GlueBall: Experiment
- The Glueball Candidate \eta(1440) as \eta Radial Excitation
Eberhard Klempt
hep-ph/0409148
The Particle Data Group decided to split the $\eta(1440)$ into two states,
called $\eta_L$ and $\eta_H$. The $\eta(1295)$ and the $\eta_H$ are supposed to
be the radial excitations of the $\eta$ and $\eta'$, respectively. The $\eta_L$
state cannot be accomodated in a quark model; it cannot be a $q\bar q$ state,
however, it might be a glueball. In this contribution it is shown that that the
$\eta(1295)$ does not have the properties which must be expected for a radially
excited state. The splitting of the $\eta(1440)$ is traced to a node in the
wave function of a radial excitation. Hence the two peaks, $\eta_L$ and
$\eta_H$, originate from one resonance which is interpreted here as first
radial excitation of the $\eta$.
- Evidence for a 4th state related to the three JPC = 2++, pi- p -> phi
phi n states explainable by 2++ Glueball production
R.S. Longacre, S.J. Lindenbaum, D.V. Bugg
hep-ex/0407054
Four separate experiments, observing the OZI forbidden disconnected reaction
pi- p -> phi phi n with increasing statistics were consistent. These
experiments very selectively completely broke down the OZI suppression by 3 phi
phi resonances with IG JPC = 0+ 2++ in the observed mass region 2.038 to 2.600
GeV. The only viable proposed explanation has been that the IG JPC = 0+ 2++
Glueball expected in this mass region caused the hard glue in the disconnection
to resonate and very selectively breakdown the OZI suppression for its quantum
numbers only. Recently a p p central production spin analysis found the
f2(1950) had a dominant decay mode f2(1270) pi pi. We consider if it is related
to the phi phi resonances, and find that it likely is.
- Tests of model of color reconnection and a search for glueballs using
gluon jets with a rapidity gap
The OPAL collaboration, G. Abbiendi, et al.
hep-ex/0306021
Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from
hadronic Z0 decay events produced in e+e- annihilations. A subsample of these
jets is identified which exhibits a large gap in the rapidity distribution of
particles within the jet. After imposing the requirement of a rapidity gap, the
gluon jet purity is 86%. These jets are observed to demonstrate a high degree
of sensitivity to the presence of color reconnection, i.e. higher order QCD
processes affecting the underlying color structure. We use our data to test
three QCD models which include a simulation of color reconnection: one in the
Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman
in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection
models can describe our gluon jet measurements only if very large values are
used for the cutoff parameters which serve to terminate the parton showers, and
that the description of inclusive Z0 data is significantly degraded in this
case. We conclude that color reconnection as implemented by these two models is
disfavored. The signal from the Herwig color reconnection model is less clear
and we do not obtain a definite conclusion concerning this model. In a separate
study, we follow recent theoretical suggestions and search for glueball-like
objects in the leading part of the gluon jets. No clear evidence is observed
for these objects.
- Possible Hints and Search for Glueball Production in Charmless Rare B
Decays
Chun-Khiang Chua, Wei-Shu Hou and Shang-Yuu Tsai
hep-ph/0204186
Recent data on B->p pbar K, K0 pi pi and K Kbar K hint at a $\sim 2.3$ GeV
object recoiling against a kaon. This could be the narrow state observed in
J/\psi -> gamma xi. Nonobservation in p pbar annihilation implies ${\cal B}(\xi
\to p\bar p) \sim$ few $\times 10^{-3}$, consistent with eta_c and J/\psi
decays, but there are actual hints in p pbar -> phi phi and p p-> p pi^+ pi^-
pi^+ pi^- p. Simple modeling shows ${\cal B}(B \to \xi K){\cal B}(\xi \to p\bar
p) \sim 1\times 10^{-6}$, appearing as a spike in the $p\bar p$ spectrum, with
$\sim$ 30 events per 100 fb$^{-1}$; modes such as K K_s K_s, K phi phi, K4 pi
(K f_2 pi pi) etc. should be explored. The underlying dynamics of g* -> g xi is
analogous to g* -> g etaprime or gluon fragmentation. Discovery of sizable B ->
xi K could be useful for CP violation studies.
