Primordial black holes (PBHs) can be produced by the perturbations that exit the horizon during the inflationary phase. While inflation models predict the power spectrum of the perturbations in Fourier space, the PBH abundance depends on the probability distribution function of density perturbations in real space. To estimate the PBH abundance in a given inflation model, we must relate the power spectrum in Fourier space to the probability density function in real space by coarse graining the perturbations with a window function. However, there are uncertainties on what window function should be used, which could change the relation between the PBH abundance and the power spectrum. This is particularly important in considering PBHs with mass $30M_{\odot }$, which account for the LIGO events because the required power spectrum is severely constrained by the observations. In this paper, we investigate how large an influence the uncertainties on the choice of a window function has over the power spectrum required for LIGO PBHs. As a result, it is found that the uncertainties significantly affect the prediction for the stochastic gravitational waves induced by the second-order effect of the perturbations. In particular, the pulsar timing array constraints on the produced gravitational waves could disappear for the real-space top-hat window function.

We revisit the Almheiri-Polchinski dilaton gravity model from a two-dimensional (2D) bulk perspective. We describe a peculiar feature of the model, namely the pattern of conformal symmetry breaking using bulk Killing vectors, a covariant definition of mass and the flow between different vacua of the theory. We show that the effect of the symmetry breaking is both the generation of an infrared scale (a mass gap) and to make local the Goldstone modes associated with the asymptotic symmetries of the 2D spacetime. In this way a nonvanishing central charge is generated in the dual conformal theory, which accounts for the microscopic entropy of the 2D black hole. The use of covariant mass allows to compare energetically the two different vacua of the theory and to show that at zero temperature the vacuum with a constant dilaton is energetically preferred. We also translate in the bulk language several features of the dual CFT discussed by Maldacena et al. The uplifting of the 2D model to ($d+2$)-dimensional theories exhibiting hyperscaling violation is briefly discussed.

We show that an inflation model in which a spectator axion field is coupled to an $SU(2)$ gauge field produces a large three-point function (bispectrum) of primordial gravitational waves, $B_h$, on the scales relevant to the cosmic microwave background experiments. The amplitude of the bispectrum at the equilateral configuration is characterized by $B_h/P_h^2=\mathcal{O}(10)\times {\mathrm{\Omega }}_A^{-1}$, where ${\mathrm{\Omega }}_A$ is a fraction of the energy density in the gauge field and $P_h$ is the power spectrum of gravitational waves produced by the gauge field.

The cosmic-ray flux of antiprotons is measured with high precision by the space-borne particle spectrometers AMS-02. Its interpretation requires a correct description of the dominant production process for antiprotons in our Galaxy, namely, the interaction of cosmic-ray proton and helium with the interstellar medium. In light of new cross section measurements by the NA61 experiment of $p+p\to \overline{p}+X$ and the first ever measurement of $p+\mathrm{He}\to \overline{p}+X$ by the LHCb experiment, we update the parametrization of proton-proton and proton-nucleon cross sections. We find that the LHCb $p\mathrm{He}$ data constrain a shape for the cross section at high energies and show for the first time how well the rescaling from the $pp$ channel applies to a helium target. By using $pp$, $p\mathrm{He}$ and $p\mathrm{C}$ data we estimate the uncertainty on the Lorentz invariant cross section for $p+\mathrm{He}\to \overline{p}+X$. We use these new cross sections to compute the source term for all the production channels, considering also nuclei heavier than He both in cosmic rays and the interstellar medium. The uncertainties on the total source term are up to $\pm 20\%$ and slightly increase below antiproton energies of 5 GeV. This uncertainty is dominated by the $p+p\to \overline{p}+X$ cross section, which translates into all channels since we derive them using the $pp$ cross sections. The cross sections to calculate the source spectra from all relevant cosmic-ray isotopes are provided in Supplemental Material. We finally quantify the necessity of new data on antiproton production cross sections, and pin down the kinematic parameter space which should be covered by future data.

