We present the upgrade of the coherent exclusive exponentiation realization of the Yennie-Frautschi-Suura theory used in our Monte Carlo ($\mathcal{K}\mathcal{K}$ MC) to the processes $f\overline{f}\to f^{\prime }{\overline{f}}^{\prime }$, $f=\mu$, $\tau$, $q$, ${\nu }_{\ell }$, $f^{\prime }=e$, $\mu$, $\tau$, $q$, ${\nu }_{\ell }$, $q=u$, $d$, $s$, $c$, $b$, $t$, $\ell =e$, $\mu$, $\tau$ with $f\ne f^{\prime }$, with an eye toward the precision physics of the LHC and possible high energy muon colliders. We give a brief summary of the coherent exclusive exponentiation theory in comparison to the older exclusive exponentiation theory and illustrate theoretical results relevant to the LHC and possible muon collider physics programs.

We derive light-cone sum rules for the electromagnetic nucleon form factors including the next-to-leading-order corrections for the contribution of twist-three and twist-four operators and a consistent treatment of the nucleon mass corrections. The essence of this approach is that soft Feynman contributions are calculated in terms of small transverse distance quantities using dispersion relations and duality. The form factors are thus expressed in terms of nucleon wave functions at small transverse separations, called distribution amplitudes, without any additional parameters. The distribution amplitudes, therefore, can be extracted from the comparison with the experimental data on form factors and compared to the results of lattice QCD simulations. A self-consistent picture emerges, with the three valence quarks carrying $40\%:30\%:30\%$ of the proton momentum.

A search is presented for direct chargino production based on a disappearing-track signature using $20.3{\mathrm{fb}}^{-1}$ of proton-proton collisions at $\sqrt{s}=8\mathrm{TeV}$ collected with the ATLAS experiment at the LHC. In anomaly-mediated supersymmetry breaking (AMSB) models, the lightest chargino is nearly mass degenerate with the lightest neutralino and its lifetime is long enough to be detected in the tracking detectors by identifying decays that result in tracks with no associated hits in the outer region of the tracking system. Some models with supersymmetry also predict charginos with a significant lifetime. This analysis attains sensitivity for charginos with a lifetime between 0.1 and 10 ns, and significantly surpasses the reach of the LEP experiments. No significant excess above the background expectation is observed for candidate tracks with large transverse momentum, and constraints on chargino properties are obtained. In the AMSB scenarios, a chargino mass below 270 GeV is excluded at 95% confidence level.

In this work we discuss a general approach for the dark energy thermodynamics considering a varying equation of state parameter of the type $\omega (a)={\omega }_0+F(a)$ and taking into account the role of a nonzero chemical potential $\mu$. We derive generalized expressions for the entropy density, chemical potential, and dark energy temperature $T$ and use the positiveness of the entropy to impose thermodynamic bounds on the equation of state parameter $\omega (a)$. In particular, we find that a phantomlike behavior $\omega (a)<-1$ is allowed only when the chemical potential is a negative quantity ($\mu <0$).

We extend the superembedding formalism for 4D $\mathcal{N}=1$ superconformal field theory to the case of fields in arbitrary representations of the superconformal group $SU(2,2|1)$. For applications we obtain manifestly superconformally covariant expressions for two- and three-point functions involving conserved currents, e.g., the supercurrent multiplet or global symmetry current superfields. The embedding space results are presented in a compact form by employing an index-free formalism. Our expressions are consistent with the literature, but the manifestly covariant forms of correlators presented here are new.

We investigate thermal one-loop effective potentials in multiflavor models with chemical potentials. We study four-dimensional models in which each flavor has different global $U(1)$ charges. Accordingly they have different chemical potentials. We call these “nonuniform chemical potentials,” which are organized into a diagonal matrix $\widehat{\mu }$. The mass matrix at a vacuum does not commute with $\widehat{\mu }$. We find that the effective potential is divided into three parts. The first part is the Coleman-Weinberg potential. The UV divergence resides only in this part. The second is the correction to the Coleman-Weinberg potential that is independent of temperature, and the third depends on both temperature and $\widehat{\mu }$. Our result is a generalization of the thermal potentials in previous studies for models with single and multiflavors with (uniform) chemical potentials, and it reproduces all the known results correctly.

