We analytically compute higher order cumulants of the azimuthal anisotropy, $c_2\{2m\}$, and corresponding $v_2\{2m\}$ at high transverse momentum in the dilute-dense limit. The dense target is considered in the framework of the McLerran-Venugopolan model. The absolute values of the harmonics $v_2\{2m\}$ of the azimuthal anisotropy are approximately equal, $|v_2\{2m\}|\approx |v_2\{2m^{\prime }\}|$, for large $m$ and $m^{\prime }$. However, the harmonics with order $2m=4n$ are complex. We argue that this is a generic property of connected graphs, which remains true in the dense-dense limit.

In this paper we propose the study of the diffractive quarkonium photoproduction in $pp$ collisions at LHC energies to probe the photon flux associated with an ultrarelativistic proton. The total photon distribution is expected to be given in terms of the elastic and inelastic components. Distinctly from the elastic photon component that can be determined from the elastic form factors, the magnitude of the inelastic component still is an open question. We consider the current parametrizations for the photon distribution of a proton and estimate the rapidity distributions and total cross sections for the production of $J/\mathrm{\Psi }$, ${\mathrm{\Psi }}^{\prime }$, and $\mathrm{\Upsilon }$ at LHC energies. We demonstrate that the predictions associated with the inelastic contribution are of the same order as those associated with the elastic one. Our results imply that a dedicated experimental analysis of diffractive quarkonium photoproduction with the tagging of the two protons in the final state can be useful to constrain the magnitude of the inelastic component of the photon distribution.

Measurements of differential cross sections are presented for the production of a $\mathrm{Z}$ boson and at least one hadronic jet in proton-proton collisions at $\sqrt{s}=7\mathrm{TeV}$, recorded by the CMS detector, using a data sample corresponding to an integrated luminosity of $4.9{\mathrm{fb}}^{-1}$. The jet multiplicity distribution is measured for up to six jets. The differential cross sections are measured as a function of jet transverse momentum and pseudorapidity for the four highest transverse momentum jets. The distribution of the scalar sum of jet transverse momenta is also measured as a function of the jet multiplicity. The measurements are compared with theoretical predictions at leading and next-to-leading order in perturbative QCD.

The dynamical effects of topological charge in two-dimensional QED can be expressed in terms of a topological order parameter via a Berry phase construction. The Berry phase describes the electric charge polarization of the vacuum in a manner similar to the theory of polarization in topological insulators. The topological order parameter labels discrete vacua which differ by units of electric flux. Here the associated Berry connection is explicitly constructed from the Dirac Hamiltonian eigenstates by introducing a small attractive Thirring coupling, so that there is still a stable boson in the limit of zero EM coupling. The Berry connection arises from the analytic structure of the Bethe ansatz states in complex rapidity near the free fermion point.

We present numerical simulations of binary neutron star mergers, comparing irrotational binaries to binaries of NSs rotating aligned to the orbital angular momentum. For the first time, we study spinning BNSs employing nuclear physics equations of state, namely the ones of Lattimer and Swesty as well as Shen, Horowitz, and Teige. We study mainly equal mass systems leading to a hypermassive neutron star (HMNS), and analyze in detail its structure and dynamics. In order to exclude gauge artifacts, we introduce a novel coordinate system used for post-processing. The results for our equal mass models show that the strong radial oscillations of the HMNS modulate the instantaneous frequency of the gravitational wave (GW) signal to an extend that leads to separate peaks in the corresponding Fourier spectrum. In particular, the high frequency peaks which are often attributed to combination frequencies can also be caused by the modulation of the $m=2$ mode frequency in the merger phase. As a consequence for GW data analysis, the offset of the high frequency peak does not necessarily carry information about the radial oscillation frequency. Further, the low frequency peak in our simulations is dominated by the contribution of the plunge and the first 1–2 bounces. The amplitude of the radial oscillations depends on the initial NS spin, which therefore has a complicated influence on the spectrum. Another important result is that HMNSs can consist of a slowly rotating core with an extended, massive envelope rotating close to Keplerian velocity, contrary to the common notion that a rapidly rotating core is necessary to prevent a prompt collapse. Finally, our estimates on the amount of unbound matter show a dependency on the initial NS spin, explained by the influence of the latter on the amplitude of radial oscillations, which in turn cause shock waves.

