The European Physical Journal C

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

List of Papers (Total 4,128)

Original Higgs inflation and phantom crossing

It is a standard practice to ignore the initial kinetic term in an inflationary analysis. Here, we overrule this practice to analyze pre-inflationary, inflationary and post-inflationary dynamics of the original Higgs-inflation model from a wider view. To this end, our calculations are not restricted to slow-roll regime. Perhaps, the most interesting result that we have found is...

Testing dark energy models in the light of \(\sigma _8\) tension

It has been pointed out that there exists a tension in \(\sigma _8-\varOmega _m\) measurement between CMB and LSS observation. In this paper we show that \(\sigma _8-\varOmega _m\) observations can be used to test the dark energy theories. We study two models, (1) Hu–Sawicki (HS) Model of f(R) gravity and (2) Chavallier–Polarski–Linder (CPL) parametrization of dynamical dark...

Scale-invariant two-component dark matter

We study a scale-invariant extension of the standard model which can simultaneously explain dark matter and the hierarchy problem. In our set-up, we introduce a scalar and a spinor as two-component dark matter in addition to a scalon field as a mediator. An interesting point about our model is that due to scale-invariant conditions, compared to other two-component dark matter...

Anisotropic compact star model: a brief study via embedding

In present article a new model of compact star is obtained in the framework of general relativity which does not suffer from any kinds of singularity. We assume that the underlying fluid distribution is anisotropic in nature along with a new form for the metric potential \(e^{\lambda }\) which is physically reasonable. Though the model parameters depend on four constants \(a,\,b...

Analytic studies of static and transport properties of (gauged) Skyrmions

We study static and transport properties of Skyrmions living within a finite spatial volume in a flat (3+1)-dimensional spacetime. In particular, we derive an explicit analytic expression for the compression modulus corresponding to these Skyrmions living within a finite box and we show that such expression can produce a reasonable value. The gauged version of these solitons can...

On the status of expansion by regions

We discuss the status of expansion by regions, i.e. a well-known strategy to obtain an expansion of a given multiloop Feynman integral in a given limit where some kinematic invariants and/or masses have certain scaling measured in powers of a given small parameter. Using the Lee–Pomeransky parametric representation, we formulate the corresponding prescriptions in a simple...

In situ calibration of large-radius jet energy and mass in 13 TeV proton–proton collisions with the ATLAS detector

The response of the ATLAS detector to large-radius jets is measured in situ using 36.2 fb\(^{-1}\) of \(\sqrt{s}=13\) TeV proton–proton collisions provided by the LHC and recorded by the ATLAS experiment during 2015 and 2016. The jet energy scale is measured in events where the jet recoils against a reference object, which can be either a calibrated photon, a reconstructed Z...

Transport coefficients of hot magnetized QCD matter beyond the lowest Landau level approximation

In this article, shear viscosity, bulk viscosity, and thermal conductivity of a QCD medium have been studied in the presence of a strong magnetic field. To model the quark–gluon plasma, an extended quasi-particle description of the hot QCD equation of state in the presence of the magnetic field has been adopted. The effects of higher Landau levels on the temperature dependence of...

On possibility of determining neutrino mass hierarchy by the charged-current and neutral-current events of supernova neutrinos in scintillation detectors

One of the unresolved mysteries in neutrino physics is the neutrino mass hierarchy. We present a new method to determine neutrino mass hierarchy by comparing the events of inverse beta decays (IBD), \({\bar{\nu }}_e + p\rightarrow n + e^+\), and neutral current (NC) interactions, \(\nu ({\overline{\nu }}) + p\rightarrow \nu ({\overline{\nu }}) + p\), of supernova neutrinos from...

Statistical models with uncertain error parameters

In a statistical analysis in Particle Physics, nuisance parameters can be introduced to take into account various types of systematic uncertainties. The best estimate of such a parameter is often modeled as a Gaussian distributed variable with a given standard deviation (the corresponding “systematic error”). Although the assigned systematic errors are usually treated as...

Holographic complexity in charged Vaidya black hole

In this paper, we use the “complexity equals action” (CA) conjecture to discuss growth rate of the complexity in a charged AdS-Vaidya black hole formed by collapsing an uncharged spherically symmetric thin shell of null fluid. Using the approach proposed by Lehner et al., we evaluate the action growth rate and the slope of the complexity of formation. Then, we demonstrate that...

Compatibility of \(A_{4}\) flavour symmetric minimal extended seesaw with \((3+1)\) neutrino data

Motivated by the recent resurrection of the evidence for an eV scale sterile neutrino from the MiniBooNE experiment, we revisit one of the most minimal seesaw model known as the minimal extended seesaw that gives rise to a \(3+1\) light neutrino mass matrix. We consider the presence of \(A_{4}\) flavour symmetry which plays a non-trivial role in generating the structure of the...

