The first full amplitude analysis of $B^{+}\to J/\psi \varphi K^{+}$ with $J/\psi \to {\mu }^{+}{\mu }^{-}$, $\varphi \to K^{+}{K}^{-}$ decays is performed with a data sample of $3{\mathrm{fb}}^{-1}$ of $pp$ collision data collected at $\sqrt{s}=7$ and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into $\varphi K^{+}$, and four $J/\psi \varphi$ structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed $X(4140)$ state. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the $K^{*}(1680{)}^{+}\to \varphi K^{+}$ transition.

We consider a general class of asymptotically locally ${\mathrm{AdS}}_5$ solutions of minimal gauged supergravity, which are dual to superconformal field theories on curved backgrounds $S^1\times M_3$ preserving two supercharges. We demonstrate that standard holographic renormalization corresponds to a scheme that breaks supersymmetry. We propose new boundary terms that restore supersymmetry, and show that for smooth solutions with topology $S^1\times {\mathbb{R}}^4$ the improved on-shell action reproduces both the supersymmetric Casimir energy and the field theory supersymmetric relation between charges.

We have searched for proton decay via $p\to e^{+}{\pi }^0$ and $p\to {\mu }^{+}{\pi }^0$ using Super-Kamiokande data from April 1996 to March 2015, $0.306\mathrm{megaton}·\mathrm{years}$ exposure in total. The atmospheric neutrino background rate in Super-Kamiokande IV is reduced to almost half that of phase I-III by tagging neutrons associated with neutrino interactions. The reach of the proton lifetime is further enhanced by introducing new signal criteria that select the decay of a proton in a hydrogen atom. No candidates were seen in the $p\to e^{+}{\pi }^0$ search. Two candidates that passed all of the selection criteria for $p\to {\mu }^{+}{\pi }^0$ have been observed, but these are consistent with the expected number of background events of 0.87. Lower limits on the proton lifetime are set at $\tau /B(p\to e^{+}{\pi }^0)>1.6\times 10^{34}\mathrm{years}$ and $\tau /B(p\to {\mu }^{+}{\pi }^0)>7.7\times 10^{33}\mathrm{years}$ at 90% confidence level.

Binary neutron star mergers are promising sources of gravitational waves for ground-based detectors such as Advanced LIGO. Neutron-rich material ejected by these mergers may also be the main source of r-process elements in the Universe, while radioactive decays in the ejecta can power bright electromagnetic postmerger signals. Neutrino-matter interactions play a critical role in the evolution of the composition of the ejected material, which significantly impacts the outcome of nucleosynthesis and the properties of the associated electromagnetic signal. In this work, we present a simulation of a binary neutron star merger using an improved method for estimating the average neutrino energies in our energy-integrated neutrino transport scheme. These energy estimates are obtained by evolving the neutrino number density in addition to the neutrino energy and flux densities. We show that significant changes are observed in the composition of the polar ejecta when comparing our new results with earlier simulations in which the neutrino spectrum was assumed to be the same everywhere in optically thin regions. In particular, we find that material ejected in the polar regions is less neutron rich than previously estimated. Our new estimates of the composition of the polar ejecta make it more likely that the color and time scale of the electromagnetic signal depend on the orientation of the binary with respect to an observer’s line of sight. These results also indicate that important observable properties of neutron star mergers are sensitive to the neutrino energy spectrum, and may need to be studied through simulations including a more accurate, energy-dependent neutrino transport scheme.

