32 research outputs found
Theoretical analysis for the apparent discrepancy between pbarp and pp data in charged particle forward-backward multiplicity correlations
The strength of charged particle forward-backward multiplicity correlation in
pbar+p and p+p collisions at s^1/2 = 200 GeV is studied by PYTHIA 6.4 and
compared to the UA5 and STAR data correspondingly. It is turned out that a
factor of 3-4 apparent discrepancy between UA5 and STAR data can be attributed
to the differences in detector acceptances and observing bin interval in both
experiments. A mixed event method is introduced and used to calculate the
statistical correlation strength and the dynamical correlation strengths
stemming from the charge conservation, four- momentum conservation, and decay,
respectively. It seems that the statistical correlation is much larger than
dynamical one and the charge conservation, four-momentum conservation and decay
may account for most part of the dynamical correlation. In addition, we have
also calculated the correlation strength by fitting the charged particle
multiplicity distribution from PYTHIA to the Negative Binomial Distribution and
found that the result agrees well with the correlation strength calculated by
mixed events.Comment: 5 pages, 4 figure
Superposition effect and clan structure in forward-backward multiplicity correlations
The main purpose of this paper is to discuss the link between
forward-backward multiplicity correlations properties and the shape of the
corresponding final charged particle multiplicity distribution in various
classes of events in different collisions. It is shown that the same mechanism
which explains the shoulder effect and the H_n vs. n oscillations in charged
particle multiplicity distributions, i.e., the weighted superposition of
different classes of events with negative binomial properties, reproduces
within experimental errors also the forward-backward multiplicity correlation
strength in e+e- annihilation at LEP energy and allows interesting predictions
for pp collisions in the TeV energy region, to be tested at LHC, for instance
with the ALICE detector. We limit ourselves at present to study substructures
properties in hadron-hadron collisions and e+e- annihilation; they are examined
as ancillary examples in the conviction that their understanding might be
relevant also in other more complex cases.Comment: 16 page
Semi-Inclusive Lambda and Kshort Production in p-Au Collisions at 17.5 GeV/c
The first detailed measurements of the centrality dependence of strangeness
production in p-A collisions are presented. Lambda and Kshort dn/dy
distributions from 17.5 GeV/c p-Au collisions are shown as a function of "grey"
track multiplicity and the estimated number of collisions, nu, made by the
proton. The nu dependence of the Lambda yield deviates from a scaling of p-p
data by the number of participants, increasing faster than this scaling for
nu<=5 and saturating for larger nu. A slower growth in Kshort multiplicity with
nu is observed, consistent with a weaker nu dependence of K-Kbar production
than Y-K production.Comment: 5 pages, 3 figures, formatted with RevTex, current version has
enlarged figure catpion
Production of photons and search for Centauro events at the SPS collider
The pseudorapidity distribution of photons produced in pp̄ interactions at s=540GeV has been measured and compared with that of charged particles. The correlation between photon and charged-particle production has been studied. A search amongst high multiplicity events for any having the properties of the Centauro events reported in cosmic-ray experiments has revealed no candidates in a sample of 3600 inelastic events. © 1982.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe