We present results for $W$-boson production at large transverse momentum at LHC and Tevatron energies. We calculate complete next-to-leading-order QCD corrections and higher-order soft-gluon corrections to the differential cross section. The soft-gluon contributions are resummed at next-to-next-to-leading-logarithm accuracy via the two-loop soft anomalous dimensions. Both next-to-leading-order and approximate next-to-next-to-leading-order $p_T$ distributions are presented. Our numerical results are in good agreement with recent data from the LHC.

The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an off-axis muon neutrino beam with a peak energy of about 0.6 GeV that originates at the Japan Proton Accelerator Research Complex accelerator facility. Interactions of the neutrinos are observed at near detectors placed at 280 m from the production target and at the far detector—Super-Kamiokande—located 295 km away. The flux prediction is an essential part of the successful prediction of neutrino interaction rates at the T2K detectors and is an important input to T2K neutrino oscillation and cross section measurements. A FLUKA and GEANT3-based simulation models the physical processes involved in the neutrino production, from the interaction of primary beam protons in the T2K target, to the decay of hadrons and muons that produce neutrinos. The simulation uses proton beam monitor measurements as inputs. The modeling of hadronic interactions is reweighted using thin target hadron production data, including recent charged pion and kaon measurements from the NA61/SHINE experiment. For the first T2K analyses the uncertainties on the flux prediction are evaluated to be below 15% near the flux peak. The uncertainty on the ratio of the flux predictions at the far and near detectors is less than 2% near the flux peak.

The lifetime of the $B_c^{-}$ meson is measured using 272 exclusive $B_c^{-}\to J/\psi (\to {\mu }^{+}{\mu }^{-}){\pi }^{-}$ decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of $6.7{\mathrm{fb}}^{-1}$ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the $B_c^{-}$ meson is measured to be $\tau (B_c^{-})=0.452\pm 0.048(\mathrm{stat})\pm 0.027(\mathrm{syst})\mathrm{ps}$. This is the first measurement of the $B_c^{-}$ meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

In this comment we show that the statement in Ahluwalia et al. [Phys. Rev. D 83, 065017 (2011)] that the existence of Elko spinor fields imply in an axis of locality is equivocated. The anticommutator $\{\Lambda (\mathbf{x},t),\Pi (\mathbf{x},t)\}$ is strictly local.

We construct mass deformed $SU(N)$ Lorentzian-Bagger-Lambert-Gustavsson theory together with $U(M-N{)}_k$ Chern-Simons theory. This mass deformed Lorentzian-Bagger-Lambert-Gustavsson theory is a low energy world volume theory of a stack of $N$ number of M2-branes far away from ${\mathbf{C}}^{\mathbf{4}}/{\mathbf{Z}}_{\mathbf{k}}$ singularity. We carry out this by defining a special scaling limit of the fields of this theory and simultaneously sending the Chern-Simons level to infinity.

In the Yang-Mills theory, the apparent thickness of the confining string is known to grow logarithmically when its length increases. The same logarithmic broadening also happens to strings in other quantum field theories and domain walls in statistical physics models. Even in quantum field theories, the correlators used to measure and characterize this phenomenon are analogous to those in statistical physics. In this paper we describe it using the string form factor which is a meaningful quantum observable, obtainable in principle from scattering experiments. We show how the form factor can be obtained from field correlation functions calculated in lattice Monte Carlo simulations. We apply this method to $2+1$-dimensional scalar theory in the strong coupling limit, where it is equivalent to the 3D Ising model, and through duality also to $2+1$-dimensional ${\mathbb{Z}}_2$ gauge theory. We measure the string form factor by simulating the Ising model, and demonstrate that it displays the same logarithmic broadening as observed by other quantities.

The decay and annihilation cross sections of dark matter particles may depend on the value of a chameleonic scalar field that both evolves cosmologically and takes different values depending on the local matter density. This possibility introduces a separation between the physics relevant for freeze-out and that responsible for dynamics and detection in the late universe. We investigate how such dark sector interactions might be implemented in a particle physics Lagrangian and consider how current and upcoming observations and experiments bound such dark matter candidates. A specific simple model allows for an increase in the annihilation cross section by a factor of ${10}^6$ between freeze-out and today, while more complicated models should also allow for scattering cross sections near the astrophysical bounds.

