The European Physical Journal C

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

List of Papers (Total 2,952)

Cracking of anisotropic cylindrical polytropes

We study the appearance of cracking in charged anisotropic cylindrical polytropes with generalized polytropic equation. We investigate the existence of cracking in two different kinds of polytropes existing in the literature through two different assumptions: (a) local density perturbation with conformally flat condition, and (b) perturbing polytropic index, charge and anisotropy ...

Kundt spacetimes minimally coupled to scalar field

We derive an exact solution belonging to the Kundt class of spacetimes both with and without a cosmological constant that are minimally coupled to a free massless scalar field. We show the algebraic type of these solutions and give interpretation of the results. Subsequently, we look for solutions additionally containing an electromagnetic field satisfying nonlinear field equations.

Status of the \(B\rightarrow K^*\mu ^+\mu ^-\) anomaly after Moriond 2017

Motivated by recent results by the ATLAS and CMS collaborations on the angular distribution of the \(B \rightarrow K^* \mu ^+\mu ^-\) decay, we perform a state-of-the-art analysis of rare B meson decays based on the \(b \rightarrow s \mu \mu \) transition. Using standard estimates of hadronic uncertainties, we confirm the presence of a sizeable discrepancy between data and SM ...

Measurement of jet fragmentation in Pb+Pb and pp collisions at \(\sqrt{{s_\mathrm{NN}}} = 2.76\) TeV with the ATLAS detector at the LHC

The distributions of transverse momentum and longitudinal momentum fraction of charged particles in jets are measured in Pb+Pb and pp collisions with the ATLAS detector at the LHC. The distributions are measured as a function of jet transverse momentum and rapidity. The analysis utilises an integrated luminosity of 0.14 nb\(^{-1}\) of Pb+Pb data and 4.0 pb\(^{-1}\) of pp data ...

Ratios of helicity amplitudes for exclusive \(\rho ^0\) electroproduction on transversely polarized protons

Exclusive \(\rho ^0\)-meson electroproduction is studied by the HERMES experiment, using the 27.6 GeV longitudinally polarized electron/positron beam of HERA and a transversely polarized hydrogen target, in the kinematic region 1.0 GeV\(^2<Q^2<\) 7.0 GeV\(^2\), 3.0 GeV \(<W<\) 6.3 GeV, and \(-t^\prime <\) 0.4 GeV\(^2\). Using an unbinned maximum-likelihood method, 25 parameters are ...

New physics contributions to \(\bar{B}_s \rightarrow \pi ^0(\rho ^0 )\,\eta ^{(')} \) decays

The decay modes \(\bar{B}_s \rightarrow \pi ^0(\rho ^0 )\,\eta ^{(')} \) are dominated by electroweak penguins that are small in the standard model. In this work we investigate the contributions to these penguins from a model with an additional \(U(1)'\) gauge symmetry and show there effects on the branching ratios of \(\bar{B}_s \rightarrow \pi ^0(\rho ^0 )\,\eta ^{(')} \). In a ...

Uncover compressed supersymmetry via boosted bosons from the heavier stop/sbottom

A light stop around the weak scale is a hopeful messenger of natural supersymmetry (SUSY), but it has not shown up at the current stage of LHC. Such a situation raises the question of the fate of natural SUSY. Actually, a relatively light stop can easily be hidden in a compressed spectra such as mild mass degeneracy between stop and neutralino plus top quark. Searching for such a ...

The effective field theory of nonsingular cosmology: II

Based on the effective field theory (EFT) of cosmological perturbations, we explicitly clarify the pathology in nonsingular cubic Galileon models and show how to cure it in EFT with new insights into this issue. With the least set of EFT operators that are capable to avoid instabilities in nonsingular cosmologies, we construct a nonsingular model dubbed the Genesis-inflation model, ...

SL(2, 7) representations and their relevance to neutrino physics

The investigation of the rôle of finite groups in flavor physics and, particularly, in the interpretation of the neutrino data has been the subject of intensive research. Motivated by this fact, in this work we derive the three-dimensional unitary representations of the projective linear group \(PSL_2(7)\). Based on the observation that the generators of the group exhibit a Latin ...

Tidal forces in Kiselev black hole

The aim of this paper is to examine the tidal forces occurring in a Kiselev black hole surrounded by radiation and dust fluids. It is noted that the radial and angular components of the tidal force change the sign between event and Cauchy horizons. We solve the geodesic deviation equation for radially free-falling bodies toward Kiselev black holes. We explain the geodesic deviation ...

Lepton number violation at colliders from kinematically inaccessible gauge bosons

We reevaluate the necessity of \(W_R\) gauge bosons being kinematically accessible to test the left–right symmetric model (LRSM) at hadron colliders. In the limit that \(W_R\) are too heavy, resonant production of sub-TeV Majorana neutrinos N can still proceed at the Large Hadron Collider (LHC) via the process \(pp\rightarrow W_R^{\pm *}\rightarrow N \ell ^\pm \rightarrow \ell ^\pm ...

