We consider a simple extension of the standard model, which could give a solution to its CP issues through both the Peccei–Quinn mechanism and the Nelson–Barr mechanism. Its low energy effective model coincides with the scotogenic model in the leptonic sector. Although leptogenesis is known not to work well at lower reheating temperature than \(10^9\) GeV in simple seesaw and scotogenic frameworks

We test the consistency of the data on the nucleon structure functions with analyticity and the Regge asymptotics of the virtual Compton amplitude. By solving a functional extremal problem, we derive an optimal lower bound on the maximum difference between the exact amplitude and the dominant Reggeon contribution for energies \(\nu \) above a certain high value \(\nu _h(Q^2)\). Considering in particular

A branching fraction measurement of the \({{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} \) decay is presented using proton–proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of \(5.0\,\text {fb} ^{-1} \). The branching fraction is found to be \({\mathcal {B}} ({{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} ) =(19.4 \pm \) \(1.8\pm 1.3 \pm 1.2)\times

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the \({\textsc {herwig}} \,7\) event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in \({\textsc {herwig}} \,7\), and are obtained from a fit to minimum-bias data collected by the CMS experiment at \(\sqrt{s}=0.9\), 7, and \(13 \,\text {Te}\text

Observing light or heavy charged Higgs bosons \(H^\pm \), lighter or heavier than the top quark, would be instant evidence of physics beyond the Standard Model. For this reason, in recent years searches for charged Higgs bosons have been in the center of attention of current colliders such as the CERN Large Hadron Collider (LHC). In spite of all efforts, no signal has been yet observed. Especially

A search for pair production of scalar leptoquarks, each decaying into either an electron or a muon and a top quark, is presented. This is the first leptoquark search using ATLAS data to investigate top-philic cross-generational couplings that could provide explanations for recently observed anomalies in B meson decays. This analysis targets high leptoquark masses which cause the decay products of

We consider interior static and spherically symmetric solutions in a gravity theory that extends the standard Hilbert–Einstein action with a Lagrangian constructed from a three-form field \(A_{\alpha \beta \gamma }\), which generates, via the field strength and a potential term, a new component in the total energy-momentum tensor of the gravitational system. We formulate the field equations in Schwarzschild

We present pion and kaon parton distribution functions from a global QCD analysis of the experimental data within the framework of dynamical parton model. We use the DGLAP equations with parton–parton recombination corrections and the valence input of uniform distribution which maximizes the information entropy. At our input scale \(Q_0^2\), there are no sea quark and gluon distributions. All the sea

We extend the basic formalism of mimetic-metric-torsion gravity theory, in a way that the mimetic scalar field can manifest itself geometrically as the source of not just the trace mode of torsion, but its axial (or, pseudo-trace) mode as well. Specifically, we consider the mimetic field to be (i) coupled explicitly to the well-known Holst extension of the Riemann–Cartan action, and (ii) identified

The classical and quantum dynamics of two particles constrained on \(S^1\) is discussed via Dirac’s approach. We show that when state is maximally entangled between two subsystems, the product of dispersion in the measurement reduces. We also quantify the upper bound on the external field \(\vec {B}\) such that \(\vec {B}\ge \vec {B}_{upper }\) implies no reduction in the product of dispersion pertaining

We present a method for the measurement of parameters of elastic and inelastic interactions of charmonium with hadrons. In this technique, we use femtoscopic analysis of charmonium-hadron correlations at low relative momentum and the Lednicky-Lyuboshitz analytical model to extract the interaction parameters. We argue that such a study is already feasible in the LHCb experiment at the LHC, and we discuss

The one-loop contributions to the trilinear neutral gauge boson couplings \(ZZV^*\) (\(V=\gamma ,Z,Z'\)), parametrized in terms of one CP-conserving \(f_5^{V}\) and one CP-violating \(f_4^{V}\) form factors, are calculated in models with CP-violating flavor changing neutral current couplings mediated by the Z gauge boson and an extra neutral gauge boson \(Z'\). Analytical results are presented in terms

