# The European Physical Journal C

## List of Papers (Total 3,331)

#### Update of the ALEPH non-strange spectral functions from hadronic $\tau$ decays

An update of the ALEPH non-strange spectral functions from hadronic $\tau$ decays is presented. Compared to the 2005 ALEPH publication, the main improvement is related to the use of a new method to unfold the measured mass spectra from detector effects. This procedure also corrects a previous problem in the correlations between the unfolded mass bins. Results from QCD studies ...

#### A scan of f(R) models admitting Rindler-type acceleration

As a manifestation of a large distance effect Grumiller modified Schwarzschild metric with an extraneous term reminiscent of Rindler acceleration. Such a term has the potential to explain the observed flat rotation curves in general relativity. The same idea has been extended herein to the larger arena of $f(R)$ theory. With particular emphasis on weak energy conditions (WECs) ...

#### The muon anomalous magnetic moment in the reduced minimal 3-3-1 model

We study the muon anomalous magnetic moment $(g-2)_{\mu }$ in the context of the reduced minimal 3-3-1 model recently proposed in the literature. In particular, its spectrum contains a doubly charged scalar ($H^{\pm \pm }$) and gauge boson ($U^{\pm \pm }$), new singly charged vectors ($V^{\pm }$) and a $Z^{\prime }$ boson, each of which might give a sizeable contribution ...

#### Quantum billiards in multidimensional models with branes

A gravitational $D$-dimensional model with $l$ scalar fields and several forms is considered. When a cosmological-type diagonal metric is chosen, an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed; the conformally covariant Wheeler–DeWitt (WDW) equation for the model is studied. Under certain restrictions asymptotic solutions ...

#### Exact solutions in modified massive gravity and off-diagonal wormhole deformations

We explore off-diagonal deformations of ‘prime’ metrics in Einstein gravity (for instance, for wormhole configurations) into ‘target’ exact solutions in $f(R,T)$-modified and massive/bi-metric gravity theories. The new classes of solutions may, or may not, possess Killing symmetries and can be characterized by effective induced masses, anisotropic polarized interactions, and ...

#### Measurement of negatively charged pion spectra in inelastic p+p interactions at $p_{\mathbf {lab}}=$ 20, 31, 40, 80 and 158 GeV/c

We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\sqrt{s} =$ 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super ...

#### Higher harmonics of azimuthal anisotropy in relativistic heavy-ion collisions in HYDJET++ model

The LHC data on azimuthal anisotropy harmonics from PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the framework of the HYDJET++ model. The cross-talk of elliptic $v_2$ and triangular $v_3$ flow in the model generates both even and odd harmonics of higher order. Comparison with the experimental data shows that this mechanism ...

#### The Hawking temperature in the context of dark energy for Reissner–Nordstrom and Kerr background

For emergent gravity metrics, the presence of dark energy modifies the Hawking temperature. We show that for the spherically symmetric Reissner–Nordstrom background metric, the emergent metric can be mapped into a Robinson–Trautman black hole. Allowed values of the dark energy density follow from rather general conditions. For some allowed values of the dark energy density this ...

#### Finite field-energy and interparticle potential in logarithmic electrodynamics

We pursue an investigation of logarithmic electrodynamics, for which the field energy of a point-like charge is finite, as happens in the case of the usual Born–Infeld electrodynamics. We also show that, contrary to the latter, logarithmic electrodynamics exhibits the feature of birefringence. Next, we analyze the lowest-order modifications for both logarithmic electrodynamics and ...

#### Implications of improved Higgs mass calculations for supersymmetric models

We discuss the allowed parameter spaces of supersymmetric scenarios in light of improved Higgs mass predictions provided by FeynHiggs 2.10.0. The Higgs mass predictions combine Feynman-diagrammatic results with a resummation of leading and subleading logarithmic corrections from the stop/top sector, which yield a significant improvement in the region of large stop masses. Scans in ...

#### A 331 WIMPy dark radiation model

Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are produced relativistically, they could mimic the effect of an extra realistic species at matter–radiation equality while obeying BBN, CMB and ...

#### Interpretation of $Z_c(4025)$ as the hidden charm tetraquark states via QCD Sum Rules

By using QCD Sum Rules, we found that the charged hidden charm tetraquark $[c u][\bar{c} \bar{d}]$ states with $J^P = 1^-$ and $2^+$, which are possible quantum numbers of the newly observed charmonium-like resonance $Z_c(4025)$, have masses of $m_{1^-}^c = (4.54 \pm 0.20) \, \text {GeV}$ and $m_{2^+}^c = (4.04 \pm 0.19) \, \text {GeV}$. The contributions up to ...