The kinematic Sunyaev-Zel’dovich (kSZ) signal is a powerful probe of the cosmic baryon distribution. The kSZ signal is proportional to the integrated free electron momentum rather than the electron pressure (which sources the thermal SZ signal). Since velocities should be unbiased on large scales, the kSZ signal is an unbiased tracer of the large-scale electron distribution, and thus can be used to detect the “missing baryons" that evade most observational techniques. While most current methods for kSZ extraction rely on the availability of very accurate redshifts, we revisit a method that allows measurements even in the absence of redshift information for individual objects. It involves cross-correlating the square of an appropriately filtered cosmic microwave background (CMB) temperature map with a projected density map constructed from a sample of large-scale structure tracers. We show that this method will achieve high signal-to-noise when applied to the next generation of high-resolution CMB experiments, provided that component separation is sufficiently effective at removing foreground contamination. Considering statistical errors only, we forecast that this estimator can yield $S/N\approx 3$, 120 and over 150 for Planck, Advanced ACTPol, and a hypothetical Stage IV CMB experiment, respectively, in combination with a galaxy catalog from WISE, and about 20% larger $S/N$ for a galaxy catalog from the proposed SPHEREx experiment. We show that the basic estimator receives a contribution due to leakage from CMB lensing, but that this term can be effectively removed by either direct measurement or marginalization, with little effect on the kSZ significance. We discuss possible sources of systematic contamination and propose mitigation strategies for future surveys. We compare the theoretical predictions to numerical simulations and validate the approximations in our analytic approach. This work serves as a companion paper to the first kSZ measurement with this method, where we used CMB temperature maps constructed from Planck and WMAP data, together with galaxies from the WISE survey, to obtain a $3.8–4.5\sigma$ detection of the ${\mathrm{kSZ}}^2$ amplitude.

We present a new mode-sum regularization prescription for computing the vacuum polarization of a scalar field in static spherically symmetric black hole spacetimes in odd dimensions. This is the first general and systematic approach to regularized vacuum polarization in higher dimensions. Remarkably, the regularization parameters can be computed in closed form in arbitrary dimensions and for arbitrary metric function $f(r)$. In fact, we show that in spite of the increasing severity and number of the divergences to be regularized, the method presented is mostly agnostic to the number of dimensions. Finally, as an explicit example of our method, we show plots for vacuum polarization in the Schwarzschild-Tangherlini spacetime for odd $d=5,\dots ,11$.

We report on WIMP search results of the XENON100 experiment, combining three runs summing up to 477 live days from January 2010 to January 2014. Data from the first two runs were already published. A blind analysis was applied to the last run recorded between April 2013 and January 2014 prior to combining the results. The ultralow electromagnetic background of the experiment, $\sim 5\times {10}^{-3}\mathrm{events}/({\mathrm{keV}}_{\mathrm{ee}}\times \mathrm{kg}\times \mathrm{day})$) before electronic recoil rejection, together with the increased exposure of $48\mathrm{kg}\times \mathrm{yr}$, improves the sensitivity. A profile likelihood analysis using an energy range of $(6.6–43.3){\mathrm{keV}}_{\mathrm{nr}}$ sets a limit on the elastic, spin-independent WIMP-nucleon scattering cross section for WIMP masses above $8\mathrm{GeV}/c^2$, with a minimum of $1.1\times {10}^{-45}{\mathrm{cm}}^2$ at $50\mathrm{GeV}/c^2$ and 90% confidence level. We also report updated constraints on the elastic, spin-dependent WIMP-nucleon cross sections obtained with the same data. We set upper limits on the WIMP-neutron (proton) cross section with a minimum of $2.0\times {10}^{-40}{\mathrm{cm}}^2$ ($52\times {10}^{-40}{\mathrm{cm}}^2$) at a WIMP mass of $50\mathrm{GeV}/c^2$, at 90% confidence level.

The hadron-quark phase transition in core-collapse supernovae (CCSNe) has the potential to trigger explosions in otherwise nonexploding models. However, those hybrid supernova equations of state (EOS) shown to trigger an explosion do not support the observational $2{\mathrm{M}}_{\odot }$ neutron star maximum mass constraint. In this work, we analyze cold hybrid stars by the means of a systematic parameter scan for the phase transition properties, with the aim to develop a new hybrid supernova EOS. The hadronic phase is described with the state-of-the-art supernova EOS HS(DD2), and quark matter by an EOS with a constant speed of sound (CSS) of $c_{\mathrm{QM}}^2=1/3$. We find promising cases which meet the $2{\mathrm{M}}_{\odot }$ criterion and are interesting for CCSN explosions. We show that the very simple CSS EOS is transferable into the well-known thermodynamic bag model, important for future application in CCSN simulations. In the second part, the occurrence of reconfinement and multiple phase transitions is discussed. In the last part, the influence of hyperons in our parameter scan is studied. Including hyperons no change in the general behavior is found, except for overall lower maximum masses. In both cases (with and without hyperons) we find that quark matter with $c_{\mathrm{QM}}^2=1/3$ can increase the maximum mass only if reconfinement is suppressed or if quark matter is absolutely stable.

