The European Physical Journal C

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

List of Papers (Total 3,650)

Pauli–Zeldovich cancellation of the vacuum energy divergences, auxiliary fields and supersymmetry

We have considered the Pauli–Zeldovich mechanism for the cancellation of the ultraviolet divergences in vacuum energy. This mechanism arises because bosons and fermions give contributions of the opposite signs. In contrast with the preceding papers devoted to this topic wherein mainly free fields were studied, here we have taken their interactions into account to the lowest order...

The waning of the WIMP? A review of models, searches, and constraints

Weakly Interacting Massive Particles (WIMPs) are among the best-motivated dark matter candidates. No conclusive signal, despite an extensive search program that combines, often in a complementary way, direct, indirect, and collider probes, has been detected so far. This situation might change in near future due to the advent of one/multi-TON Direct Detection experiments. We thus...

Hypermultiplet gaugings and supersymmetric solutions from 11D and massive IIA supergravity on $$\hbox {H}^{(p,q)}$$ spaces

Supersymmetric \(\text {AdS}_{4}\), \(\text {AdS}_{2} \times \Sigma _{2}\) and asymptotically \(\hbox {AdS}_{4}\) black hole solutions are studied in the context of non-minimal \(\mathcal {N}=2\) supergravity models involving three vector multiplets (STU-model) and Abelian gaugings of the universal hypermultiplet moduli space. Such models correspond to consistent subsectors of...

On possibility of time reversal symmetry violation in neutrino elastic scattering on polarized electron target

In this paper we indicate a possibility of utilizing the elastic scattering of Dirac low-energy (\(\sim 1\) MeV) electron neutrinos (\(\nu _e\)s) on a polarized electron target (PET) in testing the time reversal symmetry violation (TRSV). We consider a scenario in which the incoming \(\nu _e\) beam is a superposition of left chiral (LC) and right chiral (RC) states. LC \(\nu _e...

Explaining the DAMPE data with scalar dark matter and gauged $$U(1)_{L_e-L_\mu }$$ interaction

Inspired by the peak structure observed by recent DAMPE experiment in \(e^+e^-\) cosmic-ray spectrum, we consider a scalar dark matter (DM) model with gauged \(U(1)_{L_e-L_\mu }\) symmetry, which is the most economical anomaly-free theory to potentially explain the peak by DM annihilation in nearby subhalo. We utilize the process \(\chi \chi \rightarrow Z^\prime Z^\prime...

Dirac field and gravity in NC $$SO(2,3)_\star $$ model

Action for the Dirac spinor field coupled to gravity on noncommutative (NC) Moyal-Weyl spacetime is obtained without prior knowledge of the metric tensor. We emphasize gauge origins of gravity and its interaction with fermions by demonstrating that a classical action invariant under SO(2, 3) gauge transformations can be exactly reduced to the Dirac action in curved spacetime...

Twist for Snyder space

We construct the twist operator for the Snyder space. Our starting point is a non-associative star product related to a Hermitian realisation of the noncommutative coordinates originally introduced by Snyder. The corresponding coproduct of momenta is non-coassociative. The twist is constructed using a general definition of the star product in terms of a bi-differential operator...

Evading the non-continuity equation in the <Emphasis Type=

We present a new approach for the f(R, T) gravity formalism, by thoroughly exploring the extra terms of its effective energy-momentum tensor \(T_{\mu \nu }^\mathrm{eff}\), which we name \(\tilde{T}_{\mu \nu }\), so that \(T_{\mu \nu }^\mathrm{eff}=T_{\mu \nu }+\tilde{T}_{\mu \nu }\), with \(T_{\mu \nu }\) being the usual energy-momentum tensor of matter. Purely from the Bianchi...

Weak deflection gravitational lensing for photons coupled to Weyl tensor in a Schwarzschild black hole

Beyond the Einstein–Maxwell model, electromagnetic field might couple with gravitational field through the Weyl tensor. In order to provide one of the missing puzzles of the whole physical picture, we investigate weak deflection lensing for photons coupled to the Weyl tensor in a Schwarzschild black hole under a unified framework that is valid for its two possible polarizations...

Viscous cosmology in new holographic dark energy model and the cosmic acceleration

In this work, we study a flat Friedmann–Robertson–Walker universe filled with dark matter and viscous new holographic dark energy. We present four possible solutions of the model depending on the choice of the viscous term. We obtain the evolution of the cosmological quantities such as scale factor, deceleration parameter and transition redshift to observe the effect of viscosity...

Measurement of differential cross-sections of a single top quark produced in association with a W boson at $$\sqrt{s}={13}{\text {TeV}}$$ with ATLAS

The differential cross-section for the production of a W boson in association with a top quark is measured for several particle-level observables. The measurements are performed using \({36.1}\,\text {fb}^{-1}\) of pp collision data collected with the ATLAS detector at the LHC in 2015 and 2016. Differential cross-sections are measured in a fiducial phase space defined by the...

Perturbativity constraints in BSM models

Phenomenological studies performed for non-supersymmetric extensions of the Standard Model usually use tree-level parameters as input to define the scalar sector of the model. This implicitly assumes that a full on-shell calculation of the scalar sector is possible – and meaningful. However, this doesn’t have to be the case as we show explicitly at the example of the Georgi...

Status of the charged Higgs boson in two Higgs doublet models

The existence of charged Higgs boson(s) is inevitable in models with two (or more) Higgs doublets. Hence, their discovery would constitute unambiguous evidence for new physics beyond the Standard Model (SM). Taking into account all relevant results from direct charged and neutral Higgs boson searches at LEP and the LHC, as well as the most recent constraints from flavour physics...