With the aim of deriving symmetric hyperbolic free-evolution systems for general relativity (GR) that possess Hamiltonian structure and allow for the popular puncture coordinate gauge condition, we analyze the hyperbolicity of Hamiltonian systems. We develop helpful tools which are applicable to either the first order in time, second order in space or the fully second order form of the equations of motion. For toy models we find that the Hamiltonian structure can simplify the proof of symmetric hyperbolicity. In GR we use a special structure of the principal part to prove symmetric hyperbolicity of a formulation that includes conditions which are very similar to the puncture coordinate gauge.

Regularization dependence of the Nambu–Jona-Lasinio model leaves room for improvement. To help in choosing a suitable regularization scheme, we investigate the phase diagram on the temperature-chemical potential plane in the Nambu–Jona-Lasinio model with the dimensional regularization. While the structure of the resulting diagram shows resemblance to the one in the frequently used cutoff regularization, some results of our study indicate a striking difference between these regularizations. Diagrams in the dimensional regularization always indicate the first-order phase transition at high chemical potential, while the first-order transition does not occur in the cutoff method for some parameter sets.

Pseudoscalar-photon mixing in the presence of a large scale magnetic field induces polarization in light from distant cosmological sources. We study the effect of these pseudoscalars or axionlike particles on cosmic microwave background radiation and constrain the product of mixing strength $g_{\varphi }$ times background magnetic field $B$. The background magnetic field has been assumed to be primordial, and we assume large scale correlations with the correlation length of 1 Mpc. We use WMAP seven-year foreground reduced polarization and temperature data to constrain the pseudoscalar-photon mixing parameter. We look for different mass limits of the pseudoscalars and find $g_{\varphi }B\le 1.6\times {10}^{-13}{\mathrm{GeV}}^{-1}\mathrm{nG}$ with axionlike particles of mass ${10}^{-10}\mathrm{eV}$ and $g_{\varphi }B\le 3.4\times {10}^{-15}{\mathrm{GeV}}^{-1}\mathrm{nG}$ for ultralight axionlike particles of mass ${10}^{-15}\mathrm{eV}$.

At zero temperature the lowest part of the spectrum of the QCD Dirac operator is known to consist of delocalized modes that are described by random matrix statistics. In the present paper we show that the nature of these eigenmodes changes drastically when the system is driven through the finite temperature crossover. The lowest Dirac modes that are delocalized at low temperature become localized on the scale of the inverse temperature. At the same time the spectral statistics changes from random matrix to Poisson statistics. We demonstrate this with lattice QCD simulations using $2+1$ flavors of light dynamical quarks with physical masses. Drawing an analogy with Anderson transitions we also examine the mobility edge separating localized and delocalized modes in the spectrum. We show that it scales in the continuum limit and increases sharply with the temperature.

We discuss single diffractive gauge boson $({\gamma }^{*},W^{\pm },Z)$ production in proton-proton collisions at different (Large Hadron Collider and Relativistic Heavy Ion Collider) energies within the color dipole approach. The calculations are performed for gauge bosons produced at forward rapidities. The diffractive cross section is predicted as a function of the fractional momentum and invariant mass of the lepton pair. We found a dramatic breakdown of the diffractive QCD factorization caused by an interplay of hard and soft interactions. Data from the CDF experiment on diffractive production of $W$ and $Z$ are well explained in a parameter-free way.

The analysis of deeply virtual meson production is extended to neutrino-production of the pseudo-Goldstone mesons $(\pi ,K,\eta )$ on nucleons, with the flavor content of the recoil baryon either remaining intact, or changing to a hyperon from the $SU(3)$ octet. We rely on the $SU(3)$ relations and express all the cross sections in terms of the proton generalized parton distributions (GPDs). The corresponding amplitudes are calculated at the leading twist level and in the leading order in ${\alpha }_s$, using a phenomenological model of GPDs. We provide a computational code, which can be used for evaluation of the cross sections employing various GPD parametrizations. We conclude that these processes can be studied in the experiment Minerva at Fermilab, which could supplement the measurements at JLAB helping to extract the GPD flavor structure from data.

