959 research outputs found
Multiplicities in ultrarelativistic proton-(anti)proton collisions and negative binomial distribution fits
Likelihood ratio tests are performed for the hypothesis that charged-particle
multiplicities measured in proton-(anti)proton collisions at = 0.9
and 2.36 TeV are distributed according to the negative binomial form. Results
indicate that the hypothesis should be rejected in the all cases of ALICE-LHC
measurements in the limited pseudo-rapidity windows, whereas should be accepted
in the corresponding cases of UA5 data. Possible explanations of that and of
the disagreement with the least-squares fitting method are given.Comment: 14 pages, clarified version, reference added. To appear in
International Journal of Modern Physics
Two new Lower Cretaceous hymenopterous insects (Insecta: Hymenoptera) from Sierra del Montsec, Spain
Two new hymenoterans are described from the Lower Barremian lithographic limestones of Sierra del Montsec (Lleida, Spain), Leridatoma pulcherrimapulcherima n.gen., n.sp. (Xyelotomidae RASNITSYN, 1968) that combines the most and the least advanced character states in the family (in structure of antenna and fore wing RS, respectively), and Cretephialtites pedrerae n.gen., n.sp. (Ephialtitidae HANDLIRSCH, 1906)
Identity of Prosepididontus calpterys Handlirsch 1920 (Insecta: Grylloblattida: Geinitziidae)
Prosepididontus calopteryx HANDLIRSCH 1920, from the upper Lower Jurassic of Germ a ny, is transferred from Trichoptera to Grylloblattida: Geinitziidae. The anal loop like structure of Prosepididontus calopteryx is built of the concave CuP and two anal veins. Prosepididontidae HANDLIRSCH, 1920 is synonymised under Geinitziidae HANDLIRSCH, 1906.Prosepididontus calopteryx HANDLIRSCH 1920, from the upper Lower Jurassic of Germ a ny, is transferred from Trichoptera to Grylloblattida: Geinitziidae. The anal loop like structure of Prosepididontus calopteryx is built of the concave CuP and two anal veins. Prosepididontidae HANDLIRSCH, 1920 is synonymised under Geinitziidae HANDLIRSCH, 1906
Energy Scaling of Minimum-Bias Tunes
We propose that the flexibility offered by modern event-generator tuning
tools allows for more than just obtaining "best fits" to a collection of data.
In particular, we argue that the universality of the underlying physics model
can be tested by performing several, mutually independent, optimizations of the
generator parameters in different physical regions. For regions in which these
optimizations return similar and self-consistent parameter values, the model
can be considered universal. Deviations from this behavior can be associated
with a breakdown of the modeling, with the nature of the deviations giving
clues as to the nature of the breakdown. We apply this procedure to study the
energy scaling of a class of minimum-bias models based on multiple parton
interactions (MPI) and pT-ordered showers, implemented in the Pythia 6.4
generator. We find that a parameter controlling the strength of color
reconnections in the final state is the most important source of
non-universality in this model.Comment: 17 pages, 3 figures, 4 table
Electrophysiological activation by masked primes: Independence of prime-related and target-related activities
Visual stimuli that are made invisible by metacontrast masking (primes) have a
marked influence on behavioral and psychophysiological measures such as reaction
time (RT) and the lateralized readiness potential (LRP). 4 experiments are
reported that shed light on the effects that masked primes have on the LRP.
Participants had a go-nogo task in which the prime was associated with 1 of 2
responses even if the target required participants to refrain from responding.
To analyze the electrophysiological responses, we computed the LRP and applied
an averaging method separating the activation due to the prime and the target.
The results demonstrated that (a) masked primes activate responses even in a
nogo situation, (b) this prime-related activation is independent of masking, (c)
and is also independent of whether prime and target require the same responses
(congruent condition) or different responses (incongruent condition)
Analysis of Cumulant Moments in High Energy Hadron-Hadron Collisions by Truncated Multiplicity Distributions
Oscillatory behavior of cumulant moments obtained from the experimental data
in collisions and collisions are analyzed by the modified
negative binomial distribution (MNBD) and the negative binomial distribution
(NBD). Both distributions well describe the cumulant moments obtained from the
data. This fact shows sharp contrast to the result in collisions,
which is described by the the MNBD much better than by the NBD.Comment: 7 pages, Latex type, 7 figure
Scenarios for multiplicity distributions in pp collisions in the TeV energy region
Possible scenarios based on available experimental data and phenomenological
knowledge of the GeV energy region are extended to the TeV energy region in the
framework of the weighted superposition mechanism of soft and semi-hard events.
KNO scaling violations, forward-backward multiplicity correlations, Hq vs. q
oscillations and shoulder structures are discussed.Comment: 10 pages, 10 figures, talk given at "Focus on Multiplicity" (Bari,
Italy, June 2004
Top-down contingent feature-specific orienting with and without awareness of the visual input
In the present article, the role of endogenous feature-specific orienting for
conscious and unconscious vision is reviewed. We start with an overview of
orienting. We proceed with a review of masking research, and the definition of
the criteria of experimental protocols that demonstrate endogenous and exogenous
orienting, respectively. Against this background of criteria, we assess studies
of unconscious orienting and come to the conclusion that so far studies of
unconscious orienting demonstrated endogenous feature-specific orienting. The
review closes with a discussion of the role of unconscious orienting in action
control
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