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative inflation conditions proposed new consequences. On the other hand, we use anisotropic conditions and find new anisotropic constant-roll solutions with respect to noncommutative parameter. Also, we will plot

A unique feature of generalised parton distributions is their relation to the QCD energy–momentum tensor. In particular, they provide access to the mechanical properties of the proton i.e. the distributions of pressure and shear stress induced by its quark and gluon structure. In principle the pressure distribution can be experimentally determined in a model-independent way from a dispersive analysis

Ultra-pure NaI(Tl) crystals are the key element for a model-independent verification of the long standing DAMA result and a powerful means to search for the annual modulation signature of dark matter interactions. The SABRE collaboration has been developing cutting-edge techniques for the reduction of intrinsic backgrounds over several years. In this paper we report the first characterization of a

We study a spin 1/2 fermion in a thick braneworld in the context of teleparallel f(T, B) gravity. Here, f(T, B) is such that \(f_1(T,B)=T+k_1B^{n_1}\) and \(f_2(T,B)=B+k_2T^{n_2}\), where \(n_{1,2}\) and \(k_{1,2}\) are parameters that control the influence of torsion and the boundary term. We assume Yukawa coupling, where one scalar field is coupled to a Dirac spinor field. We show how the \(n_{1

We consider a model with gauged \(L_\mu ^{} - L_\tau ^{}\) symmetry in which the symmetry is spontaneously broken by a scalar field. The decay of the scalar boson into two new gauge bosons is studied as a direct consequence of the spontaneous symmetry breaking. Then, a possibility of searches for the gauge and scalar bosons through such a decay at the LHC experiment is discussed. We consider the case

The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction (\(\gamma (z)\)) is constant as a function of redshift. In this work, we look for a time evolution of \(\gamma (z)\) at \(R_{500}\) by using both the SPT-SZ and Planck Early SZ (ESZ) cluster data, in a model-independent

Motivated by two seminal models proposed to explain the Universe acceleration, this paper is devoted to study a hybrid model which is constructed through a generalized Chaplygin gas with the addition of a bulk viscosity. We call the model a viscous generalized Chaplygin gas (VGCG) and its free parameters are constrained through several cosmological data like the Observational Hubble Parameter, Type

In the framework of a mesoscopical model for dielectric media we provide an analytical description for the electromagnetic field confined in a cylindrical cavity containing a finite dielectric sample. This system is apted to simulate the electromagnetic field in a optic fiber, in which two different regions, a vacuum region and a dielectric one, appear. A complete description for the scattering basis

In the paper, we study the properties of the Z-boson hadronic decay width by using the \(\mathcal {O}(\alpha _s^4)\)-order quantum chromodynamics (QCD) corrections with the help of the principle of maximum conformality (PMC). By using the PMC single-scale approach, we obtain an accurate renormalization scale-and-scheme independent perturbative QCD (pQCD) correction for the Z-boson hadronic decay width

We consider a method for determining the QCD strong coupling constant using fits of perturbative predictions for event shape averages to data collected at the LEP, PETRA, PEP and TRISTAN colliders. To obtain highest accuracy predictions we use a combination of perturbative \({{{\mathcal {O}}}}(\alpha _{S}^{3})\) calculations and estimations of the \({{{\mathcal {O}}}}(\alpha _{S}^{4})\) perturbative

With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the \(d\sigma /dt\) data at \(\sqrt{s}= 13\) TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both t and b coordinates the amplitudes have terms identified as of non-perturbative and perturbative

The inclusive hadroproduction of a Higgs boson and of a jet, featuring large transverse momenta and well separated in rapidity, is proposed as a novel probe channel for the manifestation of the Balitsky–Fadin–Kuraev–Lipatov (BFKL) dynamics. Using the standard BFKL approach, with partial inclusion of next-to-leading order effects, predictions are presented for azimuthal Higgs-jet correlations and other

We investigate the transverse polarization of the \(\Lambda \) hyperon in the processes \(e^+e^-\rightarrow \Lambda ^\uparrow \pi ^\pm X\) and \(e^+e^-\rightarrow \Lambda ^\uparrow K^\pm X\) within the framework of the transverse momentum dependent (TMD) factorization. The transverse polarization is contributed by the convolution of the transversely polarizing fragmentation function (PFF) \(D_{1T}^\perp