We investigate the effect of a test magnetic field on the process of destroying a near-extremal Kerr black hole with a charged test particle. It has been shown that it would be possible to throw a charged test particle into the near extremal rotating black hole and make it go past the extremality, i.e., turn the Kerr black hole into the Kerr–Newmann naked singularity. Typically, in an astrophysical scenario, black holes are believed to be surrounded by a magnetic field. The magnetic field, although small, affects the motion of charged particles drastically due to the large Lorentz force, as the electromagnetic force is much stronger than the gravity. Thus, a test magnetic field can affect the process of destroying black holes and restore the cosmic censorship in the astrophysical context. We show that a test magnetic field would act as a cosmic censor beyond a certain threshold value. We try to gauge the magnitude of the magnetic field by comparing its energy density with that of the change in the curvature induced by the test particle. We find that the magnetic field required is either as strong as or slightly stronger as compared to the value for which its effect on the background geometry is comparable to the tiny backreaction as that of the test particle. In such a case, however, one has to take into account effect of the magnetic field on the background geometry, which is difficult to implement in the absence of any exact near-extremal rotating magnetized black hole solutions. We expect that magnetic field would still act as a cosmic censor.

Scalar-tensor theories (STTs) are a widely studied alternative to general relativity (GR) in which gravity is endowed with an additional scalar degree of freedom. Although severely constrained by solar system and pulsar timing experiments, there remains a large set of STTs which are consistent with all present day observations. In this paper, we investigate the possibility of probing a yet unconstrained region of the parameter space of STTs based on the fact that stability properties of highly compact neutron stars in these theories may radically differ from those in GR.

We exactly solve the Wheeler-DeWitt equation for the closed homogeneous and isotropic quantum cosmology in the presence of a conformally coupled scalar field and in the context of the generalized uncertainty principle. This form of generalized uncertainty principle is motivated by the black hole physics and it predicts a minimal length uncertainty proportional to the Planck length. We construct wave packets in momentum minisuperspace which closely follow classical trajectories and strongly peak on them upon choosing appropriate initial conditions. Moreover, based on the DeWitt criterion, we obtain wave packets that exhibit singularity-free behavior.

Temporal features during single-field inflation that break the time-translation invariance of the de Sitter expansion lead to the breaking of scale invariance in the curvature and cosmic microwave background temperature power spectra. The large-angle temperature power spectrum is known to contain low to moderate significance features whose inflationary interpretation also allows for substantial tensor contributions. We conduct a model-independent analysis of large-angle features using 20 principal components for the temporal history including the possibility of non-negligible tensor contributions. The suppression of power at low multipoles beginning with a glitch at multipoles $\ell \sim 20–40$ implies deviations in two to three of them with $2–3\sigma$ deviations in each, with larger values reflecting cases where tensors are allowed. If tensors are absent, the corresponding $E$-mode polarization features follow a similar pattern but are predicted to be up to twice as large. They offer the opportunity to soon double the significance of inflationary features or eliminate them as an explanation of temperature features. The tensor degeneracy with features in the temperature power spectrum is broken not only by $B$ but also by $E$ polarization. A precision measurement of $E$-mode polarization at multipoles from $\ell \sim 20–60$ can potentially provide an independent constraint on tensors that is less subject to dust foreground uncertainties.

We apply the idea of spiral inflation to the Coleman-Weinberg potential and show that inflation matching our observations well is allowed for a symmetry-breaking scale ranging from an intermediate scale to a grand unified theory (GUT) scale even if the quartic coupling $\lambda$ is of $\mathcal{O}(0.1)$. The tensor-to-scalar ratio can be of $\mathcal{O}(0.01)$ in the case of GUT-scale symmetry breaking.

Several groups have identified an extended excess of gamma rays over the modeled foreground and background emissions towards the Galactic center (GC) based on observations with the Fermi Large Area Telescope. This excess emission is compatible in morphology and spectrum with a telltale sign from dark matter (DM) annihilation. Here, we present a critical reassessment of DM interpretations of the GC signal in light of the foreground and background uncertainties that some of us recently outlaid in Calore et al. (2014). We find that a much larger number of DM models fits the gamma-ray data than previously noted. In particular: (1) In the case of DM annihilation into $\overline{b}b$, we find that even large DM masses up to $m_{\chi }\simeq 74\mathrm{GeV}$ are allowed at $p$-value $>0.05$. (2) Surprisingly, annihilation into nonrelativistic $hh$ gives a good fit to the data. (3) The inverse Compton emission from ${\mu }^{+}{\mu }^{-}$ with $m_{\chi }\sim 60–70\mathrm{GeV}$ can also account for the excess at higher latitudes, $|b|>2^{°}$, both in its spectrum and morphology. We also present novel constraints on a large number of mixed annihilation channels, including cascade annihilation involving hidden sector mediators. Finally, we show that the current limits from dwarf spheroidal observations are not in tension with a DM interpretation when uncertainties on the DM halo profile are accounted for.

We show that the quadratic inflation can be realized by the phase of a complex field with helicoid potential. Remarkably, this helicoid potential can be simply realized in minimal supergravity. The global $U(1)$ symmetry of the Kähler potential introduces a flat direction and evades the $\eta$ problem automatically. So such inflation is technically natural. The phase excursion is super-Planckian as required by the Lyth bound, while the norm of the complex field can be suppressed in the sub-Planckian region. This model resolves the ultraviolet sensitive problem of the large field inflation; besides, it also provides a new type of monodromy inflation in supersymmetric field theory with consistent field stabilization.

