We formulate the general form of the $\omega$-$Z$-$\gamma$ vertex in the framework based on the hidden local symmetry, which arises from the gauge-invariant terms for intrinsic parity-odd part of the effective action. Those terms are given as the homogeneous part of the general solution (having free parameters) to the Wess-Zumino anomaly equation and hence are not determined by the anomaly, in sharp contrast to the Harvey-Hill-Hill (HHH) action where the relevant vertex is claimed to be uniquely determined by the anomaly. We show that, even in the framework that HHH was based on, the $\omega$-$Z$-$\gamma$ vertex is actually not determined by the anomaly but by the homogeneous (anomaly-free) part of the general solution to the Wess-Zumino anomaly equation having free parameters in the same way as in the hidden local symmetry formulation: The HHH action is just a particular choice of the free parameters in the general solution. We further show that the $\omega$-$Z$-$\gamma$ vertex related to the neutrino ($\nu$)-nucleon ($N$) scattering cross section $\sigma (\nu N\to \nu N(N^{\prime })\gamma )$ is determined not by the anomaly but by the anomaly-free part of the general solution having free parameters. Nevertheless, we find that the cross section $\sigma (\nu N\to \nu N(N^{\prime })\gamma )$ is related through the Ward-Takahashi identity to $\Gamma (\omega \to {\pi }^0\gamma )$ which has the same parameter dependence as that of $\sigma (\nu N\to \nu N(N^{\prime })\gamma )$ and hence the ratio $\sigma (\nu N\to \nu N(N^{\prime })\gamma )/\Gamma (\omega \to {\pi }^0\gamma )$ is fixed independently of these free parameters. Other set of the free parameters of the general solution can be fixed to make the best fit of the $\omega \to {\pi }^0{l}^{+}{l}^{-}$ process, which substantially differs from the HHH action. This gives a prediction of the cross section $\sigma (\nu N\to \nu N(N^{\prime }){\gamma }^{*}(l^{+}{l}^{-}))$ to be tested at $\nu$-$N$ collision experiments in the future.

A standard-model-like Higgs boson should be light in order to comply with electroweak precision measurements from LEP. We consider five-dimensional warped models—with a deformation of the metric in the IR region—as UV completions of the standard model with a heavy Higgs boson. Provided the Higgs boson propagates in the five-dimensional bulk the Kaluza Klein (KK) modes of the gauge bosons can compensate for the Higgs boson contribution to oblique parameters while their masses lie within the range of the LHC. The little hierarchy between KK scale and Higgs mass essentially disappears and the naturalness of the model greatly improves with respect to the Anti-de Sitter (Randall-Sundrum) model. In fact the fine-tuning is better than 10% for all values of the Higgs boson mass.

Recently the CDF Collaboration reported a statistically significant excess in the distribution of the dijet invariant mass between 120–160 GeV in $Wjj$ event sample in $4.3{\mathrm{fb}}^{-1}$ of data and later confirmed with $7.3{\mathrm{fb}}^{-1}$ of data, which has generated considerable interest. We offer a possible explanation of this observation in the general framework of minimal supersymmetric standard model with $R$-parity violation through resonance production of ${\tilde{\nu }}_{\tau }$ decaying into the LSP ${\tilde{\tau }}_1$ and $W$ boson. We also give the predictions of this scenario for the LHC operating at 7 TeV center of mass energy.

It is shown that realistic models can be constructed in which the standard model Higgs field is in a nontrivial multiplet of a non-Abelian family group of the quarks and leptons. It is shown that the observed quark and lepton masses and mixing angles can be fit, while the coefficients of flavor-changing four-fermion operators mediated by the extra Higgs doublets are determined in terms of only a few unknown parameters.

We present an exploratory study for charmonium radiative transitions: $J/\psi \to {\eta }_c\gamma$, ${\chi }_{c0}\to J/\Psi \gamma$, and $h_c\to {\eta }_c\gamma$ using $N_f=2$ twisted-mass lattice QCD gauge configurations. The single-quark vector form factors for ${\eta }_c$ and ${\chi }_{c0}$ are also determined. The simulation is performed at a lattice spacing of $a=0.067(2)\mathrm{fm}$ and the lattice size is ${32}^3\times 64$ with a pion mass of about 485 MeV. After extrapolation of lattice data at nonzero $Q^2$ to 0, we compare our results with previous quenched lattice results and the available experimental values.

