4,098 research outputs found
Hadron Blind Detector for the PHENIX Experiment at RHIC
The PHENIX collaboration has designed a conceptually new Hadron Blind
Detector (HBD) for electron identification in high density hadron environment.
The HBD will identify low momentum electron-positron pairs to reduce the
combinatorial background in the mass region below 1 GeV/c^2. The HBD shall be
installed in PHENIX during the 2007 physics run. The HBD is a windowless
proximity focusing Cherenkov detector with a radiator length of 50 cm, CsI
photocathode and three layers of Gas Electron Multipliers (GEM) for gas
amplification. Pure CF_4 serves both as a radiator and as a detector gas. The
radiation budget of the device is less than 3% of a radiation length.Comment: 4 page
Emerging aerospace technologies
The United States Government has a long history of promoting the advancement of technology to strengthen the economy and national defense. An example is NASA, which was formed in 1958 to establish and maintain U.S. space technology leadership. This leadership has resulted in technological benefits to many fields and the establishment of new commercial industries, such as satellite communications. Currently, NASA's leading technology development at Ames Research Center includes the Tilt Rotor XV-15, which provides the versatility of a helicopter with the speed of a turboprop aircraft; the Numerical Aerodynamic Simulator, which is pushing the state of the art in advanced computational mathematics and computer simulation; and the Advanced Automation and Robotics programs, which will improve all areas of space development as well as life on Earth. Private industry is involved in maintaining technological leadership through NASA's Commercial Use of Space Program, which provides for synergistic relationships among government, industry, and academia. The plan for a space station by 1992 has framed much of NASA's future goals and has provided new areas of opportunity for both domestic space technology and leadership improvement of life on Earth
Non-extensivity Parameter of Thermodynamical Model of Hadronic Interactions at LHC energies
The LHC measurements above SPS and Tevatron energies give the opportunity to
test predictions of non-extensive thermodynamical picture of hadronic
interaction to examine measured transverse momenta distributions for new
interaction energy range. We determined Tsallis model non-extensivity parameter
for the hadronization process before short-lived particles decayed and distort
the initial p_t distribution. We have shown that it follows exactly smooth rise
determined at lower energies below present LHC record. The shape of the q
parameter energy dependence is consistent with expectations and the evidence of
the asymptotic limit may be seen.Comment: 2 pages, 2 figure
Construction and Expected Performance of the Hadron Blind Detector for the PHENIX Experiment at RHIC
A new Hadron Blind Detector (HBD) for electron identification in high density
hadron environment has been installed in the PHENIX detector at RHIC in the
fall of 2006. The HBD will identify low momentum electron-positron pairs to
reduce the combinatorial background in the mass spectrum, mainly
in the low-mass region below 1 GeV/c. The HBD is a windowless
proximity-focusing Cherenkov detector with a radiator length of 50 cm, a CsI
photocathode and three layers of Gas Electron Multipliers (GEM). The HBD uses
pure CF as a radiator and a detector gas. Construction details and the
expected performance of the detector are described.Comment: QM2006 proceedings, 4 pages 3 figure
Soft Physics with ATLAS and CMS
The ATLAS and CMS detectors at LHC are the two large multi-purpose detectors designed and build for the High Energy studies. Due to their universality they are perfectly suitable to conduct the Heavy Ion Measurements. I will focus in my talk on the capabilities of ATLAS and CMS detectors to measure global characteristics of the high energy ion collisions, and in particular on the Day 1 physics which main goal is to answer the question about the characteristics of the QGP which can be formed at LHC and its difference from the sQGP present at RHIC
Predictions of hadron abundances in pp collisions at the LHC
Based on the statistical hadronization model, we obtain quantitative
predictions for the relative abundances of hadron species in pp collisions at
the LHC. By using the parameters of the model determined at sqrt s = 200 GeV,
and extrapolating the overall normalization from ppbar collisions at the SPS
and Tevatron, we find that the expected rapidity densities are almost
grand-canonical. Therefore, at LHC the ratios between different species become
essentially energy-independent, provided that the hadronization temperature T_H
and the strangeness suppression factor gamma_S retain the stable values
observed in the presently explored range of pp and ppbar collisions.Comment: 4 pages. Final version published in JP
Recent Heavy Ion Results with the ATLAS Detector at the LHC
Results are presented from the ATLAS collaboration from the 2010 LHC heavy
ion run, during which nearly 10 inverse microbarns of luminosity were
delivered. Soft physics results include charged particle multiplicities and
collective flow. The charged particle multiplicity, which tracks initial state
entropy production, increases by a factor of two relative to the top RHIC
energy, with a centrality dependence very similar to that already measured at
RHIC. Measurements of elliptic flow out to large transverse momentum also show
similar results to what was measured at RHIC, but no significant pseudorapidity
dependence. Extensions of these measurements to higher harmonics have also been
made, and can be used to explain structures in the two-particle correlation
functions that had long been attributed to jet-medium interactions. New hard
probe measurements include single muons, jets and high hadrons. Single
muons at high momentum are used to extract the yield of bosons and
are found to be consistent within statistical uncertainties with binary
collision scaling. Conversely, jets are found to be suppressed in central
events by a factor of two relative to peripheral events, with no significant
dependence on the jet energy. Fragmentation functions are also found to be the
same in central and peripheral events. Finally, charged hadrons have been
measured out to 30 GeV, and their centrality dependence relative to peripheral
events is similar to that found for jets.Comment: 9 pages, 9 figures, proceedings for Quark Matter 2011, Annecy,
France, May 23-28, 201
A new mechanism for electron spin echo envelope modulation
Electron spin echo envelope modulation (ESEEM) has been observed for the
first time from a coupled hetero-spin pair of electron and nucleus in liquid
solution. Previously, modulation effects in spin echo experiments have only
been described in liquid solutions for a coupled pair of homonuclear spins in
NMR or a pair of resonant electron spins in EPR. We observe low-frequency ESEEM
(26 and 52 kHz) due to a new mechanism present for any electron spin with S>1/2
that is hyperfine coupled to a nuclear spin. In our case these are electron
spin (S=3/2) and nuclear spin (I=1) in the endohedral fullerene N@C60. The
modulation is shown to arise from second order effects in the isotropic
hyperfine coupling of an electron and 14N nucleus.Comment: 15 pages, 4 figure
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