We investigate the behavior of the lowest nonhydrodynamic modes in a class of holographic models which exhibit an equation of state closely mimicking the one determined from lattice QCD. We calculate the lowest quasinormal mode frequencies for a range of scalar self-interaction potentials and find that the damping of the quasinormal modes at the phase transition/crossover falls off by a factor of around two from conformality after factoring out standard conformal temperature dependence. The damping encoded in the imaginary part of the frequencies turns out to be correlated with the speed of sound and is basically independent of the UV details of the model. We also find that the dynamics of the nonhydrodynamic degrees of freedom remains ultralocal, even to a higher degree, as we deviate from conformality. These results indicate that the role of nonhydrodynamic degrees of freedom in the vicinity of the crossover transition may be enhanced.

A recent publication [J. D. Anderson et. al., Europhys. Lett. 110, 10002 (2015)] presented a strong correlation between the measured values of the gravitational constant $G$ and the 5.9 year oscillation of the length of day. Here, we compile published measurements of $G$ from the last 35 years. A least-squares regression to a sinusoid with period 5.9 years still yields a better fit than a straight line. However, our additions and corrections to the $G$ data reported by Anderson et al. significantly weaken the correlation.

Our goal is to obtain a complete set of angular observables arising in a generic multibody process. We show how this can be achieved without the need to carry out a likelihood fit of the angular distribution to the measured events. Instead, we apply the method of moments that relies both on the orthogonality of angular functions and the estimation of integrals by Monte Carlo techniques. The big advantage of this method is that the joint distribution of all observables can be easily extracted, even for very few events. The method of moments is shown to be robust against mismodeling of the angular distribution. Our main result is an explicit algorithm that accounts for systematic uncertainties from detector-resolution and acceptance effects. Finally, we present the necessary process-dependent formulas needed for direct application of the method to several rare decays of interest.

We measure the mass of the top quark in $\text{lepton}+\text{jets}$ final states using the full sample of $p\overline{p}$ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at $\sqrt{s}=1.96\mathrm{TeV}$, corresponding to $9.7{\mathrm{fb}}^{-1}$ of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from $t\overline{t}$ production or background. The overall jet energy scale is constrained in situ by the mass of the $W$ boson. We measure $m_t=174.98\pm 0.76\mathrm{GeV}$. This constitutes the most precise single measurement of the top-quark mass.

Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable with the Surface Detector array (SD) of the Pierre Auger Observatory. We report here on searches through Auger data from 1 January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to the diffuse flux of ultrahigh energy neutrinos that challenges the Waxman-Bahcall bound predictions. Neutrino identification is attempted using the broad time structure of the signals expected in the SD stations, and is efficiently done for neutrinos of all flavors interacting in the atmosphere at large zenith angles, as well as for “Earth-skimming” neutrino interactions in the case of tau neutrinos. In this paper the searches for downward-going neutrinos in the zenith angle bins 60°–75° and 75°–90° as well as for upward-going neutrinos, are combined to give a single limit. The 90% C.L. single-flavor limit to the diffuse flux of ultrahigh energy neutrinos with an $E^{-2}$ spectrum in the energy range $1.0\times 10^{17}\mathrm{eV}–2.5\times 10^{19}\mathrm{eV}$ is $E_{\nu }^{2}d{N}_{\nu }/d{E}_{\nu }<6.4\times {10}^{-9}\mathrm{GeV}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}{\mathrm{sr}}^{-1}$.

Merging galaxy clusters such as the Bullet Cluster provide a powerful testing ground for indirect detection of dark matter. The spatial distribution of the dark matter is both directly measurable through gravitational lensing and substantially different from the distribution of potential astrophysical backgrounds. We propose to use this spatial information to identify the origin of indirect detection signals, and we show that even statistical excesses of a few sigma can be robustly tested for consistency—or inconsistency—with a dark matter source. For example, our methods, combined with already-existing observations of the Coma Cluster, would allow the 3.55 keV line to be tested for compatibility with a dark matter origin. We also discuss the optimal spatial reweighting of photons for indirect detection searches. The current discovery rate of merging galaxy clusters and associated lensing maps strongly motivates deep exposures in these dark matter targets for both current and upcoming indirect detection experiments in the x-ray and gamma-ray bands.

