In the simplest potentially realistic renormalizable variants of the flipped $SU(5)$ unified model the right-handed neutrino masses are conveniently generated by means of the Witten’s two-loop mechanism. As a consequence, the compactness of the underlying scalar sector provides strong correlations between the low-energy flavor observables such as neutrino masses and mixing and the flavor structure of the fermionic currents governing the baryon and lepton number violating nucleon decays. In this study, the associated two-loop Feynman integrals are fully evaluated and, subsequently, are used to draw quantitative conclusions about the central observables of interest such as the proton decay branching ratios and the absolute neutrino mass scale.

In this work, we study the hidden-strange molecular states composed of a baryon and a vector meson in a coupled-channel $N\rho -N\omega -N\varphi -\mathrm{\Lambda }{K}^{*}-\mathrm{\Sigma }{K}^{*}$ interaction. With the help of the effective Lagrangians which coupling constants are determined by the SU(3) symmetry, the interaction is constructed and inserted into the quasipotential Bethe-Salpeter equation to search for poles in the complex plane, which correspond to molecular states. Two poles are found with a spin parity $3/2^{-}$ near the $N\rho$ and the $\mathrm{\Sigma }{K}^{*}$ thresholds, which can be related to the $N(1700)$ and the $N(2100)$, respectively. No pole near the $N\varphi$ threshold can be found if direct interaction between a nucleon and $\varphi$ meson is neglected according to the OZI rule. After introducing the QCD van der Waals force between a nucleon and $\varphi$ meson, a narrow state can be produced near the $N\varphi$ threshold. Inclusion of the QCD van der Waals force changes the line shape of the invariant mass spectrum in the $N\varphi$ channel leading to a worse agreement with the present low-precision data. Future experiments at BelleII, JLab, and other facilities will be very helpful to clarify the existence of these possible hidden-strange molecular states.

Semileptonic decays of the ${\mathrm{\Xi }}_b$ baryon are studied in the framework of the relativistic quark-diquark model based on the quasipotential approach. The weak decay form factors are calculated with the comprehensive account of all relativistic effects without employing nonrelativistic and heavy quark expansions. On this basis, differential and total decay rates as well as different asymmetry parameters are calculated for the heavy-to-heavy ${\mathrm{\Xi }}_b\to {\mathrm{\Xi }}_c\ell {\nu }_{\ell }$ and heavy-to-light ${\mathrm{\Xi }}_b\to \mathrm{\Lambda }\ell {\nu }_{\ell }$ semileptonic decays. Predictions for the ratios of such decays involving $\tau$ lepton and muon are presented.

We compute thermal one-point functions in Maxwell’s theory sourced by vorticity for the zilch and its higher spin extensions via the Kubo formalism. This leads to a generalization of the recent results of [M. N. Chernodub, A. Cortijo, and K. Landsteiner, Phys. Rev. D 98, 065016 (2018)] to any spin, and their value suggests a relation with possible anomalies for the higher spin tower of currents.

Treating general relativity as an effective field theory, we compute the leading-order quantum corrections to the orbits and gravitational-wave emission of astrophysical compact binaries. These corrections are independent of the (unknown) nature of quantum gravity at high energies, and generate a phase shift and amplitude increase in the observed gravitational-wave signal. Unfortunately (but unsurprisingly), these corrections are undetectably small, even in the most optimistic observational scenarios.

In this paper, we show that any solution of general relativity (GR) that can be rendered spatially flat by a coordinate change is also a solution of the self-accelerating branch of the minimal theory of massive gravity (MTMG), with or without matter. We then for the first time obtain black hole and star solutions in a theory of massive gravity that agree with the corresponding solutions in GR and that are free from strong coupling issues. This in particular implies that the parametrized post-Newtonian parameters ${\beta }^{\mathrm{PPN}}$ and ${\gamma }^{\mathrm{PPN}}$ are unity, as in GR. We further show how these solutions can be embedded in a cosmological setting. While cosmological scales have already been considered in previous works, this is the first study of the phenomenology at shorter scales of the self-accelerating branch of MTMG.

