Estimators for weak lensing observables such as shear and convergence generally have nonlinear corrections, which, in principle, make weak lensing power spectra sensitive to primordial non-Gaussianity. In this paper, we quantitatively evaluate these contributions for weak lensing autocorrelation and cross-correlation power spectra, and show that they are strongly suppressed by projection effects. This is a consequence of the central limit theorem, which suppresses departures from Gaussianity when the projection reaches over several correlation lengths of the density field, $L_P\sim 55\mathrm{Mpc}/h$. Furthermore, the typical scales that contribute to projected bispectra are generally smaller than those that contribute to projected power spectra. Neither of these effects is specific to lensing; thus they affect the statistics of nonlinear tracers (e.g., peaks) of any projected density field. Therefore, the clustering of biased tracers of the three-dimensional density field is generically more sensitive to non-Gaussianity than observables constructed from projected density fields.

I construct exact solutions for general nonextremal rotating, charged Kaluza-Klein black holes with a cosmological constant and with arbitrary angular momenta in all higher dimensions. I then investigate their thermodynamics and find their generalizations with the Newman-Unti-Tamburino charges. The metrics are given in both Boyer-Lindquist coordinates and a form very similar to the famous Kerr-Schild ansatz, which highlights its potential application to include multiple electric charges into solutions yet to be found in gauged supergravity. It is also observed that the metric ansatz in $D=4$ dimensions is similar to those previously suggested by Yilmaz and later by Bekenstein.

Lüscher’s method is routinely used to determine meson-meson, meson-baryon, and baryon-baryon s-wave scattering amplitudes below inelastic thresholds from lattice QCD calculations—presently at unphysical light-quark masses. In this work we review the formalism and develop the requisite expressions to extract phase shifts describing meson-meson scattering in partial waves with angular momentum $l\le 6$ and $l=9$. The implications of the underlying cubic symmetry, and strategies for extracting the phase shifts from lattice QCD calculations, are presented, along with a discussion of the signal-to-noise problem that afflicts the higher partial waves.

New TeV-scale physics processes at the LHC can produce Higgs bosons with substantive transverse Lorentz boost, such that the Higgs’s decay products are nominally contained in a single jet. In the case of a light Higgs decaying predominantly to $b\overline{b}$, previous studies have shown that these Higgs jets can be identified by capitalizing on jet substructure techniques. In this work, we explore the possibility of also utilizing the subdominant but very distinctive decay $h\to {\tau }^{+}{\tau }^{-}$. To this end, we introduce the concept of a “ditau jet,” or a jet consisting of two semicollinear taus where one or both decay hadronically. We perform simple modifications to ordinary tau tagging methods to account for this configuration, and estimate tag rates of $O(50\%)$ and QCD mistag rates of $O({10}^{-4}–{10}^{-3})$ for $p_T\sim \mathrm{TeV}$, even in the presence of pileup. We further demonstrate the feasibility of reconstructing the ditau invariant mass by using traditional ${\cancel{E}}_T$ decaying to $Zh$, utilizing both leptonic and hadronic $Z$ decay channels. The leptonic $Z$ channel is limited due to low statistics, but the hadronic $Z$ channel is potentially competitive with other searches.

We study double transverse spin asymmetries in the Drell-Yan process at measured transverse momentum of the lepton pair. Contrary to what a collinear factorization approach would suggest, a nonzero double transverse spin asymmetry in the laboratory frame a priori does not imply nonzero transversity. Transverse momentum dependent (TMD) effects, such as the double Sivers effect, in principle form a background. Using the current knowledge of the relevant TMDs, we estimate their contribution in the laboratory frame for Drell-Yan and $W$ production at RHIC and point out a cross-check asymmetry measurement to bound the TMD contributions. We also comment on the transverse momentum integrated asymmetries that only receive power suppressed background contributions.

We present a new technique to directly reconstruct the spectra of ${\nu }_{\mu }$, ${\nu }_{\tau }$, ${\overline{\nu }}_{\mu }$, and ${\overline{\nu }}_{\tau }$ from a supernova, using neutrino-proton elastic scattering events ($\nu +p\to \nu +p$) at scintillator detectors. These neutrinos, unlike ${\nu }_e$ and ${\overline{\nu }}_e$, have only neutral current interactions, which makes it very challenging, with any reaction, to detect them and measure their energies. With updated inputs from theory and experiments, we show that this channel provides a robust and sensitive measure of their spectra. Given the low yields and lack of spectral information in other neutral current channels, this is perhaps the only realistic way to extract such information. This will be indispensable for understanding flavor oscillations of SN neutrinos, as it is likely to be impossible to disentangle neutrino mixing from astrophysical uncertainties in a SN without adequate spectral coverage of all flavors. We emphasize that scintillator detectors, e.g., Borexino, KamLAND, and $\mathrm{SNO}+$, have the capability to observe these events, but they must be adequately prepared with a trigger for a burst of low-energy events. We also highlight the capabilities of a larger detector like LENA.

