We present the first analytic computation of the Detweiler-Barack-Sago gauge-invariant redshift function for a small mass in eccentric equatorial orbit around a spinning black hole. Our results give the redshift contributions that mix eccentricity and spin effects, through second order in eccentricity, second order in spin parameter, and the eight-and-a-half post-Newtonian order.

This paper is concerned with the construction and analysis of boson stars in the context of nonminimal derivative coupling theories. In particular, we embed our model in the biscalar extension of Horndeski gravity, considering a scalar field theory displaying a nonminimally coupled kinetic term given by the Einstein tensor. We focus on the case where the potential is given by a mass term only and when a six order self-interaction is included. In the latter case we consider specific couplings in the self-interacting terms in such a way that our self-interaction is given by a positive definite potential presenting two degenerate local vacua. We show how solutions can be obtained and we compare its principal properties with standard configurations constructed with the usual minimally coupled kinetic term.

Nonthermal histories for the early universe have received notable attention as they are a rich source of phenomenology, while also being well motivated by top-down approaches to beyond the Standard Model physics. The early (pre-big bang nucleosynthesis) matter phase in these models leads to enhanced growth of density perturbations on sub-Hubble scales. Here, we consider whether primordial black hole formation associated with the enhanced growth is in conflict with existing observations. Such constraints depend on the tilt of the primordial power spectrum, and we find that nonthermal histories are tightly constrained in the case of a significantly blue spectrum. Alternatively, if dark matter is taken to be of nonthermal origin, we can restrict the primordial power spectrum on scales inaccessible to cosmic microwave background and large scale structure observations. We establish constraints for a wide range of scalar masses (reheat temperatures) with the most stringent bounds resulting from the formation of ${10}^{15}\mathrm{g}$ black holes. These black holes would be evaporating today and are constrained by FERMI observations. We also consider whether the breakdown of the coherence of the scalar oscillations on subhorizon scales can lead to a Jean’s pressure preventing black hole formation and relaxing our constraints. Our main conclusion is that primordial black hole constraints, combined with existing constraints on nonthermal weakly interacting massive particles, favor a primordial spectrum closer to scale invariance or a red tilted spectrum.

We consider force-free plasma waves launched by the motion of conducting material through a magnetic field. We develop a spacetime-covariant formalism for perturbations of a uniform magnetic field and show how the transverse motion of a conducting fluid acts as a source. We show that fast-mode waves are sourced by the compressibility of the fluid, with incompressible fluids launching a pure-Alfvén outflow. Remarkably, this outflow can be written down in closed form for an arbitrary time-dependent, nonaxisymmetric incompressible flow. The instantaneous flow velocity is imprinted on the magnetic field and transmitted away at the speed of light, carrying detailed information about the conducting source at the time of emission. These results can be applied to transients in pulsar outflows and to jets from neutron stars orbiting in the magnetosphere of another compact object. We discuss jets from moving conductors in some detail.

We have completed the one-loop renormalisation of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) allowing for and comparing between different renormalisation schemes. A special attention is paid to on-shell schemes. We study a variety of these schemes based on alternative choices of the physical input parameters. In this paper we present our approach to the renormalization of the NMSSM and report on our results for the neutralino-chargino and sfermion sectors. We will borrow some results from our study of the Higgs sector whose full discussion is left for a separate publication. We have implemented the setup for all the sectors of the NMSSM within SloopS, a code for the automatic computation of one-loop corrections initially developed for the standard model and the MSSM. Among the many applications that allows the code, we present here the one-loop corrections to neutralino masses and to partial widths of neutralinos and charginos into final states with one gauge boson. One-loop electroweak and QCD corrections to the partial widths of third generation sfermions into a fermion and a chargino or a neutralino are also computed.

A lattice QCD study of the strong decay width and coupling constant of decuplet baryons to an octet baryon-pion state is presented. The transfer matrix method is used to obtain the overlap of lattice states with decuplet baryon quantum numbers on the one hand and octet baryon-pion quantum numbers on the other as an approximation of the matrix element of the corresponding transition. By making use of leading-order effective field theory, the coupling constants as well as the widths for the various decay channels are determined. The transitions studied are $\mathrm{\Delta }\to \pi N$, ${\mathrm{\Sigma }}^{*}\to \mathrm{\Lambda }\pi$, ${\mathrm{\Sigma }}^{*}\to \mathrm{\Sigma }\pi$ and ${\mathrm{\Xi }}^{*}\to \mathrm{\Xi }\pi$. We obtain results for two ensembles of $N_f=2+1$ dynamical fermion configurations: one using domain wall valence quarks on a staggered sea at a pion mass of 350 MeV and a box size of 3.4 fm and a second one using domain wall sea and valence quarks at pion mass 180 MeV and box size 4.5 fm.

