The European Physical Journal C

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

List of Papers (Total 3,401)

Measurement of inelastic, single- and double-diffraction cross sections in proton–proton collisions at the LHC with ALICE

Measurements of cross sections of inelastic and diffractive processes in proton–proton collisions at LHC energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single diffraction (diffractive mass M X <200 GeV/c 2) ...

Search for a light charged Higgs boson in the decay channel \(H^{+} \rightarrow c\bar{s}\) in \(t\bar{t}\) events using pp collisions at \(\sqrt{s} = 7\ \mathrm{TeV}\) with the ATLAS detector

A search for a charged Higgs boson (H +) in \(t\bar{t}\) decays is presented, where one of the top quarks decays via t→H + b, followed by H +→ two jets (\(c\bar{s}\)). The other top quark decays to Wb, where the W boson then decays into a lepton (e/μ) and a neutrino. The data were recorded in pp collisions at \(\sqrt{s} = 7~\mathrm {TeV}\) by the ATLAS detector at the LHC in 2011, ...

An update of the HLS estimate of the muon g−2

A global fit of parameters allows us to pin down the Hidden Local Symmetry (HLS) effective Lagrangian, which we apply for the prediction of the leading hadronic vacuum polarization contribution to the muon g−2. The latter is dominated by the annihilation channel e + e −→π + π −, for which data are available by scan (CMD-2 & SND) and ISR (KLOE-2008, KLOE-2010 & BaBar) experiments. ...

High voltage capacitors for low background experiments

Low background experiments place stringent constraints on amount of radioactive impurities in the materials used for their assembly. Often these are in conflict with the constraints placed on the materials by their roles in the experiment. This is especially true for certain electronic components. A high value, high voltage capacitor for use in low background experiments has been ...

Measurement of the forward energy flow in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}\)

The energy flow created in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}\) is studied within the pseudorapidity range 1.9<η<4.9 with data collected by the LHCb experiment. The measurements are performed for inclusive minimum-bias interactions, hard scattering processes and events with an enhanced or suppressed diffractive contribution. The results are compared to predictions given by ...

Measurement of k T splitting scales in W→ℓν events at \(\sqrt{s} = 7\ \mathrm{TeV}\) with the ATLAS detector

A measurement of splitting scales, as defined by the k T clustering algorithm, is presented for final states containing a W boson produced in proton–proton collisions at a centre-of-mass energy of 7 TeV. The measurement is based on the full 2010 data sample corresponding to an integrated luminosity of 36 pb−1 which was collected using the ATLAS detector at the CERN Large Hadron ...

Performance of the LHCb RICH detector at the LHC

The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2–100 GeV/c. The operation and control, software, and online monitoring of the RICH system are described. The particle ...

Search for supersymmetry in pp collisions at \(\sqrt{s} =7\) TeV in events with a single lepton, jets, and missing transverse momentum

Results are reported from a search for new physics processes in events containing a single isolated high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The analysis is based on a 4.98 fb−1 sample of proton–proton collisions at a center-of-mass energy of 7 TeV, obtained with the CMS detector at the LHC. Three separate background ...

ScannerS: constraining the phase diagram of a complex scalar singlet at the LHC

We present the first version of a new tool to scan the parameter space of generic scalar potentials, ScannerS (Coimbra et al., ScannerS project., 2013). The main goal of ScannerS is to help distinguish between different patterns of symmetry breaking for each scalar potential. In this work we use it to investigate the possibility of excluding regions of the phase diagram of several ...

Implications of LHCb measurements and future prospects

During 2011 the LHCb experiment at CERN collected 1.0 fb−1 of \(\sqrt{s} = 7\mbox{~TeV}\) pp collisions. Due to the large heavy quark production cross-sections, these data provide unprecedented samples of heavy flavoured hadrons. The first results from LHCb have made a significant impact on the flavour physics landscape and have definitively proved the concept of a dedicated ...

Measurement of charged particle spectra in deep-inelastic ep scattering at HERA

Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5<Q 2<100 GeV2, and small values of Bjorken-x, 10−4<x<10−2. The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity (η ∗) and ...

Measurement of the proton light response of various LAB based scintillators and its implication for supernova neutrino detection via neutrino–proton scattering

The proton light output function in electron-equivalent energy of various scintillators based on linear alkylbenzene (LAB) has been measured in the energy range from 1 MeV to 17.15 MeV for the first time. The measurement was performed at the Physikalisch–Technische Bundesanstalt (PTB) using a neutron beam with continuous energy distribution. The proton light output data is ...