We suppose that the observed neutrino masses can be parametrized by a lepton number violating dimension-five operator, and calculate the mixing of double insertions of this operator into lepton flavor changing dimension-six operators of the standard model effective theory. This allows to predict the log-enhanced, but $m_{\nu }^2$-suppressed lepton flavor violation that is generic to high-scale Majorana neutrino mass models. We also consider the two Higgs doublet model, where the second Higgs allows the construction of three additional dimension-five operators, and evaluate the corresponding anomalous dimensions. The sensitivity of current searches for lepton flavor violation to these additional Wilson coefficients is then examined.

Since 2003 many new hadrons, including the lowest-lying positive-parity charm-strange mesons $D_{s0}^{*}(2317)$ and $D_{s1}(2460)$, have been observed that do not conform with quark-model expectations. It was recently demonstrated that various puzzles in the charm-meson spectrum find a natural resolution if the SU(3) multiplets for the lightest scalar and axial-vector states, among them the $D_{s0}^{*}(2317)$ and the $D_{s1}(2460)$, owe their existence to the nonperturbative dynamics of Goldstone-boson scattering off $D_{(s)}$ and $D_{(s)}^{*}$ mesons. Most importantly the ordering of the lightest strange and nonstrange scalars becomes natural. We demonstrate for the first time that this mechanism is strongly supported by the recent high quality data on the $B^{-}\to D^{+}{\pi }^{-}{\pi }^{-}$ provided by the LHCb experiment. This implies that the lowest quark-model positive-parity charm mesons, together with their bottom counterparts, if realized in nature, do not form the ground-state multiplet. This is similar to the pattern that has been established for the scalar mesons made from light up, down, and strange quarks, where the lowest multiplet is considered to be made of states not described by the quark model. In a broader view, the hadron spectrum must be viewed as more than a collection of quark-model states.

Stimulated by the new experimental LHCb findings associated with the ${\mathrm{\Omega }}_c$ states, some of which we have described in a previous work as being dynamically generated through meson-baryon interaction, we have extended this approach to make predictions for new ${\mathrm{\Xi }}_{cc}$ molecular states in the $C=2$, $S=0$, and $I=1/2$ sector. These states manifest themselves as poles in the solution of the Bethe-Salpeter equation in coupled channels. The kernels of this equation were obtained using general Lagrangians coming from the hidden local gauge symmetry or massive Yang-Mills theory, and the interactions are dominated by the exchange of light vector mesons. The extension of this approach to the heavy sector stems from the realization that the dominant interaction corresponds to having the heavy quarks as spectators, which implies the preservation of the heavy quark symmetry. As a result, we get several states: three states from the pseudoscalar meson-baryon interaction with $J^P=1/2^{-}$, and masses around 3840, 4080 and 4090 MeV, and two at 3920 and 4150 MeV for $J^P=3/2^{-}$. Furthermore, from the vector meson-baryon interaction we get three states degenerate with $J^P=1/2^{-}$ and $3/2^{-}$ from 4220 MeV to 4290 MeV, and two more states around 4280 and 4370 MeV, degenerate with $J^P=1/2^{-},3/2^{-}$, and $5/2^{-}$.

A search for a time-varying ${\overline{\nu }}_e$ signal was performed with 621 days of data acquired by the Daya Bay Reactor Neutrino Experiment over 704 calendar days. The time spectrum of the measured ${\overline{\nu }}_e$ flux normalized to its prediction was analyzed with a Lomb-Scargle periodogram, which yielded no significant signal for periods ranging from 2 hours to nearly 2 years. The normalized time spectrum was also fit for a sidereal modulation under the Standard Model Extension (SME) framework to search for Lorentz and $CPT$ violation (LV-CPTV). Limits were obtained for all six flavor pairs $\overline{e}\overline{\mu },\overline{e}\overline{\tau }$, $\overline{\mu }\overline{\tau }$, $\overline{e}\overline{e},\overline{\mu }\overline{\mu }$ and $\overline{\tau }\overline{\tau }$ by fitting them one at a time, constituting the first experimental constraints on the latter three. Daya Bay’s high statistics and unique layout of multiple directions from three pairs of reactors to three experimental halls allowed the simultaneous constraint of individual SME LV-CPTV coefficients without assuming others contribute negligibly, a first for a neutrino experiment.

