European Physical Journal C (EUR PHYS J C)
Journal description
The European Physical Journal C Particles and Fields A merger of Il Nuovo Cimento A and Zeitschrift für Physik C The physics of elementary particles lies at the frontier of our understanding of nature. The journal EPJ C publishes most recent experimental and theoretical results obtained in this field. Experimental results come from the high energy physics laboratories such as CERN (Switzerland) DESY (Germany) SLAC and Fermilab (both USA) and KEK (Japan) with their accelerators and experimentral facilities and also from nonaccelerator laboratories such as Kamioka (Japan) GranSasso (Italy) and others. Theoretical topics include studies and tests of the Standard Model computer simulations of Quantum Chromodynamics search for the Higgs particle and supersymmetry and the investigation of new ideas beyond the standard model. Experimental Physics e + e  experiments Lepton nucleon scattering Hadron hadron scattering B physics Neutrino physics Nonaccelerator experiments Highenergy nuclear reactions Theoretical Physics The standard model: Electroweak interactions and QCD Nonperturbative strong interactions Soft hadron physics Lattice field theory High temperature QCD and heavy ion physics Beyond the standard model Astroparticle physics and cosmology Quantum field theory
Current impact factor: 5.08
Impact Factor Rankings
2016 Impact Factor  Available summer 2017 

2014 / 2015 Impact Factor  5.084 
2013 Impact Factor  5.436 
2012 Impact Factor  5.247 
2011 Impact Factor  3.631 
2010 Impact Factor  3.248 
2009 Impact Factor  2.746 
2008 Impact Factor  2.805 
2007 Impact Factor  3.255 
2006 Impact Factor  3.251 
2005 Impact Factor  3.209 
2004 Impact Factor  3.486 
2003 Impact Factor  3.58 
2002 Impact Factor  6.162 
2001 Impact Factor  5.194 
2000 Impact Factor  5.408 
1999 Impact Factor  6.872 
1998 Impact Factor 
Impact factor over time
Additional details
5year impact  4.12 

Cited halflife  4.20 
Immediacy index  1.43 
Eigenfactor  0.05 
Article influence  1.54 
Website  European Physical Journal C (EPJ C), The  Particles and Fields website 
Other titles  European physical journal., Particles and fields, EPJ., Eur. phys. j 
ISSN  14346044 
OCLC  39166324 
Material type  Document, Periodical, Internet resource 
Document type  Internet Resource, Computer File, Journal / Magazine / Newspaper 
Publisher details
 Preprint
 Author can archive a preprint version
 Postprint
 Author can archive a postprint version
 Conditions
 On open access repositories
 Creative Commons Attribution License
 Published source must be acknowledged
 Publisher's version/PDF may be used
 Applies to Journal of High Energy Physics and European Physical Journal C: Particles and Fields
 All titles are open access journals
 Titles are funded by SCOAP3
 This policy is an exception to the default policies of 'Springer Verlag (Germany)'
 Classificationgreen
Publications in this journal
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ABSTRACT: In this work, we study various decays of heavy B / D mesons into the \(a_1(1260)\), based on the form factors derived in different nonperturbative or factorization approaches. These decay modes are helpful to explore the dynamics in the heavy to light transitions. Meanwhile they can also provide insights to a newly discovered state, the \(a_1(1420)\) with \(I^G(J^{PC})= 1^(1^{++})\) observed in the \(\pi ^+ f_0(980)\) final state in the \(\pi ^p\rightarrow \pi ^+\pi ^\pi ^ p\) process. Available theoretical explanations include tetraquark or rescattering effects due to \(a_1(1260)\) decays. If the \(a_1(1420)\) were induced by the rescattering, its production rates are completely determined by those of the \(a_1(1260)\). Our numerical results for decays into the \(a_1(1260)\) indicate that there is a promising prospect to study these decays on experiments including BESIII, LHCb, Babar, Belle, and CLEOc, the forthcoming SuperKEKB factory and the underdesign Circular Electron–Positron Collider. 