The Abraham–Lorentz–Dirac theory predicts vanishing radiation reaction for uniformly accelerated charges. However, since an accelerating observer should detect thermal radiation, the charge should be seen absorbing photons in the accelerated frame which, if nothing else occurs, would influence its motion. This means that either there is radiation reaction seen in an inertial frame or there should be

We consider the metric-affine formulation of bumblebee gravity, derive the field equations, and show that the connection can be written as Levi-Civita of a disformally related metric in which the bumblebee field determines the disformal part. As a consequence, the bumblebee field gets coupled to all the other matter fields present in the theory, potentially leading to nontrivial phenomenological effects

In this work, we analyse the evolution of time-dependent traversable wormhole geometries in a Friedmann–Lemaître–Robertson–Walker background in the context of the scalar–tensor representation of hybrid metric-Palatini gravity. We deduce the energy–momentum profile of the matter threading the wormhole spacetime in terms of the background quantities, the scalar field, the scale factor and the shape function

The standard model leptons can be gauged in an anomaly free way by three possible gauge symmetries namely \({L_e-L_\mu }\), \({L_e-L_\tau }\), and \({L_\mu -L_\tau }\). Of these, \({L_e-L_\mu }\) and \({L_e-L_\tau }\) forces can mediate between the Sun and the planets and change the perihelion precession of planetary orbits. It is well known that a deviation from the \(1/r^2\) Newtonian force can give

We report on the measurements of the spectra of gamma radiation generated by 855 MeV electrons in bent silicon and germanium crystals at MAMI (MAinzer MIkrotron). The crystals were 15 \(\upmu \text {m}\) thick along the beam direction to ensure high deflection efficiency. Their (111) crystalline planes were bent by means of a piezo-actuated mechanical holder, which allowed to remotely change the crystal

Loop quantum gravity introduces two characteristic modifications in the classical constraints of general relativity: the holonomy and inverse-triad corrections. In this paper, a systematic construction of anomaly-free effective constraints encoding such corrections is developed for spherically symmetric spacetimes. The starting point of the analysis is a generic Hamiltonian constraint where free functions

In this paper, we show that a minimally coupled 3-form endowed with a proper potential can support a regular black hole interior. By choosing an appropriate form for the metric function representing the radius of the 2-sphere, we solve for the 3-form field and its potential. Using the obtained solution, we construct an interior black hole spacetime which is everywhere regular. The singularity is replaced

We provide a BRST formalism for the soft-collinear effective theory describing interactions of soft and collinear degrees of freedom in the presence of a hard interaction. In particular, we develop a BRST symmetry transformation for SCET theory. We further generalize the BRST formulation by making the transformation parameter field dependent. This establishes a mapping between several SCET actions

A non-monotonic behavior of the velocity gradient of a test particle revolving around a rapidly rotating black hole in the locally non-rotating frame of reference is known as the Aschenbach effect. This effect can serve as a distinguishing signature of rapidly rotating black holes, being potentially useful for the measurements of the astrophysical black hole spins. This paper is the generalization

\(SL(2,{\mathbb {Z}})\) invariant action for probe (m, n) string in \(AdS_3\times S^3\times T^4\) with mixed three-form fluxes can be described by an integrable deformation of an one-dimensional Neumann–Rosochatius (NR) system. We present the deformed features of the integrable model and study general class of rotating and pulsating solutions by solving the integrable equations of motion. For the rotating

It is shown that production of low-mass \(e^+e^-\)-pairs in ultraperipheral nuclear collisions is enhanced due to the Sommerfeld–Gamow–Sakharov (SGS) factor. This effect is especially strong near the threshold of creation of unbound \(e^+e^-\)-pairs with low masses in the two-photon fusion. Coulomb attraction of the non-relativistic components of such pairs may lead to the increased intensity of 511