#### Decays of polarized top quarks to lepton, neutrino, and jets at NLO QCD

We compute the differential and total rate of the semileptonic decay of polarized top quarks $t\rightarrow \ell \nu _\ell + b~\mathrm{jet} + \mathrm{jet}$ at next-to-leading order (NLO) in the QCD coupling with an off-shell intermediate $W$ boson. We present several normalized distributions, in particular those that reflect the $t$-spin analyzing powers of the lepton, the ...

#### Unified description for $\kappa$ -deformations of orthogonal groups

In this paper we provide universal formulas describing Drinfeld-type quantization of inhomogeneous orthogonal groups determined by a metric tensor of an arbitrary signature living in a spacetime of arbitrary dimension. The metric tensor does not need to be in diagonal form and $\kappa$-deformed coproducts are presented in terms of classical generators. It opens the possibility ...

#### Near-horizon of 5D rotating black holes from 2D perspective

We study the CFT dual to five-dimensional extremal rotating black holes, by investigating the two-dimensional perspective of their near-horizon geometry. From the two-dimensional point of view, we show that both gauge fields, related to the two rotations, appear in the same manner in the asymptotic symmetry and in the associated central charge. We find that our results are in ...

#### Boosted objects and jet substructure at the LHC. Report of BOOST2012, held at IFIC Valencia, 23rd–27th of July 2012

This report of the BOOST2012 workshop presents the results of four working groups that studied key aspects of jet substructure. We discuss the potential of first-principle QCD calculations to yield a precise description of the substructure of jets and study the accuracy of state-of-the-art Monte Carlo tools. Limitations of the experiments’ ability to resolve substructure are ...

#### Gravitational lensing of wormholes in the galactic halo region

A recent study by Rahaman et al. has shown that the galactic halo possesses the necessary properties for supporting traversable wormholes, based on two observational results, the Navarro–Frenk–White density profile and the observed flat rotation curves of galaxies. Using a method for calculating the deflection angle pioneered by V. Bozza, it is shown that the deflection angle ...

#### Information and treatment of unknown correlations in the combination of measurements using the BLUE method

We discuss the effect of large positive correlations in the combinations of several measurements of a single physical quantity using the Best Linear Unbiased Estimate (BLUE) method. We suggest a new approach for comparing the relative weights of the different measurements in their contributions to the combined knowledge about the unknown parameter, using the well-established ...

#### On noncommutative spherically symmetric spaces

Two families of noncommutative extensions are given of a general space-time metric with spherical symmetry, both based on the matrix truncation of the functions on the sphere of symmetry. The first family uses the truncation to foliate space as an infinite set of spheres, and it is of dimension four and necessarily time-dependent; the second can be time-dependent or static, is of ...

#### Dirac quasinormal modes for a $4$ -dimensional Lifshitz black hole

We study the quasinormal modes of fermionic perturbations for an asymptotically Lifshitz black hole in four dimensions with dynamical exponent $z=2$ and plane topology for the transverse section, and we find analytically and numerically the quasinormal modes for massless fermionic fields by using the improved asymptotic iteration method and the Horowitz–Hubeny method. The ...

#### Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton $\times$ year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the ...

#### Constraining anisotropy of the universe from different groups of type-Ia supernovae

Recently released Planck data and other astronomical observations show that the universe may be anisotropic on large scales. Inspired by this, anisotropic cosmological models have been proposed. We note that the Finsler–Randers spacetime provides an appropriate framework for the anisotropic cosmology. By adding an arbitrary 1-form to the Friedmann–Robertson–Walker line element, a ...

#### The thermodynamics and thermodynamic geometry of the Park black hole

We study the thermodynamics and thermodynamic geometry of the Park black hole in Hořava gravity. By incorporating the ideas of differential geometry, we investigate the thermodynamics by using the Weinhold and the Ruppeiner geometry. We have also analyzed it in the context of the newly developed geometrothermodynamics (GTD). The divergence of the specific heat is associated with a ...

#### Is Eddington–Born–Infeld theory really free of cosmological singularities?

The Eddington-inspired-Born–Infeld (EiBI) theory has recently been resurrected. Such a theory is characterized by being equivalent to Einstein theory in vacuum but differing from it in the presence of matter. One of the virtues of the theory is that it avoids the Big Bang singularity for a radiation-filled universe. In this paper, we analyze singularity avoidance in this kind of ...

#### Implementation of a local principal curves algorithm for neutrino interaction reconstruction in a liquid argon volume

A local principal curve algorithm has been implemented in three dimensions for automated track and shower reconstruction of neutrino interactions in a liquid argon time projection chamber. We present details of the algorithm and characterise its performance on simulated data sets.