We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one $D$ meson, and in addition another meson, $\overline{D}$, $K$, or $\overline{K}$. The systems are studied using the fixed center approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\overline{K}$ on a $DN$ cluster, which is known to generate the ${\Lambda }_c(2595)$, or the scattering of a nucleon on the $D\overline{D}$ cluster, which has been shown to generate a hidden charm resonance named $X(3700)$. We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^{*}(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\overline{K}DN$.

Two strategies are taken into account to determine the $f_1(1420)\mathrm{\text{−}}{f}_1(1285)$ mixing angle $\theta$. (i) First, using the Gell-Mann-Okubo mass formula together with the $K_1(1270)\mathrm{\text{−}}{K}_1(1400)$ mixing angle ${\theta }_{K_1}=(-34\pm 13)°$ extracted from the data for $\mathcal{B}(B\to K_1(1270)\gamma )$, $\mathcal{B}(B\to K_1(1400)\gamma )$, $\mathcal{B}(\tau \to K_1(1270){\nu }_{\tau })$, and $\mathcal{B}(\tau \to K_1(1420){\nu }_{\tau })$, gave $\theta =({23}_{-23}^{+17})°$. (ii) Second, from the study of the ratio for $f_1(1285)\to \varphi \gamma$ and $f_1(1285)\to {\rho }^0\gamma$ branching fractions, we have a twofold solution $\theta =({19.4}_{-4.6}^{+4.5})°$ or $({51.1}_{-4.6}^{+4.5})°$. Combining these two analyses, we thus obtain $\theta =({19.4}_{-4.6}^{+4.5})°$. We further compute the strange quark mass and strange quark condensate from the analysis of the $f_1(1420)\mathrm{\text{−}}{f}_1(1285)$ mass difference QCD sum rule, where the operator-product-expansion series is up to dimension six and to $\mathcal{O}({\alpha }_s^3,m_s^2{\alpha }_s^2)$ accuracy. Using the average of the recent lattice results and the $\theta$ value that we have obtained as inputs, we get $⟨\overline{s}s⟩/⟨\overline{u}u⟩=0.41\pm 0.09$.

We analyze the role of partonic transverse motion in unpolarized semi-inclusive deep inelastic scattering processes. Imposing appropriate kinematical conditions, we find some constraints which fix an upper limit to the range of allowed $k_{\perp }$ values. We show that, applying these additional requirements on the partonic kinematics, we obtain different results with respect to the usual phenomenological approach based on the Gaussian smearing with analytical integration over an unlimited range of $k_{\perp }$ values. These variations are particularly interesting for some observables, like the $⟨\cos {\varphi }_h⟩$ azimuthal modulation of the unpolarized semi-inclusive deep inelastic scattering cross section or the average transverse momentum of the final, detected hadron.

The light-cone distribution amplitudes for the axial current are derived within the instanton vacuum model, which incorporates nonperturbative effects including spontaneous chiral symmetry breaking. This allows one to extend applicability of the dipole approach, usually used in the perturbative domain, down to $Q^2\to 0$, where the partially conserved axial current imposes a relation between the neutrino-production cross section and the one induced by pions. A dramatic breakdown of the Adler relation for diffractive neutrino production of pions, caused by absorptive corrections, was revealed recently by Kopeliovich et al.. Indeed, comparing with the cross section predicted by the dipole phenomenology at $Q^2\to 0$ on a proton target we confirmed the sizable deviation from the value given by the Adler relation, as was estimated by Kopeliovich et al. within a simplified two-channel model. The dipole approach also confirms that in the black-disk limit, where the absorptive corrections maximize, the diffractive cross section ceases, on the contrary to the expectation based on the partially conserved axial current.

