12,454 research outputs found
Editorial: Advances in Invasive and Non-invasive Brain Stimulation for Dystonia and Other Hyperkinetic Movement Disorders
No abstract availabl
First measurement of the cross section for top-quark pair production in proton–proton collisions at √s = 7 TeV
20 páginas, 3 figuras, 1 tabla.-- This article is published Open Access at sciencedirect.com. It
is distributed under the terms of the Creative Commons Attribution
License 3.0.-- CMS Collaboration: et al.The first measurement of the cross section for top-quark pair production in pp collisions at the
Large Hadron Collider at center-of-mass energy √s = 7 TeV has been performed using a data sample
corresponding to an integrated luminosity of 3.1 ± 0.3 pb−1 recorded by the CMS detector. This result
utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse
energy, and two or more jets. Backgrounds from Drell–Yan and non-W/Z boson production are estimated
from data. Eleven events are observed in the data with 2.1 ± 1.0 events expected from background. The
measured cross section is 194±72(stat.)±24(syst.)±21(lumi.) pb, consistent with next-to-leading order
predictions.Acknowledge support from: FMSR (Austria);
FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP
(Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China);
COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy
of Sciences and NICPB (Estonia); Academy of Finland, ME, and
HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF
(Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and
DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU
(Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLPFAI
(Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR
(Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE
(Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding
Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey);
STFC (United Kingdom); DOE and NSF (USA).Peer reviewe
Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy
Acknowledge support from:
FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC
(China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus);
Academy of Sciences and NICPB (Estonia); Academy of Finland,
ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,
and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary);
DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF
and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and
UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal);
JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST
and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss
Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK
(Turkey); STFC (United Kingdom); DOE and NSF (USA).A search for supersymmetry with R-parity conservation in proton–proton collisions at a centre-of-mass
energy of 7 TeV is presented. The data correspond to an integrated luminosity of 35 pb−1 collected by
the CMS experiment at the LHC. The search is performed in events with jets and significant missing
transverse energy, characteristic of the decays of heavy, pair-produced squarks and gluinos. The primary
background, from standard model multijet production, is reduced by several orders of magnitude to a
negligible level by the application of a set of robust kinematic requirements. With this selection, the
data are consistent with the standard model backgrounds, namely t¯t, W + jet and Z + jet production,
which are estimated from data control samples. Limits are set on the parameters of the constrained
minimal supersymmetric extension of the standard model. These limits extend those set previously by
experiments at the Tevatron and LEP colliders.23 páginas, 5 figuras, 2 tablas.-- Open access:
This article is distributed under the terms of the Creative Commons Attribution
License 3.0.-- CMS Collaboration: et al.Peer reviewe
Measurement of Wγ and Zγ production in pp collisions at √s = 7 TeV
21 páginas, 7 figuras, 2 tablas.-- Open access:
This article is distributed under the terms of the Creative Commons Attribution
License 3.0.-- CMS collaboration: et al.A measurement of Wγ and Zγ production in proton–proton collisions at √s = 7 TeV is presented. Results
are based on a data sample recorded by the CMS experiment at the LHC, corresponding to an
integrated luminosity of 36 pb−1. The electron and muon decay channels of the W and Z are used. The
total cross sections are measured for photon transverse energy Eγ
T > 10 GeV and spatial separation from
charged leptons in the plane of pseudorapidity and azimuthal angle R( ,γ) > 0.7, and with an additional
dilepton invariant mass requirement of M > 50 GeV for the Zγ process. The following cross
section times branching fraction values are found: σ(pp→Wγ + X) × B(W→ ν) = 56.3 ± 5.0(stat.) ± 5.0(syst.)±2.3(lumi.) pb and σ(pp→Zγ + X)×B(Z→ ) = 9.4±1.0(stat.)±0.6(syst.)±0.4(lumi.) pb.
