The European Physical Journal C

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

List of Papers (Total 3,650)

The spectroscopy of solar sterile neutrinos

We predict the sterile neutrino spectrum of some of the key solar nuclear reactions and discuss the possibility of these being observed by the next generation of solar neutrino experiments. By using an up-to-date standard solar model with good agreement with current helioseismology and solar neutrino flux data sets, we found that from solar neutrino fluxes arriving on Earth only...

Generalised nonminimally gravity-matter coupled theory

In this paper, a new generalised gravity-matter coupled theory of gravity is presented. This theory is constructed by assuming an action with an arbitrary function \(f(T,B,L_m)\) which depends on the scalar torsion T, the boundary term \(B=\nabla _{\mu }T^{\mu }\) and the matter Lagrangian \(L_m\). Since the function depends on B which appears in \(R=-T+B\), it is possible to...

\(hh+\text {Jet}\) production at 100 TeV

Higgs pair production is a crucial phenomenological process in deciphering the nature of the TeV scale and the mechanism underlying electroweak symmetry breaking. At the Large Hadron Collider, this process is statistically limited. Pushing the energy frontier beyond the LHC’s reach will create new opportunities to exploit the rich phenomenology at higher centre-of-mass energies...

The extended BLMSSM with a 125 GeV Higgs boson and dark matter

To extend the BLMSSM, we not only add exotic Higgs superfields \((\Phi _{NL},\varphi _{NL})\) to make the exotic lepton heavy, but also introduce the superfields (Y,\(Y^\prime \)) having couplings with lepton and exotic lepton at tree level. The obtained model is called as EBLMSSM, which has difference from BLMSSM especially for the exotic slepton (lepton) and exotic sneutrino...

Quasinormal modes of gravitational perturbation around regular Bardeen black hole surrounded by quintessence

In this paper, Quasinormal modes of gravitational perturbation are investigated for the regular Bardeen black hole surrounded by quintessence. Considering the metric of the Bardeen spacetime surrounded by quintessence, we derived the perturbation equation for gravitational perturbation using Regge-Wheeler gauge. The third order Wentzel-Kramers-Brillouin (WKB) approximation method...

Parton distributions with small-x resummation: evidence for BFKL dynamics in HERA data

We present a determination of the parton distribution functions of the proton in which NLO and NNLO fixed-order calculations are supplemented by NLLx small-x resummation. Deep-inelastic structure functions are computed consistently at \(\hbox {NLO+NLL}x\) or \(\hbox {NNLO+NLL}x\), while for hadronic processes small-x resummation is included only in the PDF evolution, with...

Cosmological model-independent test of \(\varLambda \) CDM with two-point diagnostic by the observational Hubble parameter data

Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range \(0 < z \leqslant 2.36\) to make a cosmological model-independent test of the \(\varLambda \)CDM model with two-point \(Omh^2(z_{2};z_{1})\) diagnostic. In \(\varLambda \)CDM model, with equation of state (EoS) \(w=-1\), two-point diagnostic...

Cosmological aspects of the Eisenhart–Duval lift

A cosmological extension of the Eisenhart–Duval metric is constructed by incorporating a cosmic scale factor and the energy-momentum tensor into the scheme. The dynamics of the spacetime is governed by the Ermakov–Milne–Pinney equation. Killing isometries include spatial translations and rotations, Newton–Hooke boosts and translation in the null direction. Geodesic motion in...

Multi-jet merged top-pair production including electroweak corrections

We present theoretical predictions for the production of top-quark pairs in association with jets at the LHC including electroweak (EW) corrections. First, we present and compare differential predictions at the fixed-order level for \(t\bar{t}\) and \(t\bar{t}+\text {jet}\) production at the LHC considering the dominant NLO EW corrections of order \({{\mathcal {O}}}(\alpha _...

Derivation of the cut-off length from the quantum quadratic enhancement of a mass in vacuum energy constant Lambda

Ultraviolet self-interaction energies in field theory sometimes contain meaningful physical quantities. The self-energies in such as classical electrodynamics are usually subtracted from the rest mass. For the consistent treatment of energies as sources of curvature in the Einstein field equations, this study includes these subtracted self-energies into vacuum energy expressed by...

A Wilsonian energy-momentum tensor

For local conformal field theories, it is shown how to construct an expression for the energy-momentum tensor in terms of a Wilsonian effective Lagrangian. Tracelessness implies a single, unintegrated equation which enforces both the Exact Renormalization Group equation and its partner encoding invariance under special conformal transformations.

Existence of compact structures in f(R, T) gravity

The present paper is devoted to investigate the possible emergence of relativistic compact stellar objects through modified f(R, T) gravity. For anisotropic matter distribution, we used Krori and Barura solutions and two notable and viable f(R, T) gravity formulations. By choosing particular observational data, we determine the values of constant in solutions for three...