I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a noncompact discrete subgroup of $SL(2,\mathbf{R})$ whose structure is related to the Pell equation. A discrete version of the Bañados-Teitelboim-Zanelli (BTZ) black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reaches the singularity.

The matter-neutrino resonance (MNR) phenomenon has the potential to significantly alter the flavor content of neutrinos emitted from compact object mergers. We present the first calculations of MNR transitions using neutrino self-interaction potentials and matter potentials generated self-consistently from a dynamical model of a three-dimensional neutron star merger. In the context of the single angle approximation, we find that symmetric and standard MNR transitions occur in both normal and inverted hierarchy scenarios. We examine the spatial regions above the merger remnant where propagating neutrinos will encounter the matter-neutrino resonance and find that a significant fraction of the neutrinos are likely to undergo MNR transitions.

We present the first detection of a correlation between the Lyman-$\alpha$ forest and cosmic microwave background gravitational lensing. For each Lyman-$\alpha$ forest in SDSS-III/BOSS DR12, we correlate the one-dimensional power spectrum with the cosmic microwave background lensing convergence on the same line of sight from Planck. This measurement constitutes a position-dependent power spectrum, or a squeezed bispectrum, and quantifies the nonlinear response of the Lyman-$\alpha$ forest power spectrum to a large-scale overdensity. The signal is measured at $5\sigma$ and is consistent with the expectation of the standard $\mathrm{\Lambda }\mathrm{CDM}$ cosmological model. We measure the linear bias of the Lyman-$\alpha$ forest with respect to the dark matter distribution and constrain a combination of nonlinear terms including the nonlinear bias. This new observable provides a consistency check for the Lyman-$\alpha$ forest as a large-scale structure probe and tests our understanding of the relation between intergalactic gas and dark matter. In the future, it could be used to test hydrodynamical simulations and calibrate the relation between the Lyman-$\alpha$ forest and dark matter.

We study a quantum-mechanical model proposed by Sachdev, Ye and Kitaev. The model consists of $N$ Majorana fermions with random interactions of a few fermions at a time. It it tractable in the large-$N$ limit, where the classical variable is a bilocal fermion bilinear. The model becomes strongly interacting at low energies where it develops an emergent conformal symmetry. We study two- and four-point functions of the fundamental fermions. This provides the spectrum of physical excitations for the bilocal field. The emergent conformal symmetry is a reparametrization symmetry, which is spontaneously broken to $SL(2,R)$, leading to zero modes. These zero modes are lifted by a small residual explicit breaking, which produces an enhanced contribution to the four-point function. This contribution displays a maximal Lyapunov exponent in the chaos region (out-of-time-ordered correlator). We expect these features to be universal properties of large-$N$ quantum mechanics systems with emergent reparametrization symmetry. This article is largely based on talks given by Kitaev, which motivated us to work out the details of the ideas described there.

We carry out a detailed study of multi-Higgs production processes in the gluon fusion channel in the high-energy regime relevant to future circular hadron colliders and in the high-Higgs-multiplicity limit ($\ge 20$). Our results are based on the computation of the leading polygons—the triangles, boxes, pentagons and hexagons—to the scattering processes, further combined with the subsequent branchings to reach high final-state multiplicities. The factorial growth of the number of diagrams leads to an exponential enhancement of such large-multiplicity cross sections and, ultimately, to the breaking of perturbativity. We find that the characteristic energy and multiplicity scales where these perturbative rates become highly enhanced and grow with increasing energy are within the 100 TeV regime, on the order of 130 Higgses (or more) in the final state. We also show that already for a 50 TeV hadron collider, the perturbative cross sections for 140 bosons are at the picobarn level.

