Considering the existence of old neutron stars puts strong limits on the dark matter-nucleon cross section for bosonic asymmetric dark matter. Key to these bounds is formation of a Bose-Einstein condensate (BEC) of the asymmetric dark matter particles. We consider the effects of the host neutron star’s gravitational field on the BEC transition. We find this substantially shifts the transition temperature and so strengthens the bounds on cross section. In particular, for the well-motivated mass range of 5–15 GeV, we improve previous bounds by an order of magnitude.

Holographic models of superconductors successfully reproduce certain experimental features of high-temperature superconductors, such as a large gap-to-$T_{\mathrm{c}}$ ratio compared to that of conventional superconductors. By deconstructing the extra dimension of these holographic models, similar phenomenology is described by a class of models defined in the natural dimension of the superconducting system. We analyze the sensitivity of certain observables in holographic and deconstructed holographic superconductors to details of the extra-dimensional spacetime. Our results support the notion that certain quantitative successes of simple models of this type are accidental. However, we also find a certain universal relationship between superconducting observables.

In this paper we study the phenomenology of color-octet and color-singlet scalars in the flavorful top-coloron model. We discuss the relevant production mechanisms at hadron colliders and the dominant decay modes, highlighting the most promising signatures for discovery, and derive bounds on the masses of the new scalars from LHC and Tevatron data. Of particular interest is the case in which color-octet scalars are pair produced and each decay to $t\overline{c}$ or $\overline{t}c$, leading to a same-sign dilepton final state. LHC data places a lower limit of 440 GeV on the octet mass in this scenario. The case of an octet lighter than the top, where the octet only decays into jets, has been tested by the Tevatron, which excludes the mass region from 50 to 125 GeV. The 8 TeV LHC is not yet sensitive to the observation of the color-singlet states, which are produced at rates much smaller than the octets. Nevertheless, the color-singlet pseudoscalar can be discovered at the 14 TeV LHC by analyzing the channel where it is produced from the decay of a color-octet vector boson.

The production of $c\overline{c}c\overline{c}$, $b\overline{b}b\overline{b}$ and $c\overline{c}b\overline{b}$ pairs considering double parton scattering at LHC energies is investigated. We estimate the contribution of saturation effects to the different final states and predict the energy dependence of the cross sections. Moreover, we estimate the ratio between the double and single parton scattering cross sections for the full rapidity range of the LHC and for the rapidity range of the LHCb experiment. For the full rapidity range we confirm a previous prediction, namely that for charm production the double parton scattering contribution becomes comparable with the single parton scattering one at LHC energies. We also demonstrate that this result remains valid when one introduces saturation effects in the calculations. Finally we show that the production of $c\overline{c}b\overline{b}$ contributes significantly to bottom production. For the LHCb kinematical range the ratio is strongly reduced.

Even if new data indicate that direct $CP$ violation in $D$-meson decays is compatible with the standard model expectation, the first hints for direct CP violation have triggered a lot of interest, and charm phenomenology will remain an essential part of new physics searches due to its unique role as a probe for flavor-changing neutral currents among up-type quarks. Charm physics poses considerable theoretical challenges, because the charm mass is neither light nor truly heavy. The heavy quark expansion (HQE) provides a perturbative expansion in the inverse heavy quark mass for inclusive rates. It has proved to be very successful in the $B$ sector, yet its validity for charm decays has often been questioned. We present results of a HQE study of $D$-meson lifetimes including NLO QCD and subleading $1/m_c$ corrections. We find good agreement with experimental data, but with huge hadronic uncertainties due to missing lattice input for hadronic matrix elements.

We report on a measurement of the top-quark electric charge in $t\overline{t}$ events in which one $W$ boson originating from the top-quark pair decays into leptons and the other into hadrons. The event sample was collected by the CDF II detector in $\sqrt{s}=1.96\mathrm{TeV}$ proton-antiproton collisions and corresponds to $5.6{\mathrm{fb}}^{-1}$. We find the data to be consistent with the standard model and exclude the existence of an exotic quark with $-4/3$ electric charge and mass of the conventional top quark at the 99% confidence level.