These measurements are in agreement with standard model predictions. The first limits on anomalous
WWγ , ZZγ , and Zγγ trilinear gauge couplings at √s =7 TeV are set.Acknowledge support from: FMSR (Austria);
FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP
(Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China);
COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy
of Sciences and NICPB (Estonia); Academy of Finland, ME, and
HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF
(Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and
DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU
(Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLPFAI
(Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR
(Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE
(Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding
Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey);
STFC (United Kingdom); DOE and NSF (USA).Peer reviewe
FIRST experiment: Fragmentation of Ions Relevant for Space and Therapy
Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon targe
Search for a W boson decaying to a muon and a neutrino in pp collisions at √s = 7 TeV
20 páginas, 4 figuras, 3 tablas.-- Open access:
This article is distributed under the terms of the Creative Commons Attribution
License 3.0.-- CMS Collaboration: et al.A new heavy gauge boson, W', decaying to a muon and a neutrino, is searched for in pp collisions at a
centre-of-mass energy of 7 TeV. The data, collected with the CMS detector at the LHC, correspond to an
integrated luminosity of 36 pb−1. No significant excess of events above the standard model expectation
is found in the transverse mass distribution of the muon–neutrino system. Masses below 1.40 TeV are
excluded at the 95% confidence level for a sequential standard-model-like W'. The W' mass lower limit
increases to 1.58 TeV when the present analysis is combined with the CMS result for the electron channel.Acknowledge support from: FMSR (Austria);
FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP
(Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES (Croatia); RPF (Cyprus); Academy of
Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP
(Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF
(Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and
DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU
(Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLPFAI
(Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR
(Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE
(Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding
Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey);
STFC (United Kingdom); DOE and NSF (USA).Peer reviewe
Performance of upstream interaction region detectors for the FIRST experiment at GSI
The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at GSI has been designed to study carbon fragmentation, measuring 12C double differential cross sections (∂2σ/ ∂θ∂E) for different beam energies between 100 and 1000 MeV/u. The experimental setup integrates newly designed detectors in the, so called, Interaction Region around the graphite target. The Interaction Region upstream detectors are a 250 μm thick scintillator and a drift chamber optimized for a precise measurement of the ions interaction time and position on the target. In this article we review the design of the upstream detectors along with the preliminary results of the data taking performed on August 2011 with 400 MeV/u fully stripped carbon ion beam at GSI. Detectors performances will be reviewed and compared to those obtained during preliminary tests, performed with 500 MeV electrons (at the BTF facility in the INFN Frascati Laboratories) and 80 MeV/u protons and carbon ions (at the INFN LNS Laboratories in Catania)
A Cone Jet-Finding Algorithm for Heavy-Ion Collisions at LHC Energies
Standard jet finding techniques used in elementary particle collisions have
not been successful in the high track density of heavy-ion collisions. This
paper describes a modified cone-type jet finding algorithm developed for the
complex environment of heavy-ion collisions. The primary modification to the
algorithm is the evaluation and subtraction of the large background energy,
arising from uncorrelated soft hadrons, in each collision. A detailed analysis
of the background energy and its event-by-event fluctuations has been performed
on simulated data, and a method developed to estimate the background energy
inside the jet cone from the measured energy outside the cone on an
event-by-event basis. The algorithm has been tested using Monte-Carlo
simulations of Pb+Pb collisions at TeV for the ALICE detector at
the LHC. The algorithm can reconstruct jets with a transverse energy of 50 GeV
and above with an energy resolution of .Comment: 13 pages, 7 figure
Dysfunction of the magnocellular stream in Alzheimer's disease evaluated by pattern electroretinograms and visual evoked potentials
Background: Visuo-spatial disturbances could represent a clinical feature of early stage Alzheimer's disease (AD). The magnocellular (M) pathway has anatomo-physiological characteristic which make it more suitable for detecting form, motion and depth compared with parvocellular one (P). Objective: Aim of our study was to evaluate specific visual subsystem involvement in a group of AD patients, recording isoluminant chromatic and luminance pattern electroretinograms and pattern visual evoked potentials. Material and methods: data were obtained from 15 AD patients (9 females and 6 males, mean age \ub1 1SD: 77.6 \ub1 4.01 years) not yet undergoing any treatment, and from 10 age-matched healthy controls. Diagnosis of probable AD was clinically and neuroradiologically established. PERGs were recorded monocularly in response to equiluminant red-green (R-G), blue-yellow (B-Y) and luminance yellow-black (Y-Bk) horizontal square gratings of 0.3. c/deg and 90% contrast, reversed at 1. Hz. VEPs were recorded in response to full-field (14 deg) equiluminant chromatic R-G, B-Y and luminance Y-Bk sinusoidal gratings of 2. c/deg, presented in onset (300. ms)-offset (700. ms) mode, at the contrast levels of 90%. Results: All data were retrieved in terms of peak-amplitude and latency and assessed using the Student's t-test for paired data. Temporal differences of PERGs and VEPs, evoked by Y-Bk grating in AD patients compared with controls, suggest a specific impairment of the magnocellular stream. Conclusions: Our study support the hypothesis that the impairment of the PERGs and VEPs arising from the magnocellular streams of visual processing may indicate a primary dysfunction of the M-pathways in AD
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