The European Physical Journal C

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

List of Papers (Total 2,952)

Neutrino induced vorticity, Alfvén waves and the normal modes

We consider a plasma consisting of electrons and ions in the presence of a background neutrino gas and develop the magnetohydrodynamic equations for the system. We show that the electron neutrino interaction can induce vorticity in the plasma even in the absence of any electromagnetic perturbations if the background neutrino density is left–right asymmetric. This induced vorticity ...

On the gravitational seesaw in higher-derivative gravity

Local gravitational theories with more than four derivatives are superrenormalizable. They also may be unitary in the Lee–Wick sense. Thus it is relevant to study the low-energy properties of these theories, especially to identify observables which might be useful for experimental detection of higher derivatives. Using an analogy with the neutrino physics, we explore the ...

What is the scale of new physics behind the B-flavour anomalies?

Motivated by the recent hints of lepton flavour non-universality in B-meson semi-leptonic decays, we study the constraints of perturbative unitarity on the new physics interpretation of the anomalies in \(b \rightarrow c \ell \bar{\nu }\) and \(b \rightarrow s \ell \bar{\ell }\) transitions. Within an effective field theory approach we find that \(2 \rightarrow 2\) fermion ...

f(R) constant-roll inflation

The previously introduced class of two-parametric phenomenological inflationary models in general relativity in which the slow-roll assumption is replaced by the more general, constant-roll condition is generalized to the case of f(R) gravity. A simple constant-roll condition is defined in the original Jordan frame, and exact expressions for a scalaron potential in the Einstein ...

Cosmic structure sizes in generic dark energy models

The maximum allowable size of a spherical cosmic structure as a function of its mass is determined by the maximum turn around radius \(R_\mathrm{TA,max}\), the distance from its center where the attraction on a radial test particle due to the spherical mass is balanced with the repulsion due to the ambient dark energy. In this work, we extend the existing results in several ...

Quintessence background for 5D Einstein–Gauss–Bonnet black holes

As we know that the Lovelock theory is an extension of the general relativity to the higher-dimensions, in this theory the first- and the second-order terms correspond to general relativity and the Einstein–Gauss–Bonnet gravity, respectively. We obtain a 5D black hole solution in Einstein–Gauss–Bonnet gravity surrounded by the quintessence matter, and we also analyze their ...

An alternative perspective to observe the critical phenomena of dilaton black holes

The critical phenomena of dilaton black holes are probed from a totally different perspective other than the P–v criticality and the q–U criticality discussed in former literature. We investigate not only the two point correlation function but also the entanglement entropy of dilaton black holes. For both the two point correlation function and the entanglement entropy we consider ...

CUORE sensitivity to \(0\nu \beta \beta \) decay

We report a study of the CUORE sensitivity to neutrinoless double beta (\(0\nu \beta \beta \)) decay. We used a Bayesian analysis based on a toy Monte Carlo (MC) approach to extract the exclusion sensitivity to the \(0\nu \beta \beta \) decay half-life (\(T_{1/2}^{\,0\nu }\)) at \(90\%\) credibility interval (CI) – i.e. the interval containing the true value of \(T_{1/2}^{\,0\nu ...

Fiducial, total and differential cross-section measurements of t-channel single top-quark production in pp collisions at 8 TeV using data collected by the ATLAS detector

Detailed measurements of t-channel single top-quark production are presented. They use 20.2 fb\(^{-1}\) of data collected by the ATLAS experiment in proton–proton collisions at a centre-of-mass energy of 8 TeV at the LHC. Total, fiducial and differential cross-sections are measured for both top-quark and top-antiquark production. The fiducial cross-section is measured with a ...

Effective horizons, junction conditions and large-scale magnetism

The quantum mechanical generation of hypermagnetic and hyperlectric fields in four-dimensional conformally flat background geometries rests on the simultaneous continuity of the effective horizon and of the extrinsic curvature across the inflationary boundary. The junction conditions for the gauge fields are derived in general terms and corroborated by explicit examples with ...

A determination of the fragmentation functions of pions, kaons, and protons with faithful uncertainties

We present NNFF1.0, a new determination of the fragmentation functions (FFs) of charged pions, charged kaons, and protons/antiprotons from an analysis of single-inclusive hadron production data in electron–positron annihilation. This determination, performed at leading, next-to-leading, and next-to-next-to-leading order in perturbative QCD, is based on the NNPDF methodology, a ...

Einstein–Maxwell-axion theory: dyon solution with regular electric field

In the framework of the Einstein–Maxwell-axion theory we consider static spherically symmetric solutions which describe a magnetic monopole in the axionic environment. These solutions are interpreted as the solutions for an axionic dyon, the electric charge of which is composite, i.e. in addition to the standard central electric charge it includes an effective electric charge ...