The enhancement of lepton flavor violation rates due to $Z$-penguins observed in Ref. [1] was a consequence of an error in the literature. Correcting this error, the effect is gone.

We outline and investigate a set of benchmark simplified models with the aim of providing a minimal simple framework for an interpretation of the existing and forthcoming searches of dark matter particles at the LHC. The simplified models we consider provide microscopic QFT descriptions of interactions between the Standard Model partons and the dark sector particles mediated by the four basic types of messenger fields: scalar, pseudoscalar, vector and axial-vector. Our benchmark models are characterized by four to five parameters, including the mediator mass and width, the dark matter mass and the effective coupling(s). In the gluon fusion production channel we resolve the top quark in the loop and compute full top-mass effects for scalar and pseudoscalar messengers. We show the LHC limits and reach at 8 and 14 TeV for models with all four messenger types. We also outline the complementarity of direct detection, indirect detection and LHC bounds for dark matter searches. Finally, we investigate the effects which arise from extending the simplified model to include potential new physics contributions in production. Using the scalar mediator as an example, we study the impact of heavy new physics loops which interfere with the top-mediated loops. Our computations are performed within the mcfm framework, and we provide fully flexible public Monte Carlo implementation.

We calculate spatial correlation functions of in-medium mesons consisting of strange-antistrange, strange-anticharm and charm-anticharm quarks in ($2+1$)-flavor lattice QCD using the highly improved staggered quark action. A comparative study of the in-medium modifications of mesons with different flavor contents is performed. We observe significant in-medium modifications for the $\varphi$ and $D_s$ meson channels already at temperatures around the chiral crossover region. On the other hand, for the $J/\psi$ and ${\eta }_c$ meson channels in-medium modifications remain relatively small around the chiral crossover region and become significant only above 1.3 times the chiral crossover temperature.

We calculate the $B$-meson decay constants $f_B$, $f_{B_s}$, and their ratio in unquenched lattice QCD using domain-wall light quarks and relativistic $b$ quarks. We use gauge-field ensembles generated by the RBC and UKQCD collaborations using the domain-wall fermion action and Iwasaki gauge action with three flavors of light dynamical quarks. We analyze data at two lattice spacings of $a\approx 0.11$, 0.086 fm with unitary pion masses as light as $M_{\pi }\approx 290\mathrm{MeV}$; this enables us to control the extrapolation to the physical light-quark masses and continuum. For the $b$ quarks we use the anisotropic clover action with the relativistic heavy-quark interpretation, such that discretization errors from the heavy-quark action are of the same size as from the light-quark sector. We renormalize the lattice heavy-light axial-vector current using a mostly nonperturbative method in which we compute the bulk of the matching factor nonperturbatively, with a small correction, that is close to unity, in lattice perturbation theory. We also improve the lattice heavy-light current through $\mathcal{O}({\alpha }_{s}a)$. We extrapolate our results to the physical light-quark masses and continuum using SU(2) heavy-meson chiral perturbation theory, and provide a complete systematic error budget. We obtain $f_{B^0}=199.5(12.6)\mathrm{MeV}$, $f_{B^{+}}=195.6(14.9)\mathrm{MeV}$, $f_{B_s}=235.4(12.2)\mathrm{MeV}$, $f_{B_s}/f_{B^0}=1.197(50)$, and $f_{B_s}/f_{B^{+}}=1.223(71)$, where the errors are statistical and total systematic added in quadrature. These results are in good agreement with other published results and provide an important independent cross-check of other three-flavor determinations of $B$-meson decay constants using staggered light quarks.

We present next-to-leading order (NLO) predictions for $\gamma \gamma \gamma \gamma$ final states, including the effects of photon fragmentation. Our results are calculated fully analytically using the techniques of $D$-dimensional unitarity, and we discuss some refinements to existing methods, focusing particularly on the role of three-mass triangle coefficients. Using these techniques we are able to produce a numerically stable Monte Carlo code that runs fully in double precision. We investigate the $4\gamma$ signal at colliders, both for Run II of the LHC and at future machines. Our results are implemented in MCFM.

This paper provides results for the spectra of triply charmed and bottom baryons based on a constituent-quark model approach. We take advantage of the assumption that potential models are expected to describe triply heavy baryons to a similar degree of accuracy as the successful results obtained in the charmonium and bottomonium sectors. The high precision calculation of the ground state and positive and negative parity excited states recently reported by nonperturbative lattice QCD provides us with a unique opportunity to confront model predictions with the data. This comparison may also help to build a bridge between two difficult to reconcile lattice QCD results, namely, the lattice SU(3) QCD static three-quark potential and the recent results of nonperturbative lattice QCD for the triply heavy baryon spectra.