In a strong magnetic field, a high-energy photon can be absorbed and then produce an electron-positron pair. The produced electron/positron will in turn radiate a high-energy photon via synchrotron radiation, which then initiates a cascade. We built a one-dimensional Monte Carlo code to study the development of the cascade especially after it reaches the saturated status, when almost all the energy of the primary particles transfers to the photons. The photon spectrum in this status has a cutoff due to the absorption by magnetic fields, which is much sharper than the exponential one. Below the cutoff, the spectral energy distribution (SED) manifest itself as a broken power-law with a spectral index of 0.5 and 0.125, respectively, below and above the broken energy. The SED can be fitted by a simple analytical function, which is solely determined by the product of the cascade scale $R$ and the magnetic field perpendicular to the motion of the particle $B_{\perp }$, with an accuracy better than 96%. The similarity of the spectrum to that from the cascade in an isotropic black-body photon field is also studied.

Screening mechanisms are essential features of dark energy models mediating a fifth force on large scales. We study the regime of strong scalar field nonlinearities, known as Vainshtein screening, in the most general scalar-tensor theories propagating a single scalar degree of freedom. We first develop an effective approach to parametrize cosmological perturbations beyond linear order for these theories. In the quasistatic limit, the fully nonlinear effective Lagrangian contains six independent terms, one of which starts at cubic order in perturbations. We compute the two gravitational potentials around a spherical body. Outside and near the body, screening reproduces standard gravity, with a modified gravitational coupling. Inside the body, the two potentials are different and depend on the density profile, signalling the breaking of the Vainshtein screening. We provide the most general expressions for these modifications, revising and extending previous results. We apply our findings to show that the combination of the GW170817 event, the Hulse-Taylor pulsar and stellar structure physics, constrain the parameters of these general theories at the level of ${10}^{-1}$, and of Gleyzes-Langlois-Piazza-Vernizzi theories at the level of ${10}^{-2}$.

In the production of the Higgs through a bottom-quark loop, the transverse momentum distribution of the Higgs at large $P_T$ is complicated by its dependence on two other important scales: the bottom quark mass $m_b$ and the Higgs mass $m_H$. A strategy for simplifying the calculation of the cross section at large $P_T$ is to calculate only the leading terms in its expansion in $m_b^2/P_T^2$. In this paper, we consider the bottom-quark-loop contribution to the parton process $q\overline{q}\to H+g$ at leading order in ${\alpha }_s$. We show that the leading power of $1/P_T^2$ can be expressed in the form of a factorization formula that separates the large scale $P_T$ from the scale of the masses. All the dependence on $m_b$ and $m_H$ can be factorized into a distribution amplitude for $b\overline{b}$ in the Higgs, a distribution amplitude for $b\overline{b}$ in a real gluon, and an end point contribution. The factorization formula can be used to organize the calculation of the leading terms in the expansion in $m_b^2/P_T^2$ so that every calculation involves at most two scales.

We provide the complete set of radiative corrections to the Dalitz decays ${\eta }^{(\prime )}\to {\ell }^{+}{\ell }^{-}\gamma$ beyond the soft-photon approximation, i.e., over the whole range of the Dalitz plot and with no restrictions on the energy of a radiative photon. The corrections inevitably depend on the ${\eta }^{(\prime )}\to {\gamma }^{*}{\gamma }^{(*)}$ transition form factors. For the singly virtual transition form factor appearing, e.g., in the bremsstrahlung correction, recent dispersive calculations are used. For the one-photon-irreducible contribution at the one-loop level (for the doubly virtual form factor), we use a vector-meson-dominance-inspired model while taking into account the $\eta \text{−}{\eta }^{\prime }$ mixing.

The present work is intended to study the double-differential cross section of the inclusive single-jet production as the functions of the transverse momentum and the rapidity of the jet in the high-energy hadron-hadron collisions. The angular-ordering-constraint $k_t$-factorization framework is used to calculate the above cross section that is available experimentally. The conditions are taken in accordance with the LHC experiments. The results are compared and analyzed using the existing CMS LHC data. The scheme-dependent unintegrated parton distribution functions (UPDF) of Kimber-Martin-Ryskin (KMR) and Martin-Ryskin-Watt (MRW) in the leading-order and the next-to-leading order (NLO) are used to predict the input partonic UPDF. The utilized phenomenological frameworks prove to be relatively successful in generating satisfactory results compared to the different experiment data, such as CMS (8 and 13 TeV). Extensive discussions and comparisons are made regarding the behavior of the contributing partonic subprocesses. Finally, it is shown that the application of the KMR UPDF to the single-jet differential cross sections have better agreement with the CMS data; on the other hand, they are very similar to those of NLO-MRW.

