Metastable particles are common in many models of new physics at the TeV scale. If charged or colored, a reasonable fraction of all such particles produced at the LHC will stop in the detectors and give observable out-of-time decays. We discuss strategies for measuring the type of decay (two- vs three-body), the types of particles produced, and the angular distribution of the produced particles using the LHC detectors. We demonstrate that with a plausible level of control over experimental uncertainties and $\mathcal{O}(10–100)$ observed decay events, the gauge properties and some couplings of the new particles can be measured. If the new particle has a dominant three-body decay, then the spin properties of the particles and Lorentz structure of the decay operator can also be distinguished or constrained. These measurements can not only reveal the correct model of new physics at the TeV scale, but also give information on physics giving rise to the decay at energy scales far above those the LHC can probe directly.

We study exotic mesons with double charm and bottom flavor ($|C|=|B|=2$), whose quark configuration is $\overline{\mathrm{Q}}\overline{\mathrm{Q}}\mathrm{qq}$. This quark configuration has no annihilation process of quark and antiquark, and hence is a genuinely exotic state. We take a hadronic picture by considering the molecular states composed of a pair of heavy mesons, such as DD, $\mathrm{D}{\mathrm{D}}^{*}$, and ${\mathrm{D}}^{*}{\mathrm{D}}^{*}$ for charm flavor, and BB, $\mathrm{B}{\mathrm{B}}^{*}$, and ${\mathrm{B}}^{*}{\mathrm{B}}^{*}$ for bottom flavor. The interactions between heavy mesons are derived from the heavy quark effective theory. All molecular states are classified by $I(J^P)$ quantum numbers, and are systematically studied up to the total angular momentum $J\le 2$. By solving the coupled channel Schrödinger equations, due to the strong tensor force of one-pion exchange, we find bound and/or resonant states of various quantum numbers.

In this work we investigate the photoproduction of massive gauge bosons, $W^{\pm }$ and $Z^0$, as part of relevant physics topics to be studied in the proposed electron-proton collider, the Deep Inelastic Electron-Nucleon Scattering at the LHC (LHeC). The estimates for production cross sections and the number of events are presented. In addition, motivated by the intensive studies to test the deviations from the Standard Model at present and future colliders, we discuss the $W^{\pm }$ asymmetries and perform an analysis on the role played by anomalous $WW\gamma$ coupling.

We use gauge/gravity duality to explore strongly coupled superconductors with dynamical exponent $z=2$. In the probe limit we numerically establish background solutions for the matter fields and plot the condensate versus the dimensionless temperature. We then investigate electromagnetic perturbations in order to compute the ac conductivity and also calculate the spectral function. Our results for the condensate and conductivity are qualitatively similar to those of the anti-de Sitter (AdS) superconductor. However, we find that (for both the $s$-wave and $p$-wave) the condensate does not approach a constant at very low temperature and the conductivity goes to 1 from below but never exceeds it in the high frequency limit, in contrast to the AdS black hole. We do not see a peak at nonzero frequency in the imaginary part of the ac conductivity along the $x$ direction for the $p$-wave case. These features are due to the nontrivial dynamical exponent. To be specific, the black hole geometry considered in this work is anisotropic between space and time, very different from the Schwarzschild-AdS black hole, which results in different asymptotic behaviors of temporal and spatial components of gauge fields than those in the Schwarzschild-AdS black hole.

We study at quantum level correlators of supersymmetric Wilson loops with contours lying on Hopf fibers of $S^3$. In $\mathcal{N}=4$ super Yang-Mills theory the strong coupling analysis can be performed using the AdS/CFT correspondence and a connected classical string surface, linking two different fibers, is presented. More precisely, the string solution describes oppositely oriented fibers with the same scalar coupling and depends on an angular parameter, interpolating between a nonsupersymmetric configuration and a supersymmetric one. The system can be thought as an alternative deformation of the ordinary antiparallel lines giving the static quark-antiquark potential, that is indeed correctly reproduced, at weak and strong coupling, as the fibers approach one another.