Measurement of the \(\mathrm{t}\bar{\mathrm{t}}\) production cross section in the τ+jets channel in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}\)

The top-quark pair production cross section in 7 TeV center-of-mass energy proton–proton collisions is measured using data collected by the CMS detector at the LHC. The measurement uses events with one jet identified as a hadronically decaying τ lepton and at least four additional energetic jets, at least one of which is identified as coming from a b quark. The analyzed data sample ...

No drama quantum electrodynamics?

This article builds on recent work (Akhmeteli in Int. J. Quantum Inf. 9(Supp01):17, 2011; J. Math. Phys. 52:082303, 2011), providing a theory that is based on spinor electrodynamics, is described by a system of partial differential equations in 3+1 dimensions, but reproduces unitary evolution of a quantum field theory in the Fock space. To this end, after introduction of a complex ...

Inclusive production of protons, anti-protons, neutrons, deuterons and tritons in p+C collisions at 158 GeV/c beam momentum

The production of protons, anti-protons, neutrons, deuterons and tritons in minimum bias p+C interactions is studied using a sample of 385 734 inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.9 GeV/c in transverse momentum and in Feynman x from −0.8 to 0.95 for protons, from −0.2 to ...

Characterization of the energy resolution and the tracking capabilities of a hybrid pixel detector with CdTe-sensor layer for a possible use in a neutrinoless double beta decay experiment

Many different experiments are being developed to explore the existence of the neutrinoless double beta decay (0νββ) since it would imply fundamental consequences for particle physics. In this work we present results on the evaluation of Timepix detectors with cadmium-telluride sensor material to search for 0νββ in 116Cd. This work was carried out with the COBRA collaboration and ...

Towards testing a two-Higgs-doublet model with maximal CP symmetry at the LHC: Monte Carlo event generator implementation

A Monte Carlo event generator is implemented for a two-Higgs-doublet model with maximal CP symmetry, the MCPM. The model contains five physical Higgs bosons; the ρ′, behaving similarly to the standard-model Higgs boson, two extra neutral bosons h′ and h″, and a charged pair H ±. The special feature of the MCPM is that, concerning the Yukawa couplings, the bosons h′, h″ and H ± ...

Phenomenology tools on cloud infrastructures using OpenStack

We present a new environment for computations in particle physics phenomenology employing recent developments in cloud computing. On this environment users can create and manage “virtual” machines on which the phenomenology codes/tools can be deployed easily in an automated way. We analyze the performance of this environment based on “virtual” machines versus the utilization of ...

The MEG detector for μ +→e+ γ decay search

The MEG (Mu to Electron Gamma) experiment has been running at the Paul Scherrer Institut (PSI), Switzerland since 2008 to search for the decay μ +→e+ γ by using one of the most intense continuous μ + beams in the world. This paper presents the MEG components: the positron spectrometer, including a thin target, a superconducting magnet, a set of drift chambers for measuring the muon ...

Multi-channel search for squarks and gluinos in \(\sqrt{s}=7\mbox{ TeV}\) pp collisions with the ATLAS detector at the LHC

A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb−1 of \(\sqrt{s}=7\mbox{ TeV}\) pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse ...

Fooling around with the Sudakov veto algorithm

The Sudakov veto algorithm for generating emission and no-emission probabilities in parton showers is revisited and some oversampling and reweighting techniques are suggested, mainly to improve statistics. Specifically we consider the generation of Sudakov form factors in algorithms of CKKW type for matrix element/parton shower merging, both at tree- and loop-level, and the ...

Electron-hadron shower discrimination in a liquid argon time projection chamber

By exploiting structural differences between electromagnetic and hadronic showers in a multivariate analysis we present an efficient Electron-Hadron discrimination algorithm for liquid argon time projection chambers, validated using Geant4 simulated data.

Measurement of differential top-quark-pair production cross sections in pp collisions at \(\sqrt{s} = 7\ \mathrm{TeV}\)

Normalised differential top-quark-pair production cross sections are measured in pp collisions at a centre-of-mass energy of 7 TeVat the LHC with the CMS detector using data recorded in 2011 corresponding to an integrated luminosity of 5.0 fb−1. The measurements are performed in the lepton+jets decay channels (e+jets and μ+jets) and the dilepton decay channels ...