We study two-flavor neutrino oscillations in homogeneous neutrino gases in which neutrinos and antineutrinos are in nearly pure weak interaction states initially. We find that the monopole and dipole oscillation modes can trigger flavor instabilities in the opposite neutrino mass hierarchies in a nearly isotropic neutrino gas. For a class of simple neutrino systems we are able to identify the normal modes of neutrino oscillations in the linear regime. Our results provide new insights into the recently discovered multiazimuthal angle instability of neutrino oscillations in supernovae.

It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

The self-interaction for a static point charge in the space-time of a thin-shell wormhole constructed connecting two identical Schwarzschild geometries is calculated in a series expansion. The electrostatic self-force is evaluated numerically. It is found to be attractive towards the throat except for some values of the throat radius proximate to the value of the Schwarzschild horizon, for which the force is repulsive or attractive depending on the position of the charge. The result differs from the self-force in the space-time of the Schwarzschild black hole, where it is always repulsive from the center. Although these wormhole and black hole geometries are locally indistinguishable, the different topologies of both backgrounds are manifested in the electrostatic field of a point charge.

The weak-field limit of scalar-tensor theories of gravity is discussed in view of conformal transformations. Specifically, we consider how physical quantities—such as gravitational potentials derived in the Newtonian approximation for the same scalar-tensor theory—behave in the Jordan and Einstein frames. The approach allows one to discriminate features that are invariant under conformal transformations and gives contributions to the debate of how to select the true physical frame. As a particular example, the case of $f(R)$ gravity is considered.

We derive a theoretical upper bound on the oscillation frequency in the scalar perturbation power spectrum of single-field inflation. Oscillations are most naturally produced by modified vacua with varying phase. When this phase changes rapidly, it induces strong interactions between the scalar fluctuations. If the interactions are sufficiently strong the theory cannot be evaluated using perturbation theory, hence imposing a limit on the oscillation frequency. This complements the bound found by Weinberg governing the validity of effective field theory. The generalized consistency relation also allows one to use squeezed configurations of higher-point correlations to place constraints on the power spectrum oscillations.

In this article we present the cosmological equivalence between the relativistic Finsler-Randers cosmology and the dark energy and modified gravity constructions at the background level. Starting from a small deviation from the quadraticity of the Riemannian geometry, through which the local structure of general relativity is modified and the curvature theory is extended, we extract the modified Friedmann equation. The corresponding extended Finsler-Randers cosmology is very interesting, and it can mimic dark energy and modified gravity, describing a large class of scale-factor evolutions, from inflation to late-time acceleration, including the phantom regime. In this respect, the nontrivial Universe evolution is not attributed to a new scalar field, or to gravitational modification, but it arises from the modification of the geometry itself.

About a decade ago, using a specific expansion scheme, effective, on-brane scalar tensor theories of gravity were proposed by Kanno and Soda [Phys. Rev. D 66, 083506 (2002)] in the context of the warped two-brane model of Randall–Sundrum. The inter-related effective theories on both the branes were derived with the space-time dependent radion field playing a crucial role. Taking another look at this effective theory, we find cosmological and spherically symmetric, static solutions sourced by a radion-induced, effective stress energy, as well as additional, on-brane matter. The distance between the branes (governed by the time or space dependent radion) is shown to be stable and asymptotically nonzero, thereby setting aside any possibility of brane collisions. It turns out that the inclusion of on-brane matter plays a decisive role in stabilising the radion—a fact which we demonstrate through our solutions.

