The chiral magnetic effect (CME) is usually believed to not receive higher-order corrections due to the nonrenormalization of the AVV triangle diagram in the framework of quantum field theory. However, the CME-relevant triangle, which is obtained by expanding the current-current correlation, requires zero momentum on the axial vertex and is not equivalent to the general AVV triangle when taking the zero-momentum limit owing to the infrared problem on the axial vertex. Therefore, it is still significant to check if there exists perturbative higher-order corrections to the current-current correlation. In this paper, we explicitly calculate the two-loop corrections of CME within the Nambu-Jona-Lasinio model with a Chern-Simons term, which ensures a consistent ${\mu }_5$. The result shows the two-loop corrections to the CME conductivity are zero, which confirms the nonrenomalization of CME conductivity.

The relation between the mixing matrices of leptons and quarks, $U_{\mathrm{PMNS}}\approx V_{\mathrm{CKM}}^{†}{U}_0$, where $U_0$ is a matrix of special forms [e.g., bimaximal (BM) and tribimaximal], can be a clue for understanding the lepton mixing and neutrino masses. It may imply the grand unification and the existence of a hidden sector with certain symmetry that generates $U_0$ and leads to the smallness of neutrino masses. We apply the residual symmetry approach to obtain $U_0$. The residual symmetries of both the visible and hidden sectors are ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$. Their embedding in a unified flavor group is considered. We find that there are only several possible structures of $U_0$, including the BM mixing and matrices with elements determined by the golden ratio. Realization of the BM scenario based on the SO(10) grand unified theory with the $S_4$ flavor group is presented. Generic features of this scenario are discussed, in particular, the prediction of $CP$ phase $144°\lesssim {\delta }_{\mathrm{CP}}\lesssim 210°$ in the minimal version.

Direct-detection experiments sensitive to low-energy electron recoils from sub-GeV dark matter interactions will also be sensitive to solar neutrinos via coherent neutrino-nucleus scattering (CNS), since the recoiling nucleus can produce a small ionization signal. Solar neutrinos constitute both an interesting signal in their own right and a potential background to a dark matter search that cannot be controlled or reduced by improved shielding, material purification and handling, or improved detector design. We explore these two possibilities in detail for semiconductor (silicon and germanium) and xenon targets, considering several possibilities for the unmeasured ionization efficiency at low energies. For dark-matter-electron-scattering searches, neutrinos start being an important background for exposures larger than $\sim 1–10\mathrm{kg}\text{−}\mathrm{years}$ in silicon and germanium, and for exposures larger than $\sim 0.1–1\mathrm{kg}\text{−}\mathrm{year}$ in xenon. For the absorption of bosonic dark matter (dark photons and axion-like particles) by electrons, neutrinos are most relevant for masses below $\sim 1\mathrm{keV}$ and again slightly more important in xenon. Treating the neutrinos as a signal, we find that the CNS of ${}^8\mathrm{B}$ neutrinos can be observed with $\sim 2\sigma$ significance with exposures of $\sim 2$, 7, and 20 kg-years in xenon, germanium, and silicon, respectively, assuming there are no other backgrounds. We give an example for how this would constrain nonstandard neutrino interactions. Neutrino components at lower energy can only be detected if the ionization efficiency is sufficiently large. In this case, observing pep neutrinos via CNS requires exposures $\gtrsim 10–100\mathrm{kg}\text{−}\mathrm{years}$ in silicon or germanium ($\sim 1000\mathrm{kg}$-years in xenon), and observing CNO neutrinos would require an order of magnitude more exposure. Only silicon could potentially detect ${}^7\mathrm{Be}$ neutrinos. These measurements would allow for a direct measurement of the electron-neutrino survival probability over a wide energy range.