Behaviour of charged collapsing fluids after hydrostatic equilibrium in \(R^n\) gravity

The purpose of this paper is to study the transport equation and its coupling with the Maxwell equation in the framework of \(R^n\) gravity. Using Müller–Israel–Stewart theory for the conduction of dissipative fluids, we analyze the temperature, heat flux, viscosity and thermal conductivity in the scenario of relaxation time. All these thermodynamical variables appear in the form ...

On the perturbative renormalization of four-quark operators for new physics

We discuss the renormalization properties of the full set of \(\Delta F=2\) operators involved in BSM processes, including the definition of RGI versions of operators that exhibit mixing under RG transformations. As a first step for a fully non-perturbative determination of the scale-dependent renormalization factors and their runnings, we introduce a family of appropriate ...

Behavior of quasinormal modes and Van der Waals-like phase transition of charged AdS black holes in massive gravity

In this work, we utilize the quasinormal modes (QNMs) of a massless scalar perturbation to probe the Van der Waals-like small and large black holes (SBH/LBH) phase transition of charged topological Anti-de Sitter (AdS) black holes in four-dimensional massive gravity. We find that the signature of this SBH/LBH phase transition is detected in the isobaric as well as in the isothermal ...

Higgs-boson masses and mixing matrices in the NMSSM: analysis of on-shell calculations

We analyze the Higgs-boson masses and mixing matrices in the NMSSM based on an on-shell (OS) renormalization of the gauge-boson and Higgs-boson masses and the parameters of the top/scalar top sector. We compare the implementation of the OS calculations in the codes NMSSMCALC and NMSSM-FeynHiggs up to \({\mathcal {O}}(\alpha _t\alpha _s)\). We identify the sources of discrepancies ...

Analytic properties of the Virasoro modular kernel

On the space of generic conformal blocks the modular transformation of the underlying surface is realized as a linear integral transformation. We show that the analytic properties of conformal block implied by Zamolodchikov’s formula are shared by the kernel of the modular transformation and illustrate this by explicit computation in the case of the one-point toric conformal block.

Precision measurement and interpretation of inclusive \(W^+\) , \(W^-\) and \(Z/\gamma ^*\) production cross sections with the ATLAS detector

High-precision measurements by the ATLAS Collaboration are presented of inclusive \(W^+ \rightarrow \ell ^+\nu \), \(W^- \rightarrow \ell ^-\bar{\nu }\) and \(Z/\gamma ^* \rightarrow \ell \ell \) (\(\ell =e,\mu \)) Drell–Yan production cross sections at the LHC. The data were collected in proton–proton collisions at \(\sqrt{s} = 7\,\text {TeV}\) with an integrated luminosity of ...

Online \(^{222}\) Rn removal by cryogenic distillation in the XENON100 experiment

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant \(^{222}\)Rn background originating from radon emanation. After inserting an auxiliary ...

Cosmological implications of the transition from the false vacuum to the true vacuum state

We study cosmology with running dark energy. The energy density of dark energy is obtained from the quantum process of transition from the false vacuum state to the true vacuum state. We use the Breit–Wigner energy distribution function to model the quantum unstable systems and obtain the energy density of the dark energy parametrization \(\rho _\text {de}(t)\). We also use Krauss ...

All spherically symmetric charged anisotropic solutions for compact stars

In the present paper we develop an algorithm for all spherically symmetric anisotropic charged fluid distributions. Considering a new source function \(\nu (r)\) we find a set of solutions which is physically well behaved and represents compact stellar models. A detailed study specifically shows that the models actually correspond to strange stars in terms of their mass and radius. ...

Role of \(f(R,T,R_{\mu \nu }T^{\mu \nu })\) model on the stability of cylindrical stellar model

The aim of this paper is to investigate the stable/unstable regimes of the non-static anisotropic filamentary stellar models in the framework of \(f(R,T,R_{\mu \nu }T^{\mu \nu })\) gravity. We construct the field equations and conservation laws in the perspective of this model of gravity. The perturbation scheme is applied to the analysis of the behavior of a particular ...

Measurements of the production cross section of a \(Z\) boson in association with jets in pp collisions at \(\sqrt{s} = 13\) TeV with the ATLAS detector

Measurements of the production cross section of a \(Z\) boson in association with jets in proton–proton collisions at \(\sqrt{s} = 13\) TeV are presented, using data corresponding to an integrated luminosity of 3.16 fb\(^{-1}\) collected by the ATLAS experiment at the CERN Large Hadron Collider in 2015. Inclusive and differential cross sections are measured for events containing a ...

Particle dynamics near Kerr-MOG black hole

This paper explores the dynamics of both neutral and charged particles orbiting near a rotating black hole in scalar–tensor–vector gravity. We study the conditions for the particle to escape at the innermost stable circular orbit. We investigate the stability of orbits through the effective potential and Lyapunov exponent in the presence of a magnetic field. The effective force ...

Wigner’s infinite spin representations and inert matter

Positive energy ray representations of the Poincaré group are naturally subdivided into three classes according to their mass and spin content: \(m > 0, m=0\) finite helicity and \(m=0\) infinite spin. For a long time the localization properties of the massless infinite spin class remained unknown, until it became clear that such matter does not permit compact spacetime ...