In this paper we investigate, within the standard model extension framework, the influence of Lorentz- and $CPT$-violating terms on gravitational quantum states of ultracold neutrons. Using a semiclassical wave packet, we derive the effective nonrelativistic Hamiltonian which describes the neutrons vertical motion by averaging the contributions from the perpendicular coordinates to the free falling axis. We compute the physical implications of the Lorentz- and $CPT$-violating terms on the spectra. The comparison of our results with those obtained in the GRANIT experiment leads to an upper bound for the symmetries-violation $c_{\mu \nu }^n$ coefficients. We find that ultracold neutrons are sensitive to the $a_i^n$ and $e_i^n$ coefficients, which thus far are unbounded by experiments in the neutron sector. We propose two additional problems involving ultracold neutrons which could be relevant for improving our current bounds; namely, gravity-resonance spectroscopy and neutron whispering gallery wave.

The one-loop contributions to the decays of the $CP$-odd and $CP$-even scalar bosons $A\to Z\gamma \gamma$ and $\varphi \to Z\gamma \gamma$ ($\varphi =h$, $H$) are calculated within the framework of $CP$-conserving two-Higgs doublet models (THDMs), where they are induced by box and reducible Feynman diagrams. The behavior of the corresponding branching ratios are then analyzed within the type-II THDM in a region of the parameter space around the alignment limit and still consistent with experimental data. It is found that the $A\to Z\gamma \gamma$ branching ratio is only relevant when $m_A>m_H+m_Z$, but it is negligible otherwise. For $m_A>600\mathrm{GeV}$ and $t_{\beta }\simeq O(1)$, $\mathrm{BR}(A\to Z\gamma \gamma )$ can reach values of the order of ${10}^{-5}-{10}^{-4}$, but it decreases by about 1 order of magnitude as $t_{\beta }$ increases up to 10. A similar behavior is followed by the $H\to Z\gamma \gamma$ decay, which only has a non-negligible branching ratio when $m_H>m_A+m_Z$ and can reach the level of ${10}^{-4}-{10}^{-3}$ for $m_H>600\mathrm{GeV}$ and $t_{\beta }\simeq O(1)$. We also estimated the branching ratios of these rare decays in the type-I THDM, where they can be about 1 order of magnitude larger than in type-II THDM. As far as the $h\to Z\gamma \gamma$ decay is concerned, since the properties of this scalar boson must be nearly identical to those of the SM Higgs boson, the $h\to Z\gamma \gamma$ branching ratio does not deviate significantly from the SM prediction, where it is negligibly small, of the order of ${10}^{-9}$. This result is in agreement with previous calculations.

The triplet scalars $(\mathrm{\Delta }={\mathrm{\Delta }}^{++},{\mathrm{\Delta }}^{+},{\mathrm{\Delta }}^0)$ utilized in the so-called type-II seesaw model to explain the lightness of neutrinos, would generate nonstandard interactions (NSI) for a neutrino propagating in matter. We investigate the prospects to probe these interactions in long baseline neutrino oscillation experiments. We analyze the upper bounds that the proposed DUNE experiment might set on the nonstandard parameters and numerically derive upper bounds, as a function of the lightest neutrino mass, on the ratio the mass $M_{\mathrm{\Delta }}$ of the triplet scalars, and the strength $|{\lambda }_{\varphi }|$ of the coupling $\varphi \varphi \mathrm{\Delta }$ of the triplet $\mathrm{\Delta }$ and conventional Higgs doublet $\varphi$. We also discuss the possible misinterpretation of these effects as effects arising from a nonunitarity of the neutrino mixing matrix and compare the results with the bounds that arise from the charged lepton flavor violating processes.

Two different effective field theory descriptions of the pion-nucleon scattering data are constructed to describe the region of the Roper resonance. In one, the resonance is the result of strong rescattering between coupled meson-baryon channels, while in the other the resonance has a large bare-baryon (or quark-model-like) component. The predictions of these two scenarios are compared with the latest lattice QCD simulation results in this channel. We find that the second scenario is not consistent with lattice QCD results, whereas the first agrees with those constraints. In that preferred scenario, the mass of the quark-model-like state is approximately 2 GeV, with the infinite-volume Roper resonance best described as a resonance generated dynamically through strongly coupled meson-baryon channels.

