The European Physical Journal C

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

List of Papers (Total 4,483)

Transformation properties of the transverse mass under transverse Lorentz boosts at hadron colliders

The transverse mass of semi-invisibly decaying particles, calculated from the transverse momenta of their decay products, has been used in a broad range of searches and measurements at hadron colliders, such as the LHC. This variable is invariant by construction under Lorentz boosts purely in the longitudinal (beam) direction, thereby minimising sensitivity to fluctuations in the...

Study of neutrino oscillation parameters at the INO-ICAL detector using event-by-event reconstruction

We present the reach of the proposed INO-ICAL in measuring the atmospheric-neutrino-oscillation parameters \(\theta _{23}\) and \(\varDelta m^2_{32}\) using full event-by-event reconstruction for the first time. We also study the fluctuations arising from the low event statistics and their effect on the precision measurements and mass-hierarchy analysis for a 5-year exposure of...

Study of the decay \(K^{+}\rightarrow \pi ^{+}\pi ^{-}\pi ^{+}\gamma \) in the OKA experiment

A high statistics data sample of the decays of \(K^+\) mesons to three charged particles was accumulated by the OKA experiment in 2012 and 2013. This allowed to select a clean sample of about 450 events with \(K^{+}\rightarrow \pi ^{+}\pi ^{-}\pi ^{+}\gamma \) decays with the energy of the photon in the kaon rest frame greater than 30 MeV. The measured branching fraction of the...

Removal energies and final state interaction in lepton nucleus scattering

We investigate the binding energy parameters that should be used in modeling electron and neutrino scattering from nucleons bound in a nucleus within the framework of the impulse approximation. We discuss the relation between binding energy, missing energy, removal energy (\(\epsilon \)), spectral functions and shell model energy levels and extract updated removal energy...

On the trace anomaly of a Weyl fermion in a gauge background

We study the trace anomaly of a Weyl fermion in an abelian gauge background. Although the presence of the chiral anomaly implies a breakdown of gauge invariance, we find that the trace anomaly can be cast in a gauge invariant form. In particular, we find that it does not contain any odd-parity contribution proportional to the Chern–Pontryagin density, which would be allowed by...

Polyethylene naphthalate film as a wavelength shifter in liquid argon detectors

Liquid argon-based scintillation detectors are important for dark matter searches and neutrino physics. Argon scintillation light is in the vacuum ultraviolet region, making it hard to be detected by conventional means. Polyethylene naphthalate (PEN), an optically transparent thermoplastic polyester commercially available as large area sheets or rolls, is proposed as an...

Measurement of the top quark mass in the \(t\bar{t}\rightarrow \) lepton+jets channel from \(\sqrt{s}=8\) TeV ATLAS data and combination with previous results

The top quark mass is measured using a template method in the \(t\bar{t} \rightarrow \mathrm {lepton+jets}\) channel (lepton is e or \(\mu \)) using ATLAS data recorded in 2012 at the LHC. The data were taken at a proton–proton centre-of-mass energy of \({\sqrt{s}} =8\) \(\text {TeV}\) and correspond to an integrated luminosity of \(20.2\)  fb\(^{-1}\). The \(t\bar{t} \rightarrow...

Guiding new physics searches with unsupervised learning

We propose a new scientific application of unsupervised learning techniques to boost our ability to search for new phenomena in data, by detecting discrepancies between two datasets. These could be, for example, a simulated standard-model background, and an observed dataset containing a potential hidden signal of New Physics. We build a statistical test upon a test statistic...

From the colour glass condensate to filamentation: systematics of classical Yang–Mills theory

The non-equilibrium early time evolution of an ultra-relativistic heavy ion collision is often described by classical lattice Yang–Mills theory, starting from the colour glass condensate (CGC) effective theory with an anisotropic energy momentum tensor as initial condition. In this work we investigate the systematics associated with such studies and their dependence on various...

Nuclear uncertainties in the determination of proton PDFs

We show how theoretical uncertainties due to nuclear effects may be incorporated into global fits of proton parton distribution functions (PDFs) that include deep-inelastic scattering and Drell–Yan data on nuclear targets. We specifically consider the CHORUS, NuTeV and E605 data included in the NNPDF3.1 fit, which used Pb, Fe and Cu targets, respectively. We show that the...

MSSM Higgs benchmark scenarios for Run 2 and beyond: the low \(\tan \beta \) region

We propose two new benchmark scenarios for Higgs-boson searches in the Minimal Supersymmetric Standard Model (MSSM ). These scenarios are specifically designed for the low \(\tan \beta \) region. A light Higgs-boson mass prediction compatible with the observed value of \(125\,\hbox {GeV}\) is ensured in almost the entire parameter space by employing a flexible supersymmetric...

GUP parameter from maximal acceleration

We exhibit a theoretical calculation of the parameter \(\beta \) appearing in the generalized uncertainty principle (GUP) with only a quadratic term in the momentum. A specific numerical value is obtained by comparing the GUP-deformed Unruh temperature with the one predicted within the framework of Caianiello’s theory of maximal acceleration. The physical meaning of this result...

Scalar field quasinormal modes on asymptotically locally flat rotating black holes in three dimensions

The pure quadratic term of New Massive Gravity in three dimensions admits asymptotically locally flat, rotating black holes. These black holes are characterized by their mass and angular momentum, as well as by a hair of gravitational origin. As in the Myers–Perry solution in dimensions greater than five, there is no upper bound on the angular momentum. We show that, remarkably...