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ABSTRACT: Some traces of a specific Lorentz symmetry breaking scenario in the ground state of the Hydrogen atom are investigated. It is used standard RayleighSchr\"odinger perturbation theory in order to obtain the corrections to the the ground state energy and wave function. It is shown that an induced fourpole moment arises, due to the Lorentz symmetry breaking. The model considered is the one studied in reference Eur. Phys. J. C {\bf 74}, 2937 (2014), where the Lorentz symmetry is broken in the electromagnetic sector.  [Show abstract] [Hide abstract]
ABSTRACT: Combined analyses of the Higgs boson production and decay rates as well as its coupling strengths to vector bosons and fermions are presented. The combinations include the results of the analyses of the \(H\rightarrow \gamma \gamma ,\, ZZ^*,\, WW^*,\, Z\gamma ,\, b\bar{b},\, \tau \tau \) and \(\mu \mu \) decay modes, and the constraints on the associated production with a pair of top quarks and on the offshell coupling strengths of the Higgs boson. The results are based on the LHC protonproton collision datasets, with integrated luminosities of up to 4.7 \(\mathrm {fb}^{1}\) at \(\sqrt{s}=7\) TeV and 20.3 \(\mathrm {fb}^{1}\) at \(\sqrt{s}=8\) TeV, recorded by the ATLAS detector in 2011 and 2012. Combining all production modes and decay channels, the measured signal yield, normalised to the Standard Model expectation, is \(1.18^{+0.15}_{0.14}\). The observed Higgs boson production and decay rates are interpreted in a leadingorder coupling framework, exploring a wide range of benchmark coupling models both with and without assumptions on the Higgs boson width and on the Standard Model particle content in loop processes. The data are found to be compatible with the Standard Model expectations for a Higgs boson at a mass of 125.36 GeV for all models considered.  [Show abstract] [Hide abstract]
ABSTRACT: Searches for pairproduced scalar leptoquarks are performed using 20 fb\(^{1}\) of proton–proton collision data provided by the LHC and recorded by the ATLAS detector at \(\sqrt{s}=8\) TeV. Events with two electrons (muons) and two or more jets in the final state are used to search for first (second)generation leptoquarks. The results from two previously published ATLAS analyses are interpreted in terms of thirdgeneration leptoquarks decaying to \(b\nu _{\tau }\bar{b}\bar{\nu _{\tau }}\) and \(t\nu _{\tau }\bar{t}\bar{\nu _{\tau }}\) final states. No statistically significant excess above the Standard Model expectation is observed in any channel and scalar leptoquarks are excluded at 95 % CL with masses up to \(m_{\mathrm {LQ1}}<\) 1050 GeV for firstgeneration leptoquarks, \(m_{\mathrm {LQ2}}<\) 1000 GeV for secondgeneration leptoquarks, \(m_{\mathrm {LQ3}}<\) 625 GeV for thirdgeneration leptoquarks in the \(b\nu _{\tau }\bar{b}\bar{\nu _{\tau }}\) channel, and 200 \(< m_{\mathrm {LQ3}}< \) 640 GeV in the \(t\nu _{\tau }\bar{t}\bar{\nu _{\tau }}\) channel.  [Show abstract] [Hide abstract]
ABSTRACT: Fiducial crosssections for \(t\bar{t} \) production with one or two additional bjets are reported, using an integrated luminosity of 20.3 fb\(^{1}\) of proton–proton collisions at a centreofmass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The crosssection times branching ratio for \(t\bar{t} \) events with at least one additional bjet is measured to be 950 \(\pm \) 70 (stat.) \(^{+240}_{190}\) (syst.) fb in the leptonplusjets channel and 50 \(\pm \) 10 (stat.) \(^{+15}_{10}\) (syst.) fb in the \(e \mu \) channel. The crosssection times branching ratio for events with at least two additional bjets is measured to be 19.3 \(\pm \) 3.5 (stat.) \(\pm \) 5.7 (syst.) fb in the dilepton channel (\(e \mu \), \(\mu \mu \), and ee) using a method based on tight selection criteria, and 13.5 \(\pm \) 3.3 (stat.) \(\pm \) 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 \(\pm \) 0.33 (stat.) \(\pm \) 0.28 (syst.)% for the ratio of \(t\bar{t}\) production with two additional bjets to \(t\bar{t}\) production with any two additional jets. All measurements are in good agreement with recent theory predictions.  [Show abstract] [Hide abstract]
ABSTRACT: A measurement is presented of differential cross sections for Higgs boson (H) production in pp collisions at \(\sqrt{s}=8\) \(\,\text {TeV}\). The analysis exploits the \({H} \rightarrow {\gamma }{\gamma }\) decay in data corresponding to an integrated luminosity of 19.7\(\,\text {fb}^\text {1}\) collected by the CMS experiment at the LHC. The cross section is measured as a function of the kinematic properties of the diphoton system and of the associated jets. Results corrected for detector effects are compared with predictions at nexttoleading order and nexttonexttoleading order in perturbative quantum chromodynamics, as well as with predictions beyond the standard model. For isolated photons with pseudorapidities \(\eta <2.5\), and with the photon of largest and nexttolargest transverse momentum (\(p_{\mathrm {T}} ^{\gamma }\)) divided by the diphoton mass \(m_{\gamma \gamma }\) satisfying the respective conditions of \(p_{\mathrm {T}} ^{\gamma }/m_{\gamma \gamma }> 1/3\) and \({>}1/4\), the total fiducial cross section is \(32 \pm 10\) \(\text {\,fb}\).  [Show abstract] [Hide abstract]
