4,364 research outputs found
J/ production in In-In and p-A collisions
The NA60 experiment studies dimuon production in In-In and p-A collisions at
the CERN SPS. We report recent results on \jpsi production, measured through
its muon pair decay. As a function of centrality, we show that in In-In the
\jpsi yield is suppressed beyond expectations from nuclear absorption. We
present also for the first time results on \jpsi production in p-A collisions
at 158 GeV, the same energy of the nucleus-nucleus data. For both p-A and In-In
we show preliminary results on \psip suppression. Finally, we have studied the
kinematical distributions of the \jpsi produced in In-In collisions. We present
results on transverse momentum and rapidity, as well as on the angular
distribution of the \jpsi decay products.Comment: 8 pages, Quark Matter 2006 conference proceeding
The ALICE detector and trigger strategy for diffractive and electromagnetic processe
The ALICE detector at the Large Hadron Collider (LHC) consists of a central
barrel, a muon spectrometer, zero degree calorimeters and additional detectors
which are used for trigger purposes and for event classification. The main
detector systems of relevance for measuring diffractive and electromagnetic
processes are described. The trigger strategy for such measurements is
outlined. The physics potential of studying diffractive and electromagnetic
processes at the LHC is presented by discussing possible signatures of the
Odderon.Comment: 6 pages, 8 figures, Proceedings workshop on "High energy photon
collisions at the LHC", CERN, apr 22-25, 200
New results from an extensive aging test on bakelite Resistive Plate Chambers
We present recent results of an extensive aging test, performed at the CERN
Gamma Irradiation Facility on two single--gap RPC prototypes, developed for the
LHCb Muon System. With a method based on a model describing the behaviour of an
RPC under high particle flux conditions, we have periodically measured the
electrode resistance R of the two RPC prototypes over three years: we observe a
large spontaneous increase of R with time, from the initial value of about 2
MOhm to more than 250 MOhm. A corresponding degradation of the RPC rate
capabilities, from more than 3 kHz/cm2 to less than 0.15 kHz/cm2 is also found.Comment: 6 pages, 7 figures, presented at Siena 2002, 8th Topical Seminar on
Innovative Particle and Radiation Detectors 21-24 October 2002, Siena, Ital
Electromagnetic Probes
A review is presented of dilepton and real photon measurements in
relativistic heavy ion collisions over a very broad energy range from the low
energies of the BEVALAC up to the highest energies available at RHIC. The
dileptons cover the invariant mass range \mll = 0 - 2.5 GeV/c, i.e. the
continuum at low and intermediate masses and the light vector mesons, . The review includes also measurements of the light vector mesons
in elementary reactions.Comment: To be published in Landolt-Boernstein Volume 1-23A; 40 pages, 24
figures. Final version updated with small changes to the text, updated
references and updated figure
Prospectives for A Fixed-Target ExpeRiment at the LHC: AFTER@LHC
We argue that the concept of a multi-purpose fixed-target experiment with the
proton or lead-ion LHC beams extracted by a bent crystal would offer a number
of ground-breaking precision-physics opportunities. The multi-TeV LHC beams
will allow for the most energetic fixed-target experiments ever performed. The
fixed-target mode has the advantage of allowing for high luminosities, spin
measurements with a polarised target, and access over the full backward
rapidity domain --uncharted until now-- up to x_F ~ -1.Comment: 6 pages, 1 table, LaTeX. Proceedings of the 36th International
Conference on High Energy Physics (ICHEP2012), 4-11 July 2012, Melbourne,
Australi
NA60 results on thermal dimuons
The NA60 experiment at the CERN SPS has measured muon pairs with
unprecedented precision in 158A GeV In-In collisions. A strong excess of pairs
above the known sources is observed in the whole mass region 0.2<M<2.6 GeV. The
mass spectrum for M<1 GeV is consistent with a dominant contribution from
pi+pi- -> rho -> mu+mu- annihilation. The associated rho spectral function
shows a strong broadening, but essentially no shift in mass. For M>1 GeV, the
excess is found to be prompt, not due to enhanced charm production, with
pronounced differences to Drell-Yan pairs. The slope parameter Teff associated
with the transverse momentum spectra rises with mass up to the rho, followed by
a sudden decline above. The rise for M<1 GeV is consistent with radial flow of
a hadronic emission source. The seeming absence of significant flow for M>1 GeV
and its relation to parton-hadron duality is discussed in detail, suggesting a
dominantly partonic emission source in this region. A comparison of the data to
the present status of theoretical modeling is also contained. The accumulated
empirical evidence, including also a Planck-like shape of the mass spectra at
low pT and the lack of polarization, is consistent with a global interpretation
of the excess dimuons as thermal radiation. We conclude with first results on
omega in-medium effects.Comment: 10 pages, 12 figures, submitted to Eur. Phys. J.
