In a recent paper we performed a comprehensive study of the impact of new-physics operators with different Lorentz structures on $\overline{B}\to D^{*+}{l}^{-}\overline{{\nu }_{\ell }}$ decays, $\ell =e^{-}$, ${\mu }^{-}$, ${\tau }^{-}$, involving the $b\to cl{\nu }_{\ell }$ transition. In this work we extend the previous calculation by including tensor operators. In the case of $\overline{B}\to D^{*+}{\tau }^{-}\overline{{\nu }_{\tau }}$, we present the full three-angle and $q^2$ angular distribution with tensor new-physics operators with complex couplings. The impact of the tensor operators on various observables in the angular distribution, specially the azimuthal observables including the $CP$ violating triple product asymmetries are discussed. It is shown that these azimuthal observables are very useful in discriminating different new-physics operators. Finally we consider new-physics leptoquark models with tensor interactions and show how the presence of additional scalar operators modify the predictions of the tensor operators.

The IceCube Collaboration has recently announced the discovery of ultrahigh energy neutrino events. These neutrinos can be used to probe their production source, as well as leptonic mixing parameters. In this work, we have used the first IceCube data to constrain the leptonic $CP$ violating phase ${\delta }_{CP}$. For this, we have analyzed the data in the form of flux ratios. We find that the fit to ${\delta }_{CP}$ depends on the assumptions made on the production mechanism of these astrophyscial neutrinos. Consequently, we also use this data to impose constraints on the sources of the neutrinos.

We study the acceleration of an electric current-carrying and axially symmetric string loop initially oscillating in the vicinity of a Schwarzschild black hole embedded in an external asymptotically uniform magnetic field. The plane of the string loop is orthogonal to the magnetic field lines and the acceleration of the string loop occurs due to the transmutation effect turning in the deep gravitational field the internal energy of the oscillating strings to the energy of their translational motion along the axis given by the symmetry of the black hole spacetime and the magnetic field. We restrict our attention to the motion of string loop with energy high enough, when it can overcome the gravitational attraction and escape to infinity. We demonstrate that for the current-carrying string loop the transmutation effect is enhanced by the contribution of the interaction between the electric current of the string loop and the external magnetic field and we give conditions that have to be fulfilled for an efficient acceleration. The Schwarzschild black hole combined with the strong external magnetic field can accelerate the current-carrying string loop up to the velocities close to the speed of light $v\sim c$. Therefore, the string loop transmutation effect can potentially well serve as an explanation for acceleration of highly relativistic jets observed in microquasars and active galactic nuclei.

We perform a careful investigation of the problem of physically realistic gravitational collapse of massive stars in $f(R)$ gravity. We show that the extra matching conditions that arise in the modified gravity impose strong constraints on the stellar structure and thermodynamic properties. In our opinion these constraints are unphysical. We prove that no homogeneous stars with nonconstant Ricci scalar can be matched smoothly with a static exterior for any nonlinear function $f(R)$. Therefore, these extra constraints make classes of physically realistic collapse scenarios in general relativity, nonadmissible in these theories. We also find an exact solution for an inhomogeneous collapsing star in the Starobinski model that obeys all the energy and matching conditions. However, we argue that such solutions are fine-tuned and unstable to matter perturbations. Possible consequences on black hole physics and the cosmic censorship conjecture are also discussed.

Recent work in the literature has studied the restricted three-body problem within the framework of effective-field-theory models of gravity. This paper extends such a program by considering the full three-body problem, when the Newtonian potential is replaced by a more general central potential which depends on the mutual separations of the three bodies. The general form of the equations of motion is written down, and they are studied when the interaction potential reduces to the quantum-corrected central potential considered recently in the literature. A recursive algorithm is found for solving the associated variational equations, which describe small departures from given periodic solutions of the equations of motion. Our scheme involves repeated application of a $2\times 2$ matrix of first-order linear differential operators.

We study the autocorrelations of observables constructed from the topological charge density, such as the topological charge on a time slice or in a subvolume, using a series of hybrid Monte Carlo simulations of pure SU(3) gauge theory with both periodic and open boundary conditions. We show that the autocorrelation functions of these observables obey a simple diffusion equation and we measure the diffusion coefficient, finding that it scales like the square of the lattice spacing. We use this result and measurements of the rate of tunneling between topological charge sectors to calculate the scaling behavior of the autocorrelation times of these observables on periodic and open lattices. There is a characteristic lattice spacing at which open boundary conditions become worthwhile for reducing autocorrelations and we show how this lattice spacing is related to the diffusion coefficient, the tunneling rate, and the lattice Euclidean time extent.

We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute in twist-3 collinear factorization at leading order in perturbation theory. All nonperturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. However, the magnitude of the computed asymmetries tends to be larger than the data. Potential reasons for this outcome are identified. We also give predictions for future experiments and highlight in particular the unique opportunities at an electron ion collider.

We find out the smearing/transfer functions that relate a local bulk operator with its boundary values at a cutoff surface located at $z=z_0$ of the anti–de Sitter Poincaré patch. We compare these results with de Sitter counterparts and comment on their connections with a corresponding construction for dS/CFT. As the boundary values can help define the required field theory at $z=z_0$ and encode bulk locality in terms of it, our work can provide key information about the holographic renormalization group in the context of AdS/CFT.

If light-flavor squarks and gluinos are indeed heavy and chargino pair production is plagued with overwhelming backgrounds, pair production and associated production of stops and charginos will become the key signatures in the upcoming LHC runs. We present fully automated next-to-leading order predictions for heavy flavor squark production at the LHC, including stop-chargino associated production, based on MadGolem. We compute the total and differential next-to-leading order rates for a variety of minimal supersymmetric standard model scenarios with a light third generation. We focus on theoretical uncertainties on differential rates, including a comparison to multijet merging and the impact of bottom parton densities for stop-chargino associated production. We find that for the associated production channel the rates can reach tens of femtobarns, but the scale dependence does not provide a conservative estimate of the theoretical uncertainties.