The T2K Collaboration reports evidence for electron neutrino appearance at the atmospheric mass splitting, $|\Delta m_{32}^2|\approx 2.4\times {10}^{-3}{\mathrm{eV}}^2$. An excess of electron neutrino interactions over background is observed from a muon neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK) detector 295 km from the beam’s origin. Signal and background predictions are constrained by data from near detectors located 280 m from the neutrino production target. We observe 11 electron neutrino candidate events at the SK detector when a background of $3.3\pm 0.4(\mathrm{syst})$ events is expected. The background-only hypothesis is rejected with a $p$ value of 0.0009 ($3.1\sigma$), and a fit assuming ${\nu }_{\mu }\to {\nu }_e$ oscillations with ${sin}^{2}2{\theta }_{23}=1$, ${\delta }_{CP}=0$ and $|\Delta m_{32}^2|=2.4\times {10}^{-3}{\mathrm{eV}}^2$ yields ${sin}^{2}2{\theta }_{13}={0.088}_{-0.039}^{+0.049}(\mathrm{stat}+\mathrm{syst})$.

The angular distribution of the two-body decay of a boson of unknown properties is strongly constrained by angular momentum conservation and rotation invariance, as well as by the nature of the detected decay particles and of the colliding ones. Knowing the border between the “physical” and “unphysical” parameter domains defined by these “minimal constraints” (excluding specific hypotheses on what is still subject of measurement) is a useful ingredient in the experimental determinations of angular distributions and can provide model-independent criteria for spin characterizations. In particular, analyzing the angular decay distribution with the general parametrization for the $J=2$ case can provide a model-independent discrimination between the $J=0$ and $J=2$ hypotheses for a particle produced by two real gluons and decaying into two real photons.

A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the $\Delta$ to a pion-nucleon state, extracting the $\pi N\Delta$ coupling constant and $\Delta$ decay width.

We show that a previous polarized ${}^3\mathrm{He}$ experiment at Princeton, plus Eöt–Wash equivalence-principle tests, constrain exotic, long-ranged ($\lambda >0.15\mathrm{m}$) parity-violating interactions of neutrons at levels well below those inferred from a recent study of the parity-violating spin precession of neutrons transmitted through liquid ${}^4\mathrm{He}$. For $\lambda >{10}^8\mathrm{m}$ the bounds on $g_A{g}_V$ are improved by 11 orders of magnitude.

We update and detail the formulation of the duality-invariant systems of $N$ interacting Abelian gauge fields with $N$ auxiliary bispinor fields added. In this setting, the self-duality amounts to $U(N)$ invariance of the nonlinear interaction of the auxiliary fields. The $U(N)$ self-dual Lagrangians arise after solving the nonlinear equations of motion for the auxiliary fields. We also elaborate on a new extended version of the bispinor field formulation involving some additional scalar auxiliary fields and study $U(N)$ invariant interactions with derivatives of the auxiliary bispinor fields. Such interactions generate higher-derivative $U(N)$ self-dual theories.

We obtain the most general static intersecting brane solutions by directly solving the relevant equations of motion analytically and in complete generality. These solutions reduce to the known ones in special cases, and contain further a class of new static solutions which are horizonless. We describe their properties and discuss their physical relevance. Along the way, we also describe the features of the brane energy momentum tensors, the equations of motion, and their solutions which arise as consequences of the intersection rules and the U-duality symmetries of M theory.

We consider the interaction between gravitational and electromagnetic radiation propagating on a Minkowski background and look into the effects of the former upon the latter. Not surprisingly, the coupling between these two sources leads to gravitationally driven electromagnetic waves. At the second perturbative level, the driving force appears as the superposition of two waves, the properties of which are decided by the initial conditions. We find that the Weyl-Maxwell interaction typically leads to electromagnetic beatlike signals and, in some cases, to the resonant amplification of the driven electromagnetic wave. For physically reasonable initial conditions, we show that these resonances imply a linear (in time) growth for the amplitude of the electromagnetic signal, with the overall amplification also depending on the strength of the driving gravity wave. Finally, we provide order-of-magnitude estimates of the achieved amplification by applying our analysis to astrophysical environments where both gravitational and electromagnetic waves are expected to coexist.

