Aspects of a flavor-changing $W^{\prime }$ model with right-handed couplings are addressed in this paper in light of Tevatron and LHC data. Our fit to the Tevatron top-quark forward-backward asymmetry and the $t\overline{t}$ inclusive cross section includes higher-order loop effects in the effective interaction. The higher-order corrections change the best-fit value of the $W^{\prime }$ effective coupling strength as a function of the $W^{\prime }$ mass. The consistency of the model is checked against the shape of the $t\overline{t}$ invariant mass distribution. We use these updated $W^{\prime }$ parameters to compute the expected contributions from $W^{\prime }t$ associated production and, for the first time, $W^{\prime }{W}^{\prime }$ pair production at the LHC. We do a full Monte Carlo simulation of the $t\overline{t}X$ final state, including interference between the $t{W}^{\prime }$-induced $t\overline{t}j$ process and the standard model $t\overline{t}j$ process. Interference effects are shown to be quantitatively important, particularly when the $W^{\prime }$ mass is large. The jet-multiplicity distribution in $t\overline{t}$ jet production at 8 TeV constrains the $W^{\prime }$ model severely.

Using a sample of $1.06\times {10}^8$ $\psi (3686)$ events collected with the BESIII detector, we present the first observation of the decays of $\psi (3686)\to \Lambda {\overline{\Sigma }}^{+}{\pi }^{-}+\mathrm{c}.\mathrm{c}.$ and $\psi (3686)\to \Lambda {\overline{\Sigma }}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.$ The branching fractions are measured to be $\mathcal{B}(\psi (3686)\to \Lambda {\overline{\Sigma }}^{+}{\pi }^{-}+\mathrm{c}.\mathrm{c}.)=(1.40\pm 0.03\pm 0.13)\times {10}^{-4}$ and $\mathcal{B}(\psi (3686)\to \Lambda {\overline{\Sigma }}^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.)=(1.54\pm 0.04\pm 0.13)\times {10}^{-4}$, where the first errors are statistical and the second ones systematic.

We propose a graphical representation of detector sensitivity curves for stochastic gravitational-wave backgrounds that takes into account the increase in sensitivity that comes from integrating over frequency in addition to integrating over time. This method is valid for backgrounds that have a power-law spectrum in the analysis band. We call these graphs “power-law integrated curves.” For simplicity, we consider cross-correlation searches for unpolarized and isotropic stochastic backgrounds using two or more detectors. We apply our method to construct power-law integrated sensitivity curves for second-generation ground-based detectors such as Advanced LIGO, space-based detectors such as LISA and the Big Bang Observer, and timing residuals from a pulsar timing array. The code used to produce these plots is available at https://dcc.ligo.org/LIGO-P1300115/public for researchers interested in constructing similar sensitivity curves.

Given the increasingly more stringent bounds on supersymmetry (SUSY) from the LHC searches, we are motivated to explore the situation in which the only accessible SUSY states are the electroweakinos (charginos and neutralinos). In the minimal SUSY framework, we systematically study the three general scenarios classified by the relative size of the gaugino mass parameters $M_1$ and $M_2$ and the Higgsino mass parameter $\mu$, with six distinctive cases, four of which would naturally result in a compressed spectrum of nearly degenerate lightest supersymmetric particles. We present the relevant decay branching fractions and provide insightful understanding about the decay modes in connection with the Goldstone-boson equivalence theorem. We show the cross sections for electroweakino pair production at the LHC and International Linear Collider and emphasize the unique signals involving the Standard Model-like Higgs boson as a new search reference. The electroweakino signal from pair production and subsequent decay to the $Wh/Zh(h\to b\overline{b})$ final state may yield a sensitivity of 95% C.L. exclusion ($5\sigma$ discovery) to the mass scale $M_2$, $\mu \sim 350–400\mathrm{GeV}$ (220–270 GeV) at the 14 TeV LHC with a luminosity of $300{\mathrm{fb}}^{-1}$. Combining with all the other decay channels, the 95% C.L. exclusion ($5\sigma$ discovery) may be extended to $M_2$, $\mu \sim 480–700\mathrm{GeV}$ (320–500 GeV). At the ILC, the electroweakinos could be readily discovered once the kinematical threshold is crossed, and their properties could be thoroughly studied.

We extend to 10 GeV results from a microscopic calculation of charged-current neutrino-nucleus reactions that do not produce a pion in the final state. For the class of events coming from neutrino interactions with two nucleons producing two holes (2p2h), limiting the calculation to three-momentum transfers less than 1.2 GeV produces a two-dimensional distribution in momentum and energy transfer that is roughly constant as a function of energy. The cross section for 2p2h interactions approximately scales with the number of nucleons for isoscalar nuclei, similar to the quasi-elastic cross section. When limited to momentum transfers below 1.2 GeV, the cross section is 26% of the quasi-elastic cross section at 3 GeV, but 14% if we neglect a ${\Delta }_{1232}$ resonance absorption component. The same quantities are 33% and 17% for antineutrinos. For the quasi-elastic interactions, the full nuclear model with long range correlations produces an even larger, but approximately constant distortion of the shape of the four-momentum transfer at all energies above 2 GeV. The 2p2h enhancement and long-range correlation distortions to the cross section for these interactions are significant enough they should be observable in precision experiments to measure neutrino oscillations and neutrino interactions at these energies, but also balance out and produce less total distortion than each effect does individually.