Cosmic rays are the highest energy particles available for our study, and as such serve as excellent probes of the effects of Lorentz invariance violations which are expected to increase with energy. This general paradigm is investigated in this paper by studying the effects of such violations within the Coleman-Glashow model in which each particle species may have its own maximum attainable velocity, even exceeding that of light in vacuo. The particular focus here is that the muon neutrino may have the maximum speed exceeding that of light. We show that such an assumption leads to the elongation of the decay lifetime of the pion which increases with energy over and above the time dilation effects. We provide a transparent analytical derivation of the spectral intensities of muon neutrinos and muons generated in the Earth’s atmosphere by cosmic rays. In this derivation we not only account for elongation of the pion lifetime, but also for the loss of energy by the neutrinos by radiation of the electron-positron pairs through the Cohen-Glashow process during their propagation. We then compare the theoretical spectra with observations of neutrinos and muons from large instruments like IceCube and BUST to set a limit of $\sim {10}^{-13}$ on the fractional excess speed of neutrinos over that of light. We also show that the ratio of the spectral intensities of downward and upward moving neutrinos at various angles constitute an exclusive diagnostic for the Cohen-Glashow process, which may be searched for in the IceCube data set. We conclude the paper with several comments, including those related to improvements of these tests when definite signals of Griesen-Zatsepin-Kuzmin neutrinos will be observed.

In this work, one shows that a specific nonminimal coupling between the scalar curvature and matter can mimic the dark matter component of galaxy clusters. For this purpose, one assesses the Abell cluster A586, a massive nearby relaxed cluster of galaxies in virial equilibrium, where direct mass estimates and strong-lensing determinations are possible. One then extends the dark matter mimicking to a large sample of galaxy clusters whose density profiles are obtained from the Chandra high quality data, also in virial equilibrium. The total density, which generally follows a cusped profile and reveals a very small baryonic component, can be effectively described within this framework.

We investigate the motion of test bodies with internal structure in general relativity. We utilize a multipolar approximation scheme along the lines of Mathisson-Papapetrou-Dixon including the quadrupolar order. The motion of pole-dipole and quadrupole test bodies is studied in the context of the Kerr geometry. For an explicit quadrupole model, which includes spin and tidal interactions, the motion in the equatorial plane is characterized by an effective potential and by the binding energy. We compare our findings to recent results for the conservative part of the self-force of bodies in extreme mass ratio situations. Possible implications for gravitational wave physics are outlined.

Using a semianalytical approach recently developed to model the tidal deformations of neutron stars in inspiralling compact binaries, we study the dynamical evolution of the tidal tensor, which we explicitly derive at second post-Newtonian order, and of the quadrupole tensor. Since we do not assume a priori that the quadrupole tensor is proportional to the tidal tensor, i.e., the so-called “adiabatic approximation,” our approach enables us to establish to which extent such approximation is reliable. We find that the ratio between the quadrupole and tidal tensors (i.e., the Love number) increases as the inspiral progresses, but this phenomenon only marginally affects the emitted gravitational waveform. We estimate the frequency range in which the tidal component of the gravitational signal is well described using the Stationary phase approximation at next-to-leading post-Newtonian order, comparing different contributions to the tidal phase. We also derive a semianalytical expression for the Love number, which reproduces within a few percentage points the results obtained so far by numerical integrations of the relativistic equations of stellar perturbations.

We complete the Hamiltonian analysis of a specific model of nonlinear massive gravity that was started in 2012 [J. Kluson, J. High Energy Phys. 06 (2012) 170]. We identify the primary constraint and corresponding secondary constraint. We show that they are the second class constraints and hence they lead to the elimination of the additional scalar mode. We also find that the remaining constraints are the first class constraints with the structure that corresponds to the manifestly diffeomorphism-invariant theory. Finally, we determine the number of physical degrees of freedom and we show that it corresponds to the number of physical modes of massive gravity.

Recent reports of a gamma-ray line feature at $\sim 130\mathrm{GeV}$ in data from the Fermi Gamma-Ray Space Telescope have generated a great deal of interest in models in which dark matter particles annihilate with a sizable cross section to final states including photons. In this paper, we take a model-independent approach and discuss a number of possibilities for dark matter candidates which could potentially generate such a feature. While we identify several scenarios which could lead to such a gamma-ray line, these models are each fairly constrained. In particular, viable models require large couplings ($g\gtrsim 1–3$) and additional charged particles with masses in the range of approximately $\sim 130–200\mathrm{GeV}$. Furthermore, lower energy gamma-ray constraints from the Galactic center force us to consider scenarios in which the dark matter annihilates in the early Universe through velocity-suppressed processes or to final states which yield relatively few gamma-rays (such as $e^{+}{e}^{-}$, ${\mu }^{+}{\mu }^{-}$, or $\nu \overline{\nu }$). An exception to these conclusions can be found in models in which the dark matter annihilates to heavy intermediate states which decay to photons to generate a linelike gamma-ray spectrum.

