We consider a recently proposed supersymmetric model based on the discrete $Q_6$ family group. Because of the family symmetry and spontaneous $CP$ violation, the electric dipole moment, the $CP$ violation in the mixing of the neutral mesons, and the dark matter mass $m_{\mathrm{DM}}$ are closely related. This triangle relation is controlled by the size of the $\mu$ parameters. Loop effects can give rise to large contributions to the soft mass insertions, and we find that the model allows a large $CP$ violation in the $B^0$ system. Its size is comparable with the recent experimental observations by D0 and CDF, and it could be observed at the LHCb in the first years. If the parameter space is constrained by the neutron electric dipole moment, flavor changing neutral currents, and $CP$ violations in $K^0$ as well as $B^0$ mixing, the triangle relation yields the following bound on the dark matter candidate: $0.12\mathrm{TeV}<m_{\mathrm{DM}}<0.33\mathrm{TeV}$, which is directly observable at the LHC. We also compute $a_{sl}^s-a_{sl}^d$, which is observable at the LHCb, where $a_{sl}^{s(d)}$ is the semileptonic $CP$ asymmetry for the $B_{s(d)}$ system.

We study the detectability of the lightest $CP$-odd Higgs boson of the next-to-minimal supersymmetric standard model (NMSSM), $a_1$, at the LHC through its production in association with a bottom-quark pair followed by the $a_1\to b\overline{b}$ decay. It is shown that, for large $\tan \beta$ and very high luminosity of the LHC, there exist regions of the NMSSM parameter space that can be exploited to detect the $a_1$ through this channel. This signature is a characteristic feature of the NMSSM in comparison to the minimal supersymmetric standard model (MSSM), as $a_1$ masses involved are well below those allowed in the MSSM for the corresponding $CP$-odd Higgs state.

We assume that the Higgs boson or a possible resonance—playing a role in strongly interacting models of electroweak symmetry breaking—has been discovered at the LHC, and we propose a search strategy to determine its spin based on two simple asymmetries in the $ZZ$, $W^{+}{W}^{-}$, and $t\overline{t}$ decay channels. We consider some benchmark values for its mass (above the $ZZ$ threshold, in the interval from $182\mathrm{GeV}/c^2$ to $1\mathrm{TeV}/c^2$) and discuss the relative advantages of the different decay processes. A full analysis, including the background, is given. For a center-of-mass energy of 14 TeV, we find that the lowest integrated luminosity required to discriminate between the different spins is, depending on the process and the resonance mass, between $40{\mathrm{fb}}^{-1}$ and $250{\mathrm{fb}}^{-1}$.

The volume dependence of the octet baryon masses and relations among them are explored with Lattice QCD. Calculations are performed with $n_f=2+1$ clover fermion discretization in four lattice volumes, with spatial extent $L\sim 2.0$, 2.5, 3.0 and 3.9 fm, with an anisotropic lattice spacing of $b_s\sim 0.123\mathrm{fm}$ in the spatial direction, and $b_t=b_s/3.5$ in the time direction, and at a pion mass of $m_{\pi }\sim 390\mathrm{MeV}$. The typical precision of the ground-state baryon mass determination is $\lesssim 0.2\%$, enabling a precise exploration of the volume dependence of the masses, the Gell-Mann–Okubo mass relation, and of other mass combinations. A comparison of the volume dependence with the predictions of heavy baryon chiral perturbation theory is performed in both the $\mathrm{SU}(2{)}_L\otimes \mathrm{SU}(2{)}_R$ and $\mathrm{SU}(3{)}_L\otimes \mathrm{SU}(3{)}_R$ expansions. Predictions of the three-flavor expansion for the hadron masses are found to describe the observed volume dependences reasonably well. Further, the $\Delta N\pi$ axial coupling constant is extracted from the volume dependence of the nucleon mass in the two-flavor expansion, with only small modifications in the three-flavor expansion from the inclusion of kaons and $\eta$’s. At a given value of $m_{\pi }L$, the finite-volume contributions to the nucleon mass are predicted to be significantly smaller at $m_{\pi }\sim 140\mathrm{MeV}$ than at $m_{\pi }\sim 390\mathrm{MeV}$ due to a coefficient that scales as $\sim m_{\pi }^3$. This is relevant for the design of future ensembles of lattice gauge-field configurations. Finally, the volume dependence of the pion and kaon masses are analyzed with two-flavor and three-flavor chiral perturbation theory.