We explore the model building and phenomenology of flavored gauge-mediation models of supersymmetry breaking in which the electroweak Higgs doublets and the $SU(2)$ messenger doublets are connected by a discrete non-Abelian symmetry. The embedding of the Higgs and messenger fields into representations of this non-Abelian Higgs-messenger symmetry results in specific relations between the Standard Model Yukawa couplings and the messenger-matter Yukawa interactions. Taking the concrete example of an ${\mathcal{S}}_3$ Higgs-messenger symmetry, we demonstrate that, while the minimal implementation of this scenario suffers from a severe $\mu /B_{\mu }$ problem that is well known from ordinary gauge mediation, expanding the Higgs-messenger field content allows for the possibility that $\mu$ and $B_{\mu }$ can be separately tuned, allowing for the possibility of phenomenologically viable models of the soft supersymmetry-breaking terms. We construct toy examples of this type that are consistent with the observed 125 GeV Higgs boson mass.

We study the capabilities of the short-baseline neutrino program at Fermilab to probe the unitarity of the lepton mixing matrix. We find the sensitivity to be slightly better than the current one. Motivated by the future DUNE experiment, we have also analyzed the potential of an extra liquid Argon near detector in the LBNF beamline. Adding such a near detector to the DUNE setup will substantially improve the current sensitivity on nonunitarity. This would help to remove $CP$ degeneracies due to the new complex phase present in the neutrino mixing matrix. We also study the sensitivity of our proposed setup to light sterile neutrinos for various configurations.

We study the ${\mathrm{\Lambda }}_c(2595{)}^{+}$ and ${\mathrm{\Sigma }}_c(2800{)}^0$ states as the $ND$ bound systems in the Bethe-Salpeter formalism in the ladder and instantaneous approximations. With the kernel induced by $\rho$, $\omega$ and $\sigma$ exchanges, we solve the Bethe-Salpeter equations for the $ND$ bound systems numerically and find that the bound states may exist. We assume that the observed states ${\mathrm{\Lambda }}_c(2595{)}^{+}$ and ${\mathrm{\Sigma }}_c(2800{)}^0$ are $S$-wave $ND$ molecular bound states and calculate the decay widths of ${\mathrm{\Lambda }}_c(2595{)}^{+}\to {\mathrm{\Sigma }}_c^0{\pi }^{+}$ and ${\mathrm{\Sigma }}_c(2800{)}^0\to {\mathrm{\Lambda }}_c^{+}{\pi }^{-}$.

We investigate protoneutron star matter using the state-of-the-art perturbative equation of state for cold and dense QCD in the presence of a fixed lepton fraction in which both electrons and neutrinos are included. Besides computing the modifications in the equation of state due to the presence of trapped neutrinos, we show that stable strange quark matter has a more restricted parameter space. We also study the possibility of nucleation of unpaired quark matter in the core of protoneutron stars by matching the lepton-rich QCD pressure onto a hadronic equation of state, namely TM1 with trapped neutrinos. Using the inherent dependence of perturbative QCD on the renormalization scale parameter, we provide a measure of the uncertainty in the observables we compute.

In this work, an independent and detailed statistical analysis of the double-Chooz experiment is performed. In order to have a thorough understanding of the implications of the double-Chooz data on both oscillation parameters ${\sin }^2(2{\theta }_{13})$ and $\mathrm{\Delta }{m}_{31}^2$, we decided to analyze the data corresponding to the Far detector, with no additional restriction. This differs from previous analyses, which only aim to estimate the mixing angle ${\theta }_{13}$, without mentioning the effects on $\mathrm{\Delta }{m}_{31}^2$. By doing this, confidence regions and best fit values are obtained for (${\sin }^2(2{\theta }_{13}),\mathrm{\Delta }{m}_{31}^2$). This analysis yields an out-of-order $\mathrm{\Delta }{m}_{31}^2$ minimum, which has already been mentioned in previous works, and it is corrected with the inclusion of additional restrictions. With such restrictions it is obtained that ${\sin }^2(2{\theta }_{13})=0.084_{-0.028}^{+0.030}$ and $\mathrm{\Delta }{m}_{31}^2=2.444_{-0.215}^{+0.187}\times {10}^{-3}{\mathrm{eV}}^2/{\mathrm{c}}^4$. Our analysis allows us to study the effects of the so-called “spectral bump” around 5 MeV; it is observed that a variation of this spectral bump may be able to move the $\mathrm{\Delta }{m}_{31}^2$ best fit value, in such a way that $\mathrm{\Delta }{m}_{31}^2$ takes the order of magnitude of the MINOS value. In other words, if we allow the variation of the spectral bump, then we may be able to determine both oscillation parameters using Far detector data only, with no further restrictions from other experiments. Finally, and with the intention of understanding the effects of the preliminary Near detector data, we performed two different analyses, aiming to eliminate the effects of the energy bump. As a consequence, it is found that unlike the Far detector analysis, the Near detector data may be able to fully determine both oscillation parameters by itself, resulting in ${\sin }^2(2{\theta }_{13})=0.095\pm 0.053$ and $\mathrm{\Delta }{m}_{31}^2=2.63_{-1.15}^{+0.98}\times {10}^{-3}{\mathrm{eV}}^2/{\mathrm{c}}^4$. The later analyses represent an improvement with respect to previous works, where additional constraints for $\mathrm{\Delta }{m}_{31}^2$ were necessary.

