42 research outputs found
Magnetic moment of the pentaquark with light-cone QCD sum rules
In this article, we study the magnetic moment of the pentaquark state as diquark-diquark-antiquark () state in the
framework of the light-cone QCD sum rules approach. The numerical results
indicate the magnetic moment of the pentaquark state is about
.Comment: 10 pages, 1 figure. The main contents of this article is included in
hep-ph/0503007, this article will not be submitted to a journal for
publicatio
Quark-model study of few-baryon systems
We review the application of non-relativistic constituent quark models to
study one, two and three non-strange baryon systems. We present results for the
baryon spectra, potentials and observables of the NN, N,
and NN systems, and also for the binding energies of three
non-strange baryon systems. We make emphasis on observable effects related to
quark antisymmetry and its interplay with quark dynamics.Comment: 82 pages, 36 figures, 18 tables. Accepted for publication in Reports
on Progress in Physic
Prospects for Pentaquark Searches in Annihilations and Collisions
Recent strong experimental evidence of a narrow exotic S = +1 baryon
resonance, , suggests the existence of other exotic baryons. We
discuss the prospects of confirming earlier experimental evidence of
and the observation of additional hypothetical exotic baryons in
annihilations and collisions at LEP and B Factories
Atmospheric Muon Flux at Sea Level, Underground, and Underwater
The vertical sea-level muon spectrum at energies above 1 GeV and the
underground/underwater muon intensities at depths up to 18 km w.e. are
calculated. The results are particularly collated with a great body of the
ground-level, underground, and underwater muon data. In the hadron-cascade
calculations, the growth with energy of inelastic cross sections and pion,
kaon, and nucleon generation in pion-nucleus collisions are taken into account.
For evaluating the prompt muon contribution to the muon flux, we apply two
phenomenological approaches to the charm production problem: the recombination
quark-parton model and the quark-gluon string model. To solve the muon
transport equation at large depths of homogeneous medium, a semi-analytical
method is used. The simple fitting formulas describing our numerical results
are given. Our analysis shows that, at depths up to 6-7 km w. e., essentially
all underground data on the muon intensity correlate with each other and with
predicted depth-intensity relation for conventional muons to within 10%.
However, the high-energy sea-level data as well as the data at large depths are
contradictory and cannot be quantitatively decribed by a single nuclear-cascade
model.Comment: 47 pages, REVTeX, 15 EPS figures included; recent experimental data
and references added, typos correcte
Search for a strongly decaying neutral charmed pentaquark
We present a search for a charmed pentaquark decaying strongly to
. Finding no evidence for such a state, we set limits on the cross
section times branching ratio relative to and under particular
assumptions about the production mechanism.Comment: To be published in Physics Letters
A-dependence of phi-meson production in p+A collisions
A systematic analysis of the A-dependence of phi-meson production in
proton-nucleus collisions is presented. We apply different formalisms for the
evaluation of the phi-meson distortion in nuclei and discuss the theoretical
uncertainties of the data analysis. The corresponding results are compared to
theoretical predictions. We also discuss the interpretation of the extracted
results with respect to different observables and provide relations between
frequently used definitions. The perspectives of future experiments are
evaluated and estimates based on our systematical study are given.Comment: 14 pages, 8 figure
Search for Exotic S=-2 Baryons in proton-antiproton Collisions at sqrt(s) = 1.96 TeV
A search for a manifestly exotic S=-2 baryon state decaying to Xi- pi-, and
its neutral partner decaying to Xi- pi+, has been performed using 220 pb^(-1)
of pp= collisions at sqrt(s)=1.96 TeV collected by the Collider Detector at
Fermilab. The Xi trajectories were measured in a silicon tracker before their
decay, resulting in a sample with low background and excellent position
resolution. No evidence was found for S=-2 pentaquark candidates in the
invariant mass range of 1600--2100 MeV/c^2 Upper limits on the product of
pentaquark production cross section times its branching fraction to Xi-
pi^{+,-}, relative to the cross section of the well established Xi(1530)
resonance, are presented for neutral and doubly negative candidates with pT>2
GeV/c and |y|<1 as a function of pentaquark mass. At 1862 MeV/c^2, these upper
limits for neutral and doubly negative final states were found to be 3.2% and
1.7% at the 90% confidence level, respectively.Comment: 10 pages, 5 figures, Submitted to Phys. Rev.