The European Physical Journal C

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

List of Papers (Total 2,952)

Late-time cosmological evolution of a general class of \(f(\mathsf{R},\mathsf{T})\) gravity with minimal curvature-matter coupling

In this work, we study the late-time cosmological solutions of \(f(\mathsf{R},\mathsf{T})=g(\mathsf{R})+h(-\mathsf{T})\) models assuming that the conservation of the energy-momentum tensor (EMT) is violated. We perform our analysis through constructing an autonomous dynamical system for the equations of motion. We study the stability properties of solutions via considering linear ...

Production of doubly charmed baryons nearly at rest

We investigate the production cross sections, momentum distributions and rapidity distributions for doubly charmed baryons which according to the intrinsic heavy quark mechanism are produced nearly at rest. These events should be measurable at fixed-target experiments like STAR@RHIC and AFTER@LHC.

Path-integral derivation of black-hole radiance inside the de-Rham–Gabadadze–Tolley formulation of massive gravity

If we apply the path-integral formulation in order to analyze the particle creation process of black holes inside the non-linear formulation of massive gravity, it is possible to demonstrate that the effect of the extra degrees of freedom is to deform the periodicity of the poles of the propagator in the complex t-plane. This might create the effect of extra particle creation ...

New observational constraints on f(T) cosmology from radio quasars

Using a new recently compiled milliarcsecond compact radio data set of 120 intermediate-luminosity quasars in the redshift range \(0.46< z <2.76\), whose statistical linear sizes show negligible dependence on redshifts and intrinsic luminosity and thus represent standard rulers in cosmology, we constrain three viable and most popular f(T) gravity models, where T is the torsion ...

Dark matter phenomenology of high-speed galaxy cluster collisions

We perform a general computational analysis of possible post-collision mass distributions in high-speed galaxy cluster collisions in the presence of self-interacting dark matter. Using this analysis, we show that astrophysically weakly self-interacting dark matter can impart subtle yet measurable features in the mass distributions of colliding galaxy clusters even without ...

Cosmological dynamics of spatially flat Einstein–Gauss–Bonnet models in various dimensions: high-dimensional \(\Lambda \) -term case

In this paper we perform a systematic study of spatially flat \([(3+D)+1]\)-dimensional Einstein–Gauss–Bonnet cosmological models with \(\Lambda \)-term. We consider models that topologically are the product of two flat isotropic subspaces with different scale factors. One of these subspaces is three-dimensional and represents our space and the other is D-dimensional and represents ...

Solar system tests for realistic f(T) models with non-minimal torsion–matter coupling

In the previous paper, we have constructed two f(T) models with non-minimal torsion–matter coupling extension, which are successful in describing the evolution history of the Universe including the radiation-dominated era, the matter-dominated era, and the present accelerating expansion. Meantime, the significant advantage of these models is that they could avoid the cosmological ...

Bose–Einstein condensation and symmetry breaking of a complex charged scalar field

In this work the Klein–Gordon equation for a complex scalar field with U(1) symmetry endowed in a mexican-hat scalar field potential with thermal and electromagnetic contributions is written as a Gross–Pitaevskii (GP)-like equation. This equation is interpreted as a charged generalization of the GP equation at finite temperatures found in previous works. Its hydrodynamical ...

An analytic analysis of the pion decay constant in three-flavoured chiral perturbation theory

A representation of the two-loop contribution to the pion decay constant in SU(3) chiral perturbation theory is presented. The result is analytic up to the contribution of the three (different) mass sunset integrals, for which an expansion in their external momentum has been taken. We also give an analytic expression for the two-loop contribution to the pion mass based on a ...

Off-shell gluon production in interaction of a projectile with 2 or 3 targets

Within the effective QCD action for the Regge kinematics, the amplitudes for virtual gluon emission are studied in collision of a projectile with two and three targets. It is demonstrated that all non-Feynman singularities cancel between induced vertices and rescattering contributions. Formulas simplify considerably in a special gauge, which is a straightforward generalization of ...

Gluino reach and mass extraction at the LHC in radiatively-driven natural SUSY

Radiatively-driven natural SUSY (RNS) models enjoy electroweak naturalness at the 10% level while respecting LHC sparticle and Higgs mass constraints. Gluino and top-squark masses can range up to several TeV (with other squarks even heavier) but a set of light Higgsinos are required with mass not too far above \(m_h\sim 125\) GeV. Within the RNS framework, gluinos dominantly decay ...

A parametric reconstruction of the deceleration parameter

The present work is based on a parametric reconstruction of the deceleration parameter q(z) in a model for the spatially flat FRW universe filled with dark energy and non-relativistic matter. In cosmology, the parametric reconstruction technique deals with an attempt to build up a model by choosing some specific evolution scenario for a cosmological parameter and then estimate the ...