Skyrmions can be transformed into lumps or baby Skyrmions by being trapped inside a domain wall. Here we find that they can also be transformed into sine-Gordon kinks when confined by vortices, resulting in confined Skyrmions. We show this both by an effective field theory approach and by direct numerical calculations. The existence of these trapped and confined Skyrmions does not rely on higher-derivative terms when the host solitons are flat or straight. We also construct a Skyrmion as a twisted vortex ring in a model with a sixth-order derivative term.

We propose a new parametric framework to describe in generic metric theories of gravity the spacetime of spherically symmetric and slowly rotating black holes. In contrast to similar approaches proposed so far, we do not use a Taylor expansion in powers of $M/r$, where $M$ and $r$ are the mass of the black hole and a generic radial coordinate, respectively. Rather, we use a continued-fraction expansion in terms of a compactified radial coordinate. This choice leads to superior convergence properties and allows us to approximate a number of known metric theories with a much smaller set of coefficients. The measure of these coefficients via observations of near-horizon processes can be used to effectively constrain and compare arbitrary metric theories of gravity. Although our attention is here focussed on spherically symmetric black holes, we also discuss how our approach could be extended to rotating black holes.

We obtain ($2+1$)-dimensional gravity with cosmological constant which is coupled to gauge fields, using Maxwell and semisimple extension of the Poincaré gauge symmetric models (i.e., Chern-Simons models with these gauge groups). Also, we obtain some AdS-and BTZ-type solutions for the classical equations of motion for these ($2+1$)-dimensional gravities. For the semisimple extension of the Poincaré gauge group we investigate the AdS/CFT correspondence and show that the model at the boundary is equivalent to the sum of three Wess-Zumino-Witten models over group $SO(2,1)$. Then, we show that the central charge of the CFT is the same as that of CFT at the boundary of AdS spacetime related to the Chern-Simons model with gauge group $SO(2,2)$. Finally, we show that these two ($2+1$)-dimensional gravity models are dual (canonically transformed) to each other.

The (absence of detecting) lensing dispersion of supernovae type Ia (SNIa) can be used as a novel and extremely efficient probe of cosmology. In this preliminary example we analyze its consequences for the primordial power spectrum. The main setback is the knowledge of the power spectrum in the nonlinear regime, $1{\mathrm{Mpc}}^{-1}\lesssim k\lesssim {10}^2–{10}^3{\mathrm{Mpc}}^{-1}$ up to redshift of about unity. By using the lensing dispersion and conservative estimates in this regime of wave numbers, we show how the current upper bound ${\sigma }_{\mu }(z\le 1)<0.12$ on existing data gives strong indirect constraints on the primordial power spectrum. The probe extends our handle on the spectrum to a total of 12–15 inflation $e$-folds. These constraints are so strong that they are already ruling out a large portion of the parameter space allowed by PLANCK for running $\alpha \equiv d{n}_s/d\ln k$ and running of running $\beta \equiv d^2{n}_s/d\ln k^2$. The bounds follow a linear relation to a very good accuracy. A conservative bound disfavors any enhancement above the line $\beta (k_0)=0.036–0.42\alpha (k_0)$ and a realistic estimate disfavors any enhancement above the line $\beta (k_0)=0.022–0.44\alpha (k_0)$.

We consider the perturbatively modified tribimaximal (or bimaximal) mixing to estimate the (Dirac-type) CP phase in the neutrino mixing matrix. The expressions for the CP phase are derived from the equivalence between the standard parametrization of the neutrino mixing matrix for the Majorana neutrino and modified tribimaximal or bimaximal mixing matrices with appropriate CP phases. Carrying out numerical analysis based on the current experimental results for neutrino mixing angles, we can predict the values of the CP phase for several possible cases.

Motivated by the observation that the Higgs quartic coupling runs to zero at an intermediate scale, we propose a new framework for models of split supersymmetry, in which gauginos acquire intermediate scale Dirac masses of $\sim 10^{8-11}\mathrm{GeV}$. Scalar masses arise from one-loop finite contributions as well as direct gravity-mediated contributions. Like split supersymmetry, one Higgs doublet is fine-tuned to be light. The scale at which the Dirac gauginos are introduced to make the Higgs quartic zero is the same as is necessary for gauge coupling unification. Thus, gauge coupling unification persists (nontrivially, due to adjoint multiplets), though with a somewhat higher unification scale $\gtrsim 10^{17}\mathrm{GeV}$. The $\mu$ term is naturally at the weak scale, and provides an opportunity for experimental verification. We present two manifestations of split Dirac supersymmetry. In the “pure Dirac” model, the lightest Higgsino must decay through $R$-parity violating couplings, leading to an array of interesting signals in colliders. In the “hypercharge impure” model, the bino acquires a Majorana mass that is one-loop suppressed compared with the Dirac gluino and wino. This leads to weak scale Higgsino dark matter whose overall mass scale, as well as the mass splitting between the neutral components, is naturally generated from the same UV dynamics. We outline the challenges to discovering pseudo-Dirac Higgsino dark matter in collider and dark matter detection experiments.

We investigate the antitriplet and sextet heavy baryon systems with $J^P={\frac{1}{2}}^{+},{\frac{3}{2}}^{+}$ in the framework of the heavy baryon chiral perturbation theory. We first calculate the chiral corrections to the heavy baryon mass from the SU(3) flavor breaking effect up to $O(p^3)$. Then we extend the same formalism to calculate the chiral corrections to the axial charges of the heavy baryons in the isospin symmetry limit.