The European Physical Journal C

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

List of Papers (Total 2,952)

Starobinsky cosmological model in Palatini formalism

We classify singularities in FRW cosmologies, which dynamics can be reduced to the dynamical system of the Newtonian type. This classification is performed in terms of the geometry of a potential function if it has poles. At the sewn singularity, which is of a finite scale factor type, the singularity in the past meets the singularity in the future. We show that such singularities ...

Vector-like quarks at the origin of light quark masses and mixing

We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a \(Z_6\) flavour symmetry, together with three \(Q = - 1/3\) quarks, three \(Q = 2/3\) quarks, as well as a complex singlet scalar. The \(Z_6\) symmetry is extended to the additional fields and it is an exact symmetry of the Lagrangian, only softly broken in the scalar ...

DsixTools: the standard model effective field theory toolkit

We present DsixTools, a Mathematica package for the handling of the dimension-six standard model effective field theory. Among other features, DsixTools allows the user to perform the full one-loop renormalization group evolution of the Wilson coefficients in the Warsaw basis. This is achieved thanks to the SMEFTrunner module, which implements the full one-loop anomalous dimension ...

Constraining new resonant physics with top spin polarisation information

We provide a comprehensive analysis of the power of including top quark-polarisation information to kinematically challenging top pair resonance searches, for which ATLAS and CMS start losing sensitivity. Following the general modelling and analysis strategies pursued by the experiments, we analyse the semi-leptonic and the di-lepton channels and show that including polarisation ...

The photon PDF from high-mass Drell–Yan data at the LHC

Achieving the highest precision for theoretical predictions at the LHC requires the calculation of hard-scattering cross sections that include perturbative QCD corrections up to (N)NNLO and electroweak (EW) corrections up to NLO. Parton distribution functions (PDFs) need to be provided with matching accuracy, which in the case of QED effects involves introducing the photon parton ...

Different pole structures in line shapes of the X(3872)

We introduce a near-threshold parameterization that is more general than the effective-range expansion up to and including the effective range because it can also handle a near-threshold zero in the \(D^0\bar{D}^{*0}\) S-wave. In terms of it we analyze the CDF data on inclusive \(p\bar{p}\) scattering to \(J/\psi \pi ^+\pi ^-\), and the Belle and BaBar data on B decays to \(K\, ...

Validity of Maxwell equal area law for black holes conformally coupled to scalar fields in \(\text {AdS}_5\) spacetime

We investigate the \(P{-}V\) criticality and the Maxwell equal area law for a five-dimensional spherically symmetric AdS black hole with a scalar hair in the absence of and in the presence of a Maxwell field, respectively. Especially in the charged case, we give the exact \(P{-}V\) critical values. More importantly, we analyze the validity and invalidity of the Maxwell equal area ...

Stable exponential cosmological solutions with zero variation of G and three different Hubble-like parameters in the Einstein–Gauss–Bonnet model with a \(\Lambda \) -term

We consider a D-dimensional gravitational model with a Gauss–Bonnet term and the cosmological term \(\Lambda \). We restrict the metrics to diagonal cosmological ones and find for certain \(\Lambda \) a class of solutions with exponential time dependence of three scale factors, governed by three non-coinciding Hubble-like parameters \(H >0\), \(h_1\) and \(h_2\), corresponding to ...

Lorentz violation bounds from torsion trace fermion sector and galaxy M 51 data and chiral dynamos

Earlier we have computed a Lorentz violation (LV) bound for torsion terms via galactic dynamos and found bounds similar to the one obtained by Kostelecky et al. (Phys Rev Lett 100:111102, 2008) which is of the order of \(10^{-31}\) GeV. Their result was found making use of the axial torsion vector in terms of Dirac spinors and minimal torsion coupling in flat space-time of ...

A holographic bound for D3-brane

In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is ...

Thermodynamical and dynamical properties of charged BTZ black holes

We investigate the spacetime properties of BTZ black holes in the presence of the Maxwell field and Born–Infeld field and find rich properties in the spacetime structures when the model parameters are varied. Employing Landau–Lifshitz theory, we examine the thermodynamical phase transition in the charged BTZ black holes. We further study the dynamical perturbation in the background ...

Production of \({\Sigma (1385)^{\pm }}\) and \({\Xi (1530)^{0}}\) in p–Pb collisions at \({\sqrt{s_{\mathrm{NN}}}= 5.02}\) TeV

The transverse momentum distributions of the strange and double-strange hyperon resonances (\(\Sigma (1385)^{\pm }\), \(\Xi (1530)^{0}\)) produced in p–Pb collisions at \(\sqrt{s_{\mathrm{NN}}}= 5.02\) TeV were measured in the rapidity range \(-0.5< y_\mathrm {CMS}<0\) for event classes corresponding to different charged-particle multiplicity densities, \(\langle ...

Interpretation of Y(4390) as an isoscalar partner of Z(4430) from \({D^{*}}(2010){\bar{D}}_1(2420)\) interaction

Invoked by the recent observation of Y(4390) at BESIII, which is about 40 MeV below the \({D^{*}}(2010){\bar{D}}_1(2420)\) threshold, we investigate possible bound and resonance states from the \({D^{*}}(2010){\bar{D}}_1(2420)\) interaction with the one-boson-exchange model in a quasipotential Bethe–Salpeter equation approach. A bound state with quantum number \(0^-(1^{-\,-})\) is ...