We compute the $e^{+}{e}^{-}$ $C$-parameter distribution using the soft-collinear effective theory with a resummation to next-to-next-to-next-to-leading-log prime accuracy of the most singular partonic terms. This includes the known fixed-order QCD results up to $\mathcal{O}({\alpha }_s^3)$, a numerical determination of the two-loop nonlogarithmic term of the soft function, and all logarithmic terms in the jet and soft functions up to three loops. Our result holds for $C$ in the peak, tail, and far tail regions. Additionally, we treat hadronization effects using a field theoretic nonperturbative soft function, with moments ${\mathrm{\Omega }}_n$. To eliminate an $\mathcal{O}({\mathrm{\Lambda }}_{\mathrm{QCD}})$ renormalon ambiguity in the soft function, we switch from the $\overline{\mathrm{MS}}$ to a short distance “Rgap” scheme to define the leading power correction parameter ${\mathrm{\Omega }}_1$. We show how to simultaneously account for running effects in ${\mathrm{\Omega }}_1$ due to renormalon subtractions and hadron-mass effects, enabling power correction universality between $C$-parameter and thrust to be tested in our setup. We discuss in detail the impact of resummation and renormalon subtractions on the convergence. In the relevant fit region for ${\alpha }_s(m_Z)$ and ${\mathrm{\Omega }}_1$, the perturbative uncertainty in our cross section is $\simeq \hspace{0.17em}2.5\%$ at $Q=m_Z$.

We discuss various details of our derivation of the exact expression for the Adler $D$ function in $\mathcal{N}=1$ supersymmetric QCD. This exact formula relates the $D$ function to anomalous dimensions of the matter superfields. Our perturbative derivation refers to the $D$ function defined in terms of the bare coupling constant in the case of using the higher covariant derivative regularization. The exact expression for this function is obtained by direct summation of supergraphs to all orders in the non-Abelian coupling constant. As we argued previously, our formula should be valid beyond perturbation theory too. The perturbative result we present here coincides with the general formula order by order. We discuss consequences for $\mathcal{N}=1$ supersymmetric QCD in the conformal window. It is noted that our exact relation can allow one to determine the (infrared) critical anomalous dimension of the Seiberg $M$ field present in the dual theory.

An excess in $\gamma$ rays emanating from the Galactic Center has recently been observed in the Fermi-LAT data. This signal can be interpreted as resulting from weakly interacting massive particle annihilation, with the spectrum well fit by dark matter annihilating dominantly into either bottom-quark or Higgs pairs. Supersymmetric models provide a well-motivated framework to study the implications of this signal in these channels. With a neutralino dark matter candidate, the $\gamma$-ray excess cannot be easily accommodated in the minimal supersymmetric model, which in any case requires tuning below the percent level to explain the observed Higgs mass. Instead we are naturally led to consider the next-to-minimal model with a singlet superfield. This not only allows for the annihilation channel into bottom-quark pairs to be implemented but also provides new possibilities for annihilation into Higgs-pseudoscalar pairs. We show that the fit to the $\gamma$-ray excess for the Higgs-pseudoscalar channel can be just as good as for annihilation into bottom-quark pairs. Moreover, in the parameter range of interest, the next-to-minimal supersymmetric model solves the $\mu$ problem and can explain the 125 GeV Higgs mass with improved naturalness. We also consider an extension by adding a right-handed neutrino superfield with the right-handed sneutrino acting as a dark matter candidate. Interestingly, this allows for the annihilation into pseudoscalar pairs which also provide a good fit to the $\gamma$-ray excess. Furthermore, in the case of a neutralino lightest supersymmetric particle, the late decay of a sneutrino next-to-lightest supersymmetric particle can nonthermally produce the observed relic abundance. Finally, the weakly interacting massive particle annihilation into scalar pairs allows for the possibility of detecting the Higgs or pseudoscalar decay into two photons, providing a smoking-gun signal of the model.

At a distance of 50 kpc and with a dark matter mass of $\sim 10^{10}{\mathrm{M}}_{\odot }$, the large magellanic cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section. The LMC emission is generally very well described by the standard astrophysical sources, with at most a $1–2\sigma$ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. We place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.

Top quark loops in Higgs production via gluon fusion at large invariant final state masses can induce important interference effects in searches for additional Higgs bosons as predicted in, e.g., Higgs portal scenarios and the minimal supersymmetric Standard Model when the heavy scalar is broad or the final state resolution is poor. Currently, the limit setting as performed by both ATLAS and CMS is based on injecting a heavy Higgs-like signal neglecting interference effects. In this paper, we perform a study of such “on-shell” interference effects in $pp\to ZZ$ and find that they lead to a $\lesssim \mathcal{O}(30\%)$ width scheme-dependent modification of the signal strength. Including the continuum contributions to obtain, e.g., the full $pp\to ZZ\to 4\ell$ final state, this modification is reduced to the 10% level in the considered intermediate mass range.

