We propose an experimental test of local hidden variable theories against quantum mechanics by measuring the polarization correlation of entangled vector meson pairs. In our study, the form of the polarization correlation probability is reproduced in a natural way by interpreting the two-body decay of the meson as a measurement of its polarization vector within the framework of quantum mechanics. This provides more detailed information on the quantum entanglement, thus a new Monte Carlo method to simulate the quantum correlation is introduced. We discuss the feasibility of carrying out such a test at experiments in operation currently and expect that the measured correlated distribution may provide us with deeper insight into the fundamental question about locality and reality.

We show that a 125 GeV Higgs boson and percent-level fine-tuning are simultaneously attainable in the minimal supersymmetric standard model, with no additional fields and supersymmetry breaking generated at the grand unification theory scale. The Higgs mass is raised by large radiative contributions from top squarks with significant left-right mixing, and naturalness is preserved by the focus point mechanism with large $A$-terms, which suppresses large log-enhanced sensitivities to variations in the fundamental parameters. The focus point mechanism is independent of almost all supersymmetry-breaking parameters, but is predictive in the top sector, requiring the grand unification theory-scale relation $m_{H_u}^2\mathrm{\text{:}}{m}_{U_3}^2\mathrm{\text{:}}{m}_{Q_3}^2\mathrm{\text{:}}{A}_t^2=1\mathrm{\text{:}}1+x-3y\mathrm{\text{:}}1-x\mathrm{\text{:}}9y$, where $x$ and $y$ are constants. We derive this condition analytically and then investigate three representative models through detailed numerical analysis. The models generically predict heavy superpartners, but dark matter searches in the case of nonunified gaugino masses are promising, as are searches for top squarks and gluinos with top- and bottom-rich cascade decays at the LHC. This framework may be viewed as a simple update to mSUGRA/CMSSM to accommodate both naturalness and current Higgs boson constraints, and provides an ideal framework for presenting new results from LHC searches.

The decay $B\to J/\psi K_S$ remains the most important source of information for the $B_d$ mixing phase, determined by the Cabibbo, Kobayashi, and Maskawa (CKM) angle $\beta$ in the standard model. When aiming at a precision appropriate for present and coming high luminosity colliders, the corresponding hadronic matrix elements are a major obstacle, as their precise calculation is still not feasible with existing methods. Flavor symmetries offer a possibility to extract them from data, however, again with limited precision. In this article, we propose a framework to take subleading contributions in $B_{u,d,s}\to J/\psi P$ decays into account, $P\in \{\pi ,K,({\eta }_8)\}$, using an $SU(3)$ analysis, together with the leading corrections to the symmetry limit. This allows for a model-independent extraction of the $B_d$ mixing phase adequate for coming high precision data, and additionally yields information on possible new physics contributions in these modes. We find the penguin-induced correction to be small, $\Delta S_{J/\psi K_S}\lesssim 0.01$, a limit that can be improved with coming data on $CP$ asymmetries and branching ratios. Finally, the sensitivity on the CKM angle $\gamma$ from these modes is critically examined, yielding a less optimistic picture than previously envisaged.

This paper presents a study of the possible ordering of charged hadrons in the azimuthal angle relative to the beam axis in high-energy proton-proton collisions at the Large Hadron Collider (LHC). A spectral analysis of correlations between longitudinal and transverse components of the momentum of the charged hadrons, driven by the search for phenomena related to the structure of the QCD field, is performed. Data were recorded with the ATLAS detector at center-of-mass energies of $\sqrt{s}=900\mathrm{GeV}$ and $\sqrt{s}=7\mathrm{TeV}$. The correlations measured in a kinematic region dominated by low-$p_T$ particles are not well described by conventional models of hadron production. The measured spectra show features consistent with the fragmentation of a QCD string represented by a helixlike ordered gluon chain.

