16250559
Determination of the local dark matter density in our Galaxy
Context. The rotation curve, the total mass and the gravitational potential of the Galaxy are sensitive measurements of the dark matter halo profile. Aims. Cuspy and cored DM halo profiles are analysed with respect to recent astronomical constraints in order to constrain the shape of the Galactic DM halo and the local DM density. Methods. All Galactic density components (luminous matter and DM) are parametrized. Then the total density distribution is constrained by astronomical observations: 1) the total mass of the Galaxy, 2) the total matter density at the position of the Sun, 3) the surface density of the visible matter, 4) the surface density of the total matter in the vicinity of the Sun, 5) the rotation speed of the Sun and 6) the shape of the velocity distribution within and above the Galactic disc. The mass model of the Galaxy is mainly constrained by the local matter density (Oort limit), the rotation speed of the Sun and the total mass of the Galaxy from tracer stars in the halo. Results. We showed from a statistical χ 2 fit to all data that the local DM density is strongly positively (negatively) correlated with the scale length of the DM halo (baryonic disc). Since these scale lengths are poorly constrained the local DM density can vary from 0.2 · �
125660697
IS THE DARK MATTER INTERPRETATION OF THE EGRET GAMMA RAY EXCESS COMPATIBLE WITH ANTIPROTON MEASUREMENTS
121921718
Hadronic response and e / pi separation with the H1 lead / fiber calorimeter
Hadronic response and electron identification performance of the new H1 lead-scintillating fibre calorimeter are investigated in the 1 to 7 GeV energy range using data taken at the CERN Proton Synchrotron. The energy response to minimum ionizing particles and interacting pions are studied and compared to Monte Carlo simulations. The measured energy of pions interacting either in the electromagnetic or in the hadronic section is found to scale linearly with the incident energy, providing an energy resolution σE ∼ 38% within a depth of one interaction length and σE ∼ 29% for a total depth of two interaction lengths. Several electron identification estimators are studied and combined as a function of energy and impact point. The probability for pions to be misidentified as electrons of any measured energy above 1 GeV ranges from 5% (for 2 GeV incident pions) to 0.4% (at 7 GeV) for an electron detection efficiency of 90%. The probability for pions of a given energy to be misidentified as electrons of the same energy falls to 0.25% at 7 GeV.
119389130
Electroweak corrections to e+ e- -> nu anti-nu H and e+ e- -> t anti-t H
The most interesting Higgs-production processes at future e+ e- colliders belong to the process class e+ e- ->f anti-f H. We study the full O(alpha) corrections to this reaction in the Standard Model for neutrinos and top quarks in the final state. Leading higher-order corrections from initial-state radiation and QCD corrections are also taken into account. Although cancellations between the different kinds of corrections occur, the full corrections are of the order of +/-10% and thus important ingredients in the theoretical predictions for future e+ e- colliders.
120765978
Silicon Trackers for the Super-LHC
The Large Hadron Collider (LHC) will be upgraded to the Super-LHC in 2015 to provide a tenfold increased luminosity and data rate. The inner silicon tracking detectors of the ATLAS and CMS experiments will be replaced by even more powerful devices. The technical challenges and possible solutions for the SLHC silicon trackers are described.
122383524
DIELECTRON SPECTROSCOPY IN COLD NUCLEAR MATTER
We report recent data on e+e- pair emission in proton nucleus collisions at energies slightly above the light vector meson production threshold. Invariant mass distributions for the p+Nb system at Ekin = 3.5 GeV/c2 show a clear ρ/ω signal and are compared to data from elementary p+p reactions. We observe a constant π0/ω yield ratio for both systems.
109729787
Development of a silicon-microstrip super module prototype for the high luminosity LHC
Following the Phase II upgrade of the CERN Large Hadron Collider (LHC) currently foreseen in 2022–2023, the High Luminosity LHC (HL-LHC) is expected to deliver a peak luminosity in excess of 5×1034cm−2s−1 and an integrated luminosity of order 3000fb−1 until 2033. The ATLAS Collaboration plans to replace the existing Inner Tracking Detector by a new tracker, with readout electronics as well as silicon pixel and strip sensor technology capable of maintaining the excellent tracking performance of the existing tracker in the severe radiation and high collision rate environment of the HL-LHC. The promising super-module integration concept extends the proven design of the existing barrel silicon strip tracker to the HL-LHC, with double-sided stereo silicon micro-strip modules assembled into a low mass local support structure. The Super-Module R&D program is described, with reference to HL-LHC requirements, and key prototype results are summarized.