This paper describes searches for the pair production of first or second generation scalar leptoquarks using $35{\mathrm{pb}}^{-1}$ of proton-proton collision data recorded by the ATLAS detector at $\sqrt{s}=7\mathrm{TeV}$. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses $M_{\mathrm{LQ}}<376$ (319) GeV and $M_{\mathrm{LQ}}<422$ (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark to a charged lepton is equal to 1.0 (0.5).

The ${\rm Y}\left(1S\right)$, ${\rm Y}\left(2S\right)$, and ${\rm Y}\left(3S\right)$ production cross sections in proton-proton collisions at $\sqrt{s}=7\mathrm{TeV}$ are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of $3.1\pm 0.3{\mathrm{pb}}^{-1}$. Integrated over the rapidity range $|y|<2$, we find the product of the ${\rm Y}\left(1S\right)$ production cross section and branching fraction to dimuons to be $\sigma (pp\to {\rm Y}(1S\left)X\right)·\mathcal{B}\left({\rm Y}\right(1S)\to {\mu }^{+}{\mu }^{-})=7.37\pm {0.13}_{-0.42}^{+0.61}\pm 0.81\mathrm{nb}$, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized ${\rm Y}\left(1S\right)$ production. With the assumption of fully transverse or fully longitudinal production polarization, the measured cross section changes by about 20%. We also report the measurement of the ${\rm Y}\left(1S\right)$, ${\rm Y}\left(2S\right)$, and ${\rm Y}\left(3S\right)$ differential cross sections as a function of transverse momentum and rapidity.

The Dyson-Schwinger equation for the four-point quark Green’s functions is studied. In the limit of the heavy quark mass and with the truncation to include only the dressed two-point functions for the Yang-Mills sector, we provide an exact solution for the four-point quark Green’s functions, in both quark-antiquark and diquark channels, and show that the corresponding poles relate to the bound-state energy of the heavy quark systems. Moreover, a natural separation between physical and unphysical poles in the Green’s functions emerges.

Carr and Hawking showed that the proper size of a spherical overdense region surrounded by a flat Friedmann Robertson Walker (FRW) universe cannot be arbitrarily large as otherwise the region would close up on itself and become a separate universe. From this result, they derived a condition connecting size and density of the overdense region ensuring that it is part of our universe. Carr used this condition to obtain an upper bound for the density fluctuation amplitude with the property that for smaller amplitudes the formation of a primordial black hole is possible, while larger ones indicate a separate universe. In contrast, we find that the appearance of a maximum is not a consequence of avoiding separate universes but arises naturally from the geometry of the chosen slicing. Using instead of density a volume fluctuation variable reveals that a fluctuation is a separate universe if this variable diverges on superhorizon scales. Hence, Carr’s and Hawking’s condition does not pose a physical constraint on density fluctuations. The dynamics of primordial black hole formation with an initial curvature fluctuation amplitude larger than the one corresponding to the maximum density fluctuation amplitude was previously not considered in detail and so we compare it to the well-known case where the amplitude is smaller by presenting embedding and conformal diagrams of both types in dust spacetimes.

Photons produced in the annihilations of dark matter particles can be detected by gamma-ray telescopes; this technique of indirect detection serves as a cornerstone of the upcoming assault on the dark matter paradigm. The main obstacle to the extraction of information about dark matter from the annihilation photons is the presence of large and uncertain gamma-ray backgrounds. We present a new technique for using gamma-ray data to constrain the properties of dark matter that makes minimal assumptions about the dark matter and the backgrounds. The technique relies on two properties of the expected signal from annihilations of the smooth dark matter component in our Galaxy: (1) it is approximately rotationally symmetric around the axis connecting us to the Galactic center, and (2) variations from the mean signal are uncorrelated from one pixel to the next. We apply this technique to recent data from the Fermi telescope to generate constraints on the dark matter mass and cross section for a variety of annihilation channels. We quantify the uncertainty introduced into our constraints by uncertainties in the halo profile and by the possibility that the halo is triaxial. The resultant constraint, the flux $F\le 4.5\times {10}^{-6}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}{\mathrm{sr}}^{-1}$ for energies between 1 and 100 GeV at an angle 15° away from the Galactic center, translates into an upper limit on the velocity-weighted annihilation cross section of order ${10}^{-25}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$, depending on the annihilation mode.

