The European Physical Journal C

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

List of Papers (Total 3,659)

Realistic simplified gaugino-higgsino models in the MSSM

We present simplified MSSM models for light neutralinos and charginos with realistic mass spectra and realistic gaugino-higgsino mixing, that can be used in experimental searches at the LHC. The formerly used naive approach of defining mass spectra and mixing matrix elements manually and independently of each other does not yield genuine MSSM benchmarks. We suggest the use of...

Hidden role of Maxwell superalgebras in the free differential algebras of D = 4 and D = 11 supergravity

The purpose of this paper is to show that the so-called Maxwell superalgebra in four dimensions, which naturally involves the presence of a nilpotent fermionic generator, can be interpreted as a hidden superalgebra underlying \(\mathcal {N}=1, {\hbox {D}}=4\) supergravity extended to include a 2-form gauge potential associated to a 2-index antisymmetric tensor. In this scenario...

On the coverage of the pMSSM by simplified model results

We investigate to which extent the SUSY search results published by ATLAS and CMS in the context of simplified models actually cover the more realistic scenarios of a full model. Concretely, we work within the phenomenological MSSM (pMSSM) with 19 free parameters and compare the constraints obtained from SModelS v1.1.1 with those from the ATLAS pMSSM study in arXiv:1508.06608. We...

Disclosing $$D^*\bar{D}^*$$ molecular states in the $$B_c^- \rightarrow \pi ^- J/\psi \omega $$Bc-→π-J/ψω decay

We study the \(B_c^- \rightarrow \pi ^- J/\psi \omega \) and \(B_c^- \rightarrow \pi ^- D^* \bar{D}^*\) reactions and show that they are related by the presence of two resonances, the X(3940) and X(3930), that are of molecular nature and couple most strongly to \(D^* \bar{D}^*\), but also to \(J/\psi \omega \). Because of that, in the \(J/\psi \omega \) mass distribution we find...

Radiative seesaw model and DAMPE excess from leptophilic gauge symmetry

In the light of the \(e^{+}+e^{-}\) excess observed by DAMPE experiment, we propose an anomaly-free radiative seesaw model with an alternative leptophilic \(U(1)_X\) gauge symmetry. In the model, only right-handed leptons are charged under \(U(1)_X\) symmetry. The tiny Dirac neutrino masses are generated at one-loop level and charged leptons acquire masses though the type-I...

keV-Scale sterile neutrino sensitivity estimation with time-of-flight spectroscopy in KATRIN using self-consistent approximate Monte Carlo

We investigate the sensitivity of the Karlsruhe Tritium Neutrino Experiment (KATRIN) to keV-scale sterile neutrinos, which are promising dark matter candidates. Since the active-sterile mixing would lead to a second component in the tritium \(\upbeta \)-spectrum with a weak relative intensity of order \(\sin ^2\theta \lesssim 10^{-6}\), additional experimental strategies are...

Running bumps from stealth bosons

For the ‘stealth bosons’ S, light boosted particles with a decay \(S \rightarrow A A \rightarrow q \bar{q} q \bar{q}\) into four quarks and reconstructed as a single fat jet, the groomed jet mass has a strong correlation with groomed jet substructure variables. Consequently, the jet mass distribution is strongly affected by the jet substructure selection cuts when applied on the...

Singlet structure function $$F_1$$ in double-logarithmic approximation

The conventional ways to calculate the perturbative component of the DIS singlet structure function \(F_1\) involve approaches based on BFKL which account for the single-logarithmic contributions accompanying the Born factor 1 / x. In contrast, we account for the double-logarithmic (DL) contributions unrelated to 1 / x and because of that they were disregarded as negligibly small...

Three waves for quantum gravity

Using effective field theoretical methods, we show that besides the already observed gravitational waves, quantum gravity predicts two further massive classical fields leading to two new massive waves. We set a limit on the masses of these new modes using data from the Eöt-Wash experiment. We point out that the existence of these new states is a model independent prediction of...

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...