We study heavy baryons with an exotic flavor quantum number formed by a heavy meson and a nucleon ($\overline{D}N$ and $BN$) through a long range one pion exchange interaction. The bound state found previously in the $(I,J^P)=(0,1/2^{-})$ channel survives when short range interaction is included. In addition, we find a resonant state with $(I,J^P)=(0,3/2^{-})$ as a Feshbach resonance predominated by a heavy vector meson and a nucleon (${\overline{D}}^{*}N$ and $B^{*}N$). We find that these exotic states exist for the charm and heavier flavor region.

We perform a systematic study of the possible loosely bound states composed of two charmed baryons or a charmed baryon and an anticharmed baryon within the framework of the one-boson-exchange model. We consider not only the $\pi$ exchange but also the $\eta$, $\rho$, $\omega$, $\varphi$, and $\sigma$ exchanges. The $S-D$ mixing effects for the spin triplets are also taken into account. With the derived effective potentials, we calculate the binding energies and rms radii for the systems ${\Lambda }_c{\Lambda }_c({\overline{\Lambda }}_c)$, ${\Xi }_c{\Xi }_c({\overline{\Xi }}_c)$, ${\Sigma }_c{\Sigma }_c({\overline{\Sigma }}_c)$, ${\Xi }_c^{\prime }{\Xi }_c^{\prime }({\overline{\Xi }}_c^{\prime })$, and ${\Omega }_c{\Omega }_c({\overline{\Omega }}_c)$. Our numerical results indicate that (1) the $H$-dibaryonlike state ${\Lambda }_c{\Lambda }_c$ does not exist and (2) there may exist four loosely bound deuteronlike states for the ${\Xi }_c{\Xi }_c$ and ${\Xi }_c^{\prime }{\Xi }_c^{\prime }$ systems with small binding energies and large rms radii.

We present a measurement of the inclusive top quark pair production cross section in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ utilizing data corresponding to an integrated luminosity of $5.3{\mathrm{fb}}^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider. We consider final states containing one high-$p_T$ isolated electron or muon and at least two jets, and we perform three analyses: one exploiting specific kinematic features of $t\overline{t}$ events, the second using $b$-jet identification, and the third using both techniques to separate the $t\overline{t}$ signal from the background. In the third case, we determine simultaneously the $t\overline{t}$ cross section and the ratio of the production rates of $W+\mathrm{\text{heavy}}$ flavor jets and $W+\mathrm{\text{light}}$ flavor jets, which reduces the impact of the systematic uncertainties related to the background estimation. Assuming a top quark mass of 172.5 GeV, we obtain ${\sigma }_{t\overline{t}}={7.78}_{-0.64}^{+0.77}\mathrm{pb}$. This result agrees with predictions of the standard model.

In this report we have studied the implication of a parity and charge-parity (PCP) violating interaction in varying-alpha theory. Because of this interaction, the state of photon polarization can change when it passes through a strong background magnetic field. We have calculated the optical rotation and ellipticity of the plane of polarization of an electro-magnetic wave and tested our results against different laboratory experiments. Our model contains a PCP violating parameter $\beta$ and a scale of alpha variation $\omega$. By analyzing the laboratory experimental data, we found the most stringent constraints on our model parameters to be parameters to be $1\le \omega \le {10}^{13}{\mathrm{GeV}}^2$ and $-0.5\le \beta \le 0.5$. We also found that with the existing experimental input parameters it is very difficult to detect the ellipticity in the near future.

We give some evidences which imply that ${\mathcal{W}}_{1+\infty }$ algebra describes the symmetry behind the Alday-Gaiotto-Tachikawa(-Wyllard) conjecture: a correspondence between the partition function of $\mathcal{N}=2$ supersymmetric quiver gauge theories and the correlators of Liouville (Toda) field theory.