Spin physics at A Fixed-Target ExpeRiment at the LHC (AFTER@LHC)
We outline the opportunities for spin physics which are offered by a next
generation and multi-purpose fixed-target experiment exploiting the proton LHC
beam extracted by a bent crystal. In particular, we focus on the study of
single transverse spin asymetries with the polarisation of the target.Comment: Contributed to the 20th International Spin Physics Symposium,
SPIN2012, 17-22 September 2012, Dubna, Russia, 4 pages, LaTe
A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) : luminosities, target polarisation and a selection of physics studies
We report on a future multi-purpose fixed-target experiment with the proton
or lead ion LHC beams extracted by a bent crystal. The multi-TeV LHC beams
allow for the most energetic fixed-target experiments ever performed. Such an
experiment, tentatively named AFTER for "A Fixed-Target ExperRiment", gives
access to new domains of particle and nuclear physics complementing that of
collider experiments, in particular at RHIC and at the EIC projects. The
instantaneous luminosity at AFTER using typical targets surpasses that of RHIC
by more than 3 orders of magnitude. Beam extraction by a bent crystal offers an
ideal way to obtain a clean and very collimated high-energy beam, without
decreasing the performance of the LHC. The fixed-target mode also has the
advantage of allowing for spin measurements with a polarised target and for an
access over the full backward rapidity domain up to xF ~ - 1. Here, we
elaborate on the reachable luminosities, the target polarisation and a
selection of measurements with hydrogen and deuterium targets.Comment: 6 pages. Proceedings of the Sixth International Conference on Quarks
and Nuclear Physics QNP2012 (16-20 April 2012, Ecole Polytechnique,
Palaiseau,France
The degree of urinary hypercortisolism is not correlated with the severity of cushing’s syndrome
Cushing syndrome (CS) is characterized by increased morbidity and mortality compared to the general population. However, there are patients who have moreclinical aggressive forms than others. Aim of the study is to evaluate whether the degree of hypercortisolism, defined by the number of times urinary free cortisol (UFC) levels exceed the upper limit of the normal range (ULN), is related to the worsening of phenotypic features, as well as metabolic and cardiovascular parameters, in a cohort of CS patients. A cross-sectional study was conducted on 192 patients with active CS, consecutively presenting at the outpatients’ clinic of the University Hospitals of Ancona, Naples, and Palermo. Patients were grouped into mild (UFC not exceeding twice the ULN), moderate (2–5 times the ULN), and severe (more than 5 times the ULN) hypercortisolism. Thirty-seven
patients (19.3 %) had mild, 115 (59.8 %) moderate, and 40 (20.9 %) severe hypercortisolism. A significant trend of increase among the three groups was demonstrated for 8-, 16-, and 24-h serum cortisol levels (p.001) and serum cortisol after low dose of dexamethasone suppression test
(p = 0.001). No significant trend of increase was found regarding phenotype and comorbidities. The degree of hypercortisolism by itself does not appear to be a sufficient parameter to express the severity of CS. Therefore, estimating the severity of CS according to biochemical parameters
remains a challenge, while the clinical phenotype and the associated comorbidities might be more useful to assessing the severity of the CS
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