The European Physical Journal C

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

List of Papers (Total 3,581)

Gravito-magnetic currents in the inflationary universe from WIMT

Using the Weitzenböck representation of a Riemann-flat 5D spacetime, we study the possible existence of primordial gravito-magnetic currents from Gravito-electromagnetic Inflation (GEMI). We found that these currents decrease exponentially in the Weitzenböck representation, but they are null in a Levi-Civita representation because we are dealing with a 5D Riemann-flat spacetime...

Branes as solutions of gauge theories in gravitational field

The idea of the Gauss map is unified with the concept of branes as hypersurfaces embedded into \(D\)-dimensional Minkowski space. The map introduces new generalized coordinates of branes alternative to their world vectors \(\mathbf {x}\) and identified with the gauge and other massless fields. In these coordinates the Dirac \(p\)-branes realize extremals of the Euler–Lagrange...

Radion cosmology and stabilization

We solve the Einstein equation in five-dimensional space-time for Randall–Sundrum Brane world model with time dependent radion field to study the variation of brane scale factor with time. We have shown that as the radion field decreases with time compactifying the extra dimension, the scale factor increases exponentially with time leading to an inflationary scenario. We have...

Higher order light-cone distribution amplitudes of the Lambda baryon

The improved light-cone distribution amplitudes (LCDAs) of the \(\Lambda \) baryon are examined on the basis of the QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin accuracy with consideration of twist \(6\). The next leading order conformal expansion coefficients are related to the nonperturbative...

Large J expansion in ABJM theory revisited

Recently there has been progress in the computation of the anomalous dimensions of gauge theory operators at strong coupling by making use of the AdS/CFT correspondence. On the string theory side they are given by dispersion relations in the semiclassical regime. We revisit the problem of a large-charge expansion of the dispersion relations for simple semiclassical strings in an...

Wightman function and the Casimir effect for a Robin sphere in a constant curvature space

We evaluate the Wightman function, the mean field squared and the vacuum expectation value of the energy–momentum tensor for a scalar field with the Robin boundary condition on a spherical shell in the background of a constant negative curvature space. For the coefficient in the boundary condition there is a critical value above which the scalar vacuum becomes unstable. In both...

Muon reconstruction efficiency and momentum resolution of the ATLAS experiment in proton–proton collisions at \(\sqrt{s}=7\) TeV in 2010

This paper presents a study of the performance of the muon reconstruction in the analysis of proton–proton collisions at \(\sqrt{s}=7\) TeV at the LHC, recorded by the ATLAS detector in 2010. This performance is described in terms of reconstruction and isolation efficiencies and momentum resolutions for different classes of reconstructed muons. The results are obtained from an...

The global electroweak fit at NNLO and prospects for the LHC and ILC

For a long time, global fits of the electroweak sector of the standard model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC) and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top...

Self-dual chiral boson: augmented superfield approach

We exploit the standard tools and techniques of the augmented version of the Bonora–Tonin superfield formalism to derive the off-shell nilpotent and absolutely anticommuting (anti-)Becchi–Rouet–Stora–Tyutin (BRST) and (anti-)co-BRST symmetry transformations for the BRST-invariant Lagrangian density of a self-dual bosonic system. In the derivation of the full set of the above...

Effect of vacuum polarization of charged massive fermions in an Aharonov–Bohm field

The effect of vacuum polarization of charged massive fermions in an Aharonov–Bohm (AB) potential in 2 + 1 dimensions is investigated. The causal Green function of the Dirac equation with the AB potential is represented via the regular and irregular solutions of the two-dimensional radial Dirac equation. It is shown that the vacuum current density contains the contribution from...

Transverse momentum dependence of inclusive primary charged-particle production in p–Pb collisions at \(\sqrt{s_\mathrm{{NN}}}=5.02~\text {TeV}\)

The transverse momentum (\(p_{\mathrm T}\)) distribution of primary charged particles is measured at midrapidity in minimum-bias p–Pb collisions at \(\sqrt{s_{\mathrm {NN}}}=5.02\) TeV with the ALICE detector at the LHC in the range \(0.15<p_{\mathrm T}<50\) GeV/\(c\). The spectra are compared to the expectation based on binary collision scaling of particle production in pp...

Flavour models with three Higgs generations

We construct models with a spontaneously broken \(\mathrm{SU}(3)_\mathrm{F}\) flavour symmetry where three generations of Higgs multiplets transform in a flavour-triplet representation. The models are embedded in a supersymmetric Pati–Salam GUT framework, which includes left–right symmetry. We study the possible flavon representations and show that a model with flavons in the...

Measurement of top quark–antiquark pair production in association with a W or Z boson in pp collisions at \(\sqrt{s} = 8\) \(\,\text {TeV}\)

A measurement of the cross section for the production of top quark–antiquark pairs (\({\mathrm {t}}\overline{{\mathrm {t}}}\)) in association with a vector boson V (W or Z) in proton-proton collisions at \(\sqrt{s} = 8\) \(\,\text {TeV}\) is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb\(^{-1}\) recorded with the CMS detector...