We present a complete discussion of the boundary term in the action functional of general relativity when the boundary includes null segments in addition to the more usual timelike and spacelike segments. We confirm that ambiguities appear in the contribution from a null segment, because it depends on an arbitrary choice of parametrization for the generators. We also show that similar ambiguities appear in the contribution from a codimension-two surface at which a null segment is joined to another (spacelike, timelike, or null) segment. The parametrization ambiguity can be tamed by insisting that the null generators be affinely parametrized; this forces each null contribution to the boundary action to vanish, but leaves intact the fredom to rescale the affine parameter by a constant factor on each generator. Once a choice of parametrization is made, the ambiguity in the joint contributions can be eliminated by formulating well-motivated rules that ensure the additivity of the gravitational action. Enforcing these rules, we calculate the time rate of change of the action when it is evaluated for a so-called “Wheeler-DeWitt patch” of a black hole in asymptotically anti de Sitter space. We recover a number of results cited in the literature, obtained with a less complete analysis.

We calculate the ${\pi }^0\to {\gamma }^{*}{\gamma }^{*}$ transition form factor ${\mathcal{F}}_{{\pi }^0{\gamma }^{*}{\gamma }^{*}}(q_1^2,q_2^2)$ in lattice QCD with two flavors of quarks. Our main motivation is to provide the input to calculate the ${\pi }^0$-pole contribution to hadronic light-by-light scattering in the muon ($g-2$), $a_{\mu }^{\mathrm{HLbL};{\pi }^0}$. We therefore focus on the region where both photons are spacelike up to virtualities of about $1.5{\mathrm{GeV}}^2$, which has so far not been experimentally accessible. Results are obtained in the continuum at the physical pion mass by a combined extrapolation. We reproduce the prediction of the chiral anomaly for real photons with an accuracy of about 8–9%. We also compare to various recently proposed models and find reasonable agreement for the parameters of some of these models with their phenomenological values. Finally, we use the parametrization of our lattice data by these models to calculate $a_{\mu }^{\mathrm{HLbL};{\pi }^0}$.

Motivated by a recent experiment of J. Steinhauer, we reconsider the spectrum and the correlations of the phonons spontaneously emitted in stationary transonic flows. The latter are described by “waterfall” configurations which form a one-parameter family of stable flows. For parameters close to their experimental values, in spite of high gradients near the sonic horizon, the spectrum is accurately Planckian in the relevant frequency domain, where the temperature differs from the relativistic prediction by less than 10%. We then study the density correlations across the horizon and the nonseparable character of the final state. We show that the relativistic expressions provide accurate approximations when the initial temperature is not too high. We also show that the phases of the scattering coefficients introduce a finite shift of the location of the correlations which has so far been overlooked. This shift is due to the asymmetry of the flow across the horizon, and persists in the dispersionless regime. Finally we show how the formation of the sonic horizon modifies both local and nonlocal density correlations.

We present results from a search for neutrinoless double-$\beta$ ($0\nu \beta \beta$) decay using 36.6 g of the isotope ${}^{150}\mathrm{Nd}$ with data corresponding to a live time of 5.25 y recorded with the NEMO-3 detector. We construct a complete background model for this isotope, including a measurement of the two-neutrino double-$\beta$ decay half-life of $T_{1/2}^{2\nu }=[9.34\pm 0.22(\text{stat}){}_{-0.60}^{+0.62}(\text{syst})]\times {10}^{18}\mathrm{y}$ for the ground state transition, which represents the most precise result to date for this isotope. We perform a multivariate analysis to search for $0\nu \beta \beta$ decays in order to improve the sensitivity and, in the case of observation, disentangle the possible underlying decay mechanisms. As no evidence for $0\nu \beta \beta$ decay is observed, we derive lower limits on half-lives for several mechanisms involving physics beyond the standard model. The observed lower limit, assuming light Majorana neutrino exchange mediates the decay, is $T_{1/2}^{0\nu }>2.0\times 10^{22}\mathrm{y}$ at the 90% C.L., corresponding to an upper limit on the effective neutrino mass of $⟨m_{\nu }⟩<1.6–5.3\mathrm{eV}$.

