# The European Physical Journal C

## List of Papers (Total 3,333)

#### 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 ...

#### Experimental search for the “LSND anomaly” with the ICARUS detector in the CNGS neutrino beam

We report an early result from the ICARUS experiment on the search for a ν μ →ν e signal due to the LSND anomaly. The search was performed with the ICARUS T600 detector located at the Gran Sasso Laboratory, receiving CNGS neutrinos from CERN at an average energy of about 20 GeV, after a flight path of ∼730 km. The LSND anomaly would manifest as an excess of ν e events, ...

#### A study of measurement precision of the Higgs boson branching ratios at the International Linear Collider

Precise measurement of the Higgs boson couplings is an important task for International Linear Collider (ILC) experiments and will clarify the understanding of the particle mass generation mechanism. In particular, high precision measurement of Higgs branching ratios plays a key role in the search for the origin of the Yukawa and Higgs interactions. In this study, the measurement ...

#### A survey of backward proton and pion production in p + C interactions at beam momenta from 1 to 400 GeV/c

Recent data on proton and pion production in p+C interactions from the CERN PS and SPS accelerators are used in conjunction with other available data sets to perform a comprehensive survey of backward hadronic cross sections. This survey covers the complete backward hemisphere in the range of lab angles from 10 to 180 degrees, from 0.2 to 1.4 GeV/c in lab momentum and from 1 to 400 ...

#### Measurement of the strong coupling α S from the three-jet rate in e+e−-annihilation using JADE data

We present a measurement of the strong coupling α S using the three-jet rate measured with the Durham algorithm in $\mathrm{e^{+}e^{-}}$-annihilation using data of the JADE experiment at centre-of-mass energies between 14 and 44 GeV. Recent theoretical improvements provide predictions of the three-jet rate in $\mathrm{e^{+}e^{-}}$-annihilation at next-to-next-to-leading order. ...

#### Jet energy measurement with the ATLAS detector in proton-proton collisions at $\sqrt{\mathrm{s}}=7\ \mathrm{TeV}$

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=7\ \mathrm{TeV}$ corresponding to an integrated luminosity of 38 pb−1. Jets are reconstructed with the anti-k t algorithm with distance parameters R=0.4 or R=0.6. Jet energy and angle ...

#### Jet energy resolution in proton-proton collisions at $\sqrt{\mathrm{s}}=7\mbox{ TeV}$ recorded in 2010 with the ATLAS detector

The measurement of the jet energy resolution is presented using data recorded with the ATLAS detector in proton-proton collisions at $\sqrt{s}=7\mbox{ TeV}$. The sample corresponds to an integrated luminosity of 35 pb−1. Jets are reconstructed from energy deposits measured by the calorimeters and calibrated using different jet calibration schemes. The jet energy resolution is ...

#### Measurement of the $t\bar{t}$ production cross section in the tau + jets channel using the ATLAS detector

A measurement of the top quark pair production cross section in the final state with a hadronically decaying tau lepton and jets is presented. The analysis is based on proton–proton collision data recorded by the ATLAS experiment at the LHC, with a centre-of-mass energy of 7 TeV. The data sample corresponds to an integrated luminosity of 1.67 fb−1. The cross section is measured to ...

#### Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of $\sqrt{s} = 900~\mbox{GeV}$ and 7 TeV collected during ...

#### The Gerda experiment for the search of 0νββ decay in 76Ge

The Gerda collaboration is performing a search for neutrinoless double beta decay of 76Ge with the eponymous detector. The experiment has been installed and commissioned at the Laboratori Nazionali del Gran Sasso and has started operation in November 2011. The design, construction and first operational results are described, along with detailed information from the R&D phase.

#### Automated mass spectrum generation for new physics

We describe an extension of the FeynRules package dedicated to the automatic generation of the mass spectrum associated with any Lagrangian-based quantum field theory. After introducing a simplified way to implement particle mixings, we present a new class of FeynRules functions allowing both for the analytical computation of all the model mass matrices and for the generation of a ...

#### Limit on sterile neutrino contribution from the Mainz Neutrino Mass Experiment

The recent analysis of the normalization of reactor antineutrino data, the calibration data of solar neutrino experiments using gallium targets, and the results from the neutrino oscillation experiment MiniBooNE suggest the existence of a fourth light neutrino mass state with a mass of $\mathcal{O}~(\mathrm{eV})$, which contributes to the electron neutrino with a sizable mixing ...

#### Combination and QCD analysis of charm production cross section measurements in deep-inelastic ep scattering at HERA

Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections $\sigma_{\rm red}^{c\bar{c}}$ for charm production are obtained in the kinematic range of photon virtuality 2.5≤Q 2≤2000 GeV2 and Bjorken scaling variable 3⋅10−5≤x≤5⋅10−2. The combination method accounts for the ...

#### ColorMath—a package for color summed calculations in SU(N c )

A Mathematica package for color summed calculations in QCD (SU(N c )) is presented. Color contractions of any color amplitude appearing in QCD may be performed, and the package uses a syntax which is very similar to how color structure is written on paper. It also supports the definition of color vectors and bases, and special functions such as scalar products are defined for such ...

Evidence of a new particle with mass ∼125 GeV decaying into a pair of tau leptons at the Large Hadron Collider spurs interest in ascertaining its spin in this channel. Here we present a comparative study between spin-0 and spin-2 nature of this new particle, using spin correlations and decay product directions. The TauSpinner algorithm is used to re-weight distributions from $q ... #### Measurement of the flavour composition of dijet events in pp collisions at \(\sqrt{s}=7\ \mbox{TeV}$ with the ATLAS detector

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at $\sqrt{s} =7\mbox {~TeV}$ using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is ...

#### Measurement of the sum of WW and WZ production with W+dijet events in pp collisions at $\sqrt{s} = 7\ \mbox{TeV}$

A measurement of the inclusive WW+WZ diboson production cross section in proton–proton collisions is reported, based on events containing a leptonically decaying W boson and exactly two jets. The data sample, collected at $\sqrt{s} = 7~\mbox{TeV}$ with the CMS detector at the LHC, corresponds to an integrated luminosity of 5.0 fb−1. The measured value of the sum of the inclusive ...

#### Prospects for the measurement of the Higgs Yukawa couplings to b and c quarks, and muons at CLIC

The investigation of the properties of the Higgs boson, especially a test of the predicted linear dependence of the branching ratios on the mass of the final state is going to be an integral part of the physics program at colliders at the energy frontier for the foreseeable future. The large Higgs boson production cross section at a 3 TeV CLIC machine allows for a precision ...