Forward two-photon exchange in elastic lepton–proton scattering and hyperfine-splitting correction

We relate the forward two-photon exchange (TPE) amplitudes to integrals of the inclusive lepton–proton scattering cross sections. These relations yield an alternative way for the evaluation of the TPE correction to hyperfine-splitting (HFS) in the hydrogen-like atoms with an equivalent to the standard approach (Iddings, Drell and Sullivan) result implying the Burkhardt–Cottingham ...

CP violation induced by the double resonance for pure annihilation decay process in perturbative QCD

In a perturbative QCD approach we study the direct CP violation in the pure annihilation decay process of \(\bar{B}^0_{s}\rightarrow \pi ^+\pi ^-\pi ^+\pi ^-\) induced by the \(\rho \) and \(\omega \) double resonance effect. Generally, the CP violation is small in the pure annihilation type decay process. However, we find that the CP violation can be enhanced by double \(\rho ...

On the choice of beam polarization in \(e^+e^-\rightarrow ZZ/Z\gamma \) and anomalous triple gauge-boson couplings

The anomalous trilinear gauge couplings of Z and \(\gamma \) are studied in \(e^+e^-\rightarrow ZZ/Z\gamma \) with longitudinal beam polarizations using a complete set of polarization asymmetries for the Z boson. We quantify the goodness of the beam polarization in terms of the likelihood and find the best choice of \(e^-\) and \(e^+\) polarizations to be (\(+0.16\), \(-0.16\)), ...

On new bulk singularity structures, RR couplings in the asymmetric picture and their all order \(\alpha '\) corrections

We have analyzed in detail four and five point functions of the string theory amplitudes, including a closed string Ramond–Ramond (RR) in an asymmetric picture and either two or three transverse scalar fields in both IIA and IIB. The complete forms of these S-matrices are derived and these asymmetric S-matrices are also compared with their own symmetric results. This leads us to ...

Studying the intervention of an unusual term in f(T) gravity via the Noether symmetry approach

As has been done before, we study an unknown coupling function, i.e. \(F(\varphi )\), together with a function of torsion and also curvature, i.e. f(T) and f(R), generally depending upon a scalar field. In the f(R) case, it comes from quantum correlations and other sources. Now, what if beside this term in f(T) gravity context, we enhance the action through another term which ...

Axial gravity, massless fermions and trace anomalies

This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference ...

Quark matter and quark stars at finite temperature in Nambu–Jona-Lasinio model

We extend the SU(3) Nambu–Jona-Lasinio (NJL) model to include two types of vector interaction. Using these two types of vector interaction in NJL model, we study the quark symmetry free energy in asymmetric quark matter, the constituent quark mass, the quark fraction, the equation of state (EOS) for \(\beta \)-equilibrium quark matter, the maximum mass of QSs at finite temperature, ...

The Maxwell–Chern–Simons gravity, and its cosmological implications

We consider the cosmological implications of a gravitational theory containing two vector fields coupled via a generalized Chern–Simons term. One of the vector fields is the usual Maxwell field, while the other is a constrained vector field with constant norm included in the action via a Lagrange multiplier. The theory admits a de Sitter type solution, with healthy cosmological ...

LHC phenomenology of composite 2-Higgs doublet models

We investigate the phenomenology of Composite 2-Higgs doublet models (C2HDMs) of various Yukawa types based on the global symmetry breaking \(SO(6)\rightarrow SO(4)\times SO(2)\). The kinetic part and the Yukawa Lagrangian are constructed in terms of the pseudo Nambu–Goldstone Boson (pNGB) matrix and a 6-plet of fermions under SO(6). The scalar potential is assumed to be the same ...

Accreting fluids onto regular black holes via Hamiltonian approach

We investigate the accretion of test fluids onto regular black holes such as Kehagias–Sfetsos black holes and regular black holes with Dagum distribution function. We analyze the accretion process when different test fluids are falling onto these regular black holes. The accreting fluid is being classified through the equation of state according to the features of regular black ...

The \(\nu \) -cleus experiment: a gram-scale fiducial-volume cryogenic detector for the first detection of coherent neutrino–nucleus scattering

We discuss a small-scale experiment, called \(\nu \)-cleus, for the first detection of coherent neutrino–nucleus scattering by probing nuclear-recoil energies down to the 10 eV regime. The detector consists of low-threshold CaWO\(_4\) and Al\(_2\)O\(_3\) calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. ...

Extended chiral Khuri–Treiman formalism for \(\eta \rightarrow 3\pi \) and the role of the \(a_0(980)\) , \(f_0(980)\) resonances

Recent experiments on \(\eta \rightarrow 3\pi \) decays have provided an extremely precise knowledge of the amplitudes across the Dalitz region which represent stringent constraints on theoretical descriptions. We reconsider an approach in which the low-energy chiral expansion is assumed to be optimally convergent in an unphysical region surrounding the Adler zero, and the ...