A search for dinucleon decay into pions with the Super-Kamiokande detector has been performed with an exposure of 282.1 kiloton-years. Dinucleon decay is a process that violates baryon number by two units. We present the first search for dinucleon decay to pions in a large water-Cherenkov detector. The modes ${}^{16}\mathrm{O}(pp)\to {}^{14}\mathrm{C}{\pi }^{+}{\pi }^{+}$, ${}^{16}\mathrm{O}(pn)\to {}^{14}\mathrm{N}{\pi }^{+}{\pi }^0$, and ${}^{16}\mathrm{O}(nn)\to {}^{14}\mathrm{O}{\pi }^0{\pi }^0$ are investigated. No significant excess in the Super-Kamiokande data has been found, so a lower limit on the lifetime of the process per oxygen nucleus is determined. These limits are ${\tau }_{pp\to {\pi }^{+}{\pi }^{+}}>7.22\times 10^{31}\mathrm{years}$, ${\tau }_{pn\to {\pi }^{+}{\pi }^0}>1.70\times 10^{32}\mathrm{years}$, and ${\tau }_{nn\to {\pi }^0{\pi }^0}>4.04\times 10^{32}\mathrm{years}$. The lower limits on each mode are about 2 orders of magnitude better than previous limits from searches for dinucleon decay in iron.

During and after recombination, in addition to Thomson scattering with free electrons, photons also couple to neutral hydrogen and helium atoms through Rayleigh scattering. This coupling influences both cosmic microwave background (CMB) anisotropies and the distribution of matter in the Universe. The frequency dependence of the Rayleigh cross section breaks the thermal nature of CMB temperature and polarization anisotropies and effectively doubles the number of variables needed to describe CMB intensity and polarization statistics, while the additional atomic coupling changes the matter distribution and the lensing of the CMB. We introduce a new method to capture the effects of Rayleigh scattering on cosmological power spectra. Rayleigh scattering modifies CMB temperature and polarization anisotropies at the $\sim 1\%$ level at 35 GHz (scaling $\propto {\nu }^4$), and modifies matter correlations by as much as $\sim 0.3\%$. We show the Rayleigh signal, especially the cross-spectra between the thermal (Rayleigh) $E$-polarization and Rayleigh (thermal) intensity signal, may be detectable with future CMB missions even in the presence of foregrounds, and how this new information might help to better constrain the cosmological parameters.

We provide an invariant characterization of the physical properties of the Kerr spacetime. We introduce two dimensionless invariants, constructed out of some known curvature invariants, that act as detectors for the event horizon and ergosurface of the Kerr black hole. We also show that the mass and angular momentum can be extracted from local measurements of the curvature invariants, which in the weak field limit could be used to approximate the total angular momentum and mass of a system of merging black holes. Finally, we introduce a dimensionless invariant that gives a local measure of the “Kerrness” of the spacetime.

We present limits on sterile neutrino mixing using 4,438 live-days of atmospheric neutrino data from the Super-Kamiokande experiment. We search for fast oscillations driven by an ${\mathrm{eV}}^2$-scale mass splitting and for oscillations into sterile neutrinos instead of tau neutrinos at the atmospheric mass splitting. When performing both of these searches we assume that the sterile mass splitting is large, allowing ${\sin }^2(\mathrm{\Delta }{m}^{2}L/4E)$ to be approximated as 0.5, and we assume that there is no mixing between electron neutrinos and sterile neutrinos ($|U_{e4}{|}^2=0$). No evidence of sterile oscillations is seen and we limit $|U_{\mu 4}{|}^2$ to less than 0.041 and $|U_{\tau 4}{|}^2$ to less than 0.18 for $\mathrm{\Delta }{m}^2>0.1{\mathrm{eV}}^2$ at the 90% C.L. in a $3+1$ framework. The approximations that can be made with atmospheric neutrinos allow these limits to be easily applied to $3+\mathrm{N}$ models, and we provide our results in a generic format to allow comparisons with other sterile neutrino models.