- Anti-Search for the Glueball Candidate f_J(2220) in Two-Photon
Interactions
K. Benslama, et al, CLEO Collaboration
hep-ex/0204019
Using 13.3 fb^{-1} of e^+e^- data recorded with the CLEO II and CLEO II.V
detector configurations at CESR, we have searched for f_J(2220) decays to
K^0_{S} K^0_{S} in untagged two-photon interactions. We report an upper limit
on the product of the two-photon partial width and the branching fraction,
Gamma_gamma gamma cdot B (f_J(2220) to K^0_{S} K^0_{S}) of less than 1.1 eV at
the 95% C.L: systematic uncertainties are included. This dataset is four times
larger than that used in the previous CLEO publication.
- The width of the \xi(2230) meson
L. C. Liu
hep-ph/0201237
A lower bound of 135 MeV for the width of the \xi meson is obtained from
analyzing the pp and pbar-p interactions by use of Regge theory. The pp data
exclude a narrow \xi as the latter would lead to total pbar-p cross sections
far exceeding the measured ones. The broad width explains why the \xi may not
be seen in pbarp-p experiments.
- Light Hadron Spectroscopy at BEPC
B.S. Zou
hep-ph/0011174
The $J/\Psi$ and $\Psi'$ experiments at the Beijing Electron Positron
Collider (BEPC) play a unique role in many aspects of light hadron
spectroscopy, such as hunting for glueballs and hybrids, extracting $u\bar
u+d\bar d$ and $s\bar s$ components of mesons, and studying excited nucleons
and hyperons, i.e., $N^*$, $\Lambda^*$, $\Sigma^*$ and $\Xi^*$ resonances.
Physics objectives, recent results and future prospects of light hadron
spectroscopy at BEPC are presented.
- K0sK0s Final State and Glueball Searches and Lambda-Lambdabar Production
in Two-Photon Collisions in L3 at LEP
Saverio Braccini
hep-ex/0010030
The K0sK0s final state in two-photon collisions is studied with the L3
detector at LEP using data collected at centre-of-mass energies from 91 GeV to
202 GeV. The mass spectrum is dominated by the formation of the f_2'(1525)
tensor meson in the helicity two state. The two-photon width times the
branching ratio is measured to be Gamma_{gamma
gamma}(f_2'(1525))Br(f_2'(1525)->KKbar) = 0.076 +- 0.006 +- 0.011 keV. Clear
evidence for destructive f_2(1270)-a_2(1320) interference is observed. In
addition a clear signal for f_J(1750) is observed. The study of the decay
angular distribution in the 1750 MeV mass region shows that the spin two
helicity two wave is dominant. No signal is observed in the region around 2.2
GeV. The upper limit for the two-photon partial width of the \xi(2230) tensor
glueball candidate of Gamma_{gamma gamma}(\xi(2230))Br(\xi(2230)->K0sK0s)<1.4
eV at 95% C.L. is derived. The production of Lambda-Lambdabar pairs in
two-photon collisions is also studied. The cross section is compared to
quark-diquark model predictions.
- A study of the f0(1370), f0(1500), f0(2000) and f2(1950) observed in the
centrally produced 4pi final states
The WA102 Collaboration, D. Barberis, et al
hep-ex/0001017
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.
- A spin analysis of the 4pi channels produced in central pp interactions
at 450 GeV/c
The WA102 Collaboration, D. Barberis, et al
hep-ex/9912005
The reactions pp -> pf (X0) ps, where X0 is observed decaying to
pi0pi0pi0pi0, pi+pi-pi0pi0 and pi+pi-pi+pi-, have been studied at 450 GeV/c.
There is evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870)
in the pi+pi-pi0pi0 and pi+pi-pi+pi- final states. The f2(1950) is consistent
with being a single resonance with a dominant f2(1270)pipi decay mode. The
f0(1370) is found to decay dominantly to rho-rho while the f0(1500) is found to
decay to rho-rho and sigma-sigma.