SUSY induced top quark FCNC decay \(t \rightarrow { ch}\) after Run I of LHC

In light of the Higgs discovery and the nonobservation of sparticles at the LHC, we revisit the supersymmetric theory (SUSY) induced top quark flavor-changing decay into the Higgs boson. We perform a scan over the relevant SUSY parameter space by considering the constraints from the Higgs mass measurement, the LHC search for SUSY, the vacuum stability, the precision electroweak...

Thermodynamics of phase transition in higher-dimensional Reissner–Nordström–de Sitter black hole

It is well known that there are the black hole horizon and the cosmological horizon for the Reissner–Nordström–de Sitter (RN-dS) spacetime. The thermodynamic quantities on the both horizons satisfy the first law of the black hole thermodynamics, respectively; moreover, there are some additional connections between them. In this paper by considering the relations between the two...

Covariant holography of a tachyonic accelerating universe

We apply the holographic principle to a flat dark energy dominated Friedmann–Robertson–Walker spacetime filled with a tachyon scalar field with constant equation of state \(w=p/\rho \), both for \(w>-1\) and \(w<-1\). By using a geometrical covariant procedure, which allows the construction of holographic hypersurfaces, we have obtained for each case the position of the preferred...

Light-quark and gluon jet discrimination in \(pp\) collisions at \(\sqrt{s}=7\mathrm {\ TeV}\) with the ATLAS detector

A likelihood-based discriminant for the identification of quark- and gluon-initiated jets is built and validated using 4.7 fb\(^{-1}\) of proton–proton collision data at \(\sqrt{s}=7\) \(\mathrm {\ TeV}\) collected with the ATLAS detector at the LHC. Data samples with enriched quark or gluon content are used in the construction and validation of templates of jet properties that...

Tuning PYTHIA 8.1: the Monash 2013 tune

We present an updated set of parameters for the PYTHIA 8 event generator. We reevaluate the constraints imposed by LEP and SLD on hadronization, in particular with regard to heavy-quark fragmentation and strangeness production. For hadron collisions, we combine the updated fragmentation parameters with the new NNPDF2.3 LO PDF set. We use minimum-bias, Drell–Yan, and underlying...

Measurement of quarkonium production at forward rapidity in \(\mathbf {pp}\) collisions at \(\mathbf {\sqrt{s}=7}~\) TeV

The inclusive production cross sections at forward rapidity of \({\mathrm{J}/\psi }\), \({\psi (\mathrm{2S})}\), \(\Upsilon \)(1S) and \(\Upsilon \)(2S) are measured in \(\mathrm{pp}\) collisions at \(\sqrt{s}=7~\mathrm{TeV}\) with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb\(^{-1}\). Quarkonia are...

Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes

A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a \(\mathrm {b}\overline{\mathrm {b}}\) quark pair. The searches use the 8 \(\text {TeV}\) pp collision dataset collected by the CMS detector at the LHC, corresponding to an...

Initial performance of the CUORE-0 experiment

CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of \(\mathrm {^{130}Te}\). We present the first data analysis with \(7.1 \,\mathrm {kg\cdot y}\) of total \(\mathrm {TeO_2}\) exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay...

Large extra dimension effects through light-by-light scattering at the CERN LHC

Observing light-by-light scattering at the large hadron collider (LHC) has received quite some attention and it is believed to be a clean and sensitive channel to possible new physics. In this paper, we study the diphoton production at the LHC via the process \({{pp}}\rightarrow {{p}}\gamma \gamma {{p}}\rightarrow {{p}}\gamma \gamma {{p}}\) through graviton exchange in the large...

Resolution of curvature singularities from quantum mechanical and loop perspective

We analyze the persistence of curvature singularities when analyzed using quantum theory. First, quantum test particles obeying the Klein–Gordon and Chandrasekhar–Dirac equation are used to probe the classical timelike naked singularity. We show that the classical singularity is felt even by our quantum probes. Next, we use loop quantization to resolve a singularity hidden...

Free energy of a Lovelock holographic superconductor

We study thermodynamics of black hole solutions in Lanczos–Lovelock anti-de Sitter gravity in \(d+1\) dimensions coupled to nonlinear electrodynamics and a Stückelberg scalar field. This class of theories is used in the context of gauge/gravity duality to describe a high-temperature superconductor in \(d\) dimensions. A larger number of coupling constants in the gravitational...

Lurking pseudovectors below the TeV scale

If electroweak symmetry breaking is driven by a new strongly coupled dynamical sector, one expects the bound states to appear at the TeV scale or slightly below. However, electroweak precision data imposes severe constraints on most of the existing models, putting them under strain. Conventional models require the new composite states to come in pairs of rather heavy, close to...