Using information from the marginality conditions of vertex operators for the ${\mathrm{AdS}}_5\times S^5$ superstring, we determine the structure of the dependence of the energy of quantum string states on their conserved charges and the string tension $\sim \sqrt{\lambda }$. We consider states on the leading Regge trajectory in the flat space limit which carry one or two (equal) spins in ${\mathrm{AdS}}_5$ or $S^5$ and an orbital momentum in $S^5$, with Konishi multiplet states being particular cases. We argue that the coefficients in the energy may be found by using a semiclassical expansion. By analyzing the examples of folded spinning strings in ${\mathrm{AdS}}_5$ and $S^5$, as well as three cases of circular two-spin strings, we demonstrate the universality of transcendental (zeta-function) parts of few leading coefficients. We also show the consistency with target space supersymmetry with different states belonging to the same multiplet having the same nontrivial part of the energy. We suggest, in particular, that a rational coefficient (found by Basso for the folded string using Bethe Ansatz considerations and which, in general, is yet to be determined by a direct two-loop string calculation) should, in fact, be universal.

For the free massless spin-one and spin-two field theories one may write the action in a form which is manifestly invariant under electric-magnetic duality. This is achieved by introducing new potentials through solving the constraints of the Hamiltonian formulation. The price for making electric-magnetic duality invariance manifest through this direct procedure is losing manifest Lorentz invariance. Both theories admit supersymmetric extensions, which make the bosonic fields and their corresponding fermionic partners to be parts of the same geometrical object, a supermultiplet. We present in this paper the supersymmetric extension of the manifestly electric-magnetic duality invariant actions for the photon and the photino; and for the graviton and the gravitino. In each case the spinor fields transform under electric-magnetic duality in a chiral manner. For the spin-tree-half field, which possesses a gauge invariance, it is necessary to bring in a spinor “prepotential.” As in previous cases the introduction of additional potentials to solve the constraints increases the number of gauge invariances of the action, thus keeping the number of degrees of freedom unaltered. The similarity in the formulations for the photon-photino and graviton-gravitino systems is remarkable.

We study doubly periodic Bogomol’nyi-Prasad-Sommerfield lumps in supersymmetric $\mathbb{C}{P}^{N-1}$ nonlinear sigma models on a torus $T^2$. Following the philosophy of the Harrington-Shepard construction of calorons in Yang-Mills theory, we obtain the $n$-lump solutions on compact spaces by suitably arranging the $n$ lumps on ${\mathbb{R}}^2$ at equal intervals. We examine the modular invariance of the solutions and find that there are no modular invariant solutions for $n=1$, 2 in this construction.

A star orbiting a supermassive black hole can be tidally disrupted if the black hole’s gravitational tidal field exceeds the star’s self gravity at pericenter. Some of this stellar tidal debris can become gravitationally bound to the black hole, leading to a bright electromagnetic flare with bolometric luminosity proportional to the rate at which material falls back to pericenter. In the Newtonian limit, this flare will have a light curve that scales as $t^{-5/3}$ if the tidal debris has a flat distribution in binding energy. We investigate the time dependence of the black-hole mass accretion rate when tidal disruption occurs close enough the black hole that relativistic effects are significant. We find that for orbits with pericenters comparable to the radius of the marginally bound circular orbit, relativistic effects can double the peak accretion rate and halve the time it takes to reach this peak accretion rate. The accretion rate depends on both the magnitude of the black-hole spin and its orientation with respect to the stellar orbit; for orbits with a given pericenter radius in Boyer-Lindquist coordinates, a maximal black-hole spin anti-aligned with the orbital angular momentum leads to the largest peak accretion rate.

We show how Hořava-Lifshitz (HL) theory appears naturally in the Ashtekar formulation of relativity if one postulates the existence of a fermionic field playing the role of aether. The spatial currents associated with this field must be switched off for the equivalence to work. Therefore the field supplies the preferred frame associated with breaking refoliation (time diffeomorphism) invariance, but obviously the symmetry is only spontaneously broken if the field is dynamic. When Dirac fermions couple to the gravitational field via the Ashtekar variables, the low energy limit of HL gravity, recast in the language of Ashtekar variables, naturally emerges (provided the spatial fermion current identically vanishes). HL gravity can therefore be interpreted as a timelike current, or a Fermi aether, that fills space-time, with the Immirzi parameter, a chiral fermionic coupling, and the fermionic charge density fixing the value of the parameter $\lambda$ determining HL theory. This reinterpretation sheds light on some features of HL theory, namely its good convergence properties.