Interpretation of the new \(\Omega _c^{0}\) states via their mass and width

The masses and pole residues of the ground and first radially excited \( \Omega _c^{0}\) states with spin–parities \(J^{P}=1/2^{+},\,3/2^{+}\), as well as P-wave \(\Omega _c^{0}\) with \(J^{P}=1/2^{-},\,3/2^{-}\) are calculated by means of the two-point QCD sum rules. The strong decays of \(\Omega _c^{0}\) baryons are also studied and the widths of these decay channels are ...

Interacting diffusive unified dark energy and dark matter from scalar fields

Here we generalize ideas of unified dark matter–dark energy in the context of two measure theories and of dynamical space time theories. In two measure theories one uses metric independent volume elements and this allows one to construct unified dark matter–dark energy, where the cosmological constant appears as an integration constant associated with the equation of motion of the ...

Higher spin currents in the orthogonal coset theory

In the coset model \((D_N^{(1)} \oplus D_N^{(1)},D_N^{(1)})\) at levels \((k_1,k_2)\), the higher spin 4 current that contains the quartic WZW currents contracted with a completely symmetric SO(2N) invariant d tensor of rank 4 is obtained. The three-point functions with two scalars are obtained for any finite N and \(k_2\) with \(k_1=1\). They are determined also in the large N ’t ...

Search for dark matter at \(\sqrt{s}=13~\mathrm{TeV}\) in final states containing an energetic photon and large missing transverse momentum with the ATLAS detector

Results of a search for physics beyond the Standard Model in events containing an energetic photon and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. As the number of events observed in data, corresponding to an integrated luminosity of 36.1 fb\(^{-1}\) of proton–proton collisions at a centre-of-mass energy of ...

Energy dependence of forward-rapidity \(\mathrm {J}/\psi \) and \(\psi \mathrm {(2S)}\) production in pp collisions at the LHC

We present results on transverse momentum (\(p_{\mathrm {\textsc {t}}}\)) and rapidity (\(y\)) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive \(\mathrm {J}/\psi \) and \(\psi \mathrm {(2S)}\) at forward rapidity (\(2.5<y<4\)) as well as \(\psi \mathrm {(2S)}\)-to-\(\mathrm {J}/\psi \) cross section ratios. These ...

Sterile neutrino portal to Dark Matter II: exact dark symmetry

We analyze a simple extension of the standard model (SM) with a dark sector composed of a scalar and a fermion, both singlets under the SM gauge group but charged under a dark sector symmetry group. Sterile neutrinos, which are singlets under both groups, mediate the interactions between the dark sector and the SM particles, and generate masses for the active neutrinos via the ...

Analytic expressions of amplitudes by the cross-ratio identity method

In order to obtain the analytic expression of an amplitude from a generic CHY-integrand, a new algorithm based on the so-called cross-ratio identities has been proposed recently. In this paper, we apply this new approach to a variety of theories including the non-linear sigma model, special Galileon theory, pure Yang–Mills theory, pure gravity, Born–Infeld theory, Dirac–Born–Infeld ...

Lorentz invariance violation in the neutrino sector: a joint analysis from big bang nucleosynthesis and the cosmic microwave background

We investigate constraints on Lorentz invariance violation in the neutrino sector from a joint analysis of big bang nucleosynthesis and the cosmic microwave background. The effect of Lorentz invariance violation during the epoch of big bang nucleosynthesis changes the predicted helium-4 abundance, which influences the power spectrum of the cosmic microwave background at the ...

Augmented superfield approach to gauge-invariant massive 2-form theory

We discuss the complete sets of the off-shell nilpotent (i.e. \(s^2_{(a)b} = 0\)) and absolutely anticommuting (i.e. \(s_b s_{ab} + s_{ab} s_b = 0\)) Becchi–Rouet–Stora–Tyutin (BRST) \((s_b)\) and anti-BRST \((s_{ab})\) symmetries for the \((3+1)\)-dimensional (4D) gauge-invariant massive 2-form theory within the framework of an augmented superfield approach to the BRST formalism. ...

A new relativistic viscous hydrodynamics code and its application to the Kelvin–Helmholtz instability in high-energy heavy-ion collisions

We construct a new relativistic viscous hydrodynamics code optimized in the Milne coordinates. We split the conservation equations into an ideal part and a viscous part, using the Strang spitting method. In the code a Riemann solver based on the two-shock approximation is utilized for the ideal part and the Piecewise Exact Solution (PES) method is applied for the viscous part. We ...

Dihadron production at the LHC: full next-to-leading BFKL calculation

The study of the inclusive production of a pair of charged light hadrons (a “dihadron” system) featuring high transverse momenta and well separated in rapidity represents a clear channel for the test of the BFKL dynamics at the Large Hadron Collider (LHC). This process has much in common with the well-known Mueller–Navelet jet production; however, hadrons can be detected at much ...

Top–down holographic G-structure glueball spectroscopy at (N)LO in N and finite coupling

The top–down type IIB holographic dual of large-N thermal QCD as constructed in Mia et al. (Nucl Phys B 839:187, 2010) involving a fluxed resolved warped deformed conifold, its delocalized type IIA Strominger–Yau–Zaslow-mirror (SYZ-mirror) as well as its M-theory uplift constructed in Dhuria and Misra (JHEP 1311:001, 2013) – both in the finite coupling (\(g_s\mathop {\sim }\limits ...