714 research outputs found
Multi-Quark Hadrons and S=-2 Hypernuclei
The general character of 4-quark (mesonic) and strange 6-quark (baryonic)
quark systems is very briefly reviewed a la Jaffe, i.e. in the MIT bag, and so
far still possibly viable candidates are indicated. Concentration is on S=-2
systems. Traditionally, one employs the (K^-,K^+) reaction on a relatively
light target and hopes to retain two units of strangeness on a single final
state fragment. Alternatively, heavy ion reactions can be used to produce
Lambda-hyperons copiously and one seeks to observe coalescence of two of these
particles into the lightest S=-2 nucleus, the H-dibaryon. The complications
arising from the presence of a repulsive core in the baryon-baryon interaction
on the production of the H are discussed. Also considered is the possible
presence in the data from the AGS experiment E906, of slightly heavier S=-2
nuclei, in particular_{Lambda Lambda}^{4}H
Elliptical Flow in Relativistic Ion Collisions at s^(1/2)= 200 A GeV
A consistent picture of the Au+Au and D+Au, s^1/2 = 200 A GeV measurements at
RHIC obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors including both
the rapidity and transverse momentum spectra was previously developed with the
simulation LUCIFER. The approach was modeled on the early production of a fluid
of pre-hadrons after the completion of an initial, phase of high energy
interactions. The formation of pre-hadrons is discussed here, in a perturbative
QCD approach as advocated by Kopeliovich, Nemchik and Schmidt. In the second
phase of LUCIFER, a considerably lower energy hadron-like cascade ensues. Since
the dominant collisions occurring in this latter phase are meson-meson in
character while the initial collisions are between baryons, i.e. both involve
hadron sized interaction cross-sections, there is good reason to suspect that
the observed elliptical flow will be produced naturally, and this is indeed
found to be the case.Comment: 7 pages, 6 figure
The H-Dibaryon and the Hard Core
The H dibaryon, a single, triply magic bag containing two up, two down and
two strange quarks, has long been sought after in a variety of experiments. Its
creation has been attempted in , proton and most recently in relativistic
heavy ion induced reactions. We concentrate on the latter, but our conclusions
are more generally applicable. The two baryons coalescing to form the single
dibaryon, likely in the case of heavy ions, must penetrate
the short range repulsive barrier which is expected to exist between them. We
find that this barrier can profoundly affect the probability of producing the H
state, should it actually exist.Comment: 9 pages including 4 figure
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