We consider collision of particles in a wormhole near its throat. Particles come from the opposite mouths. If the lapse function is small enough there, the energy $E$ of debris at infinity grows unbounded, so we are faced with the so-called super-Penrose process. This requires the existence of the ergoregion, so a wormhole should be rotating.

Gravitational waves emitted from compact binary coalescence can be subject to wave diffraction if they are gravitationally lensed by an intervening mass clump whose Schwarzschild time scale matches the wave period. Waves in the ground-based frequency band $f\sim 10–10^3\mathrm{Hz}$ are sensitive to clumps with masses $M_E\sim {10}^2–10^3{M}_{\odot }$ enclosed within the impact parameter. These can be the central parts of low mass $M_L\sim {10}^3–10^6{M}_{\odot }$ dark matter halos, which are predicted in cold dark matter scenarios but are challenging to observe. Neglecting finely-tuned impact parameters, we focus on lenses aligned generally on the Einstein scale for which multiple lensed images may not form in the case of an extended lens. In this case, diffraction induces amplitude and phase modulations whose sizes $\sim 10\%–20\%$ are small enough so that standard matched filtering with unlensed waveforms do not degrade, but are still detectable for events with high signal-to-noise ratio. We develop and test an agnostic detection method based on dynamic programming, which does not require a detailed model of the lensed waveforms. For pseudo-Jaffe lenses aligned up to the Einstein radius, we demonstrate that a pair of fully upgraded aLIGO/Virgo detectors can extract diffraction imprints from binary black hole mergers out to $z_s\sim 0.2–0.3$. The prospect will improve dramatically for a third-generation detector for which binary black hole mergers out to $z_s\sim 2–4$ will all become valuable sources.

With the recent advent of multimessenger gravitational-wave astronomy and in anticipation of more sensitive, next-generation gravitational-wave detectors, we investigate the dynamics, gravitational-wave emission, and nucleosynthetic yields of numerous eccentric binary neutron-star mergers having different equations of state. For each equation of state, we vary the orbital properties around the threshold of the immediate merger, as well as the binary mass ratio. In addition to a study of the gravitational-wave emission including $f$-mode oscillations before and after the merger, we couple the dynamical ejecta output from the simulations to the nuclear-reaction network code skynet to compute nucleosynthetic yields and compare to the corresponding results in the case of a quasicircular merger. We find that the amount and velocity of dynamically ejected material are always much larger than in the quasicircular case, reaching maximal values of $M_{\mathrm{ej},\max }\sim 0.1M_{\odot }$ and $v_{\max }/c\sim 0.75$. At the same time, the properties of this material are rather insensitive to the details of the orbit, such as the pericenter distance or postencounter apoastron distance. Furthermore, while the composition of the ejected matter depends on the orbital parameters and on the equation of state, the relative nucleosynthetic yields do not, thus indicating that kilonova signatures could provide information on the orbital properties of dynamically captured neutron-star binaries.

We derive the Schrödinger-Newton equation as the nonrelativistic limit of the Einstein-Dirac equations. Our analysis relaxes the assumption of spherical symmetry, made in an earlier work in the literature, while deriving this limit. Since the spin of the Dirac field couples naturally to torsion, we generalize our analysis to the Einstein-Cartan-Dirac equations, again recovering the Schrödinger-Newton equation.

Almost a third of the cosmic baryons are “missing” at low redshifts, as they reside in the invisible warm-hot intergalactic medium (WHIM). The thermal Sunyaev-Zeldovich (tSZ) effect, which measures the line-of-sight integral of the plasma pressure, can potentially detect this WHIM, although its expected signal is hidden below the noise. Extragalactic dispersion measures (DMs)—obtained through observations of fast radio bursts (FRBs)—are excellent tracers of the WHIM, as they measure the column density of plasma, regardless of its temperature. Here we propose cross correlating DMs and tSZ maps as a new way to find and characterize the missing baryons in the WHIM. Our method relies on the precise ($\sim$ arcminute) angular localization of FRBs to assign each burst a DM and a $y$ parameter. We forecast that the signal from the WHIM should be confidently detected in a cross-correlation analysis of $\sim {10}^4$ FRBs, expected to be gathered in a year of operation of the upcoming CHIME and HIRAX radio arrays, confirming the recent tentative detections of filamentary WHIM. Using this technique, future CMB probes (which might lower the tSZ noise) could determine both the temperature of the WHIM and its evolution to within tens of percent. Altogether, DM-tSZ cross correlations hold great promise for studying the baryons in the local Universe.