We study cylindrically symmetric Abelian wormholes in ($4+n$)-dimensional Kaluza-Klein theory. It is shown that static, four-dimensional, cylindrically symmetric solutions in ($4+n$)-dimensional Kaluza-Klein theory with maximal Abelian isometry group $\mathrm{U}(1{)}^n$ of the internal space with diagonal internal metric can be obtained, as in the case of a supersymmetric static black hole [M. Cvetič and D. Youm, Phys. Rev. D 52, 2144 (1995)], only if the isometry group of the internal space is broken down to the $\mathrm{U}(1{)}_e\times \mathrm{U}(1{)}_m$ gauge group; they correspond to dyonic configurations with one electric ($Q_e$) and one magnetic ($Q_m$) charge that are related either to the same $\mathrm{U}(1{)}_e$ or $\mathrm{U}(1{)}_m$ gauge field or to different factors of the $\mathrm{U}(1{)}_e\times \mathrm{U}(1{)}_m$ gauge group of the effective six-dimensional Kaluza-Klein theory. We find new exact solutions of the six-dimensional Kaluza-Klein theory with two Abelian gauge fields, a dilaton field and a scalar field, associated with the internal metric. We obtain new types of cylindrically symmetric wormholes supported by the radial and longitudinal electric and magnetic fields.

We present a method for calculating the maximum elastic quadrupolar deformations of relativistic stars, generalizing the previous Newtonian Cowling approximation integral given by Ushomirsky et al. [Mon. Not. R. Astron. Soc. 319, 902 (2000)]. (We also present a method for Newtonian gravity with no-Cowling approximation.) We apply these methods to the $m=2$ quadrupoles most relevant for gravitational radiation in three cases: crustal deformations, deformations of crystalline cores of hadron-quark hybrid stars, and deformations of entirely crystalline color superconducting quark stars. In all cases, we find suppressions of the quadrupole due to relativity compared to the Newtonian Cowling approximation, particularly for compact stars. For the crust these suppressions are up to a factor of $\sim 6$, for hybrid stars they are up to $\sim 4$, and for solid quark stars they are at most $\sim 2$, with slight enhancements instead for low mass stars. We also explore ranges of masses and equations of state more than in previous work and find that for some parameters the maximum quadrupoles can still be very large. Even with the relativistic suppressions, we find that $1.4M_{\odot }$ stars can sustain crustal quadrupoles of a $\mathrm{\text{few}}\times {10}^{39}\mathrm{g}{\mathrm{cm}}^2$ for the SLy equation of state or close to ${10}^{40}\mathrm{g}{\mathrm{cm}}^2$ for equations of state that produce less compact stars. Solid quark stars of $1.4M_{\odot }$ can sustain quadrupoles of around ${10}^{44}\mathrm{g}{\mathrm{cm}}^2$. Hybrid stars typically do not have solid cores at $1.4M_{\odot }$, but the most massive ones ($\sim 2M_{\odot }$) can sustain quadrupoles of a $\mathrm{\text{few}}\times {10}^{41}\mathrm{g}{\mathrm{cm}}^2$ for typical microphysical parameters and a $\mathrm{\text{few}}\times {10}^{42}\mathrm{g}{\mathrm{cm}}^2$ for extreme ones. All of these quadrupoles assume a breaking strain of ${10}^{-1}$ and can be divided by ${10}^{45}\mathrm{g}{\mathrm{cm}}^2$ to yield the fiducial “ellipticities” quoted elsewhere.

We further examine the capability of the 7 and 8 TeV LHC to explore the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with neutralino lightest supersymmetric particles. Here we present an updated study employing all of the relevant ATLAS supersymmetry (SUSY) analyses, as well as all relevant LHC non-missing-transverse-energy searches, whose data were publically available as of mid-September 2012. We find that roughly $1/3$ of our pMSSM model points, and 38% of the points with colored sparticles below 1 TeV, are excluded at present. An important role in excluding these models is being played by both the heavy-flavor and multilepton searches, as well as those for heavy stable charged particles. Nonetheless, we find that light gluinos, first/second generation squarks, and top squark/sbottoms (of order 400–700 GeV), as well as models with low fine-tuning (of order 1% according to the Barbieri-Giudice measure), are still viable in the pMSSM. In addition, we see that increased luminosity at 8 TeV is unlikely to significantly improve the reach of the standard $\mathrm{\text{jets}}+\mathrm{MET}$ searches. The impact of these null searches on the SUSY sparticle spectrum is discussed in detail and the implications of these results for models with low fine-tuning, a future lepton collider and dark matter searches are examined.