We discuss the gauge-Higgs unification in a framework of Lifshitz-type gauge theory. We study a higher-dimensional gauge theory on $R^{D-1}\times S^1$ in which the normal second- (first-) order derivative terms for scalar (fermion) fields in the action are replaced by higher-order derivative ones for the direction of the extra dimension. We provide some mathematical tools to evaluate a one-loop effective potential for the zero mode of the extra component of a higher-dimensional gauge field and clarify how the higher-order derivative terms affect the standard form of the effective potential. Our results show that they can make the Higgs mass heavier and change its vacuum expectation value drastically. Some extensions of our framework are briefly discussed.

We generalize the virial theorem to the warped Dvali, Gabadadze, and Porrati brane-world scenario and consider its implications on the virail mass. In this theory the four-dimensional scalar curvature term is included in the bulk action and the resulting four-dimensional effective Einstein equation is augmented with extra terms which can be interpreted as geometrical mass, contributing to the gravitational energy. Estimating the geometrical mass $\mathcal{M}(r)$ using the observational data, we show that these geometric terms may account for the virial mass discrepancy in clusters of galaxies. Finally, we obtain the radial velocity dispersion of galaxy clusters ${\sigma }_r(r)$ and show that it is compatible with the radial velocity dispersion profile of such clusters.

Cosmological runaway solutions may exhibit an exact dilatation symmetry in the asymptotic limit of infinite time. In this limit, the massless dilaton or cosmon could be accompanied by another massless scalar field—the bolon. At finite time, small time-dependent masses for both the cosmon and the bolon are still present due to imperfect dilatation symmetry. For a sufficiently large mass, the bolon will start oscillating and play the role of dark matter, while the cosmon is responsible for dark energy. The common origin of the mass of both fields leads to an effective interaction between dark matter and dark energy. Realistic cosmologies are possible for a simple form of the effective cosmon-bolon potential. We find an inverse bolon mass of a size where it could reduce subgalactic structure formation.

We use the excursion set formalism to compute the properties of the halo mass distribution for a stochastic barrier model which encapsulates the main features of the ellipsoidal collapse of dark matter halos. Non-Markovian corrections due to the sharp filtering of the linear density field in real space are computed with the path-integral technique introduced by Maggiore and Riotto [M. Maggiore and A. Riotto, Astrophys. J. 711, 907 (2010).]. Here, we provide a detailed derivation of the results presented in [P. S. Corasaniti and I. Achitouv, Phys. Rev. Lett. 106, 241302 (2011).] and extend the mass function analysis to higher redshift. We also derive an analytical expression for the linear halo bias. We find a remarkable agreement with $N$-body simulation data from Tinker et al. [J. L. Tinker et al., Astrophys. J. 688, 709 (2008).] with differences $\lesssim 5\%$ over the range of mass probed by simulations. The excursion set solution from Monte Carlo generated random walks shows the same level of agreement, thus confirming the validity of the path-integral approach for the barrier model considered here. Similarly, the analysis of the linear halo bias shows deviations no greater than 20%. Overall these results indicate that the excursion set formalism in combination with a realistic modeling of the conditions of halo collapse can provide an accurate description of the halo mass distribution.

The topcolor-assisted technicolor (TC2) model predicts the existence of the charged top-pions (${\pi }_t^{\pm }$), whose large couplings with the third generation fermions will induce the charged top-pion production associated with the bottom and antibottom quark pair at the CERN Large Hadron Collider (LHC) through the parton processes $c\overline{b}\to {\pi }_t^{+}b\overline{b}$ and $u\overline{d}(c\overline{s})\to {\pi }_t^{+}b\overline{b}$. In this report, we examine these productions and find that, due to the small standard model backgrounds, their production rates can exceed the $3\sigma$ sensitivity of the LHC in a large part of parameter space, so these processes may serve as a good probe of the TC2 model.

Since the $N^{*}(1535)$ resonance was found to have large coupling to the strangeness due to its possible large $s\overline{s}$ component, we investigate the possible contribution of the $t$-channel $N^{*}(1535)$ exchange for the $p\overline{p}\to \varphi \varphi$ reaction. Our calculation indicates that the new mechanism may give significant contribution for the energies above 2.25 GeV and may be an important source for evading the Okubo-Zweig-Iizuka rule in the $\varphi$ production from $N\overline{N}$ annihilation.