- A study of the eta etaprime and etaprime etaprime channels produced in
central pp interactions at 450 GeV/c
The WA102 Collaboration, D. Barberis, et al
hep-ex/9911041
The reactions pp -> pf (X0) ps, where X0 is observed decaying to eta etaprime
and etaprime etaprime, have been studied at 450 GeV/c. This is the first time
that these channels have been observed in central production and only the
second time that the etaprime etaprime channel has been observed in any
production mechanism. In the eta etaprime channel there is evidence for the
f0(1500) and a peak at 1.95 GeV. The etaprime etaprime channel shows a peak at
threshold which is compatible with having JPC = 2++ and spin projection JZ = 0.
- Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions
ALEPH Collaboration
hep-ex/9911022
Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma
production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal
is observed and upper limits to the product of gamma gamma width and pi+pi- branching ratio
of the f0(1500) and the fJ(1710) have been measured to be Gamma_(gamma gamma ->
f0(1500)). BR(f0(1500)->pi+pi-) < 0.31 keV and Gamma_(gamma gamma -> fJ(1710)).
BR(fJ(1710)->pi+pi-) < 0.55 keV at 95% confidence level.
- Search for Glueballs from Three-body Annihilation of Antiproton-Proton
in-Flight
By Bing-Song Zou
hep-ex/9812007
Lattice QCD and other theoretical models predict that the 0(-+), 2(++) and
2(-+) glueballs have masses in the range of 2.0 to 2.4 GeV. For resonances in
such an energy range, three-body decay modes are expected to be large. The
strategy for looking for these glueballs and the newest results from studying
Crystal Barrel data on the three-body annihilation of proton-antiproton in
flight are presented.
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FURTHER SEARCH FOR THE TWO PHOTON PRODUCTION OF THE GLUEBALL CANDIDATE
F(J)(2220).
By CLEO Collaboration (M.S. Alam et al.). CLNS-98-1560, May 1998. 8pp.
e-Print Archive: hep-ex/9805033
The CLEOII detector at the Cornell e+ e- storage ring CESR
has been used to search for the two-photon production of the $f_J(2220)$
decaying into pi+ pi-. No evidence for a signal is found in data corresponding
to an integrated luminosity of 4.77/fb and a 95% CL upper limit on $\Gamma_{two-photon}
* BR{pi+ pi-}$ of 2.5 eV is set. If this result is combined with the BES
Collaboration's measurement of $f_J(2220) -> pi+ pi-$ in radiative $J/\psi$
decay, a 95% CL lower limit on the stickiness of the $f_J(2220)$ of 73
is obtained. If the recent CLEO result for $\Gamma_{two-photon} * BR{\K_S
K_S}$ is combined with the present result, the stickiness of the $f_J(2220)$
is found to be larger than 102 at the 95% CL. These results for the stickiness
(the ratio of the probabilities for two-gluon coupling and two-photon coupling)
provide further support for a substantial neutral parton content in the
$f_J(2220)$.
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INCLUSIVE ETA-MESONS PRODUCTION AT HIGH HADRON ENERGIES AND POSSIBLE
GLUEBALL FORMATION IN CENTRAL COLLISIONS.
A.A. Komar, S.P. Baranov (Lebedev Inst.). 1996. In *Protvino 1987,
The experimental program at UNK* 98-101.
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EXPERIMENT TO STUDY GLUON INTERACTIONS AND GLUEBALL PRODUCTION IN THE
CENTRAL REGION OF HADRON COLLISIONS IN THE ENERGY RANGE 500-GEV TO 3000-GEV
AT UNK. (DESIGN STUDY OF THE EXPERIMENT GLUON).
Yu.D. Prokoshkin (Serpukhov, IFVE). 1996. In *Protvino 1987, The
experimental program at UNK* 214-252.
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SEARCH FOR A VECTOR GLUEBALL BY A SCAN OF THE J / PSI RESONANCE.