Recent results from ATLAS and CMS point to a narrow range for the Higgs mass: $M_H\in (124,126)\mathrm{GeV}$. Given this range, a case may be made for new physics beyond the Standard Model (SM) because of the resultant vacuum stability problem, i.e., the SM Higgs quartic coupling may run to negative values at a scale below the Planck scale. We study representative minimal extensions of the SM that can keep the SM Higgs vacuum stable to the Planck scale by introducing new scalar or fermion interactions at the TeV scale while solving other phenomenological problems. In particular, we consider the type-II seesaw model, which is introduced to explain the nonzero Majorana masses of the active neutrinos. Similarly, we observe that if the stability of the SM Higgs vacuum is ensured by the running of the gauge sector couplings, then one may require a series of new electroweak multiplets, the neutral component of which can be a cold dark matter candidate. Stability may also point to a new $U(1)$ gauge symmetry, in which the SM Higgs carries a nonzero charge.

We present a search for Lorentz violation with 8249 candidate electron antineutrino events taken by the Double Chooz experiment in 227.9 live days of running. This analysis, featuring a search for a sidereal time dependence of the events, is the first test of Lorentz invariance using a reactor-based antineutrino source. No sidereal variation is present in the data and the disappearance results are consistent with sidereal time independent oscillations. Under the Standard-Model Extension, we set the first limits on 14 Lorentz violating coefficients associated with transitions between electron and tau flavor, and set two competitive limits associated with transitions between electron and muon flavor.

The photon spectrum in $B\to X_s\gamma$ decay, where $X_s$ is any strange hadronic state, is studied using a data sample of $(382.8\pm 4.2)\times {10}^6$ $e^{+}{e}^{-}\to {\rm Y}(4S)\to B\overline{B}$ events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction $\mathcal{B}(B\to X_s\gamma )=(3.21\pm 0.15\pm 0.29\pm 0.08)\times {10}^{-4}$ and the first, second, and third moments $⟨E_{\gamma }⟩=2.267\pm 0.019\pm 0.032\pm 0.003\mathrm{GeV}$, $⟨(E_{\gamma }-⟨E_{\gamma }⟩{)}^2⟩=0.0484\pm 0.0053\pm 0.0077\pm 0.0005{\mathrm{GeV}}^2$, and $⟨(E_{\gamma }-⟨E_{\gamma }⟩{)}^3⟩=-0.0048\pm 0.0011\pm 0.0011\pm 0.0004{\mathrm{GeV}}^3$, for the range $E_{\gamma }>1.8\mathrm{GeV}$, where $E_{\gamma }$ is the photon energy in the $B$-meson rest frame. Results are also presented for narrower $E_{\gamma }$ ranges. In addition, the direct $CP$ asymmetry $A_{CP}(B\to X_{s+d}\gamma )$ is measured to be $0.057\pm 0.063$. The spectrum itself is also unfolded to the $B$-meson rest frame; that is the frame in which theoretical predictions for its shape are made.

We demonstrate that relativistic conformal hydrodynamics in $2+1$ dimensions displays a turbulent behavior which cascades energy to longer wavelengths on both flat and spherical manifolds. Our motivation for this study is to understand the implications for gravitational solutions through the AdS/CFT correspondence. The observed behavior implies gravitational perturbations of the corresponding black brane/black hole spacetimes (for sufficiently large scales/temperatures) will display a similar cascade towards longer wavelengths.

If one is not ready to pay a large fine-tuning price within supersymmetric models given the current measurement of the Higgs boson mass, one can envisage a scenario where the supersymmetric spectrum is made of heavy scalar sparticles and much lighter fermionic superpartners. We offer a cosmological explanation of why nature might have chosen such a mass pattern: the opposite mass pattern is not observed experimentally because it is not compatible with the plausible idea that the Universe went through a period of primordial inflation.

We study the dynamics of Dirac-Born-Infeld (DBI) dark energy interacting with dark matter. The DBI dark energy model considered here has a scalar field with a nonstandard kinetic energy term, and has potential and brane tension that are power-law functions. The new feature considered here is an interaction between the DBI dark energy and dark matter through a phenomenological interaction between the DBI scalar field and the dark matter fluid. We analyze two different types of interactions between the DBI scalar field and the dark matter fluid. In particular we study the phase-space diagrams of and look for critical points of the phase space that are both stable and lead to accelerated, late-time expansion. In general we find that the interaction between the two dark components does not appear to give rise to late-time accelerated expansion. However, the interaction can make the critical points in the phase space of the system stable. Whether such stabilization occurs or not depends on the form of the interaction between the two dark components.