Recent studies have shown that the well-established ${\mathrm{\Lambda }}_c(2595)$ resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors ($N_c$) expansion. We examine three different models fulfilling two body unitarity in coupled-channels, and adopting renormalization schemes where the mass of the ${\mathrm{\Lambda }}_c(2595)$ resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the ${\mathrm{\Lambda }}_c(2595)$ depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the ${\mathrm{\Lambda }}_c(2595)$ in the large $N_c$ expansion, within a scheme involving only the $\pi {\mathrm{\Sigma }}_c$ and $K{\mathrm{\Xi }}_c^{\prime }$ channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of $N_c$, we show that for moderate $N_c>3$ values, the mass and width of the ${\mathrm{\Lambda }}_c(2595)$ deviate from those of a genuine $qqq$ baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the ${\mathrm{\Lambda }}_c(2595)$, in the strict $N_c\to \infty$ limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) subdominant $qqq$ component in the ${\mathrm{\Lambda }}_c(2595)$ resonance wave function, which would become dominant when the number of colors gets sufficiently large.

Estimated are the contributions of the following mechanisms responsible for the decay $f_1(1285)\to f_0(980){\pi }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$: (1) the contribution of the $a_0^0(980)-f_0(980)$ mixing, $f_1(1285)\to a_0(980){\pi }^0\to (K^{+}{K}^{-}+K^0{\overline{K}}^0){\pi }^0\to f_0(980){\pi }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$, (2) the contribution of the transition $f_1(1285)\to (K^{+}{K}^{-}+K^0{\overline{K}}^0){\pi }^0\to f_0(980){\pi }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$, arising due to the pointlike decay $f_1(1285)\to K\overline{K}{\pi }^0$, (3) the contribution of the transition $f_1(1285)\to (K^{*}\overline{K}+{\overline{K}}^{*}K)\to (K^{+}{K}^{-}+K^0{\overline{K}}^0){\pi }^0\to f_0(980){\pi }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$, where $K^{*}=K^{*}(892)$, and (4) the contribution of the transition $f_1(1285)\to (K_0^{*}\overline{K}+{\overline{K}}_0^{*}K)\to (K^{+}{K}^{-}+K^0{\overline{K}}^0){\pi }^0\to f_0(980)\to {\pi }^{+}{\pi }^{-}{\pi }^0$, where $K_0^{*}=K_0^{*}(800)$ (or $\kappa$) and $K_0^{*}(1430)$. These mechanisms break the conservation of the isospin due to the nonzero mass difference of the $K^{+}$ and $K^0$ mesons. They result in the appearance of the narrow resonance structure in the ${\pi }^{+}{\pi }^{-}$ mass spectrum in the region of the $K\overline{K}$ thresholds, with the width $\approx 2m_{K^0}-2m_{K^{+}}\approx 8\mathrm{MeV}$. The observation of such a structure in experiment is the direct indication on the $K\overline{K}$ loop mechanism of the breaking of the isotopic invariance. We point out that existing data should be more precise, and it is difficult to explain them using the single specific mechanism from those listed above. Taking the decay $f_1(1285)\to f_0(980){\pi }^0\to {\pi }^{+}{\pi }^{-}{\pi }^0$ as the example, we discuss the general approach to the description of the $K\overline{K}$ loop mechanism of the breaking of isotopic invariance.

Amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, $F_A(q^2)$, which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of $F_A$ from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of $F_A$. A complete error budget for the nucleon isovector axial radius leads to $r_A^2=0.46(22){\mathrm{fm}}^2$, with a much larger uncertainty than determined in the original analyses. The quasielastic neutrino-neutron cross section is determined as $\sigma ({\nu }_{\mu }n\to {\mu }^{-}p){|}_{E_{\nu }=1\mathrm{GeV}}=10.1(0.9)\times {10}^{-39}{\mathrm{cm}}^2$. The propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using MINERvA data and the GENIE event generator. These techniques can be readily extended to other amplitudes and processes.

Neutrinoless double-beta decay is a beyond the Standard Model process that would indicate that neutrinos are Majorana fermions, and the lepton number is not conserved. It could be interesting to use the neutrinoless double-beta decay observations to distinguish between several beyond Standard Model mechanisms that could contribute to this process. Accurate nuclear structure calculations of the nuclear matrix elements necessary to analyze the decay rates could be helpful to narrow down the list of contributing mechanisms. We investigate the information one can get from the angular and energy distribution of the emitted electrons and from the half-lives of several isotopes, assuming that the right-handed currents exist. For the analysis of these distributions, we calculate the necessary nuclear matrix elements using shell model techniques, and we explicitly consider interference terms.

We develop an operator description, much like thermofield dynamics, for quantum field theories on a real time path with an arbitrary parameter $\sigma (0\le \sigma \le \beta )$. We point out new features which arise when $\sigma \ne \frac{\beta }{2}$ in that the Hilbert space develops a natural, modified inner product different from the standard Dirac inner product. We construct the Bogoliubov transformation which connects the doubled vacuum state at zero temperature to the thermal vacuum in this case. We obtain the thermal Green’s function (propagator) for the real massive Klein-Gordon theory as an expectation value in this thermal vacuum (with a modified inner product). The factorization of the thermal Green’s function follows from this analysis. We also discuss, in the main text as well as in two appendices, various other interesting features which arise in such a description.