We present a new lattice QCD analysis of heavy-quark pseudoscalar-pseudoscalar correlators, using gluon configurations from the MILC Collaboration that include vacuum polarization from $u$, $d$, $s$, and $c$ quarks ($n_f=4$). We extract new values for the QCD coupling and for the $c$ quark’s $\overline{\mathrm{MS}}$ mass: ${\alpha }_{\overline{\mathrm{MS}}}(M_Z,n_f=5)=0.11822(74)$ and $m_c(3\mathrm{GeV},n_f=4)=0.9851(63)\mathrm{GeV}$. These agree well with our earlier simulations using $n_f=3$ sea quarks, vindicating the perturbative treatment of $c$ quarks in that analysis. We also obtain a new nonperturbative result for the ratio of $c$ and $s$ quark masses: $m_c/m_s=11.652(65)$. This ratio implies $m_s(2\mathrm{GeV},n_f=3)=93.6(8)\mathrm{MeV}$ when it is combined with our new $c$ mass. Combining $m_c/m_s$ with our earlier $m_b/m_c$ gives $m_b/m_s=52.55(55)$, which is several standard deviations (but only 4%) away from the Georgi-Jarlskop prediction from certain grand unified theories. Finally we obtain an $n_f=4$ estimate for $m_b/m_c=4.528(54)$ which agrees well with our earlier $n_f=3$ result. The new ratio implies $m_b(m_b,n_f=5)=4.162(48)\mathrm{GeV}$.

We compute the spectral density of the (Hermitian) Dirac operator in quantum chromodynamics with two light degenerate quarks near the origin. We use CLS/ALPHA lattices generated with two flavors of $\mathrm{O}(a)$-improved Wilson fermions corresponding to pseudoscalar meson masses down to 190 MeV and with spacings in the range 0.05–0.08 fm. Thanks to the coverage of parameter space, we can extrapolate our data to the chiral and continuum limits with confidence. The results show that the spectral density at the origin is nonzero because the low modes of the Dirac operator do condense as expected in the Banks-Casher mechanism. Within errors, the spectral density turns out to be a constant function up to eigenvalues of $\approx 80\mathrm{MeV}$. Its value agrees with the one extracted from the Gell-Mann-Oakes-Renner relation.

The cosmological scenario where the Peccei-Quinn symmetry is broken after inflation is investigated. In this scenario, topological defects such as strings and domain walls produce a large number of axions, which contribute to the cold dark matter of the Universe. The previous estimations of the cold dark matter abundance are updated and refined based on the field-theoretic simulations with improved grid sizes. The possible uncertainties originated in the numerical calculations are also discussed. It is found that axions can be responsible for the cold dark matter in the mass range $m_a=(0.9–1.4)\times 10^{-4}\mathrm{eV}$ for the models with the domain wall number $N_{\mathrm{DW}}=1$, and $m_a\approx \mathcal{O}(10^{-4}–10^{-2})\mathrm{eV}$ with a mild tuning of parameters for the models with $N_{\mathrm{DW}}>1$. Such higher mass ranges can be probed in future experimental studies.

Coupled-channel $\pi K$ and $\eta K$ scattering amplitudes are determined by studying the finite-volume energy spectra obtained from dynamical lattice QCD calculations. Using a large basis of interpolating operators, including both those resembling a $q\overline{q}$ construction and those resembling a pair of mesons with relative momentum, a reliable excited-state spectrum can be obtained. Working at $m_{\pi }=391\mathrm{MeV}$, we find a gradual increase in the $J^P=0^{+}$ $\pi K$ phase shift which may be identified with a broad scalar resonance that couples strongly to $\pi K$ and weakly to $\eta K$. The low-energy behavior of this amplitude suggests a virtual bound state that may be related to the $\kappa$ resonance. A bound state with $J^P=1^{-}$ is found very close to the $\pi K$ threshold energy, whose coupling to the $\pi K$ channel is compatible with that of the experimental $K^{\star }(892)$. Evidence is found for a narrow resonance in $J^P=2^{+}$. Isospin-$3/2$ $\pi K$ scattering is also studied, and nonresonant phase shifts spanning the whole elastic scattering region are obtained.

A search for neutrino oscillations induced by Lorentz violation has been performed using 4,438 live-days of Super-Kamiokande atmospheric neutrino data. The Lorentz violation is included in addition to standard three-flavor oscillations using the nonperturbative standard model extension (SME), allowing the use of the full range of neutrino path lengths, ranging from 15 to 12,800 km, and energies ranging from 100 MeV to more than 100 TeV in the search. No evidence of Lorentz violation was observed, so limits are set on the renormalizable isotropic SME coefficients in the $e\mu$, $\mu \tau$, and $e\tau$ sectors, improving the existing limits by up to 7 orders of magnitude and setting limits for the first time in the neutrino $\mu \tau$ sector of the SME.