ABSTRACT: A first measurement is presented of exclusive photoproduction of \(\rho ^0\) mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years 2006 and 2007 at a centreofmass energy of \(\sqrt{s}=319\) GeV and correspond to an integrated luminosity of 1.16 pb\(^{1}\). The \(\rho ^0\) mesons with transverse momenta \(p_T<1\) GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, \(x_L>0.35\), are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality \(Q^2 < 2\) GeV\(^2\), the total energy of the photon–proton system \(20 < W_{\gamma p}< 100\) GeV and the polar angle of the leading neutron \(\theta _n < 0.75\) mrad. The cross section of the reaction \(\gamma p \rightarrow \rho ^0 n \pi ^+\) is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a \(\rho ^0\) meson on the virtual pion. In the framework of onepionexchange dominance the elastic cross section of photonpion scattering, \(\sigma ^\mathrm{el}(\gamma \pi ^+ \rightarrow \rho ^0\pi ^+)\), is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction \(\gamma p \rightarrow \rho ^0 n \pi ^+\).  [Show abstract] [Hide abstract]
ABSTRACT: Supersymmetry (SUSY) is an attractive extension of the Standard Model (SM) of particle physics which solves the SM hierarchy problem. Motivated by the theoretical \(\mu \)term problem of the Minimal Supersymmetric Model (MSSM), the Nextto MSSM (NMSSM) can also account for experimental deviations from the SM like the anomalous muon magnetic moment and the dark matter relic density. Natural SUSY, motivated by naturalness considerations, exhibits small fine tuning and a characteristic phenomenology with light higgsinos, stops, and gluinos. We describe a scan in NMSSM parameter space motivated by Natural SUSY and guided by the phenomenology of an NMSSM with a slightly broken Peccei–Quinn symmetry and a lightly coupled singlet. We identify a scenario which survives experimental constraints with a light singlet Higgs and a singlino lightest SUSY particle. We then discuss how the scenario is not presently excluded by searches at the Large Hadron Collider (LHC) and which channels are promising for discovery at the LHC and International Linear Collider. 
Article: Inflation in a viscous fluid model
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ABSTRACT: We explore a fluid description of the inflationary universe. In particular, we investigate a fluid model in which the equation of state (EoS) for a fluid includes bulk viscosity. We find that the three observables of inflationary cosmology, i.e., the spectral index of the curvature perturbations, the tensortoscalar ratio of the density perturbations, and the running of the spectral index, can be consistent with the recent Planck results. We also reconstruct the explicit EoS for a fluid from the spectral index of the curvature perturbations compatible with the Planck analysis. In the reconstructed models of a fluid, the tensortoscalar ratio of the density perturbations can satisfy the constraints obtained from the Planck satellite. The running of the spectral index can explain the Planck data. In addition, it is demonstrated that in the reconstructed models of a fluid, the graceful exit from inflation can be realized. Moreover, we show that the singular inflation can occur in a fluid model. Furthermore, we show that a fluid description of inflation can be equivalent to the description of inflation in terms of scalar field theories.  [Show abstract] [Hide abstract]
ABSTRACT: We briefly discuss some of the known and new properties of rotating geometries that are relevant to this work. We generalize the analytical method of superposition of fields, known for generating nonrotating solutions, and apply it to construct massless and massive rotating physical wormholes sourced by a sourcefree electromagnetic field and an exotic fluid both anisotropic. Their stressenergy tensors are presented in compact and general forms. For the massive rotating wormholes there exists a masscharge constraint yielding almost no more dragging effects than ordinary stars. There are conical spirals through the throat along which no local negative energy densities are noticed for these rotating wormholes. This conclusion extends to nonrotating massive type I wormholes derived previously by the author that seem to be the first kind of nonrotating wormholes with this property. Based on the classification made in J. Cosmol. Astropart. Phys. 07 (2015) 037 [arXiv:1412.8282]: "Type I wormholes have their radial pressure dying out faster, as one moves away from the throat, than any other component of the stressenergy and thus violate the least the local energy conditions. In type II (resp. III) the radial and transverse pressures are asymptotically proportional and die out faster (resp. slower) than the energy density".  [Show abstract] [Hide abstract]