Measurement of exclusive \(\mathrm {\Upsilon }\) photoproduction from protons in \(\mathrm {p}\) Pb collisions at \(\sqrt{\smash [b]{s_{_{\mathrm {NN}}}}} = 5.02\,\text {TeV} \)

The exclusive photoproduction of \(\mathrm {\Upsilon }\mathrm {(nS)} \) meson states from protons, \(\gamma \mathrm {p} \rightarrow \mathrm {\Upsilon }\mathrm {(nS)} \,\mathrm {p}\) (with \(\mathrm {n}=1,2,3\)), is studied in ultraperipheral \(\mathrm {p}\)Pb collisions at a centre-of-mass energy per nucleon pair of \(\sqrt{\smash [b]{s_{_{\mathrm {NN}}}}} = 5.02\,\text {TeV...

Surface operators, dual quivers and contours

We study half-BPS surface operators in four dimensional \({{{\mathcal {N}}}}=2\) SU(N) gauge theories, and analyze their low-energy effective action on the four dimensional Coulomb branch using equivariant localization. We also study surface operators as coupled 2d/4d quiver gauge theories with an SU(N) flavour symmetry. In this description, the same surface operator can be...

D-dimensional Bardeen–AdS black holes in Einstein–Gauss–Bonnet theory

We present a D-dimensional Bardeen like Anti-de Sitter (AdS) black hole solution in Einstein–Gauss–Bonnet (EGB) gravity, viz., Bardeen–EGB–AdS black holes. The Bardeen–EGB–AdS black hole has an additional parameter due to magnetic charge (e), apart from mass (M) and Gauss–Bonnet parameter (\(\alpha \)). Interestingly, for each value of \(\alpha \), there exist a critical \(e...

Performance study of the full hadronic WW and ZZ events’ separation at the CEPC

The full hadronic WW and ZZ events’ separation is an important benchmark for the Circular Electron Positron Collider (CEPC) detector design and reconstruction algorithm development. This separation performance is determined by the intrinsic boson mass distributions, the detector performance, and the jet confusion. The latter refers to the uncertainties induced by the jet...

Measurement of associated production of a \(\mathrm {W}\) boson and a charm quark in proton–proton collisions at \(\sqrt{s} = 13\,\text {Te}\text {V} \)

Measurements are presented of associated production of a \(\mathrm {W}\) boson and a charm quark (\(\mathrm {W}+\mathrm {c}\)) in proton–proton collisions at a center-of-mass energy of 13\(\,\text {Te}\text {V}\). The data correspond to an integrated luminosity of 35.7\(\,\text {fb}^{-1}\) collected by the CMS experiment at the CERN LHC. The \(\mathrm {W}\) bosons are identified...

Stability of the Einstein static Universe in Einstein–Cartan–Brans–Dicke gravity

In the present work we consider the existence and stability of Einstein static ES Universe in Brans–Dicke (BD) theory with non-vanishing spacetime torsion. In this theory, torsion field can be generated by the BD scalar field as well as the intrinsic angular momentum (spin) of matter. Assuming the matter content of the Universe to be a Weyssenhoff fluid, which is a generalization...

\(b \rightarrow c \tau \nu _{\tau }\) Decays: a catalogue to compare, constrain, and correlate new physics effects

In this article, we predict the standard model (SM) values of the asymmetric and angular observables in \(B\rightarrow D^{(*)}\tau \nu _{\tau }\) decays, using the results of the new up-to-date analysis in \(B\rightarrow D^{(*)}\ell \nu _{\ell }\). We also revisit the SM prediction of the inclusive ratio \({\mathcal {R}}_{X_c}\), and we give its values in different schemes of the...

Thin shells associated to black string spacetimes

In this article, we study thin shells of matter connecting charged black string geometries with different values of the corresponding parameters. We analyze the matter content and the mechanical stability of the shells undergoing perturbations that preserve the cylindrical symmetry. Two different global configurations are considered: an interior geometry connected to an exterior...

Ultra-relativistic gravity has properties associated with the strong force

The equations of motion, as well as the potential energy V of a self-gravitating N-body system in the first post-Minkowskian approximation have recently been derived. Here, for the particular case of two equal masses, the ultra-relativistic limit of these equations is analysed. It is shown that the requirement that the component of the gravitational force along the vector...

Instability of Reissner–Nordström black hole in Einstein-Maxwell-scalar theory

The scalarization of Reissner–Nordström black holes was recently proposed in the Einstein-Maxwell-scalar theory. Here, we show that the appearance of the scalarized Reissner–Nordström black hole is closely related to the Gregory-Laflamme instability of the Reissner–Nordström black hole without scalar hair.

Production of \(Z_c(3900\) ) and \(Z_c(4020)\) in \(B_c\) decay

In the present work, we propose to search the charmonium-like states \(Z_c(3900\)) and \(Z_c(4020)\) in the \(B_c\) decay. In an effective Lagrangian approach, the branching ratios of \(B_c^+ \rightarrow Z_c(3900)^+ \pi ^0\) and \(B_c^+\rightarrow Z_c (4020)^+ \pi ^0\) are estimated to be of order of \(10^{-4}\) and \(10^{-7}\), respectively. The large production rate of \(Z_c...

Effective action of a dynamical Dp-brane with background fluxes

We shall construct the Dirac-Born-Infeld like and the Wess–Zumino like actions for a dynamical Dp-brane with the U(1) gauge potential and the Kalb–Ramond background field. The brane dynamics simultaneously has both tangential and transverse components. Our calculations will be in the context of the type II superstring theory, via the boundary state formalism.