We present a simple theory where baryon and lepton numbers are spontaneously broken at the supersymmetry scale. In this context $R$ parity must be spontaneously broken but the theory still contains a stable field which can play the role of the cold dark matter of the Universe. We discuss the spectrum of the theory, the properties of the dark matter candidate and the predictions for direct detection experiments. This theory provides a concrete example of exotic supersymmetric signatures associated with having the simultaneous presence of $R$-parity-violating and missing energy signals at the Large Hadron Collider.

By incorporating renormalization procedure into bold diagrammatic Monte Carlo, we propose a method for studying quantum field theories in the strong coupling regime. Bold diagrammatic Monte Carlo essentially samples Feynman diagrams using local Metropolis-type updates. Applying the method to three-dimensional ${\varphi }^4$ theory, we analyze the strong coupling limit of the theory and confirm the existence of a nontrivial IR fixed point in agreement with prior studies. Interestingly, we find that working with bold correlation functions as building blocks of the Monte Carlo procedure renders the scheme convergent, and no further resummation method is needed.

Based on the truncated Dyson–Schwinger equation, we first study the influence of the vertex correction on the staggered spin susceptibility ${\chi }^s$. The numerical results show that the vertex correction plays an important role in the study of the staggered spin susceptibility. We then generalize the above work to the case of finite temperature. It is found for the first time that, as the temperature increases, the chiral condensate vanishes at the phase transition point where ${\chi }^s$ reveals an obvious skip, and therefore as a physical observable, the staggered spin susceptibility could be regarded as the order parameter of chiral phase transition in ${\mathrm{QED}}_3$.

The variational approach to Yang-Mills theory in Coulomb gauge is extended to full QCD. For the quark sector we use a trial wave functional, which goes beyond the previously used BCS-type state and which explicitly contains the coupling of the quarks to transverse gluons. This quark wave functional contains two variational kernels: one is related to the quark condensate and occurs already in the BCS-type states; the other represents the form factor of the coupling of the quarks to the transverse gluons. Minimization of the energy density with respect to these kernels results in two coupled integral (gap) equations. These equations are solved numerically using the confining part of the non-Abelian color Coulomb potential and the lattice static gluon propagator as input. With the additional coupling of quarks to transverse gluons included, the low energy chiral properties increase substantially towards their phenomenological values. We obtain a reasonable description of the chiral condensate, which for a vanishing current quark mass is obtained in the range of 190–235 MeV. The coupling of the quarks to the transverse gluons enhances the constituent quark mass by about 60% in comparison to the pure BCS Ansatz.

We study the evolution of a quantum scalar field in a toy universe which has three stages of evolution, viz., (i) an early (inflationary) de Sitter phase (ii) radiation-dominated phase and (iii) late-time (cosmological constant dominated) de Sitter phase. Using the Schrödinger picture, the scalar field equations are solved separately for the three stages and matched at the transition points. The boundary conditions are chosen so that field modes in the early de Sitter evolves from the Bunch-Davies vacuum state. We determine the (time-dependent) particle content of this quantum state for the entire evolution of the universe and describe the various features both numerically and analytically. We also describe the quantum to classical transition in terms of a classicality parameter which tracks the particle creation and its effect on phase space correlation of the quantum field.

If space-time is emergent from a fundamentally nongeometric theory it will generically be left with defects. Such defects need not respect the locality that emerges with the background. Here, we develop a phenomenological model that parametrizes the effects of nonlocal defects on the propagation of particles. In this model, Lorentz invariance is preserved on the average. We derive constraints on the density of defects from various experiments.

Stationary $D$-dimensional test branes interacting with $N$-dimensional Myers-Perry bulk black holes are investigated in arbitrary brane and bulk dimensions. The branes are asymptotically flat and axisymmetric around the rotation axis of the black hole with a single angular momentum. They are also spherically symmetric in all other dimensions allowing a total of $O(1)\times O(D-2)$ group of symmetry. It is shown that even though this setup is the most natural extension of the spherical symmetric problem to the simplest rotating case in higher dimensions, the obtained solutions are not compatible with the spherical solutions in the sense that the latter ones are not recovered in the nonrotating limit. The brane configurations are qualitatively different from the spherical problem, except in the special case of a three-dimensional brane. Furthermore, a quasistatic phase transition between the topologically different solutions cannot be studied here, due to the lack of a general, stationary, equatorial solution.

