presence of is confirmed with mass MeV/c^2 and width MeV/c^2
and a new state, , is observed with mass
MeV/c^2 and width MeV/c^2. The decay properties of
these last two states are consistent with flux tube model predictions for
hybrid mesons with non-exotic quantum numbers
Observation of a New J(PC)=1(+-) Isoscalar State in the Reaction Pi- Proton -> Omega Eta Neutron at 18 GeV/c
Results are presented on a partial wave analysis of the Omega Eta final state
produced in Pi- Proton interactions at 18 GeVc where Omega -> Pi+ Pi- Pi0, Pi0
-> 2 Gammas, and Eta -> 2 Gammas. We observe the previously unreported decay
mode Omega(1650) -> Omega Eta and a new 1(+-) meson state h1(1595) with a mass
M=1594(15)(+10)(-60) MeV/c^2 and a width Gamma=384(60)(+70)(-100) MeV/c^2. The
h1(1595) state exhibits resonant-like phase motion relative to the Omega(1650).Comment: Submitted to Physics Letters B Eight total pages including 11 figures
and 1 tabl