The European Physical Journal C

http://link.springer.com/journal/10052

List of Papers (Total 3,082)

Electron neutrino tagging through tertiary lepton detection

We discuss an experimental technique aimed at tagging electron neutrinos in multi-GeV artificial sources on an event-by-event basis. It exploits in a novel manner calorimetric and tracking technologies developed in the framework of the LHC experiments and of rare kaon decay searches. The setup is suited for slow-extraction, moderate power beams and it is based on an instrumented ...

Measurement of leading neutron production in deep-inelastic scattering at HERA

The production of leading neutrons, where the neutron carries a large fraction x L of the incoming proton’s longitudinal momentum, is studied in deep-inelastic positron-proton scattering at HERA. The data were taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of 122 pb−1. The semi-inclusive cross section is measured in the phase space ...

Charged-particle multiplicity measurement in proton–proton collisions at \(\sqrt{s}=7\) TeV with ALICE at LHC

The pseudorapidity density and multiplicity distribution of charged particles produced in proton–proton collisions at the LHC, at a centre-of-mass energy \(\sqrt{s}=7\) TeV, were measured in the central pseudorapidity region |η|<1. Comparisons are made with previous measurements at \(\sqrt{s}=0.9\) TeV and 2.36 TeV. At \(\sqrt{s}=7\) TeV, for events with at least one charged ...

Inelastic production of J/ψ mesons in photoproduction and deep inelastic scattering at HERA

A measurement is presented of inelastic photo- and electroproduction of J/ψ mesons in ep scattering at HERA. The data were recorded with the H1 detector in the period from 2004 to 2007. Single and double differential cross sections are determined and the helicity distributions of the J/ψ mesons are analysed. The results are compared to theoretical predictions in the colour singlet ...

A global treatment of VMD physics up to the φ: II. τ decay and hadronic contributions to g−2

Relying on the Hidden Local Symmetry (HLS) model equipped with a mechanism breaking the U(3)/SU(3)/SU(2) symmetries and generating a dynamical vector meson mixing, it has been shown that a global fit successfully describes the cross sections for the e + e −→π + π −, e + e −→(π 0/η)γ and e + e −→π 0 π + π − annihilation channels. One extends this global fit in order to include also ...

Results of the ALICE time-of-flight detector from the 2009 cosmic-ray data taking

The Time-Of-Flight detector (TOF) of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs). The TOF detector consists of 152928 readout channels covering a total area of 141 m2. In this paper the results of the calibration with cosmic-ray data collected during 2009 are presented.

Pulse shape simulation for segmented true-coaxial HPGe detectors

A new package to simulate the formation of electrical pulses in segmented true-coaxial high purity germanium detectors is presented. The computation of the electric field and weighting potentials inside the detector as well as of the trajectories of the charge carriers is described. In addition, the treatment of bandwidth limitations and noise are discussed. Comparison of simulated ...

Inclusive production of charged kaons in p+p collisions at 158 GeV/c beam momentum and a new evaluation of the energy dependence of kaon production up to collider energies

New data on the production of charged kaons in p+p interactions are presented. The data come from a sample of 4.8 million inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The kaons are identified by energy loss in a large TPC tracking system. Inclusive invariant cross sections are obtained in intervals from 0 to 1.7 GeV/c in transverse ...

Charged-particle multiplicity measurement in proton–proton collisions at \(\sqrt{s}=0.9\) and 2.36 TeV with ALICE at LHC

Charged-particle production was studied in proton–proton collisions collected at the LHC with the ALICE detector at centre-of-mass energies 0.9 TeV and 2.36 TeV in the pseudorapidity range |η|η| \(\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta=3.02\pm 0.01(\mathit{stat.})^{+0.08}_{-0.05}(\mathit{syst.})\) for inelastic interactions, and ...

Measurement of the direct emission and interference terms and search for CP violation in the decay K ±→π ± π 0 γ

We report on the measurement of the direct emission (DE) and interference (INT) terms of the K ±→π ± π 0 γ decay by the NA48/2 experiment at the CERN SPS. From the data collected during 2003 and 2004 about 600k such decay candidates have been selected. The relative amounts of DE and INT with respect to the internal bremsstrahlung (IB) contribution have been measured in the range ...

Study of multi-muon events produced in \(p\bar{p}\) interactions at \(\sqrt{s}=1.96\) TeV

We report the results of a study of multi-muon events produced at the Fermilab Tevatron collider and acquired with the CDF II detector using a dedicated dimuon trigger. The production cross section and kinematics of events in which both muon candidates are produced inside the beam pipe of radius 1.5 cm are successfully modeled by known processes which include heavy flavor ...

Comments and Reply on: “Study of multi-muon events produced in \(p\bar{p}\) interactions at \(\sqrt{s}=1.96\) TeV”; T. Aaltonen et al. (The CDF Collaboration)

The European Physical Journal C—Particles and Fields—publishes scientific manuscripts of relevance to the scientific community following careful and strict peer reviewing and, whenever appropriate and necessary, through discussion with the authors, so as to optimise scientific content and style of presentation prior to publication. In some cases significant disagreement between ...

