4,892 research outputs found
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
Evidence that the Pomeron transforms as a non-conserved vector current
The detailed dependences of central meson production on the azimuthal angle
phi, t and the meson J^P are shown to be consistent with the hypothesis that
the soft Pomeron transforms as a non-conserved vector current. Further tests
are proposed. This opens the way for a quantitative description of q-qbar and
glueball production in p p -> p M p.Comment: 12 pages, latex, 4 figure
Exact Description of Rotational Waves in an Elastic Solid
Conventional descriptions of transverse waves in an elastic solid are limited
by an assumption of infinitesimally small gradients of rotation. By assuming a
linear response to variations in orientation, we derive an exact description of
a restricted class of rotational waves in an ideal isotropic elastic solid. The
result is a nonlinear equation expressed in terms of Dirac bispinors. This
result provides a simple classical interpretation of relativistic quantum
mechanical dynamics. We construct a Lagrangian of the form L=-E+U+K=0, where E
is the total energy, U is the potential energy, and K is the kinetic energy.Comment: 9 pages; Added references in revisio
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
Scalar Glueball-qqbar Mixing above 1 GeV and implications for Lattice QCD
Lattice QCD predictions have motivated several recent studies of the mixing
between the predicted JPC = 0++ glueball and a qqbar nonet in the 1.3 to 1.7
GeV region. We show that results from apparently different approaches have some
common features, explain why this is so and abstract general conclusions. We
place particular emphasis on the flavour dependent constraints imposed by
decays of the f0(1370), f0(1500) and f0(1700) to all pairs of pseudoscalar
mesons. From these results we identify a systematic correlation between
glueball mass, mixing, and flavour symmetry breaking and conclude that the
glueball may be rather lighter than some quenched lattice QCD computations have
suggested. We identify experimental tests that can determine the dynamics of a
glueball in this mass region and discuss quantitatively the feasibility of
decoding glueball-qqbar mixing.Comment: 33 pages, Latex, 4 Figure
Light Hadron Spectroscopy: Theory and Experiment
Rapporteur talk at the Lepton-Photon Conference, Rome, July 2001: reviewing
the evidence and strategies for understanding scalar mesons, glueballs and
hybrids, the gluonic Pomeron and the interplay of heavy flavours and light
hadron dynamics. Dedicated to the memory of Nathan Isgur, long-time
collaborator and friend, whose original ideas in hadron spectroscopy formed the
basis for much of the talk.Comment: to be published in "Lepton Photon 2001 Conference Proceedings" (World
Scientific Publishing), 19 pages with 6 figure
Scalar mesons above and below 1 GeV
We show that two nonets and a glueball provide a consistent description of
data on scalar mesons below 1.7 GeV. Above 1 GeV the states form a conventional
(q bar q) nonet mixed with the glueball of lattice QCD. Below 1 GeV the states
also form a nonet, as implied by the attractive forces of QCD, but of more
complicated nature. Near the center they are 4 quark states of the Jaffe type
in S-wave, with some (q bar q) in P-wave, but further out they rearrange in
colour to two colourless (q bar q) pairs and finally as meson-meson states. A
simple effective chiral model for such a system with two scalar nonets can be
made involving two coupled linear sigma models. One of these could be looked
upon as the Higgs sector of nonpertubative QCD.Comment: 34 pages in Latex, minor improvements in sec
Central production of mesons: Exotic states versus Pomeron structure
We demonstrate that the azimuthal dependence of central meson production in
hadronic collisions, when suitably binned, provides unambiguous tests of
whether the Pomeron couples like a conserved vector-current to protons. We
discuss the possibility of discriminating between q-qbar and glueball
production in such processes. Our predictions apply also to meson production in
tagged two-photon events at electron--positron colliders and to vector-meson
production in ep collisions at HERA.Comment: 15 pages, latex, no figur
The role of secondary Reggeons in central meson production
We estimate the contribution of f_2 trajectory exchange to the central \eta
and \eta^\prime production. It is shown that secondary Reggeons may give a
large contribution to processes of double diffractive meson production at high
energy.Comment: 7 pages, Latex, 5 figure
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