Measurements of W and Z boson production in pp collisions at \(\sqrt{s}=5.02\) TeV with the ATLAS detector

Measurements of fiducial integrated and differential cross sections for inclusive \(W^+\), \(W^-\) and Z boson production are reported. They are based on \(25.0 \pm 0.5\; \mathrm {pb}^{-1}\) of pp collision data at \(\sqrt{s} = 5.02\) TeV collected with the ATLAS detector at the CERN Large Hadron Collider. Electron and muon decay channels are analysed, and the combined \(W...

MoMEMta, a modular toolkit for the Matrix Element Method at the LHC

The Matrix Element Method has proven to be a powerful method to optimally exploit the information available in detector data. Its widespread use is nevertheless impeded by its complexity and the associated computing time. MoMEMta, a C++ software package to compute the integrals at the core of the method, provides a versatile implementation of the Matrix Element Method to both the...

General modified Friedmann equations in Rainbow flat universe, by thermodynamics

We investigate the derivation of Friedmann equations in Rainbow gravity following Jacobson thermodynamic approach. We do not restrict the rainbow functions to be constant as is customarily used, and show that the first law of thermodynamics with a corresponding ‘classical’ proportionality between entropy and surface area, supplemented eventually by a ‘quantum’ logarithmic...

A simple and natural interpretations of the DAMPE cosmic-ray electron/positron spectrum within two sigma deviations

The DArk Matter Particle Explorer (DAMPE) experiment has recently announced the first results for the measurement of total electron plus positron fluxes between 25 GeV and 4.6 TeV. A spectral break at about 0.9 TeV and a tentative peak excess around 1.4 TeV have been found. However, it is very difficult to reproduce both the peak signal and the smooth background including...

Implications of the lens redshift distribution of strong lensing systems: cosmological parameters and the global properties of early-type galaxies

In this paper, we assemble a well-defined sample of early-type gravitational lenses extracted from a large collection of 158 systems, and use the redshift distribution of galactic-scale lenses to test the standard cosmological model (\(\varLambda \)CDM) and the modified gravity theory (DGP). Two additional sub-samples are also included to account for possible selection effect...

Study of the underlying event in top quark pair production in \(\mathrm {p}\mathrm {p}\) collisions at 13 \(~\text {Te}\text {V}\)

Measurements of normalized differential cross sections as functions of the multiplicity and kinematic variables of charged-particle tracks from the underlying event in top quark and antiquark pair production are presented. The measurements are performed in proton-proton collisions at a center-of-mass energy of 13\(~\text {Te}\text {V}\), and are based on data collected by the CMS...

Ground state instability in nonrelativistic QFT and Euler–Heisenberg Lagrangian via holography

We study the ground state instability of a strongly coupled QFT with the \(z=2\) Schrödinger symmetry in a constant electric field using probe branes holography. The system is \(N_f\) \({\mathcal {N}}=2\) hypermultiplet fermions at zero charge density in the supergravity Schrödinger background. We show that the instability occurs due to Schwinger-like effect and an insulator...

A strategy for a general search for new phenomena using data-derived signal regions and its application within the ATLAS experiment

This paper describes a strategy for a general search used by the ATLAS Collaboration to find potential indications of new physics. Events are classified according to their final state into many event classes. For each event class an automated search algorithm tests whether the data are compatible with the Monte Carlo simulated expectation in several distributions sensitive to the...

Van der Waals universe with adiabatic matter creation

A FRWL cosmological model with perfect fluid comprising of van der Waals gas and dust has been studied in the context of dynamical analysis of a three-component autonomous non-linear dynamical system for the particle number density n, the Hubble parameter H, and the temperature T. Perfect fluid isentropic particle creation at rate proportional to an integer power \(\alpha \) of H...

Two-fluid solutions of particle-creation cosmologies

Cosmological evolution driven incorporating continuous particle creation by the time-varying gravitational field is investigated. We consider a spatially flat, homogeneous and isotropic universe with two matter fluids in the context of general relativity. One fluid is endowed with gravitationally induced “adiabatic” particle creation, while the second fluid simply satisfies the...

The quark-gluon vertex and the QCD infrared dynamics

The Dyson–Schwinger quark equation is solved for the quark-gluon vertex using the most recent lattice data available in the Landau gauge for the quark, gluon and ghost propagators, the full set of longitudinal tensor structures in the Ball-Chiu vertex, taking into account a recently derived normalisation for a quark-ghost kernel form factors and the gluon contribution for the...

Graviton mass and memory

Gravitational memory, a residual change, arises after a finite gravitational wave pulse interacts with free masses. We calculate the memory effect in massive gravity as a function of the graviton mass \((m_g)\) and show that it is discretely different from the result of general relativity: the memory is reduced not just via the usual expected Yukawa decay but by a numerical...