24,455 research outputs found
Search for Physics beyond the Standard Model at the Tevatron
Recent searches for physics beyond the standard model at the Tevatron are
reported, with emphasis on supersymmetry.Comment: to appear in Proceedings of SUSY06, the 14th International Conference
on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine,
California, 12-17 June 200
Using the Balance Function to study the charge correlations of hadrons
We present the recent Balance Function (BF) results obtained by the NA49
collaboration for the pseudo-rapidity dependence of non-identified charged
particle correlations for two SPS energies. Experimental results indicate a
clear centrality dependence only in the mid-rapidity region. The results of an
energy dependence study of the BF throughout the whole SPS energy range will
also be discussed. In addition, the correlation of identified hadrons is
studied and presented for the first time. The study of hadron correlation has
also been extended in order to cope with the high multiplicity environment that
is expected to be seen at LHC. We will present the latest results from
simulations concerning the extension of these studies to the ALICE experiment.Comment: To appear in the proccedings of the "Quark Confinement and Hadron
Spectrum VII" conferenc
Prospects for SUSY searches in CMS and ATLAS
We discuss how the CMS and ATLAS experiments are preparing for the analysis
of first LHC data with emphasis on the search for supersymmetry. We will show
the importance of the understanding of detector, trigger, reconstruction and
backgrounds, and we will present realistic estimates of the reach of CMS and
ATLAS.Comment: 9 pages, 12 figures. Contribution to the proceedings of the 16th
international conference on supersymmetry and the unification of fundamental
interactions, SUSY08, Seoul, Korea, June 16-21, 200
Charged Particle Production at High Rapidity in p+p Collisions at RHIC
This report describes the recent analysis of identified charged particle
production at high rapidity performed on data collected from p+p collisions at
RHIC (sqrt{s}=200 GeV). The extracted invariant cross-sections compare well to
NLO pQCD calculations. However, a puzzling high yield of protons at high
rapidity and p_T has been found.Comment: 5 pages, four figures. The labels of the x-axis in figure 1 have been
correcte
IRSF/SIRIUS JHKs near-infrared variable star survey in the Magellanic Clouds
We carried out a NIR variable star survey toward the Large and Small
Magellanic Clouds using the InfraRed Survey Facility (IRSF) at Sutherland,
South African Astronomical Observatory. This survey project was initiated in
Dember 2000, and since then, we kept monitoring a total area of 3 square
degrees along the LMC bar and also an area of 1 square degree around the center
of the SMC, sufficiently large to do statistical analysis and to make complete
catalog of variable red giants in the Magellanic Clouds. The detection limits
(S/N=10) of the survey are 17.0, 16.5 and 15.5 at J, H and Ks, respectively. In
this article, we present some results on infrared variables that are not
detected by the previous optical surveys. We show that they do not fall on the
standard period-Ks magnitude relation for Mira-type variables pulsating in the
fundamental mode.Comment: 3 pages, 2 figures. To appear in "Stellar Pulsation: Challenges for
Theory and Observation", Eds. J. Guzik and P. Bradle
High Rapidity Physics with the BRAHMS Experiment
We report the study of the nuclear modification factor R_{AuAu} as function
of pT and pseudo-rapidity in Au+Au collisions at top RHIC energy. We find this
quantity almost independent of pseudo-rapidity. We use the pbar/pi- ratio as a
probe of the parton density and the degree of thermalization of the medium
formed by the collision. The pbar/pi- ratio has a clear rapidity dependence.
The combination of these two measurements suggests that the pseudo-rapidity
dependence of the R_{AuAu results from the competing effects of energy loss in
a dense and opaque medium and the modifications of the wave function of the
high energy beams in the initial state.Comment: 5 pages, four figures, to appear in the proceedings of the 9th
Conference on the Intersections of Particle and Nuclear Physics (CIPANP
2006), Puerto Rico, 30 May - 3 June 200
Mesons in the nuclear Medium
We discuss recent experimental results on the modification of hadron
properties in a nuclear medium. Particular emphasis is placed on an
production experiment performed by the CBELSA/TAPS collaboration at the ELSA
accelerator. The data shows a smaller meson mass together with a
significant increase of its width in the nuclear medium.Comment: Proceedings for CIPANP 2006 Puerto Ric
Direct-Photon Production in Au+Au Collisions at RHIC
Results from the PHENIX experiment on direct-photon production in Au+Au
collisions at sqrt{s_{NN}} = 200 GeV for transverse momenta 1 < p_T < 13 GeV/c
are presented. Direct-photon yields at high p_T scale as expected for particle
production in hard processes. This supports jet-quenching models which
attribute the suppression of high-p_T hadrons to the energy loss of fast
partons in the quark-gluon plasma. The low-p_T direct-photon spectra, measured
via e+e- pairs with small invariant masses, are possibly related to the
production of thermal direct photons in Au+Au collisions at RHIC.Comment: 5 pages, 3 figures, to appear in the proceedings of the 9th
Conference on the Intersections of Particle and Nuclear Physics (CIPANP
2006), Puerto Rico, 30 May - 3 June 200
Precision Calibration of the D0 HCAL in Run II
Most of the physics analyses at a hadron collider rely on a precise
measurement of the energy of jets in the final state. This requires a precise
in situ calibration of the calorimeter with the final detector setup. We
present the basic procedure and results of the in situ gain calibration of the
D0 HCAL in Run II. The gain calibration works on top of the pulser-based
calibration of the readout electronics and is based entirely on collision data.Comment: 8 pages, 5 figures, presented at XII International Conference on
Calorimetry in High-Energy Physic
Study of the Flux and Spectral Variations in the VHE Emission from the Blazar Markarian 501, with the MAGIC Telescope
The blazar Markarian 501 (Mrk 501) was observed above 100 GeV with the MAGIC
Telescope during May, June and July 2005. The high sensitivity of the
instrument made possible the detection of the source with high significance in
each of the observing nights. During this observational campaign, the emitted
gamma-ray flux from Mkn 501 was found to vary by one order of magnitude, and
showed a high correlation with spectral changes. Intra-night flux variability
was also observed, with flux-doubling times of ~2 minutes. The data showed a
clear evidence of a spectral peak (in the nuFnu representation) during the
nights when the gamma-ray activity was highest. The location of this spectral
feature was found to be correlated with the emitted gamma-ray flux. In these
proceedings we discuss some of the results of this unprecedented spectral and
temporal analysis of Mrk 501 observations in the very high energy range.Comment: 4 pages, 3 figures, manuscript submitted on behalf of the MAGIC
collaboration to the First GLAST Symposium (oral presentation
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