Recently, the BABAR Collaboration reported the first evidence for new physics in $B\to D\tau \nu$ and $B\to D^{*}\tau \nu$. Combining both processes, the significance is $3.4\sigma$. This result cannot be explained in a two Higgs doublet model of type II. Furthermore, the CKMfitter Group finds a $2.9\sigma$ discrepancy between the Standard Model prediction for $\mathrm{Br}[B\to \tau \nu ]$ (using $V_{ub}$ from a global fit to the unitary triangle) and the measurements of the $B$ factories. Altogether, these measurements are strong indications for physics beyond the Standard Model in $B$-meson decays to taus. We show that in a two Higgs doublet model of type III it is possible to simultaneously explain $B\to D\tau \nu$ and $B\to D^{*}\tau \nu$ using a single free parameter ${ϵ}_{32}^u$. Also, $\mathrm{Br}[B\to \tau \nu ]$ can be brought into agreement with experiment using ${ϵ}_{31}^u$. Furthermore, for Higgs ($A^0$, $H^0$, $H^{\pm }$) masses around 500 GeV, as preferred by recent CMS results, all bounds from flavor changing neutral current processes are satisfied and $B\to D\tau \nu$, $B\to D^{*}\tau \nu$ and $B\to \tau \nu$ can be explained without a significant degree of fine tuning.

The ongoing searches for Higgs-boson signals in data taken at the CERN LHC and the Fermilab Tevatron crucially rely on the decay channels $H\to Z\ell \ell$ and $H\to W\ell {\nu }_l$. We present a precision study of the partial widths of these decay channels including the full one-loop electroweak corrections and the dominant contributions at two and three loops, of $\mathcal{O}(G_F^2{m}_t^4)$, $\mathcal{O}(G_F{m}_t^2{\alpha }_s)$, and $\mathcal{O}(G_F{m}_t^2{\alpha }_s^2)$. Since the invariant mass of the off-shell intermediate boson is relatively low in the mass window $115\mathrm{GeV}<m_H<129\mathrm{GeV}$ of current interest, lepton mass effects are relevant, especially for the $\tau$ lepton.

We propose a phenomenological model of Dirac neutrino mass operator based on the Friedberg-Lee neutrino mass model to include $CP$ violation. By considering the most general set of complex coefficients, and imposing the condition that the mass eigenvalues are real, we find a neutrino mass matrix which is non-Hermitian, symmetric, and magic. In particular, we find that the requirement of obtaining real mass eigenvalues by transferring the residual phases to the mass eigenstates self-consistently dictates the following relationship between the imaginary part of the mass matrix elements $B$ and the parameters of the Friedberg-Lee model: $B=\pm \sqrt{\frac{3}{4}(a-b_r{)}^2{sin}^{2}2{\theta }_{13}{cos}^2{\theta }_{12}}$. We obtain inverted neutrino mass hierarchy $m_3=0$. Making a correspondence between our model and the experimental data produces stringent conditions on the parameters as follows: $35.06°\lesssim {\theta }_{12}\lesssim 36.27°$, ${\theta }_{23}=45°$, $7.27°\lesssim {\theta }_{13}\lesssim 11.09°$, and $82.03°\lesssim \delta \lesssim 85.37°$. We get mildly broken $\mu \mathrm{\text{−}}\tau$ symmetry, which reduces the resultant neutrino mixing pattern from tri-bimaximal to trimaximal. The $CP$ violation as measured by the Jarlskog parameter is restricted by $0.027\lesssim J\lesssim 0.044$.

Decays of the ${\chi }_{cJ}$ states ($J=0$, 1, 2) to $\Lambda \overline{\Lambda }{\pi }^{+}{\pi }^{-}$, including processes with intermediate $\Sigma (1385)$, are studied through the $E1$ transition ${\psi }^{\prime }\to \gamma {\chi }_{cJ}$ using $106\times {10}^6$ ${\psi }^{\prime }$ events collected with the BESIII detector at BEPCII. This is the first observation of ${\chi }_{cJ}$ decays to the final state $\Lambda \overline{\Lambda }{\pi }^{+}{\pi }^{-}$. The branching ratio of the intermediate process ${\chi }_{cJ}\to \Sigma (1385{)}^{\pm }\overline{\Sigma }(1385{)}^{\mp }$ is also measured for the first time, and the results agree with the theoretical predictions based on the color-octet effect.