BES Collaboration (J.Z. Bai et al.). PRINT-96-127 (BEIJING), Feb
1996. 18pp. Published in Phys.Rev. D54:1221-1224, 1996, Erratum-ibid.D57:3187,1998.
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CRYSTAL BARREL RESULTS ON TWO BODY DECAYS OF THE SCALAR GLUEBALL.
Crystal Barrel collaboration (Stefan Spanier for the collaboration).
UZH-PH-23-98, Jan 1998. 5pp. Talk given at International Europhysics Conference
on High-Energy Physics (HEP 97), Jerusalem, Israel, 19-26 Aug 1997.
e-Print Archive: hep-ex/9801006
The Crystal Barrel Collaboration observes scalar meson resonances
in $\bar p p$ annihilation. Based on the measurements and partial wave
analyses these are candidates for the $^3$P$_0$ groundstate nonet. The
supernummerary $f_0(1500)$ resonance is identified as a scalar groundstate
glueball. Important information for its characterization comes from the
decay pattern into pseudoscalar and scalar mesons. Data on kaonic decays
in the mass region up to 1700 MeV are now avaible at Crystal Barrel. New
analysis results are presented.
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LIMIT ON THE TWO PHOTON PRODUCTION OF THE GLUEBALL CANDIDATE F(J) (2220)
AT CLEO.
By CLEO Collaboration (R. Godang et al.). CLNS-97-1467, Mar 1997. 9pp.
Published in Phys.Rev.Lett.79:3829-3833,1997. e-Print Archive: hep-ex/9703009
We use the CLEO detector at the Cornell electron-positron
storage ring, CESR, to search for the two-photon production of the glueball
candidate f_J(2220) in its decay to K_s K_s. We present a restrictive upper
limit on the product of the two-photon partial width and the K_s K_s branching
fraction. We use this limit to calculate a lower limit on the stickiness,
which is a measure of the two-gluon coupling relative to the two-photon
coupling. This limit on stickiness indicates that the f_J(2220) has substantial
glueball content.
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A KINEMATICAL SELECTION OF GLUEBALL CANDIDATES IN CENTRAL PRODUCTION.
WA102 Collaboration (D. Barberis et al.). CERN-PPE-96-197, Dec 1996.
11pp. Published in Phys.Lett.B397:339-344,1997
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OBSERVATION OF F2 (2175) MESON AS A POSSIBLE TENSOR GLUEBALL.
GAMS Collaboration (Yu.D. Prokoshkin for the collaboration). 1995.
Published in Phys.Dokl.40:495-499,1995, Dokl.Akad.Nauk Ser.Fiz.344:469-473,1995
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GLUEBALL CANDIDATES SEEN IN THE REACTIONS ANTI-P NE-20 AND ANTI-P HE-4
AT 607-MEV/C.
F. Balestra (Cagliari U.), G. Bendiscioli, V. Filippini, A. Rotondi,
P. Salvini, A. Zenoni (Pavia U.), S. Bossolasco, M.P. Bussa, L. Busso,
L. Fava, L. Ferrero, A. Grasso, A. Maggiora, D. Panzieri, G. Piragino,
F. Tosello (Turin U.), C. Guaraldo (Frascati), E. Lodi Rizzini (Brescia
U.), Yu.A. Batusov, S.A. Bunyatov, I.V. Falomkin, F. Nichitiu, G.B. Pontecorvo,
A.M. Rozhdestvenskii, M.G. Sapozhnikov, V.I. Tretyak (Dubna, JINR), A.
Haatuft, A. Halsteinslid, K. Myklebost, J.M. Olsen (Bergen U.), K.M. Danielsen,
T. Jacobsen (Oslo U.). 1991. Published in Phys.Scripta 44:323-327,1991
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LOW LYING GLUEBALL PRODUCTIONS IN POLARIZED GAMMA GAMMA COLLISIONS.
Zai- Xin Xu, Cheng- Guo Hu (East China Normal U.). 1988. In *Minneapolis
1988, Proceedings, High-energy spin physics, vol. 1* 295-297.