We consider the growth rate of matter perturbations in the Einstein dark energy theory. The theory consists of the Einstein–Hilbert Lagrangian plus the trace of the energy momentum tensor, coupled non-minimally to a dynamical vector field. We will show that the theory has three fixed points corresponding to the dust, radiation and de Sitter universes. Due to the present of trace of the energy–momentum

In this work, we employ the light-cone QCD sum rule to calculate the magnetic dipole moments of the \(P_c(4440)\), \(P_c(4457)\) and \(P_{cs}(4459)\) pentaquark states by considering them as the diquark–diquark–antiquark and molecular pictures with quantum numbers \(J^P = \frac{3}{2}^-\), \(J^P = \frac{1}{2}^-\) and \(J^P = \frac{1}{2}^-\), respectively. In the analyses, we use the diquark–diquark–antiquark

We consider a gravitational theory with an additional non-minimal coupling between baryonic matter fields and geometry. The coupling is second order in the energy momentum tensor and can be seen as a generalization of the energy–momentum squared gravity model. We will add a constraint through a Lagrange multiplier to ensure the conservation of the energy–momentum tensor. Background cosmological implications

Inspired by the stringy quintessence F-term problem we highlight a generic contribution to the effective moduli masses that arises due to kinetic mixings between the moduli and the quintessence sector. We then proceed to discuss few supergravity toy models that accommodate such effect, and point out possible shortcomings. Interestingly, in the standard 2-derivative supergravity action there is no term

The gravitational dynamics of a collapsing matter configuration which is simultaneously radiating heat flux is studied in f(R) gravity. Three particular functional forms in f(R) gravity are considered to show that it is possible to envisage boundary conditions such that the end state of the collapse has a weak singularity and that the matter configuration radiates away all of its mass before collapsing

A viable model for inflation driven by a torsion function in a Friedmann background is presented. The scalar spectral index in the interval \(0.92\lesssim n_{s}\lesssim 0.97\) is obtained in order to satisfy the initial conditions for inflation. The post inflationary phase is also studied, and the analytical solutions obtained for scale factor and energy density generalizes that ones for a matter dominated

We use the framework of asymptotically safe quantum gravity to derive predictions for scalar leptoquark solutions to the \(b\rightarrow s\) and \(b\rightarrow c\) flavor anomalies. The presence of an interactive UV fixed point in the system of gauge and Yukawa couplings imposes a set of boundary conditions at the Planck scale, which allows one to determine low-energy values of the leptoquark Yukawa

Many eigenvalue matrix models possess a peculiar basis of observables that have explicitly calculable averages. This explicit calculability is a stronger feature than ordinary integrability, just like the cases of quadratic and Coulomb potentials are distinguished among other central potentials, and we call it superintegrability. As a peculiarity of matrix models, the relevant basis is formed by the

In the present paper, we have investigated the motion of charged particles together with magnetic dipoles to determine how well the spacetime deviation parameter \(\epsilon \) and external uniform magnetic field can mimic the spin of a rotating Kerr black hole. Investigation of charged particle motion has shown that the deviation parameter \(\epsilon \) in the absence of an external magnetic fields

Intense fluxes of reactor antineutrinos offer a unique possibility to probe the fully coherent character of elastic neutrino scattering off atomic nuclei. In this regard, detectors face the challenge to register tiny recoil energies of a few keV at the maximum. The Conus experiment was installed in 17.1 m distance from the reactor core of the nuclear power plant in Brokdorf, Germany, and was designed

The main focus of this paper is to explore the possibility of providing a new family of exact solutions for suitable anisotropic spherically symmetric systems in the realm of general relativity involving the embedding spherically symmetric static metric into the five-dimensional pseudo-Euclidean space. In this regard, we ansatz a new metric potential \(\lambda (r)\), and we obtained the other metric

We develop a model to study the \(D^0 \rightarrow K^- \pi ^+ \eta \) weak decay, starting with the color favored external emission and Cabibbo favored mode at the quark level. A less favored internal emission decay mode is also studied as a source of small corrections. Some pairs of quarks are allowed to hadronize producing two pseudoscalar mesons, which posteriorly are allowed to interact to finally