We consider rotating Lorentzian wormholes with a phantom field in five dimensions. These wormhole solutions possess equal angular momenta and thus represent cohomogeneity-1 configurations. For a given size of the throat, the angular momenta are bounded by the value of the corresponding extremal Myers-Perry black hole, which represents the limiting configuration. With increasing angular momenta the throat becomes increasingly deformed. At the same time, the violation of the null energy condition decreases to zero, as the limiting configuration is approached. Symmetric wormhole solutions satisfy a Smarr-like relation, which is analogous to the Smarr relation of extremal black holes. A stability analysis shows that the unstable mode of the static wormhole solutions vanishes when the angular momentum exceeds some critical value.

The energy spectra of two nucleons in a cubic volume provide access to the two phase shifts and one mixing angle that define the S matrix in the ${}^{3}S_1\mathrm{\text{−}}{}^{3}D_1$ coupled channels containing the deuteron. With the aid of recently derived energy quantization conditions for such systems, and the known scattering parameters, these spectra are predicted for a range of volumes. It is found that extractions of the infinite-volume deuteron binding energy and leading scattering parameters, including the $S$-$D$ mixing angle at the deuteron pole, are possible from lattice QCD calculations of two-nucleon systems with boosts of $|\mathbf{P}|\le \frac{2\pi }{\mathrm{L}}\sqrt{3}$ in volumes with $10\mathrm{fm}\lesssim \mathrm{L}\lesssim 14\mathrm{fm}$. The viability of extracting the asymptotic $D/S$ ratio of the deuteron wave function from lattice QCD calculations is discussed.

Corrections to energy levels in light muonic atoms are investigated in order ${\alpha }^2(Z\alpha {)}^{4}m$. We pay attention to corrections which are specific for muonic atoms and include the electron vacuum polarization loop. In particular, we calculate relativistic and relativistic-recoil two-loop electron vacuum polarization contributions. The results are obtained for the levels with $n=1$, 2 and in particular for the Lamb shift ($2p_{1/2}-2s_{1/2}$) and fine-structure intervals ($2p_{3/2}-2p_{1/2}$) in muonic hydrogen, deuterium, and muonic helium ions.

We discuss the one-loop effects of massless fermion fields on the low energy vector brane-to-brane propagators in the framework of two QED brane-world scenarios. We show that the one-loop photon brane-to-brane propagator has a power-law pathologic IR divergence in the five-dimensional QED brane-world model with a mass gap between the vector zero mode and continuous states. We also find that bulk fermions do not give rise to IR divergences in a photon brane-to-brane Green’s function, at least at the one-loop level in the framework of a six-dimensional QED brane model with a gapless mass spectrum between vector zero mode and higher states.

We investigate the dynamical breaking of local supersymmetry (supergravity), including the Deser-Zumino super-Higgs effect, via the corresponding one-loop effective potential for the simple but quite representative cases of $\mathcal{N}=1$, $D=4$ simple supergravity and a (simplified) conformal version of it. We find solutions to the effective equations which indicate dynamical generation of a gravitino mass, thus breaking supergravity. In the case of conformal supergravity models, the gravitino mass can be much lower than the Planck scale, for global supersymmetry breaking scales below the grand unification scale. The absence of instabilities in the effective potential arising from the quantum fluctuations of the metric field is emphasized, contrary to previous claims in the literature.

We perform full two-dimensional (2D) numerical relaxations of isospinning soliton solutions in the baby Skyrme model in which the global $O(3)$ symmetry is broken by the 2D analogue of the pion mass term in the Skyrme model. In our calculations we explicitly allow the isospinning solitons to deform and to break the symmetries of the static configurations. We find that stable isospinning baby Skyrme solutions can be constructed numerically for all angular frequencies $\omega \le \min (\mu ,1)$, where $\mu$ is the mass parameter of the model. Stable, rotationally symmetric baby Skyrmion solutions for higher angular velocities are simply an artefact of the hedgehog approximation. Isospinning multisoliton solutions of topological charge $B$ turn out to be unstable to break up into their $B$ charge-1 constituents at some critical breakup frequency value. Furthermore, we find that for $\mu$ sufficiently large the rotational symmetry of charge-2 baby Skyrmions becomes broken at a critical angular frequency $\omega$.

We reanalyze the perturbative radiative corrections to the Higgs mass within the Standard Model in the light of the Taylor-Lagrange renormalization scheme. This scheme naturally leads to completely finite corrections, depending on an arbitrary scale. The formulation avoids very large individual corrections to the Higgs mass. This illustrates the fact that the so-called fine-tuning problem in the Standard Model is just an artifact of the regularization scheme. It should therefore not lead to any physical interpretation in terms of the energy scale at which new physics should show up, nor in terms of a new symmetry. We analyze the intrinsic physical scales relevant for the description of these radiative corrections.

Some nonrenormalizable theories are less singular than all renormalizable theories, and one can use lattice simulations to extract physical information from them. This paper discusses four nonrenormalizable theories that have finite Euclidian and Minkowskian Green’s functions. Two of them have finite energy densities and describe scalar bosons of finite mass. The space of nonsingular nonrenormalizable theories is vast.