The cosmological dark sector as a scalar σ-meson field

Previous quantum field estimations of the QCD vacuum in the expanding space-time lead to a dark energy component scaling linearly with the Hubble parameter, which gives the correct figure for the observed cosmological term. Here we show that this behaviour also appears at the classical level, as a result of the chiral symmetry breaking in a low energy, effective \(\sigma \)-model...

Search for single production of vector-like top partner decaying to Wb at $$e\gamma $$ collision

In a simplified model including an SU(2) singlet T quark with charge 2/3, we investigate the single vector-like T production at the high energy \(e\gamma \) collision. We study the observability of the vector-like T focusing on the \(T\rightarrow Wb\) decay channel with \(W\rightarrow l\bar{\nu }\) at \(\sqrt{s}=2.0\) TeV. In this analysis, only two free parameters are involved...

Evidence of ghost suppression in gluon mass scale dynamics

In this work we study the impact that the ghost sector of pure Yang–Mills theories may have on the generation of a dynamical gauge boson mass scale, which hinges on the appearance of massless poles in the fundamental vertices of the theory, and the subsequent realization of the well-known Schwinger mechanism. The process responsible for the formation of such structures is itself...

Effective theory of the D = 3 center vortex ensemble

By means of lattice calculations, center vortices have been established as the infrared dominant gauge field configurations of Yang–Mills theory. In this work, we investigate an ensemble of center vortices in D = 3 Euclidean space-time dimension where they form closed flux loops. To account for the properties of center vortices detected on the lattice, they are equipped with...

TMD splitting functions in $$k_T$$ factorization: the real contribution to the gluon-to-gluon splitting

We calculate the transverse momentum dependent gluon-to-gluon splitting function within \(k_T\)-factorization, generalizing the framework employed in the calculation of the quark splitting functions in Hautmann et al. (Nucl Phys B 865:54-66, arXiv:1205.1759, 2012), Gituliar et al. (JHEP 01:181, arXiv:1511.08439, 2016), Hentschinski et al. (Phys Rev D 94(11):114013, arXiv:1607...

Rotating effects on the scalar field in the cosmic string spacetime, in the spacetime with space-like dislocation and in the spacetime with a spiral dislocation

In the interface between general relativity and relativistic quantum mechanics, we analyse rotating effects on the scalar field subject to a hard-wall confining potential. We consider three different scenarios of general relativity given by the cosmic string spacetime, the spacetime with space-like dislocation and the spacetime with a spiral dislocation. Then, by searching for a...

On the thermodynamics of the black hole and hairy black hole transitions in the asymptotically flat spacetime with a box

We study the asymptotically flat quasi-local black hole/hairy black hole model with nonzero mass of the scalar field. We disclose effects of the scalar mass on transitions in a grand canonical ensemble with condensation behaviors of the parameter \(\psi _{2}\), which is similar to approaches in holographic theories. We find that a more negative scalar mass makes the phase...

A proposal of a renormalizable Nambu–Jona-Lasinio model

A local and gauge invariant gauge field model including Nambu–Jona-Lasinio (NJL) and QCD Lagrangian terms in its action is introduced. Surprisingly, it becomes power counting renormalizable. This occurs thanks to the presence of action terms which modify the quark propagators, to become more decreasing that the Dirac one at large momenta in a Lee–Wick form, implying power...

Measurement of quarkonium production in proton–lead and proton–proton collisions at $$5.02~\mathrm {TeV}$$ with the ATLAS detector

The modification of the production of \(J/\psi \), \(\psi (2\mathrm {S})\), and \(\varUpsilon (n\mathrm {S})\) (\(n = 1, 2, 3\)) in p+Pb collisions with respect to their production in pp collisions has been studied. The p+Pb and pp datasets used in this paper correspond to integrated luminosities of \(28~\mathrm {nb}^{-1}\) and \(25~\mathrm {pb}^{-1}\) respectively, collected in...

New constraints on the 3-3-1 model with right-handed neutrinos

In the framework of a 3-3-1 model with right-handed neutrinos and three scalar triplets we consider different spontaneous symmetry breaking patterns seeking for a non-linear realization of accidental symmetries of the model, which will produce physical Nambu–Goldstone (NG) bosons in the neutral scalar spectrum. We make a detailed study of the safety of the model concerning the NG...

Measurement of $$\tau $$ polarisation in $$Z/\gamma ^{*}\rightarrow \tau \tau $$Z/γ∗→ decays in proton–proton collisions at $$\sqrt{s}=8$$s=8 TeV with the ATLAS detector

This paper presents a measurement of the polarisation of \(\tau \) leptons produced in \(Z/\gamma ^{*}\rightarrow \tau \tau \) decays which is performed with a dataset of proton—proton collisions at \(\sqrt{s}=8\) TeV, corresponding to an integrated luminosity of 20.2 fb\(^{-1}\) recorded with the ATLAS detector at the LHC in 2012. The \(Z/\gamma ^{*}\rightarrow \tau \tau...

Nonsymmetric dynamical thin-shell wormhole in Robinson–Trautman class

The thin-shell wormhole created using the Darmois–Israel formalism applied to Robinson–Trautman family of spacetimes is presented. The stress energy tensor created on the throat is interpreted in terms of two dust streams and it is shown that asymptotically this wormhole settles to the Schwarzschild wormhole with a throat located at the position of the horizon. This behavior...