We study the detection of the $t^{\prime }$ of a fourth family during the early running of LHC with 7 TeV collision energy and $1{\mathrm{fb}}^{-1}$ integrated luminosity. By the use of a neural network we show that it is feasible to search for the $t^{\prime }$ even with a mass close to the unitarity upper bound, which is in the 500 to 600 GeV range. We also present results for the Tevatron with $10{\mathrm{fb}}^{-1}$. In both cases the search for a fourth family quark doublet can be significantly enhanced if one incorporates the contribution that the $b^{\prime }$ can make to a $t^{\prime }$-like signal. Thus, the bound on the mass of a degenerate quark doublet should be stronger than the bounds obtained by treating $t^{\prime }$ and $b^{\prime }$ in isolation.

The $N$-jettiness event shape divides phase space into $N+2$ regions, each containing one jet or beam. Using a geometric measure, these regions correspond to jets with circular boundaries. We give a factorization theorem for the cross section fully differential in the mass of each jet, and compute the corresponding soft function at next-to-leading order (NLO). The ultraviolet divergences are analytically extracted by exploiting hemispheres for interactions between each pair of hard partons, leaving only convergent integrals that are sensitive to the precise boundaries. This hemisphere decomposition can also be applied to other $N$-jet soft functions, including other observables. For $N$-jettiness, the final result for the soft function involves stable one-dimensional numerical integrals, and all ingredients are now available to extend NLO cross sections to resummed predictions at next-to-next-to-leading logarithmic order.

The discrepancy between theory and data in the momentum distribution of slow $J/\psi$ in $B$ decays has been several times addressed as a puzzle. Using the most recent results on exclusive $B$ decays into $J/\psi$ and heavy kaons or exotic mesons and reconsidering the non-relativistic-QCD calculation of the color octet fragmentation component, we show that an improvement in the comparison between data and theory can be obtained. There is still room for a better fit to data, and this may imply that new exotic mesons of the $XYZ$ kind have yet to be discovered.

We investigate the chiral properties of QCD in the presence of a magnetic background field and in the low temperature regime, by lattice numerical simulations of $N_f=2$ QCD. We adopt a standard staggered discretization, with a pion mass around 200 MeV, and explore a range of magnetic fields $(180\mathrm{MeV}{)}^2\le |e|B\le (700\mathrm{MeV}{)}^2$, in which we study magnetic catalysis, i.e. the increase of chiral symmetry breaking induced by the background field. We determine the dependence of the chiral condensate on the external field, compare our results with existing model predictions and show that a substantial contribution to magnetic catalysis comes from the modified distribution of non-Abelian gauge fields, induced by the magnetic field via dynamical quark loop effects.

We discuss the classical tests of general relativity in the presence of Rindler acceleration. Among these tests, the perihelion shifts give the tightest constraints and indicate that the Pioneer anomaly cannot be caused by a universal solar system Rindler acceleration. We address potential caveats for massive test objects. Our tightest bound on Rindler acceleration that comes with no caveats is derived from radar echo delay and yields $|a|<3\mathrm{nm}/{\mathrm{s}}^2$.

Once the critical temperature of a cosmological boson gas is less than the critical temperature, a Bose-Einstein condensation process can always take place during the cosmic history of the Universe. In the Bose-Einstein condensation model, dark matter can be described as a nonrelativistic, Newtonian gravitational condensate, whose density and pressure are related by a barotropic equation of state, with a barotropic index equal to one. In the present work, we study the Bose-Einstein condensation process in a cosmological context by assuming that this process can be described (at least approximately) as a first-order phase transition. We analyze the evolution of the physical quantities relevant for the physical description of the early universe, namely, the energy density, temperature, and scale factor, before, during, and after the Bose-Einstein condensation (phase transition). We also consider in detail the epoch when the Universe evolved through a mixed condensate—normal dark matter phase—with a monotonically growing Bose-Einstein dark matter component. An important parameter characterizing the Bose-Einstein condensation is the condensate dark matter fraction, whose time evolution describes the time dynamics of the conversion process. The behavior of this parameter during the cosmological condensation process is also analyzed in detail. To study the cosmological dynamics and evolution we use both analytical and numerical methods. The presence of the condensate dark matter and of the Bose-Einstein phase transition could have modified drastically the cosmological evolution of the early universe, as well as the large scale structure formation process.