$B^{\pm }\to (D^0,{\overline{D}}^0,D_{CP})K_{0,2}^{*\pm }$ decays are helpful in determining the $CP$ violation angle $\gamma$, and we analyze these decay processes within the perturbative QCD approach based on $k_T$ factorization. We found that the branching ratio of $B^{-}\to D^0{K}_0^{*-}$ can reach the order of ${10}^{-4}$, due to the enhancement of nonfactorizable contributions in color-suppressed $D^0$-emission, while the branching ratio of $B^{-}\to {\overline{D}}^0{K}_0^{*-}$ is of the order ${10}^{-5}$. The ratio of decay amplitudes is about 3 times larger than the one in the channel $B^{\pm }\to D{K}^{\pm }$. Large branching ratios provide a good opportunity to observe $B^{\pm }\to D{K}_2^{*\pm }$ on the ongoing and forthcoming experimental facilities and consequently these channels may be of valuable avail in reducing the errors in the $CP$ violation phase angle $\gamma$. We also explore the possible time-dependent $CP$ asymmetries of $B_s$ decay into a scalar meson to determine the phase angle $\gamma$.

We calculate the annihilation decay widths of spin-singlet heavy quarkonia $h_c$, $h_b$ and ${\eta }_b$ into light hadrons with both QCD and relativistic corrections at order $O({\alpha }_s{v}^2)$ in nonrelativistic QCD. With appropriate estimates for the long-distance matrix elements by using the potential model and operator evolution method, we find that our predictions of these decay widths are consistent with recent experimental measurements. We also find that the $O({\alpha }_s{v}^2)$ corrections are small for $b\overline{b}$ states but substantial for $c\overline{c}$ states. In particular, the negative contribution of $O({\alpha }_s{v}^2)$ correction to the $h_c$ decay can lower the decay width, as compared with previous predictions without the $O({\alpha }_s{v}^2)$ correction, and thus result in a good agreement with the recent BESIII measurement.

The work of Jaffe, Jenkins and Kimchi [Phys. Rev. D 79, 065014 (2009)] is revisited to see if indeed the region of congeniality found in their analysis survives further restrictions from nucleosynthesis. It is observed that much of their congenial region disappears when imposing conditions required to produce the correct and required abundances of the primordial elements as well as ensure that stars can continue to burn hydrogen nuclei to form helium as the first step in forming heavier elements in stellar nucleosynthesis. The remaining region is a very narrow slit reduced in width from around 29 MeV found by Jaffe et al. to only about 2.2 MeV in the difference of the nucleon/quark masses. Further bounds on $\delta m_q/m_q$ seem to reduce even this narrow slit to the physical point itself.

If the massive neutrinos are identified to be the Majorana particles via a convincing measurement of the neutrinoless double beta ($0\nu \beta \beta$) decay, how to determine the Majorana $CP$-violating phases in the $3\times 3$ lepton flavor mixing matrix $U$ will become a desirable experimental question. The answer to this question is to explore all the possible lepton-number-violating (LNV) processes in which the Majorana phases really matter. In this paper we carry out a systematic study of $CP$ violation in neutrino-antineutrino oscillations, whose $CP$-conserving parts involve six independent $0\nu \beta \beta$-like mass terms $⟨m{⟩}_{\alpha \beta }$ and $CP$-violating parts are associated with nine independent Jarlskog-like parameters ${\mathcal{V}}_{\alpha \beta }^{ij}$ (for $\alpha$, $\beta =e$, $\mu$, $\tau$ and $i$, $j=1$, 2, 3). With the help of current neutrino oscillation data, we analyze the sensitivities of $|⟨m{⟩}_{\alpha \beta }|$ and ${\mathcal{V}}_{\alpha \beta }^{ij}$ to the three $CP$-violating phases of $U$, and illustrate the salient features of six independent $CP$-violating asymmetries between ${\nu }_{\alpha }\to {\overline{\nu }}_{\beta }$ and ${\overline{\nu }}_{\alpha }\to {\nu }_{\beta }$ oscillations. As a by-product, the effects of the $CP$-violating phases on the LNV decays of doubly and singly charged Higgs bosons are reexamined by taking account of the unsuppressed value of ${\theta }_{13}$. Such $CP$-conserving LNV processes can be complementary to the possible measurements of neutrino-antineutrino oscillations in the distant future.