123036925
The low energy limit of the minimal nonlinear supersymmetric SU(5)-model; production and decay of Higgs particles
Abstract. We consider the Higgssector in the low energy limit of the minimal nonlinear supersymmetric SU(5) model. We estimate radiative corrections to the Higgs masses using the effective potential. Furthermore Higgs boson decays are investigated and differences to the MSSM are discussed.
123173797
Calibration, alignment and tracking performance of the CMS silicon strip tracker
Abstract After its installation in the CMS experiment, the CMS silicon tracker has been commissioned, calibrated and aligned based on several million reconstructed tracks, recorded during extended cosmic ray data-taking in 2008 and 2009. The collision data at 900 GeV and 2.36 TeV which were recorded by the CMS experiment in December 2009 allowed to repeat the calibration measurements and derive compatible results. Calibration results are shown for the silicon strip detector only, whereas alignment and tracking performance are given for the complete CMS tracker, including the silicon pixel system.
123205836
The E760 lead-glass central calorimeter: design and initial test results
The central calorimeter in Fermilab experiment E760++ has been designed to measure the topology and energies of electrons and photons in the decay of charmonium formed in pp annihilation. The calorimeter is composed of 1280 lead-glass Cherenkov counters read out with photomultiplier tubes. This paper discusses design criteria for the calorimeter and describes how these criteria were met. Data from tests in low energy (10–84 MeV) and medium energy (1–4 GeV) beams are presented showing a spatial resolution of 9 mm, an energy resolution of (3.0 ± 0.3)%√E[GeV] + (1.5 ± 0.5)%, and an effective energy threshold below 10 MeV.
17991299
Strangelets, strangeness and antimatter: results from the experiment NA52 at CERN
We present results of the CERN experiment NA52 which measures Pb+Pb collisions at 158 A GeV. The topics we address are: 1. strangelet search, 2. nuclei and antinuclei production and 3. strangeness production. No strangelets have been found. We set upper limits which stretch down to the minimal values of ∼ 2 10−10 for negatively and 3 10−9 for positively charged strangelets. We observed 5 3He near midrapidity. Nuclei and antinuclei cross sections suggest production mainly through coalescence, out of a thermalised particle source, at the time of the thermal freeze-out as witnessed by their temperature of 100-120 MeV. Charged kaons per participant nucleon (Np) show an onset of enhancement followed by saturation at Np ∼ 80, corresponding approximately to an initial energy density of i ∼ 1.3 GeV/fm. This onset may be connected to the onset of the QCD phase transition.
119932741
Electroweak radiative corrections to e+ e- -> t anti-t H
We have calculated the complete electroweak O(alpha) radiative corrections to the Higgs-boson production process e+ e- -> t anti-t H in the electroweak Standard Model. Initial-state radiation beyond O(alpha) is included in the structure-function approach. The calculation of the corrections is briefly described, and numerical results are presented for the total cross section. Both the photonic and the genuine weak corrections reach the order of about 10% or even more and show a non-trivial dependence on the Higgs-boson mass and on the scattering energy. We compare our results with two previous calculations that obtained differing results at high energies.
14164208
A prototype liquid Argon Time Projection Chamber for the study of UV laser multi-photonic ionization
This paper describes the design, realization and operation of a prototype liquid Argon Time Projection Chamber (LAr TPC) detector dedicated to the development of a novel online monitoring and calibration system exploiting UV laser beams. In particular, the system is intended to measure the lifetime of the primary ionization in LAr, in turn related to the LAr purity level. This technique could be exploited by present and next generation large mass LAr TPCs for which monitoring of the performance and calibration play an important role. Results from the first measurements are presented together with some considerations and outlook.
109501139
Power distribution for SLHC trackers: Challenges and solutions
Abstract The inner tracking detectors of the Large Hadron Collider (LHC) detectors consume tens of kilowatts of power. Getting power from the rack supply to the detectors has proved to be challenging, inefficient and cumbersome. At Super-LHC (SLHC), the traditional approach of delivering power for each detector module independently will fail. Solving the power distribution problem at SLHC has been recognized as a critical challenge, and significant R&D effort is being devoted to solving it. There are a number of promising concepts, including serial powering and parallel powering combined with local DC–DC conversion, which will be discussed in this introduction and overview article.