The gravitational wave observations GW150914 and GW151226 by Advanced LIGO provide the first opportunity to learn about physics in the extreme gravity environment of coalescing binary black holes. The LIGO Scientific Collaboration and the Virgo Collaboration have verified that this observation is consistent with Einstein’s theory of general relativity, constraining the presence of certain parametric anomalies in the signal. This paper expands their analysis to a larger class of anomalies, highlighting the inferences that can be drawn on nonstandard theoretical physics mechanisms that could otherwise have affected the observed signals. We find that these gravitational wave events constrain a plethora of mechanisms associated with the generation and propagation of gravitational waves, including the activation of scalar fields, gravitational leakage into large extra dimensions, the variability of Newton’s constant, the speed of gravity, a modified dispersion relation, gravitational Lorentz violation and the strong equivalence principle. Though other observations limit many of these mechanisms already, GW150914 and GW151226 are unique in that they are direct probes of dynamical strong-field gravity and of gravitational wave propagation. We also show that GW150914 constrains inferred properties of exotic compact object alternatives to Kerr black holes. We argue, however, that the true potential for GW150914 to both rule out exotic objects and constrain physics beyond general relativity is severely limited by the lack of understanding of the coalescence regime in almost all relevant modified gravity theories. This event thus significantly raises the bar that these theories have to pass, both in terms of having a sound theoretical underpinning and reaching the minimal level of being able to solve the equations of motion for binary merger events. We conclude with a discussion of the additional inferences that can be drawn if the lower-confidence observation of an electromagnetic counterpart to GW150914 holds true, or such a coincidence is observed with future events; this would provide dramatic constraints on the speed of gravity and gravitational Lorentz violation.

We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from ${10}^{-19}({\mathrm{cm}}^2\mathrm{sr}\mathrm{s}{)}^{-1}$ for a Lorentz factor $\gamma =10^9$ to $2.5\times {10}^{-21}({\mathrm{cm}}^2\mathrm{sr}\mathrm{s}{)}^{-1}$ for $\gamma =10^{12}$. These results—the first obtained with a UHECR detector—improve previously published limits by up to an order of magnitude.

Upgraded electronics, improved water system dynamics, better calibration and analysis techniques allowed Super-Kamiokande-IV to clearly observe very low-energy ${}^8\mathrm{B}$ solar neutrino interactions, with recoil electron kinetic energies as low as $\sim 3.5\mathrm{MeV}$. Super-Kamiokande-IV data-taking began in September of 2008; this paper includes data until February 2014, a total livetime of 1664 days. The measured solar neutrino flux is $(2.308\pm 0.020{(\mathrm{stat})}_{-0.040}^{+0.039}(\mathrm{syst}))\times 10^6/({\mathrm{cm}}^2\sec )$ assuming no oscillations. The observed recoil electron energy spectrum is consistent with no distortions due to neutrino oscillations. An extended maximum likelihood fit to the amplitude of the expected solar zenith angle variation of the neutrino-electron elastic scattering rate in SK-IV results in a day/night asymmetry of $(-3.6\pm 1.6(\mathrm{stat})\pm 0.6(\mathrm{syst}))\%$. The SK-IV solar neutrino data determine the solar mixing angle as ${\sin }^2{\theta }_{12}={0.327}_{-0.031}^{+0.026}$, all SK solar data (SK-I, SK-II, SK III and SK-IV) measures this angle to be ${\sin }^2{\theta }_{12}={0.334}_{-0.023}^{+0.027}$, the determined mass-squared splitting is $\mathrm{\Delta }{m}_{21}^2={4.8}_{-0.8}^{+1.5}\times {10}^{-5}{\mathrm{eV}}^2$.