The European Physical Journal C

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

List of Papers (Total 3,248)

Matter–antimatter asymmetry induced by a running vacuum coupling

We show that a CP-violating interaction induced by a derivative coupling between the running vacuum and a non-conserving baryon current may dynamically break CPT and trigger baryogenesis through an effective chemical potential. By assuming a non-singular class of running vacuum cosmologies which provides a complete cosmic history (from an early inflationary de Sitter stage to the ...

Einstein–Yang–Mills–Lorentz black holes

Different black hole solutions of the coupled Einstein–Yang–Mills equations have been well known for a long time. They have attracted much attention from mathematicians and physicists since their discovery. In this work, we analyze black holes associated with the gauge Lorentz group. In particular, we study solutions which identify the gauge connection with the spin connection. ...

Possible signature of the magnetic fields related to quasi-periodic oscillations observed in microquasars

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole binaries can provide a powerful tool for testing of the phenomena occurring in the strong gravity regime. Magnetized versions of the standard geodesic models of QPOs can explain the observationally fixed data from the three microquasars. We perform a successful fitting of the HF ...

A \(1+5\) -dimensional gravitational-wave solution: curvature singularity and spacetime singularity

We solve a \(1+5\)-dimensional cylindrical gravitational-wave solution of the Einstein equation, in which there are two curvature singularities. Then we show that one of the curvature singularities can be removed by an extension of the spacetime. The result exemplifies that the curvature singularity is not always a spacetime singularity; in other words, the curvature singularity ...

R-parity violation at the LHC

We investigate the phenomenology of the MSSM extended by a single R-parity-violating coupling at the unification scale. For all R-parity-violating couplings, we discuss the evolution of the particle spectra through the renormalization group equations and the nature of the lightest supersymmetric particle (LSP) within the CMSSM, as an example of a specific complete supersymmetric ...

The anomalous \(U(1)_{\mathrm{anom}}\) symmetry and flavors from an SU(5) \(\times \) SU(5) \('\) GUT in \(\mathbf{Z}_{12-I}\) orbifold compactification

In string compactifications, frequently the anomalous U(1) gauge symmetry appears which belongs to \(E_8 \times E_8'\) of the heterotic string. This anomalous U(1) gauge boson obtains mass at the compactification scale (\(\approx 10^{18\,}\,\text {GeV}\)) by absorbing one pseudoscalar (corresponding to the model-independent axion) from the second rank antisymmetric tensor field ...

A nearly cylindrically symmetric source in Brans–Dicke gravity as the generator of the rotational curves of the galaxies

Observation shows that the velocities of stars grow by approximately 2–3 orders of magnitude when the distances from the centers of the galaxies are in the range of 0.5–82.3 kpc, before they begin to tend to a constant value. Up to now, the reason for this behavior is still a matter for debate. In this work, we propose a model which adequately describes this unusual behavior using ...

Effective potential in Lorentz-breaking field theory models

We calculate explicitly the one-loop effective potential in different Lorentz-breaking field theory models. First, we consider a Yukawa-like theory and some examples of Lorentz-violating extensions of scalar QED. We observe, for the extended QED models, that the resulting effective potential converges to the known result in the limit in which Lorentz symmetry is restored. Besides, ...

Heavy neutrino mixing in the T2HK, the T2HKK and an extension of the T2HK with a detector at Oki Islands

We study the discovery potential for the mixing of heavy isospin-singlet neutrinos in extensions of the Tokai-to-Kamioka (T2K) experiment, the Tokai-to-Hyper-Kamiokande (T2HK), the Tokai-to-Hyper-Kamiokande-to-Korea (T2HKK) with a Korea detector with \(\simeq 1000\) km baseline length and \(1^\circ \) off-axis angle, and a plan of adding a small detector at Oki Islands to the T2HK. ...

S- and T-self-dualities in dilatonic \(f(R)\) theories

We search for theories, in general spacetime dimensions, that would incorporate a dilaton and higher powers of the scalar Ricci curvature such that they have exact S- or T-self-dualities. The theories we find are free of Ostrogradsky instabilities. We also show that within the framework we are confining ourselves, a theory of the form mentioned above cannot have both T- and ...

Spectroscopic parameters and decays of the resonance \(Z_b(10610)\)

The resonance \(Z_b(10610)\) is investigated as the diquark–antidiquark \( Z_b=[bu][\overline{bd}]\) state with spin–parity \(J^{P}=1^{+}\). The mass and current coupling of the resonance \(Z_b(10610)\) are evaluated using QCD two-point sum rule and taking into account the vacuum condensates up to ten dimensions. We study the vertices \(Z_b\Upsilon (nS)\pi \ (n=1,2,3)\) by applying ...