We consider a two-atom system uniformly moving through a circular ring at an ultra-relativistic speed and weakly interacting with the common quantum fields. Two kinds of fields are introduced here: a massive free scalar field and electromagnetic (EM) vector fields. The vacuum fluctuations of the quantum fields give rise to the resonance Casimir–Polder interaction (RCPI) in the system. Using the quantum

The propagation length of high-energy photons through the Universe is limited by \(e^{+}e^{-}\) pair production on the extragalactic background radiation. Previous studies reported discrepancies between predicted and observed attenuation, suggesting explanations in terms of new physics. However, these effects are dominated by a limited number of observed sources, while many do not show any discrepancy

We study collective features of the scattering of gravitational waves on relic wormholes and normal matter objects. We derive and solve the GW energy transport equation and show that the scattered signal lies in the same frequency spectrum bands as the basic signal. The scattering forms long living tails which always accompany the basic signal and have a universal form. The scattering on normal matter

A correction to this paper has been published: https://doi.org/10.1140/epjc/s10052-021-08902-6

In the present work we study the implications at the future \(e^+e^-\) colliders of the modified interaction vertices WWH, WWHH, HHH and HHHH within the context of the non-linear effective field theory given by the Electroweak Chiral Lagrangian. These vertices are given by four parameters, a, b, \(\kappa _3\) and \(\kappa _4\), respectively, that are independent and without any constraint from symmetry

Long-lived particles decaying to \({e ^\pm } {\mu ^\mp } {\nu } \), with masses between 7 and \(50 \,\text {GeV/}c^2 \) and lifetimes between 2 and \(50 \,\text {ps} \), are searched for by looking at displaced vertices containing electrons and muons of opposite charges. The search is performed using \(5.4 \,\text {fb} ^{-1} \) of \(p \) \(p \) collisions collected with the LHCb detector at a centre-of-mass

We extend the already existing two-loop calculation of the effective bottom-Yukawa coupling in the MSSM. In addition to the resummation of the dominant corrections for large values of tg\(\beta \), we include the subleading terms related to the trilinear Higgs coupling \(A_b\) and contributions induced by the electroweak gauge couplings. This calculation has been extended to the NNLO corrections to

We provide a complete characterization of the metric Killing bundles (or metric bundles) of the Kerr geometry. Metric bundles can be generally defined for axially symmetric spacetimes with Killing horizons and, for the case of Kerr geometries, are sets of black holes (BHs) or black holes and naked singularities (NSs) geometries. Each metric of a bundle has an equal limiting photon (orbital) frequency

We explore the properties of polynomial Lagrangians for chiral p-forms previously proposed by the last named author, and in particular, provide a self-contained treatment of the symmetries and equations of motion that shows a great economy and simplicity of this formalism. We further use analogous techniques to construct polynomial democratic Lagrangians for general p-forms where electric and magnetic

The production of \(\pi ^{\pm }\), \(\mathrm{K}^{\pm }\), \(\mathrm{K}^{0}_{S}\), \(\mathrm{K}^{*}(892)^{0}\), \(\mathrm{p}\), \(\phi (1020)\), \(\Lambda \), \(\Xi ^{-}\), \(\Omega ^{-}\), and their antiparticles was measured in inelastic proton–proton (pp) collisions at a center-of-mass energy of \(\sqrt{s}\) = 13 TeV at midrapidity (\(|y|<0.5\)) as a function of transverse momentum (\(p_{\mathrm{T}}\))

We consider a Lorentz violating scalar field cosmological model given by the modified Einstein-æther theory defined in Weyl integrable geometry. The existence of exact and analytic solutions is investigated for the case of a spatially flat Friedmann–Lemaître–Robertson–Walker background space. We show that the theory admits cosmological solutions of special interests. In addition, we prove that the

We present the results of a non-perturbative determination of the improvement coefficient \(c_\mathrm{V}\) and the renormalisation factor \(Z_\mathrm{V}\), which define the renormalised vector current in three-flavour \(\mathrm{O}(a)\) improved lattice QCD with Wilson quarks and tree-level Symanzik-improved gauge action. In case of the improvement coefficient, we consider both lattice descriptions