In this paper, we study nondecoupling $\mu \mathrm{\text{−}}e$ transition effects by a Higgs-mediated contribution in the MSSM, when some SUSY mass parameters are much greater than the TeV scale. In order to treat $CP$-odd Higgs mass $m_{A^0}$ as a free parameter, we consider the nonuniversal Higgs mass model and assume the only left- or right-handed sleptons had flavor-mixing mass terms. As a result, when only right-handed sleptons have flavor violation, there is some Higgs-dominant region although SUSY particle masses are around the TeV scale. We found it is necessary to consider the Higgs effect in the region where the gaugino effect receives destructive interference. Moreover, the ratio of branching ratios $\mathrm{BR}(\mu \to e\gamma )/\mathrm{BR}(\mu \mathrm{Al}\to e\mathrm{Al})$ drastically depends on the mass spectrum structure and chirality of flavor violation. The log factor from two split mass scales influences the way of interference between gaugino- and Higgs-mediated contributions significantly.

Using $e^{+}{e}^{-}$ collision data corresponding to $5.88\times {10}^6{\rm Y}(3S)$ [$25.9\times {10}^6\psi (2S)$] decays and acquired by the CLEO III [CLEO-c] detectors operating at the Cornell Electron Storage Ring, we study the single-pion transitions from ${\rm Y}(3S)[\psi (2S)]$ to the respective spin-singlet states $h_{b[c]}$. Utilizing only the momentum of suitably selected transition-${\pi }^0$ candidates, we obtain the upper limit $\mathcal{B}({\rm Y}(3S)\to {\pi }^0{h}_b)<1.2\times {10}^{-3}$ at 90% confidence level, and measure $\mathcal{B}(\psi (2S)\to {\pi }^0{h}_c)=(9.0\pm 1.5\pm 1.3)\times {10}^{-4}$. Signal sensitivities are enhanced by excluding very asymmetric ${\pi }^0\to \gamma \gamma$ candidates.

We reinvestigate a simple relation between the semileptonic $CP$ asymmetry $a_{sl}^s$, the decay rate difference $\Delta {\Gamma }_s$, the mass difference $\Delta M_s$ and $S_{\psi \varphi }$ extracted from the angular analysis of the decay $B_s\to \psi \varphi$, which is regularly used in the literature. We find that this relation is not suited to eliminate the theory prediction for ${\Gamma }_{12}$, it can, however be used to determine the size of the penguin contributions to the decay $B_s\to \psi \varphi$. Moreover we comment on the current precision of the theory prediction for ${\Gamma }_{12}$.

There are two nonequivalent ways to check if quantum effects in the context of semiclassical gravity can moderate or even cancel the final singularity appearing in a universe filled with dark energy: The method followed in [J. D. Bates and P. R. Anderson, Phys. Rev. D 82, 024018 (2010).] is to introduce the classical Friedmann solution in the energy density of the quantum field, and to compare the result with the density of dark energy determined by the Friedmann equation. The method followed in this comment is to solve directly the semiclassical equations. The results obtained by either method are very different, leading to opposed conclusions. The authors of [J. D. Bates and P. R. Anderson, Phys. Rev. D 82, 024018 (2010)] find that for a perfect fluid with state equation $p=\omega \rho$ and $\omega <-1$ (phantom fluid), considering realistic values of $\omega$ leads to a quantum field energy density that remains small compared to the dark energy density until the curvature reaches the Planck scale or higher, at which point the semiclassical approach stops being valid. The conclusion is that quantum effects do not affect significantly the expansion of the universe until the scalar curvature reaches the Planck scale. In this comment we will show by numerical integration of the semiclassical equations that quantum effects modify drastically the expansion of the universe from an early point. We also present an analytic argument explaining why the method of [J. D. Bates and P. R. Anderson, Phys. Rev. D 82, 024018 (2010)] fails to detect this. The units employed are the same as in [J. D. Bates and P. R. Anderson, Phys. Rev. D 82, 024018 (2010)] ($c=\hslash =G=1$).