We study the low transverse momentum ($p_T$) distribution of the $Z$-boson at hadron colliders for $p_T\sim {\Lambda }_{\mathrm{QCD}}$ using a factorization and resummation formula derived in the soft-collinear effective theory (SCET). In the region $p_T\sim {\Lambda }_{\mathrm{QCD}}$, new nonperturbative effects arise that cannot be entirely captured by the standard parton distribution functions, and require an additional new nonperturbative transverse momentum function (TMF). The TMF is field-theoretically defined in SCET, fully gauge-invariant, and captures the nonperturbative dynamics that affect the $p_T$-distribution in the region $p_T\sim {\Lambda }_{\mathrm{QCD}}$. The TMF also reduces to the expected perturbative result in the region $p_T\gg {\Lambda }_{\mathrm{QCD}}$. We develop phenomenological models for these TMFs in the nonperturbative region, and discuss in detail fits to Tevatron data in which both experimental and theoretical errors are carefully treated.

A sequential fourth generation is still viable, but the $t^{\prime }$ and $b^{\prime }$ quarks are constrained not to be too far apart in mass. The $t^{\prime }\to bW$ and $b^{\prime }\to tW$ decay channels are still being pursued at the Tevatron, which will soon be surpassed by the LHC. We use a convolution method with up to five-body final states to study $t^{\prime }$ and $b^{\prime }$ decays. We show how the two decay branches for $m_{b^{\prime }}$ below the $tW$ threshold, $b^{\prime }\to t{W}^{*}$ and $t^{*}W$, merge with $b^{\prime }\to tW$ above the threshold. We then consider the heavy-to-heavy transitions $b^{\prime }\to t^{\prime (*)}{W}^{(*)}$ (or $t^{\prime }\to b^{\prime (*)}{W}^{(*)}$), as they are not suppressed by quark mixing. We find that, because of the threshold sensitivity of the branching fraction of $t^{\prime }\to b^{\prime }{W}^{*}$ (or $b^{\prime }\to t^{\prime }{W}^{*}$), it is possible to measure the strength of the CKM mixing element $V_{t^{\prime }b}$ (or $V_{t{b}^{\prime }}$), especially when it is rather small. We urge experimenters to pursue and separate the $t^{\prime }\to b^{\prime }{W}^{*}$ (or $b^{\prime }\to t^{\prime }{W}^{*}$) decay in their search programs.

Dark matter pair production at high energy colliders may leave observable signatures in the energy and momentum spectra of the objects recoiling against the dark matter. We use LEP data on monophoton events with large missing energy to constrain the coupling of dark matter to electrons. Within a large class of models, our limits are complementary to and competitive with limits on dark matter annihilation and on WIMP-nucleon scattering from indirect and direct searches. Our limits, however, do not suffer from systematic and astrophysical uncertainties associated with direct and indirect limits. For example, we are able to rule out light ($\lesssim 10\mathrm{GeV}$) thermal relic dark matter with universal couplings exclusively to charged leptons. In addition, for dark matter mass below about 80 GeV, LEP limits are stronger than Fermi constraints on annihilation into charged leptons in dwarf spheroidal galaxies. Within its kinematic reach, LEP also provides the strongest constraints on the spin-dependent direct detection cross section in models with universal couplings to both quarks and leptons. In such models the strongest limit is also set on spin-independent scattering for dark matter masses below $\sim 4\mathrm{GeV}$. Throughout our discussion, we consider both low energy effective theories of dark matter, as well as several motivated renormalizable scenarios involving light mediators.

We consider the problem of neutrino masses and mixing within the framework of a nonminimal supersymmetric $SU(5)$ model extended by adding a set of $\underline{\mathbf{1}}$, $\underline{\mathbf{24}}$ chiral superfields accommodating three right-handed neutrinos. A type $\mathrm{I}+\mathrm{III}$ seesaw mechanism can then be realized, giving rise to a hierarchical mass spectrum for the light neutrinos of the form $m_3>m_2\gg m_1$, consistent with present data. The extra colored states are pushed to the unification scale by proton stability constraints, while the intermediate seesaw energy scale and the unification scale are maintained in phenomenologically acceptable ranges. We also examine the issue of the large neutrino mixing hierarchy ${\theta }_{23}>{\theta }_{12}\gg {\theta }_{13}$ in the above framework of hierarchical neutrino masses.