Anisotropic cosmological solutions in \(R + R^2\) gravity

In this paper we investigate the past evolution of an anisotropic Bianchi I universe in \(R+R^2\) gravity. Using the dynamical system approach we show that there exists a new two-parameter set of solutions that includes both an isotropic “false radiation” solution and an anisotropic generalized Kasner solution, which is stable. We derive the analytic behavior of the shear from a...

B-meson anomalies and Higgs physics in flavored \(U(1)'\) model

We consider a simple extension of the Standard Model with flavor-dependent \(U(1)'\), that has been proposed to explain some of B-meson anomalies recently reported at LHCb. The \(U(1)'\) charge is chosen as a linear combination of anomaly-free \(B_3-L_3\) and \(L_\mu -L_\tau \). In this model, the flavor structure in the SM is restricted due to flavor-dependent \(U(1)'\) charges...

Gravitational waves in theories with a non-minimal curvature-matter coupling

Gravitational waves in the presence of a non-minimal curvature-matter coupling are analysed, both in the Newman–Penrose and perturbation theory formalisms. Considering a cosmological constant as a source, the non-minimally coupled matter-curvature model reduces to f(R) theories. This is in good agreement with the most recent data. Furthermore, a dark energy-like fluid is briefly...

Magnetic dipole moments of the negative parity \(J^{PC}=2^{--}\) mesons in QCD

Magnetic dipole moments of the negative parity light and heavy tensor mesons are calculated within the light cone QCD sum rules method. The results are compared with the positive parity counterparts of the corresponding tensor mesons. The results of the analysis show that the magnetic dipole moments of the negative parity light mesons are smaller compared to those of the positive...

Heavy-to-light scalar form factors from Muskhelishvili–Omnès dispersion relations

By solving the Muskhelishvili–Omnès integral equations, the scalar form factors of the semileptonic heavy meson decays \(D\rightarrow \pi \bar{\ell }\nu _\ell \), \(D\rightarrow {\bar{K}} \bar{\ell }\nu _\ell \), \({\bar{B}}\rightarrow \pi \ell \bar{\nu }_\ell \) and \({\bar{B}}_s\rightarrow K \ell \bar{\nu }_\ell \) are simultaneously studied. As input, we employ unitarized...

Singlet-triplet fermionic dark matter and LHC phenomenology

It is well known that for the pure standard model triplet fermionic WIMP-type dark matter (DM), the relic density is satisfied around 2 TeV. For such a heavy mass particle, the production cross-section at 13 TeV run of LHC will be very small. Extending the model further with a singlet fermion and a triplet scalar, DM relic density can be satisfied for even much lower masses. The...

Analysis of the triply-charmed pentaquark states with QCD sum rules

In this article, we construct the scalar-diquark–scalar-diquark–antiquark type current to study the ground state triply-charmed pentaquark states with the QCD sum rules. We separate the contributions of the negative-parity and positive-parity triply-charmed pentaquark states explicitly, and take the energy scale formula \(\mu =\sqrt{M^2_{P}-(3{\mathbb {M}}_c)^2}\) to determine...

The method of generating functions in exact scalar field inflationary cosmology

The construction of exact solutions in scalar field inflationary cosmology is of growing interest. In this work, we review the results which have been obtained with the help of one of the most effective methods, viz., the method of generating functions for the construction of exact solutions in scalar field cosmology. We also include in the debate the superpotential method, which...

Collapsing spherical star in Scalar-Einstein-Gauss-Bonnet gravity with a quadratic coupling

We study the evolution of a self interacting scalar field in Einstein-Gauss-Bonnet theory in four dimension where the scalar field couples non minimally with the Gauss-Bonnet term. Considering a polynomial coupling of the scalar field with the Gauss-Bonnet term, a self-interaction potential and an additional perfect fluid distribution alongwith the scalar field, we investigate...

The magnetic moment of the \(Z_c(3900)\) as an axialvector tetraquark state with QCD sum rules

In this article, we assign the \(Z_c^\pm (3900)\) to be the diquark-antidiquark type axialvector tetraquark state, study its magnetic moment with the QCD sum rules in the external weak electromagnetic field by carrying out the operator product expansion up to the vacuum condensates of dimension 8. We pay special attention to matching the hadron side with the QCD side of the...

Is pulsar timing a hopeful tool for detection of relic gravitational waves by using GW150914 data?

The inflation stage has a behaviour as power law expansion like \(S(\eta )\propto \eta ^{1+\beta }\) where \(\beta \) constrained on the \(1+\beta <0\). If the inflation were preceded by a radiation era, then there would be thermal spectrum of relic gravitational waves at the time of inflation. Based on this idea we find new upper bound on \(\beta \) by comparison the thermal...

Cosmic acceleration in the nonlocal approach to the cosmological constant problem

We have recently constructed a manifestly local formulation of a nonlocal approach to the cosmological constant problem which can treat with quantum effects from both matter and gravitational fields. In this formulation, it has been explicitly shown that the effective cosmological constant is radiatively stable even in the presence of the gravitational loop effects. Since we are...