Recent measurements of the neutrino mixing angles cast doubt on the validity of the so-far popular tribimaximal mixing Ansatz. We propose a parametrization for the neutrino mixing matrix where the reactor angle seeds the large solar and atmospheric mixing angles, equal to each other in first approximation. We suggest such a bilarge mixing pattern as a model-building standard, realized when the leading order value of ${\theta }_{13}$ equals the Cabibbo angle ${\lambda }_C$.

We reconsider the problem of determining the semiclassical three-point function in the Euclidean ${\mathrm{AdS}}_3$ model. Exploiting the affine symmetry of the model, we use solutions of the classical Knizhnik-Zamolodchikov equation to compute the saddle point of the action in the presence of three vertex operators. This alternative derivation reproduces the “heavy charge” classical limit of the quantum three-point correlator. It is different from the recently proposed expression obtained by the generalized Pohlmeyer reduction in ${\mathrm{AdS}}_2$.

Models of spontaneous wave function collapse modify the linear Schrödinger equation of standard quantum mechanics by adding stochastic nonlinear terms to it. The aim of such models is to describe the quantum (linear) nature of microsystems along with the classical nature (violation of superposition principle) of macroscopic ones. The addition of such nonlinear terms in the Schrödinger equation leads to nonconservation of energy of the system under consideration. Thus, a striking feature of collapse models is to heat nonrelativistic particles with a constant rate. If such a process is physical, then it has the ability to perturb the well-understood thermal history of the universe. In this article we will try to investigate the impacts of such heating terms, according to the continuous spontaneous localization model, on the standard evolution of nonrelativistic matter and on the formation of cosmic microwave background radiation. We will also put constraints on the continuous spontaneous localization collapse rate $\lambda$ by considering that the standard evolution of nonrelativistic matter is not hampered and the observed precise blackbody spectrum of cosmic microwave background radiation would not get distorted (in the form of $\mu$-type and $y$-type distortions) so as to violate the observed bounds.

In general neutron stars in binaries are spinning. Recently, a new quasi-equilibrium approximation that includes a rotational velocity piece for each star has been proposed to describe binary neutron stars with arbitrary rotation states in quasicircular orbits. We have implemented this approximation numerically for the first time, to generate initial data for neutron star binaries with spin. If we choose the rotational velocity piece such that it equals the Newtonian rigid rotation law, we obtain stars with fluid 4-velocities that have expansion and shear of approximately zero, as one would expect for quasi-equilibrium configurations. We also use the new approach to construct and study initial data sequences for irrotational, corotating, and fixed rotation binaries.

Scalar-tensor theory offers the possibility of a modification of Newtonian gravity due to the presence of a 4d scalar dilaton field. The prototypical version of such a theory, massless Brans-Dicke theory, is considered here in the Einstein frame representation. The acceleration of a test mass is obtained from the exact 4d Xanthopoulos-Zannias solutions with spherical symmetry. The deviation of this acceleration from the pure Newtonian gravitational acceleration is examined to see if it can account for the anomalous Pioneer acceleration, while satisfying solar system constraints. Theoretical considerations, along with limits inferred from Pioneer 10 data, suggest that Brans-Dicke gravity could account for no more than a small fraction of the Pioneer anomaly, so that a complete explanation of the anomaly must lie elsewhere.

We compute the analogue Hawking radiation for modes which possess a small wave vector perpendicular to the horizon. For low frequencies, the resulting mass term induces a total reflection. This reflection is accompanied by an extra mode mixing which occurs in the supersonic region, and which cancels out the infrared divergence of the near horizon spectrum. As a result, the amplitude of the undulation (0-frequency wave with macroscopic amplitude) emitted in white hole flows now saturates at the linear level, unlike what is found in the massless case. In addition, we point out that the mass introduces a new type of undulation which is produced in black hole flows, and which is well described in the hydrodynamical regime.

We show that the area-angular momentum-charge inequality $(A/(4\pi ){)}^2\ge (2J{)}^2+(Q_{\mathrm{E}}^2+Q_{\mathrm{M}}^2{)}^2$ holds for axisymmetric apparent horizons of electrically and magnetically charged rotating black holes in dynamical and nonvacuum spacetimes. More specifically, this quasilocal inequality applies to axially symmetric closed stably outermost marginally (outer) trapped surfaces, embedded in non-necessarily axisymmetric black hole spacetimes with non-negative cosmological constant and matter content satisfying the dominant energy condition.