The advanced worldwide network of gravitational waves (GW) observatories is scheduled to begin operations within the current decade. Thanks to their improved sensitivity, they promise to yield a number of detections and thus to open new observational windows for astronomy and astrophysics. Among the scientific goals that should be achieved, there is the independent measurement of the value of the cosmological parameters, hence an independent test of the current cosmological paradigm. Because of the importance of such a task, a number of studies have evaluated the capabilities of GW telescopes in this respect. However, since GW do not yield information about the source redshift, different groups have made different assumptions regarding the means through which the GW redshift can be obtained. These different assumptions imply also different methodologies to solve this inference problem. This work presents a formalism based on Bayesian inference developed to facilitate the inclusion of all assumptions and prior information about a GW source within a single data analysis framework. This approach guarantees the minimization of information loss and the possibility of including naturally event-specific knowledge (such as the sky position for a gamma ray burst–GW coincident observation) in the analysis. The workings of the method are applied to a specific example, loosely designed along the lines of the method proposed by Schutz in 1986, in which one uses information from wide-field galaxy surveys as prior information for the location of a GW source. I show that combining the results from few tens of observations from a network of advanced interferometers will constrain the Hubble constant $H_0$ to an accuracy of $\sim 4\%–5\%$ at 95% confidence.

Temporal quark correlation functions are analyzed in quenched lattice QCD for two values of temperature above the critical temperature ($T_c$) for deconfinement, $T=1.5T_c$ and $3T_c$. A two-pole ansatz for the quark spectral function is used to determine the bare quark mass and the momentum dependence of excitation spectra on large lattices of size up to ${128}^3\times 16$. The dependence of the quark correlator on these parameters as well as the finite volume dependence of the excitation energies are analyzed in detail in order to examine the reliability of our analysis. Our results suggest the existence of quasiparticle peaks in the quark spectrum. We furthermore find evidence that the dispersion relation of the plasmino mode has a minimum at nonzero momentum even in the nonperturbative region near $T_c$. We also elaborate on the enhancement of the quark correlator near the chiral limit which is observed at $T=1.5T_c$ on about half of the gauge configurations. We attribute this to the presence of near zero-modes of the fermion matrix that are associated with nontrivial topology of the gauge configurations.

The “Miranda procedure” proposed for analyzing Dalitz plots for $CP$ asymmetries in charged $B$ and $D$ decays in a model-independent manner is extended and refined in this paper. The complexity of Cabibbo-Kobayashi-Maskawa $CP$ phenomenology through order ${\lambda }^6$ is needed in searches for new dynamics (ND). Detailed analyses of three-body final states offer great advantages: (i) They give us more powerful tools for deciding whether an observed $CP$ asymmetry represents the manifestation of ND and its features. (ii) Many advantages can already be obtained by the Miranda procedure without construction of a detailed Dalitz plot description. (iii) One studies $CP$ asymmetries independent of production asymmetries. We illustrate the power of a second generation Miranda procedure with examples with time integrated rates for $B_d/{\overline{B}}_d$ decays to final states $K_S{\pi }^{+}{\pi }^{-}$ as trial runs, with comments on $B^{\pm }\to K^{\pm }{\pi }^{+}{\pi }^{-}/K^{\pm }{K}^{+}{K}^{-}$.

In the heavy quark limit, we establish the Bethe-Salpeter equation for the possible molecular state containing one heavy meson $D$ and one light meson $K$. With the kernel induced by one-particle-exchange diagrams, we solve the Bethe-Salpeter equation numerically in the ladder and covariant instantaneous approximations and find that the $DK$ bound state may exist. Assuming the observed state $D_{s0}^{*}(2317{)}^{+}$ is an S-wave $DK$ molecular bound state we calculate the strong decay width of $D_{s0}^{*}(2317{)}^{+}$. Our prediction for the decay width $\Gamma (D_{s0}^{*}(2317{)}^{+}\to D_s^{+}{\pi }^0)$ is consistent with the previous investigations and the current experimental data.

The high rates of multiparton interactions at the LHC can provide a unique opportunity to study the multiparton structure of the hadron. To this purpose high-energy collisions of protons with nuclei are particularly suitable. The rates of multiparton interactions depend, in fact, both on the partonic multiplicities and on the distributions of partons in transverse space, which produce different effects on the cross section in $pA$ collisions, as a function of the atomic mass number $A$. Differently with respect to the case of multiparton interactions in $pp$ collisions, the possibility of changing the atomic mass number thus provides an additional handle to distinguish the diverse contributions. Some relevant features of double parton interactions in $pD$ collisions have been discussed in a previous paper. In the present paper we show how the effects of double and triple correlation terms of the multiparton structure can be disentangled, by comparing the rates of multiple parton interactions in collisions of protons with $D$, ${}^3\mathrm{H}$, and ${}^3\mathrm{He}$.