Strong gravitational lensing has been identified as a promising astrophysical probe to study the particle nature of dark matter. In this paper we present a detailed study of the power spectrum of the projected mass density (convergence) field of substructure in a Milky Way-sized halo. This power spectrum has been suggested as a key observable that can be extracted from strongly-lensed images and yield important clues about the matter distribution within the lens galaxy. We use two different $N$-body simulations from the ETHOS framework: one with cold dark matter and another with self-interacting dark matter and a cutoff in the initial power spectrum. Despite earlier works that identified $k\gtrsim 100{\mathrm{kpc}}^{-1}$ as the most promising scales to learn about the particle nature of dark matter we find that even at lower wave numbers—which are actually within reach of observations in the near future—we can gain important information about dark matter. Comparing the amplitude and slope of the power spectrum on scales $0.1\lesssim k/{\mathrm{kpc}}^{-1}\lesssim 10$ from lenses at different redshifts can help us distinguish between cold dark matter and other exotic dark matter scenarios that alter the abundance and central densities of subhalos. Furthermore, by considering the contribution of different mass bins to the power spectrum we find that subhalos in the mass range $10^7-{10}^8{\mathrm{M}}_{\odot }$ are on average the largest contributors to the power spectrum signal on scales $2\lesssim k/{\mathrm{kpc}}^{-1}\lesssim 15$, despite the numerous subhalos with masses $>{10}^8{\mathrm{M}}_{\odot }$ in a typical lens galaxy. Finally, by comparing the power spectra obtained from the subhalo catalogs to those from the particle data in the simulation snapshots we find that the seemingly-too-simple halo model is in fact a fairly good approximation to the much more complex array of substructure in the lens.

The origin and nature of the ultrahigh energy cosmic rays remains a mystery. However, considerable progress has been achieved in past years due to observations performed by the Pierre Auger Observatory and Telescope Array. Above ${10}^{18}\mathrm{eV}$ the observed energy spectrum presents two features: a hardening of the slope at $\sim {10}^{18.6}\mathrm{eV}$, which is known as the ankle, and a suppression at $\sim {10}^{19.6}\mathrm{eV}$. The composition inferred from the experimental data, interpreted by using the current high energy hadronic interaction models, seems to be light below the ankle, showing a trend to heavier nuclei for increasing values of the primary energy. Also, the anisotropy information is consistent with an extragalactic origin of this light component that would dominate the spectrum below the ankle. Therefore, the models that explain the ankle as the transition from the galactic and extragalactic components are disfavored by present data. Recently, it has been proposed that this light component originates from the photodisintegration of more energetic and heavier nuclei in the source environment. The formation of the ankle can also be explained by this mechanism. In this work, we study in detail this general scenario, but in the context of the central region of active galaxies. In this case, the cosmic rays are accelerated near the supermassive black hole present in the central region of these types of galaxies, and the photodisintegration of heavy nuclei takes place in the radiation field that surrounds the supermassive black hole.

A classical nonrelativistic effective field theory for a real Lorentz-scalar field $\varphi$ is most conveniently formulated in terms of a complex scalar field $\psi$. There have been two derivations of effective Lagrangians for the complex field $\psi$ in which terms in the effective potential were determined to order $({\psi }^{*}\psi {)}^4$. We point out an error in each of the effective Lagrangians. After correcting the errors, we demonstrate the equivalence of the two effective Lagrangians by verifying that they both reproduce $T$-matrix elements of the relativistic real scalar field theory and by also constructing a redefinition of the complex field $\psi$ that transforms terms in one effective Lagrangian into the corresponding terms of the other.