Various new measurements in charmless $B_{u,d,s}\to PP$ modes, where $P$ is a low lying pseudoscalar meson, are reported by Belle and LHCb. These include the rates of $B^0\to {\pi }^0{\pi }^0$, $\eta {\pi }^0$, $B_s\to {\eta }^{\prime }{\eta }^{\prime }$, $B^0\to K^{+}{K}^{-}$ and $B_s^0\to {\pi }^{+}{\pi }^{-}$ decays. Some of these modes are highly suppressed and are among the rarest $B$ decays. Direct $CP$ asymmetries on various modes are constantly updated. It is well known that direct $CP$ asymmetries and rates of suppressed modes are sensitive to final state interaction (FSI). As new measurements are reported and more data will be collected, it is interesting and timely to revisit the rescattering effects in $B_{u,d,s}\to PP$ states. We perform a ${\chi }^2$ analysis with all available data on $CP$-averaged rates and $CP$ asymmetries in ${\overline{B}}_{u,d,s}\to PP$ decays. Our numerical results are compared to data and those from factorization approach. The quality of the fit is improved significantly from the factorization results in the presence of rescattering. The relations on topological amplitudes and rescattering are explored and they help to provide a better understanding of the effects of FSI. As suggested by U(3) symmetry on topological amplitudes and FSI, a vanishing exchange rescattering scenario is considered. The exchange, annihilation, $u$-penguin, $u$-penguin annihilation, and some electroweak penguin amplitudes are enhanced significantly via annihilation and total annihilation rescatterings. In particular, the $u$-penguin annihilation amplitude is sizably enhanced by the tree amplitude via total annihilation rescattering. These enhancements affect rates and $CP$ asymmetries. Predictions can be checked in the near future.

A search for new physics using events containing an imbalance in transverse momentum and one or more energetic jets arising from initial-state radiation or the hadronic decay of $W$ or $Z$ bosons is presented. A data sample of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$, collected with the CMS detector at the LHC and corresponding to an integrated luminosity of $35.9{\mathrm{fb}}^{-1}$, is used. The observed data are found to be in agreement with the expectation from standard model processes. The results are interpreted as limits on the dark matter production cross section in simplified models with vector, axial-vector, scalar, and pseudoscalar mediators. Interpretations in the context of fermion portal and nonthermal dark matter models are also provided. In addition, the results are interpreted in terms of invisible decays of the Higgs boson and set stringent limits on the fundamental Planck scale in the Arkani-Hamed, Dimopoulos, and Dvali model with large extra spatial dimensions.

We present a proof that differential equations for Feynman loop integrals can always be derived in Baikov representation without involving dimension-shift identities. We moreover show that in a large class of two- and three-loop diagrams it is possible to avoid squared propagators in the intermediate steps of setting up the differential equations.

We consider a theory of scalar superfields in two dimensions with arbitrary superpotential. By imposing no particle production in tree-level scattering, we constrain the form of the admissible interactions, recovering a supersymmetric extension of the sinh-Gordon model.