We formulate $\mathcal{N}=2^{*}$ supersymmetric Yang-Mills theory on a Euclidean spacetime lattice using the method of topological twisting. The lattice formulation preserves one scalar supersymmetry charge at finite lattice spacing. The lattice theory is also local, gauge invariant and free from doublers. We can use the lattice formulation of $\mathcal{N}=2^{*}$ supersymmetric Yang-Mills to study finite temperature nonperturbative sectors of the theory and thus validate the gauge-gravity duality conjecture in a nonconformal theory.

As a basic requirement of the renormalization group invariance, any physical observable must be independent of the choice of both the renormalization scheme and the initial renormalization scale. In this paper, we show that by using the newly suggested $C$-scheme coupling, one can obtain a demonstration that the principle of maximum conformality prediction is scheme-independent to all-orders for any renormalization schemes, thus satisfying all of the conditions of the renormalization group invariance. We illustrate these features for the nonsinglet Adler function and for $\tau$ decay to $\nu +$ hadrons at the four-loop level.

We introduce the semiclassical Wehrl entropy for the nucleon as a measure of complexity of the multiparton configuration in phase space. This gives a new perspective on the nucleon tomography. We evaluate the entropy in the small-$x$ region and compare with the quantum von Neumann entropy. We also argue that the growth of entropy at small $x$ is eventually slowed down due to the Pomeron loop effect.

We study the phenomenological impact of the interaction of spin-2 fields with those of the Standard Model in a model independent framework up to next-to-next-to-leading order in perturbative quantum chromodynamics. We use the invariant mass distribution of the pair of leptons produced at the Large Hadron Collider to demonstrate this. A minimal scenario where the spin-2 fields couple to two gauge invariant operators with different coupling strengths has been considered. These operators not being conserved show very different ultraviolet behavior increasing the searches options of spin-2 particles at the colliders. We find that our results using the higher order quantum corrections stabilize the predictions with respect to renormalization and factorization scales. We also find that corrections are appreciable which need to be taken into account in such searches at the colliders.

Pion production is a significant component of the signal in accelerator-based neutrino experiments. Over the last years, the MiniBooNE, T2K, and MINERvA collaborations have reported a substantial amount of data on (anti)neutrino-induced pion production on the nucleus. However, a comprehensive and consistent description of the whole data set is still missing. We aim at improving the current understanding of neutrino-induced pion production on the nucleus. To this end, the comparison of experimental data with theoretical predictions, preferably based on microscopic models, is essential to disentangle the different reaction mechanisms involved in the process. To describe single-pion production, we use a hybrid model that combines low- and a high-energy approaches. The low-energy model contains resonances and background terms. At high invariant masses, a high-energy model based on a Regge approach is employed. The model is implemented in the nucleus using the relativistic plane wave impulse approximation (RPWIA). We present a comparison of the hybrid-RPWIA and low-energy model with the recent neutrino-induced charged-current $1{\pi }^{+}$-production cross section on water reported by T2K. In order to judge the impact of final-state interactions (FSI), we confront our results with those of the nuwro Monte Carlo generator. The hybrid-RPWIA model and nuwro results compare favorably to the data, albeit that FSI are not included in the former. The need of a high-energy model at T2K kinematics is made clear. These results complement our previous work [Phys. Rev. D 97, 013004 (2018)], in which we compared the models to the MINERvA and MiniBooNE $1{\pi }^{+}$ data. The hybrid-RPWIA model tends to overpredict both the T2K and MINERvA data in kinematic regions where the largest suppression due to FSI is expected and agrees remarkably well with the data in other kinematic regions. On the contrary, the MiniBooNE data are underpredicted over the whole kinematic range.

We propose a holographic duality between a 2 dimensional (2d) chiral superconformal field theory and a certain theory of supergravity in 3d with flatspace boundary conditions that is obtained as a double scaling limit of a parity breaking theory of supergravity. We show how the asymptotic symmetries of the bulk theory reduce from the “despotic” super Bondi-Metzner-Sachs algebra (or equivalently the inhomogeneous super Galilean conformal algebra) to a single copy of the super-Virasoro algebra in this limit and also reproduce the same reduction from a study of null vectors in the putative 2d dual field theory.