Performance studies of a full-length prototype for the CASTOR forward calorimeter at the CMS experiment

We present performance studies of a full-length prototype for the CASTOR quartz-tungsten sampling calorimeter, installed in the very forward region of the CMS experiment at the LHC. The response linearity and energy resolution, the uniformity, as well as the showers’ spatial properties in the prototype have been studied with electrons, pions and muons of various energies. A special ...

Study of the dependence of direct soft photon production on the jet characteristics in hadronic Z 0 decays

An analysis of the direct soft photon production rate as a function of the parent jet characteristics is presented, based on hadronic events collected by the DELPHI experiment at LEP1. The dependences of the photon rates on the jet kinematic characteristics (momentum, mass, etc.) and on the jet charged, neutral and total hadron multiplicities are reported. Up to a scale factor of ...

Ultracold neutrons extracted from a superfluid-helium converter coated with fluorinated grease

We report experiments on the production of ultracold neutrons (UCN) in a converter of superfluid helium coated with fluorinated grease (fomblin). We employed our special technique of window-free extraction of accumulated UCN from the superfluid helium, in which they were produced by downscattering neutrons of a cold beam from the Munich research reactor. The fomblin-coating reduced ...

A simple event weighting technique: optimizing the measurement of the forward-backward asymmetry of Drell-Yan dilepton and top-antitop pairs at hadron colliders

We describe a simple technique for optimizing the extraction of the forward-backward asymmetry (A fb) of Drell-Yan lepton pairs (e + e −, μ + μ −) produced in \(\bar{p}p\) and pp collisions at hadron colliders. The method employs simple event weights which are functions of the rapidity and |cos θ| decay angle of the lepton pair. It yields the best estimate of the acceptance ...

Measurement of the atmospheric muon charge ratio with the OPERA detector

The OPERA detector at the Gran Sasso underground laboratory (LNGS) was used to measure the atmospheric muon charge ratio \(R_{\mu}=N_{\mu^{+}}/N_{\mu^{-}}\) in the TeV energy region. We analyzed 403069 atmospheric muons corresponding to 113.4 days of livetime during the 2008 CNGS run. We computed separately the muon charge ratio for single and for multiple muon events in order to ...

New results from DAMA/LIBRA

DAMA/LIBRA is running at the Gran Sasso National Laboratory of the I.N.F.N. Here the results obtained with a further exposure of 0.34 ton × yr are presented. They refer to two further annual cycles collected one before and one after the first DAMA/LIBRA upgrade occurred on September/October 2008. The cumulative exposure with those previously released by the former DAMA/NaI and by ...

Observation of the Higgs Boson of strong interaction via Compton scattering by the nucleon

It is shown that the Quark-Level Linear σ Model (QLLσM) leads to a prediction for the diamagnetic term of the polarizabilities of the nucleon which is in excellent agreement with experimental data. The bare mass of the σ meson is predicted to be m σ =666 MeV and the two-photon width Γ(σ→γ γ)=(2.6±0.3) keV. It is argued that the mass predicted by the QLLσM corresponds to the ...

Jet production in ep collisions at low Q 2 and determination of α s

The production of jets is studied in deep-inelastic e + p scattering at low negative four momentum transfer squared 5Q 22 and at inelasticity 0.2y−1. Inclusive jet, 2-jet and 3-jet cross sections as well as the ratio of 3-jet to 2-jet cross sections are measured as a function of Q 2 and jet transverse momentum. The 2-jet cross section is also measured as a function of the proton ...

Searching for high speed long-lived charged massive particles at the LHC

The conventional way to search for long-lived CHArged Massive Particles (CHAMPs) is to identify slow (small β) tracks using delayed time of flight and high ionization energy loss. But at the 7–14 TeV center of mass energy of the LHC, a CHAMP may be highly boosted (high β) and therefore look more like a minimum ionizing particle, while for high momentum muons (≳500 GeV/c) the ...

An updated description of heavy-hadron interactions in Geant-4

Exotic stable massive particles (SMP) are proposed in a number of scenarios of physics beyond the Standard Model. LHC experiments are expected to be able both to detect and extract the quantum numbers of any SMP with masses around the TeV scale. An understanding of the interactions of SMPs in matter is required to optimise the detection methods and calculate acceptances in an SMP ...

A posteriori inclusion of parton density functions in NLO QCD final-state calculations at hadron colliders: the APPLGRID project

A method to facilitate the consistent inclusion of cross-section measurements based on complex final-states from HERA, TEVATRON and the LHC in proton parton density function (PDF) fits has been developed. This can be used to increase the sensitivity of LHC data to deviations from Standard Model predictions. The method stores perturbative coefficients of NLO QCD calculations of ...

Dijet angular distributions at \(\sqrt{s}=14\) TeV

We present a Monte Carlo study of dijet angular distributions at \(\sqrt{s}=14\) TeV. First we perform a next-to-leading order QCD study; we calculate the distributions in four different bins of dijet invariant mass using different Monte Carlo programs and different jet algorithms, and we also investigate the systematic uncertainties coming from the choice of the parton ...