Scale-dependent three-dimensional charged black holes in linear and non-linear electrodynamics

In the present work we study the scale dependence at the level of the effective action of charged black holes in Einstein–Maxwell as well as in Einstein–power-Maxwell theories in \((2+1)\)-dimensional spacetimes without a cosmological constant. We allow for scale dependence of the gravitational and electromagnetic couplings, and we solve the corresponding generalized field ...

f(R) global monopole revisited

In this paper the f(R) global monopole is reexamined. We provide an exact solution for the modified field equations in the presence of a global monopole for regions outside its core, generalizing previous results. Additionally, we discuss some particular cases obtained from this solution. We consider a setup consisting of a possible Schwarzschild black hole that absorbs the ...

Automation of NLO QCD and EW corrections with Sherpa and Recola

This publication presents the combination of the one-loop matrix-element generator Recola with the multipurpose Monte Carlo program Sherpa. Since both programs are highly automated, the resulting Sherpa +Recola framework allows for the computation of – in principle – any Standard Model process at both NLO QCD and EW accuracy. To illustrate this, three representative LHC processes ...

Impact of topology in foliated quantum Einstein gravity

We use a functional renormalization group equation tailored to the Arnowitt–Deser–Misner formulation of gravity to study the scale dependence of Newton’s coupling and the cosmological constant on a background spacetime with topology \(S^1 \times S^d\). The resulting beta functions possess a non-trivial renormalization group fixed point, which may provide the high-energy completion ...

Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1

The reconstruction of the signal from hadrons and jets emerging from the proton–proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In ...

Stability of generic thin shells in conformally flat spacetimes

Some important spacetimes are conformally flat; examples are the Robertson–Walker cosmological metric, the Einstein–de Sitter spacetime, and the Levi-Civita–Bertotti–Robinson and Mannheim metrics. In this paper we construct generic thin shells in conformally flat spacetime supported by a perfect fluid with a linear equation of state, i.e., \(p=\omega \sigma .\) It is shown that, ...

Covariant quantizations in plane and curved spaces

We present covariant quantization rules for nonsingular finite-dimensional classical theories with flat and curved configuration spaces. In the beginning, we construct a family of covariant quantizations in flat spaces and Cartesian coordinates. This family is parametrized by a function \(\omega (\theta )\), \(\theta \in (1,0)\), which describes an ambiguity of the quantization. We ...

Higgs physics at the CLIC electron–positron linear collider

The Compact Linear Collider (CLIC) is an option for a future \({\mathrm{e}^{+}}{\mathrm{e}^{-}} \) collider operating at centre-of-mass energies up to \(3\,\text {TeV} \), providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC ...

Measurements of electroweak \(Wjj \) production and constraints on anomalous gauge couplings with the ATLAS detector

Measurements of the electroweak production of a W boson in association with two jets at high dijet invariant mass are performed using \(\sqrt{s} =\) 7 and 8 \(\text {TeV}\) proton–proton collision data produced by the Large Hadron Collider, corresponding respectively to 4.7 and 20.2 fb\(^{-1}\) of integrated luminosity collected by the ATLAS detector. The measurements are sensitive ...

Electromagnetic vacuum fluctuations around a cosmic string in de Sitter spacetime

The electromagnetic field correlators are evaluated around a cosmic string in background of \((D+1)\)-dimensional dS spacetime assuming that the field is prepared in the Bunch–Davies vacuum state. The correlators are presented in the decomposed form where the string-induced topological parts are explicitly extracted. With this decomposition, the renormalization of the local vacuum ...

On functional representations of the conformal algebra

Starting with conformally covariant correlation functions, a sequence of functional representations of the conformal algebra is constructed. A key step is the introduction of representations which involve an auxiliary functional. It is observed that these functionals are not arbitrary but rather must satisfy a pair of consistency equations corresponding to dilatation and special ...

Is the cosmological dark sector better modeled by a generalized Chaplygin gas or by a scalar field?

Both scalar fields and (generalized) Chaplygin gases have been widely used separately to characterize the dark sector of the universe. Here we investigate the cosmological background dynamics for a mixture of both these components and quantify the fractional abundances that are admitted by observational data from supernovae of type Ia and from the evolution of the Hubble rate. ...

The simplest non-minimal matter–geometry coupling in the f(R, T) cosmology

f(R, T) gravity is an extended theory of gravity in which the gravitational action contains general terms of both the Ricci scalar R and the trace of the energy-momentum tensor T. In this way, f(R, T) models are capable of describing a non-minimal coupling between geometry (through terms in R) and matter (through terms in T). In this article we construct a cosmological model from ...