We examine the gravitational collapse and black hole formation of multiple nonspherical configurations constructed from Szekeres dust models with positive spatial curvature that smoothly match to a Schwarzschild exterior. These configurations are made of an almost spherical central core region surrounded by a network of “pancake-like” overdensities and voids with spatial positions prescribed through standard initial conditions. We show that a full collapse into a focusing singularity, without shell crossings appearing before the formation of an apparent horizon, is not possible unless the full configuration becomes exactly or almost spherical. Seeking for black hole formation, we demand that shell crossings are covered by the apparent horizon. This requires very special fine-tuned initial conditions that impose very strong and unrealistic constraints on the total black hole mass and full collapse time. As a consequence, nonspherical nonrotating dust sources cannot furnish even minimally realistic toy models of black hole formation at astrophysical scales: demanding realistic collapse time scales yields huge unrealistic black hole masses, while simulations of typical astrophysical black hole masses collapse in unrealistically small times. We note, however, that the resulting time-mass constraint is compatible with early Universe models of primordial black hole formation, suitable in early dust-like environments. Finally, we argue that the shell crossings appearing when nonspherical dust structures collapse are an indicator that such structures do not form galactic mass black holes but virialize into stable stationary objects.

We present the Hamiltonian formalism for $f(T)$ gravity, and prove that the theory has $\frac{n(n-3)}{2}+1$ degrees of freedom (d.o.f.) in $n$ dimensions. We start from a scalar-tensor action for the theory, which represents a scalar field minimally coupled with the torsion scalar $T$ that defines the teleparallel equivalent of general relativity (TEGR) Lagrangian. $T$ is written as a quadratic form of the coefficients of anholonomy of the vierbein. We obtain the primary constraints through the analysis of the structure of the eigenvalues of the multi-index matrix involved in the definition of the canonical momenta. The auxiliary scalar field generates one extra primary constraint when compared with the TEGR case. The secondary constraints are the super-Hamiltonian and supermomenta constraints, that are preserved from the Arnowitt-Deser-Misner formulation of GR. There is a set of $\frac{n(n-1)}{2}$ primary constraints that represent the local Lorentz transformations of the theory, which can be combined to form a set of $\frac{n(n-1)}{2}-1$ first-class constraints, while one of them becomes second class. This result is irrespective of the dimension, due to the structure of the matrix of the brackets between the constraints. The first-class canonical Hamiltonian is modified due to this local Lorentz violation, and the only one local Lorentz transformation that becomes second-class pairs up with the second-class constraint $\pi \approx 0$ to remove one d.o.f. from the $n^2+1$ pairs of canonical variables. The remaining $\frac{n(n-1)}{2}+2n-1$ primary constraints remove the same number of d.o.f., leaving the theory with $\frac{n(n-3)}{2}+1$ d.o.f. This means that $f(T)$ gravity has only one extra d.o.f., which could be interpreted as a scalar d.o.f.

We study the relationship between the null geodesics and thermodynamic phase transition for the charged AdS black hole. In the reduced parameter space, we find that there exist nonmonotonic behaviors of the photon sphere radius and the minimum impact parameter for the pressure below its critical value. The study also shows that the changes of the photon sphere radius and the minimum impact parameter can serve as order parameters for the small-large black hole phase transition. In particular, these changes have an universal exponent of $\frac{1}{2}$ near the critical point for any dimension $d$ of spacetime. These results imply that there may exist universal critical behavior of gravity near the thermodynamic critical point of the black hole system.

We evolve a binary black hole system bearing a mass ratio of $q=m_1/m_2=2/3$ and individual spins of $S_1^z/m_1^2=0.95$ and $S_2^z/m_2^2=-0.95$ in a configuration where the large black hole has its spin antialigned with the orbital angular momentum, $L^z$, and the small black hole has its spin aligned with $L^z$. This configuration was chosen to measure the maximum recoil of the remnant black hole for nonprecessing binaries. We find that the remnant black hole recoils at just above $500\mathrm{km}/\mathrm{s}$, the largest recorded value from numerical simulations for aligned spin configurations. The remnant mass, spin, and gravitational waveform peak luminosity and frequency also provide a valuable point in parameter space for source modeling.