It has been long known that by appropriately modifying gravity one can always reproduce the expansion history of any dark energy model, e.g. the $\Lambda \mathrm{CDM}$. This degeneracy cannot be broken with geometric probes like the Type Ia supernovae, the cosmic microwave background, or the baryon acoustic oscillations since they are based on the measurement of distances and scales and therefore require the expansion history $H(z)$, so one may only hope to break this degeneracy by using dynamic probes like the growth rate data that track the matter density perturbations. We demonstrate that breaking this degeneracy is not currently possible by explicitly constructing $f(R)$, $f(G)$, and $f(T)$ theories that mimic exactly the $\Lambda \mathrm{CDM}$ model at the background level and confronting them against the latest observational cosmological data. We also determine the necessary improvement in the growth rate data in order to discriminate these theories from $\Lambda \mathrm{CDM}$. We found that at least a threefold improvement is necessary, something which will be possible with a survey like Euclid.

We compare the efficiency of moments and Minkowski functionals (MFs) in constraining the subset of cosmological parameters $({\Omega }_m,w,{\sigma }_8)$ using simulated weak lensing convergence maps. We study an analytic perturbative expansion of the MFs [T. Matsubara, Phys. Rev. D 81, 083505 (2010); D. Munshi et al., Mon. Not. R. Astron. Soc. 419, 536 (2012)] in terms of the moments of the convergence field and of its spatial derivatives. We show that this perturbation series breaks down on smoothing scales below $5^{\prime }$, while it shows a good degree of convergence on larger scales ($\sim {15}^{\prime }$). Most of the cosmological distinguishing power is lost when the maps are smoothed on these larger scales. We also show that, on scales comparable to $1^{\prime }$, where the perturbation series does not converge, cosmological constraints obtained from the MFs are approximately 1.5–2 times better than the ones obtained from the first few moments of the convergence distribution—provided that the latter include spatial information, either from moments of gradients or by combining multiple smoothing scales. Including a set of either these moments or the MFs can significantly tighten constraints on cosmological parameters, compared to the conventional method of using the power spectrum alone.

Although various pieces of indirect evidence about the nature of dark matter have been collected, its direct detection has eluded experimental searches despite extensive effort. If the mass of dark matter is below 1 MeV, it is essentially imperceptible to conventional detection methods because negligible energy is transferred to nuclei during collisions. Here I propose directly detecting dark matter through the quantum decoherence it causes rather than its classical effects, such as recoil or ionization. I show that quantum spatial superpositions are sensitive to low-mass dark matter that is inaccessible to classical techniques. This provides new independent motivation for matter interferometry with large masses, especially on spaceborne platforms. The apparent dark matter wind we experience as the Sun travels through the Milky Way ensures interferometers and related devices are directional detectors, and so are able to provide unmistakable evidence that decoherence has Galactic origins.

We investigate the possibility of obtaining sizeable $R$-parity-breaking interactions violating baryon number but not lepton number within supersymmetric grand unified theories. Such a possibility allows us to ameliorate the naturalness status of supersymmetry while maintaining successful gauge coupling unification, one of its main phenomenological motivations. We show that this can be achieved without fine-tuning or the need of large representations in simple SO(10) models.

We study single inclusive hadron production in proton-proton and proton-nucleus collisions in the CGC framework. The parameters in the calculation are determined solely by standard nuclear geometry and by electron-proton deep inelastic scattering data, which are fit using the running coupling BK equation. We show that it also is possible to obtain a good fit of the HERA inclusive cross section without an anomalous dimension in the initial condition. We argue that one must consistently also use the proton transverse area as measured by a high virtuality probe in DIS for the single inclusive cross section in proton-proton and proton-nucleus collisions. We show that this leads to a midrapidity nuclear modification ratio $R_{pA}$ that approaches unity at high transverse momentum independently of $\sqrt{s}$, in contrast to most CGC calculations in the literature. We also present predictions for future forward $R_{pA}$ measurements at the LHC.