Impact of the heavy-quark matching scales in PDF fits

We investigate the impact of displaced heavy-quark matching scales in a global fit. The heavy-quark matching scale \(\mu _{m}\) determines at which energy scale \(\mu \) the QCD theory transitions from \(N_{F}\) to \(N_{F}+1\) in the variable flavor number scheme (VFNS) for the evolution of the parton distribution functions (PDFs) and strong coupling \(\alpha _S(\mu )\). We study ...

Jet-associated resonance spectroscopy

We present a model-independent study aimed at characterising the nature of possible resonances in the jet-photon or jet-Z final state at hadron colliders. Such resonances are expected in many models of compositeness and would be a clear indication of new physics. At leading order, in the narrow width approximation, the matrix elements are parameterised by just a few constants ...

Finite entanglement entropy and spectral dimension in quantum gravity

What are the conditions on a field theoretic model leading to a finite entanglement entropy density? We prove two very general results: (1) Ultraviolet finiteness of a theory does not guarantee finiteness of the entropy density; (2) If the spectral dimension of the spatial boundary across which the entropy is calculated is non-negative at all scales, then the entanglement entropy ...

Probing the two-scale-factor universality hypothesis by exact rotation symmetry-breaking mechanism

We probe the two-scale-factor universality hypothesis by evaluating, firstly explicitly and analytically at the one-loop order, the loop quantum corrections to the amplitude ratios for O(N) \(\lambda \phi ^{4}\) scalar field theories with rotation symmetry breaking in three distinct and independent methods in which the rotation symmetry-breaking mechanism is treated exactly. We ...

Electroweak Higgs production with HiggsPO at NLO QCD

We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus ...

Very heavy dark Skyrmions

A dark sector with a solitonic component provides a means to circumvent the problem of generically low annihilation cross sections of very heavy dark matter particles. At the same time, enhanced annihilation cross sections are necessary for indirect detection of very heavy dark matter components beyond 100 TeV. Non-thermally produced dark matter in this mass range could therefore ...

Reevaluation of the hadronic vacuum polarisation contributions to the Standard Model predictions of the muon \(g-2\) and \({\alpha (m_Z^2)}\) using newest hadronic cross-section data

We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest \(e^+e^- \rightarrow \mathrm{hadrons}\) cross-section data (among others) from the BABAR and VEPP-2000 experiments. For the muon \((g-2)/2\) we find for the lowest-order hadronic contribution ...

Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected ...

Precise predictions for \(V+\) jets dark matter backgrounds

High-energy jets recoiling against missing transverse energy (MET) are powerful probes of dark matter at the LHC. Searches based on large MET signatures require a precise control of the \(Z(\nu {\bar{\nu }})+\) jet background in the signal region. This can be achieved by taking accurate data in control regions dominated by \(Z(\ell ^+\ell ^-)+\) jet, \(W(\ell \nu )+\) jet and ...

Two Ramond–Ramond corrections to type II supergravity via field-theory amplitude

Motivated by the standard form of the string-theory amplitude, we calculate the field-theory amplitude to complete the higher-derivative terms in type II supergravity theories in their conventional form. We derive explicitly the \( O(\alpha '^3) \) interactions for the RR (Ramond–Ramond) fields with graviton, B-field and dilaton in the low-energy effective action of type II ...

Comments on gravitoelectromagnetism of Ummarino and Gallerati in “Superconductor in a weak static gravitational field” vs other versions

Recently reported [Eur. Phys. J. C., 77, 549 (2017). https://​doi.​org/​10.​1140/​epjc/​s10052-017-5116-y] gravitoelectromagnetic equations of Ummarino and Gallerati (UG) in their linearized version of general relativity (GR) are shown to match with (a) our previously reported special relativistic Maxwellian Gravity equations in the non-relativistic limit and with (b) the ...

Global fits of GUT-scale SUSY models with GAMBIT

We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: the constrained minimal supersymmetric standard model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 and NUHM2. We include likelihoods from a number of direct and indirect dark matter searches, a large collection of electroweak precision and flavour ...

Bouncing solutions from generalized EoS

We present an exact analytical bouncing solution for a closed universe filled with only one exotic fluid with negative pressure, obeying a generalized equation of state (GEoS) of the form \(p(\rho )=A\rho +B\rho ^{\lambda }\), where A, B and \(\lambda \) are constants. In our solution \(A=-1/3\), \(\lambda =1/2\), and \(B<0\) is kept as a free parameter. For particular values of ...