By employing the moduli space approximation, we analytically calculate the gravitational wave signatures emitted upon the merger of two extremally charged dilatonic black holes. We probe several values of the dilatonic coupling constant $a$, and find significant departures from the Einstein-Maxwell ($a=0$) counterpart studied in [Phys. Rev. D 96, 061501 (2017)]. For (low-energy) string theory black holes ($a=1$) there are no coalescence orbits and only a memory effect is observed, whereas for an intermediate value of the coupling ($a=1/\sqrt{3}$) the late-time merger signature becomes exponentially suppressed, compared to the polynomial decay in the $a=0$ case without a dilaton. Such an imprint shows a clear difference between the case with and without a scalar field (as, for example, predicted by string theory) in black hole mergers.

To date, the most precise tests of general relativity have been achieved through pulsar timing, albeit in the weak-field regime. Since pulsars are some of the most precise and stable “clocks” in the Universe, present observational efforts are focused on detecting pulsars in the vicinity of supermassive black holes (most notably in the Galactic Centre), enabling pulsar timing to be used as an extremely precise probe of strong-field gravity. In this paper, a mathematical framework to describe test-particle dynamics in general black-hole spacetimes is presented and subsequently used to study a binary system comprising a pulsar orbiting a black hole. In particular, taking into account the parameterization of a general spherically symmetric black-hole metric, general analytic expressions for both the advance of the periastron and for the orbital period of a massive test particle are derived. Furthermore, these expressions are applied to four representative cases of solutions arising in both general relativity and in alternative theories of gravity. Finally, this framework is applied to the Galactic center $S$-stars and four distinct pulsar toy models. It is shown that by adopting a fully general-relativistic description of test-particle motion which is independent of any particular theory of gravity, observations of pulsars can help impose better constraints on alternative theories of gravity than is presently possible.

We investigate boson star (BS) solutions in the Einstein-Proca theory with the quartic order self-interaction of the vector field $\lambda (A^{\mu }{\overline{A}}_{\mu }{)}^2/4$ and the mass term $\mu {\overline{A}}^{\mu }{A}_{\mu }/2$, where $A_{\mu }$ is the complex vector field and ${\overline{A}}_{\mu }$ is the complex conjugate of $A_{\mu }$, and $\lambda$ and $\mu$ are the coupling constant and the mass of the vector field, respectively. The vector BSs are characterized by the two conserved quantities, the Arnowitt-Deser-Misner (ADM) mass and the Noether charge associated with the global $U(1)$ symmetry. We show that in comparison with the case without the self-interaction $\lambda =0$, the maximal ADM mass and Noether charge increase for $\lambda >0$ and decrease for $\lambda <0$. We also show that there exists the critical central amplitude of the temporal component of the vector field above which there is no vector BS solution, and for $\lambda >0$ it can be expressed by the simple analytic expression. For a sufficiently large positive coupling $\mathrm{\Lambda }≔M_{\mathrm{pl}}^2\lambda /(8\pi {\mu }^2)\gg 1$, the maximal ADM mass and Noether charge of the vector BSs are obtained from the critical central amplitude and of $\mathcal{O}[\sqrt{\lambda }{M}_{\mathrm{pl}}^3/{\mu }^2\ln (\lambda M_{\mathrm{pl}}^2/{\mu }^2)]$, which is different from that of the scalar BSs, $\mathcal{O}(\sqrt{{\lambda }_{\varphi }}{M}_{\mathrm{pl}}^3/{\mu }_{\varphi }^2)$, where ${\lambda }_{\varphi }$ and ${\mu }_{\varphi }$ are the coupling constant and the mass of the complex scalar field.

We study the metric perturbations induced by a classical spinning particle moving along a circular orbit on a Schwarzschild background, limiting the analysis to effects which are first order in spin. The particle is assumed to move on the equatorial plane and has its spin aligned with the $z$ axis. The metric perturbations are obtained by using two different approaches, i.e., by working in two different gauges: the Regge-Wheeler gauge (using the Regge-Wheeler-Zerilli formalism) and a radiation gauge (using the Teukolsky formalism). We then compute the linear-in-spin contribution to the first-order self-force contribution to Detweiler’s redshift invariant up to the 8.5 post-Newtonian order. We check that our result is the same in both gauges, as appropriate for a gauge-invariant quantity, and agrees with the currently known 3.5 post-Newtonian results.