The definition of topological invariants ${\tilde{\mathcal{N}}}_4$, ${\tilde{\mathcal{N}}}_5$ suggested in M. A. Zubkov and G. E. Volovik, Nucl. Phys. B860, 295 (2012) is extended to the case when there are zeros and poles of the Green function in momentum space. It is shown how to extend the index theorem suggested by Zubkov and Volovik to this case. The nonanalytical exceptional points of the Green function appear in the intermediate vacuum, which exists at the transition line between the massive vacua with different values of topological invariants. Their number is related to the jump $\Delta {\tilde{\mathcal{N}}}_4$ across the transition. The given construction is illustrated by momentum space topology of the lattice model with overlap fermions. The fermion excitations that appear in the vicinities of the given points cannot be considered as usual fermion particles. We, therefore, feel it is appropriate to call them generalized unparticles. This notion is, in the general case, different from the Georgi’s unparticle. However, in the case of lattice overlap fermions, the propagator of such excitations is indeed that of the fermionic unparticle suggested in M. Luo and G. Zhu, Phys. Lett. B 659, 341 (2008).

In this work we investigate the effects of the littlest Higgs model (LHM) up to the QCD next-to-leading order (NLO) on the $Z^0{H}^0$ associated production at the CERN Large Hadron Collider (LHC). We study the dependences of the leading order and NLO QCD corrected integrated cross sections for this process on the factorization/renormalization scale and the LHM parameters. We also provide the distributions of the transverse momenta of final decay products ${\mu }^{-}$ and ${\tau }^{-}$. Our results show that the heavy neutral gauge bosons $Z_H$ and $A_H$ could induce significant discrepancies from the standard model predictions. It is found that when the LHM parameters are taken as $c=0.5$, $c^{\prime }=0.22$, $f=4\mathrm{TeV}$, and $\mu =(M_H+M_Z)/2$, the effects at the $\sqrt{s}=14\mathrm{TeV}$ LHC from the heavy neutral gauge boson are about 12.83 and 10.37% to the leading order and NLO QCD corrected integrated cross sections, respectively. We also conclude that the NLO QCD corrections at the $\sqrt{s}=14\mathrm{TeV}$ LHC can obviously reduce the scale uncertainty of the integrated cross section, and significantly enhance the differential cross sections of $p_T^{{\mu }^{-}}$ and $p_T^{{\tau }^{-}}$. It demonstrates that the precision measurement of the $Z^0{H}^0$ associated production process at the LHC could provide the clue of the LHM physics.

We present a search for the standard model Higgs boson produced in association with a $W^{\pm }$ boson. This search uses data corresponding to an integrated luminosity of $7.5{\mathrm{fb}}^{-1}$ collected by the CDF detector at the Tevatron. We select $WH\to \ell \nu b\overline{b}$ candidate events with two jets, large missing transverse energy, and exactly one charged lepton. We further require that at least one jet be identified to originate from a bottom quark. Discrimination between the signal and the large background is achieved through the use of a Bayesian artificial neural network. The number of tagged events and their distributions are consistent with the standard model expectations. We observe no evidence for a Higgs boson signal and set 95% C.L. upper limits on the $WH$ production cross section times the branching ratio to decay to $b\overline{b}$ pairs, $\sigma (p\overline{p}\to W^{\pm }H)\times \mathcal{B}(H\to b\overline{b})$, relative to the rate predicted by the standard model. For the Higgs boson mass range of $100$ to $150\mathrm{GeV}/c^2$ we set observed (expected) upper limits from 1.34 (1.83) to 38.8 (23.4). For $115\mathrm{GeV}/c^2$ the upper limit is 3.64 (2.78). The combination of the present search with an independent analysis that selects events with three jets yields more stringent limits ranging from 1.12 (1.79) to 34.4 (21.6) in the same mass range. For 115 and $125\mathrm{GeV}/c^2$ the upper limits are 2.65 (2.60) and 4.36 (3.69), respectively.

We present a search for the standard model Higgs boson using events with two oppositely charged leptons and large missing transverse energy as expected in $H\to WW$ decays. The events are selected from data corresponding to $8.6{\mathrm{fb}}^{-1}$ of integrated luminosity in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ collected with the D0 detector at the Fermilab Tevatron Collider. No significant excess above the standard model background expectation in the Higgs boson mass range this search is sensitive to is observed, and upper limits on the Higgs boson production cross section are derived.