Recently [N. E. Mavromatos and S. Sarkar, New J. Phys. 10, 073009 (2008) ; N. E. Mavromatos, S. Sarkar, and W. Tarantino, Phys. Rev. D 80, 084046 (2009)], we argued that a particular model of string-inspired quantum space-time foam (D-foam) may induce oscillations and mixing among flavored particles. As a result, rather than the mass-eigenstate vacuum, the correct ground state to describe the underlying dynamics is the flavor vacuum, proposed some time ago by Blasone and Vitiello as a description of quantum field theories with mixing. At the microscopic level, the breaking of target-space supersymmetry is induced in our space-time foam model by the relative transverse motion of brane defects. Motivated by these results, we show that the flavor vacuum, introduced through an inequivalent representation of the canonical (anti-) commutation relations, provides a vehicle for the breaking of supersymmetry at a low-energy effective field-theory level; on considering the flavor-vacuum expectation value of the energy-momentum tensor and comparing with the form of a perfect relativistic fluid, it is found that the bosonic sector contributes as dark energy while the fermion contribution is like dust. This indicates a strong and novel breaking of supersymmetry, of a nonperturbative nature, which may characterize the low-energy field theory of certain quantum-gravity models.

In general relativity, the fields on a black hole horizon are obtained from those in the bulk by pullback and restriction. Similarly, in quantum gravity, the quantized horizon degrees of freedom should result from restricting, or pulling back, the quantized bulk degrees of freedom. This is not yet fully realized in the—otherwise very successful—quantization of isolated horizons in loop quantum gravity. In this work we outline a setting in which the quantum horizon degrees of freedom are simply components of the quantized bulk degrees of freedom. There is no need to quantize them separately. We present evidence that for a horizon of sphere topology, the resulting horizon theory is remarkably similar to what has been found before.

The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations provide the natural stage for resonances to occur, gravitoelectromagnetic resonances have been investigated as a means of more efficient gravity-wave detection methods. In this report, we consider the coupling between the Weyl and the Maxwell fields on a Minkowski background, which also applies to astrophysical environments where gravity is weak, at the second perturbative level. We use covariant methods that describe gravitational waves via the transverse component of the shear, instead of pure-tensor metric perturbations. The aim is to calculate the properties of the electromagnetic signal, which emerges from the interaction of its linear counterpart with an incoming gravitational wave. Our analysis shows how the wavelength and the amplitude of the gravitationally driven electromagnetic wave vary with the initial conditions. More specifically, for certain initial data, the amplitude of the induced electromagnetic signal is found to diverge. Analogous, diverging, gravitoelectromagnetic resonances were also reported in cosmology. Given that, we extend our Minkowski space study to cosmology and discuss analogies and differences in the physics and in the phenomenology of the Weyl-Maxwell coupling between the aforementioned two physical environments.

At the LHC, a generic supersymmetric cascade can be a source of top quark. Specifically third generation squarks and gluino are the major sources of top quark which could also be boosted. In this article, we have shown that jet substructure algorithm can be very useful in identifying such boosted top quarks in the cascade. We take inclusive three jets plus zero lepton plus missing energy final state and try to reconstruct at least one hadronically decaying top quark by using top tagging technique which has good prospect at the LHC.

We have shown that in a large number of generic and renormalizable Wess-Zumino models, existence of a $Z_n$ R-symmetry is sufficient to break supersymmetry spontaneously. This implies that the existence of a $Z_n$ R-symmetry is a necessary condition for supersymmetry breaking in generic and renormalizable Wess-Zumino models.

The available data on the $Q^2$ dependence of the $\gamma {\gamma }^{*}(Q^2)\to K\overline{K}\pi$ reaction cross section in the energy region 1.35–1.55 GeV is explained by the $\eta (1475)$ resonance production in contrast to their conventional interpretation with the use of the $f_1(1420)$ resonance. It resolves theoretically the contradiction between the suppression of the $\eta (1475)\to \gamma \gamma$ decay width and the strong couplings of the $\eta (1475)$ to the $\rho \rho$, $\omega \omega$, and $\gamma {\rho }^0$ channels. The experimental check of our explanation requires definition of the spin-parity of the resonance contributions, $R$, in $\gamma {\gamma }^{*}(Q^2)\to R\to K\overline{K}\pi$ and in $J/\psi \to \gamma R\to \gamma \gamma ({\rho }^0,\varphi )$. This will help to solve difficulties accumulated in understanding properties of the $\eta (1475)$ state and its nearest partners.