Horndeski’s theory of gravity is the most general scalar-tensor theory with a single scalar whose equations of motion contain at most second-order derivatives. A subsector of Horndeski’s theory known as “Fab Four” gravity allows for dynamical self-tuning of the quantum vacuum energy, and therefore it has received particular attention in cosmology as a possible alternative to the $\mathrm{\Lambda }\mathrm{CDM}$ model. Here we study compact stars in Fab Four gravity, which includes as special cases general relativity (“George”), Einstein-dilaton-Gauss-Bonnet gravity (“Ringo”), theories with a nonminimal coupling with the Einstein tensor (“John”), and theories involving the double-dual of the Riemann tensor (“Paul”). We generalize and extend previous results in theories of the John class and were not able to find realistic compact stars in theories involving the Paul class.

The impact of biasing schemes on the clustering of tracers of the large-scale structure is analytically studied in the weakly nonlinear regime. For this purpose, we use the one-loop approximation of the integrated perturbation theory together with the renormalized bias functions of various, physically motivated Lagrangian bias schemes. These include the halo, peaks, and excursion set peaks model, for which we derive useful formulas for the evaluation of their renormalized bias functions. The shapes of the power spectra and correlation functions are affected by the different bias models at the level of a few percent on weakly nonlinear scales. These effects are studied quantitatively both in real and redshift space. The amplitude of the scale-dependent bias in the presence of primordial non-Gaussianity also depends on the details of the bias models. If left unaccounted for, these theoretical uncertainties could affect the robustness of the cosmological constraints extracted from galaxy clustering data.

Neutrinos are copiously emitted from neutrino-cooled black hole accretion disks playing a fundamental role in their evolution, as well as in the production of gamma ray bursts and r-process nucleosynthesis. The black hole generates a strong gravitational field able to change the properties of the emerging neutrinos. We study the influence of the black hole spin on the structure of the neutrino surfaces, neutrino luminosities, average neutrino energies, and event counts at SuperK. We consider several disk models and provide estimates that cover different black hole efficiency scenarios. We discuss the influence of the detector’s inclination with respect to the axis of the torus on neutrino properties. We find that tori around spinning black holes have larger luminosities, energies, and rates compared to tori around static black holes and that the inclination of the observer causes a reduction in the luminosities and detection rates but an increase in the average energies.

BepiColombo is a joint ESA/JAXA mission to Mercury with challenging objectives regarding geophysics, geodesy, and fundamental physics. The Mercury Orbiter Radioscience Experiment (MORE) is one of the on-board experiments, including three different but linked experiments: gravimetry, rotation, and relativity. The aim of the relativity experiment is the measurement of the post-Newtonian parameters. Thanks to accurate tracking between Earth and spacecraft, the results are expected to be very precise. However, the outcomes of the experiment strictly depend on our “knowledge” about solar system: ephemerides; number of bodies (planets, satellites, and asteroids); and their masses. In this paper we describe a semianalytic model used to perform a covariance analysis to quantify the effects on the relativity experiment, due to the uncertainties of Solar System bodies’ parameters. In particular, our attention is focused on the Nordtvedt parameter $\eta$ used to parametrize the strong equivalence principle violation. After our analysis we estimated $\sigma [\eta ]⪅4.5\times {10}^{-5}$, which is about 1 order of magnitude larger than the “ideal” case where masses of planets and asteroids have no errors. The current value, obtained from ground-based experiments and lunar laser ranging measurements, is $\sigma [\eta ]\approx 4.4\times {10}^{-4}$. Therefore, we conclude that, even in the presence of uncertainties on Solar System parameters, the measurement of $\eta$ by MORE can improve the current precision of about 1 order of magnitude.

We argue that the diphoton excess recently reported by ATLAS and CMS can be explained, along with several anomalies seen in the flavor sector, in models where a Standard Model singlet scalar resonance with mass $M_S\approx 750\mathrm{GeV}$ is produced in gluon fusion via loops containing a scalar color-triplet leptoquark $\varphi$. For a leptoquark mass $M_{\varphi }\lesssim 1\mathrm{TeV}$, the production cross section is naturally in the 10 fb range. A large $S\to \gamma \gamma$ branching ratio can be obtained by coupling the scalar $S$ to new color-singlet fermions $\chi$ with electroweak scale masses, which can be part of an $SU(2{)}_L$ multiplet, whose neutral component has the right mass and quantum numbers to be a dark matter candidate. Our model reveals a connection between flavor anomalies, the nature of dark matter and a new scalar, which acts as a mediator to the dark sector. The loop-mediated decay $S\to {\tau }^{+}{\tau }^{-}$ could be a striking signature of this model.

Typical searches for supersymmetry cannot test models in which the two lightest particles have a small (“compressed”) mass splitting, due to the small momentum of the particles produced in the decay of the second-to-lightest particle. However, data sets with large missing transverse momentum ($E_{\mathrm{T}}^{\mathrm{miss}}$) can generically search for invisible particle production and therefore provide constraints on such models. We apply data from the ATLAS monojet ($\text{jet}+E_{\mathrm{T}}^{\text{miss}}$) and vector-boson-fusion (forward jets and $E_{\mathrm{T}}^{\text{miss}}$) searches to such models. In all cases, experimental limits are at least five times weaker than theoretical predictions.