ABSTRACT: A search is presented for a highmass Higgs boson in the \(H\rightarrow ZZ\rightarrow \ell ^+\ell ^\ell ^+\ell ^\), \(H\rightarrow ZZ\rightarrow \ell ^+\ell ^\nu \bar{\nu }\), \(H\rightarrow ZZ\rightarrow \ell ^+\ell ^ q \bar{q}\), and \(H\rightarrow ZZ\rightarrow \nu \bar{\nu } q \bar{q}\) decay modes using the ATLAS detector at the CERN Large Hadron Collider. The search uses proton–proton collision data at a centreofmass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb\(^{1}\). The results of the search are interpreted in the scenario of a heavy Higgs boson with a width that is small compared with the experimental mass resolution. The Higgs boson mass range considered extends up to \(1~\mathrm{TeV}\) for all four decay modes and down to as low as 140 \(\mathrm{GeV}\), depending on the decay mode. No significant excess of events over the Standard Model prediction is found. A simultaneous fit to the four decay modes yields upper limits on the production crosssection of a heavy Higgs boson times the branching ratio to \(Z\) boson pairs. 95 % confidence level upper limits range from 0.53 pb at \(m_{H} =195\) GeV to 0.008 pb at \(m_{H} =950\) GeV for the gluonfusion production mode and from 0.31 pb at \(m_{H} =195\) GeV to 0.009 pb at \(m_{H} =950\) GeV for the vectorbosonfusion production mode. The results are also interpreted in the context of TypeI and TypeII twoHiggsdoublet models.  [Show abstract] [Hide abstract]
ABSTRACT: We construct and investigate an infraredimproved softwall AdS/QCD model for mesons. Both linear confinement and chiral symmetry breaking of low energy QCD are well characterized in such an infraredimproved softwall AdS/QCD model. The model enables us to obtain a more consistent numerical prediction for the mass spectra of resonance scalar, pseudoscalar, vector, and axialvector mesons. In particular, the predicted mass for the lightest ground state scalar meson shows good agreement with the experimental data. The model also provides a remarkable check for the GellMann–Oakes–Renner relation and a sensible result for the spacelike pion form factor.  [Show abstract] [Hide abstract]
ABSTRACT: The Friedmann equation in the Friedmann–Robertson–Walker (FRW) universe with any spatial curvature is derived from the first law of thermodynamics on the event horizon. The key idea is to redefine a Hawking temperature on the event horizon. Furthermore, we obtain the evolution equations of the universe including the quantum correction and explore the evolution of the universe in f(R) gravity. In addition, we also investigate the generalized second law of thermodynamics in Einstein gravity and f(R) gravity. This perspective also implies that the first law of thermodynamics on the event horizon has a general description in respect of the evolution of the FRW universe.  [Show abstract] [Hide abstract]
ABSTRACT: Lack of a consistent metric for generating rotating wormholes motivates us to present a new one endowed with interesting physical and geometrical properties. When combined with the generalized method of superposition of fields, which consists in attaching a form of matter to each moving frame, it generates massive and charged (charge without charge) twofluidsourced, massive and twocharged threefluidsourced, rotating as well as new static wormholes which, otherwise, can hardly be derived by integration. If the lapse function of the static wormhole is bounded from above, no closed timelike curves occur in the rotating counterpart. For positive energy densities dying out faster than $1/r$, the angular velocity includes in its expansion a correction term, to the leading one that corresponds to ordinary stars, proportional to $\ln r/r^4$. Such a term is not present in the corresponding expansion for the KerrNewman black hole. Based on this observation and our previous work, the dragging effects of falling neutral objects may constitute a substitute for other known techniques used for testing the nature of the rotating black hole candidates that are harbored in the center of galaxies. We discuss the possibility of generating ($n+1$)fluidsourced, $n$charged, rotating as well as static wormholes.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.