Recently a new class of time-dependent Bell inequalities in Wigner form was introduced. The structure of the inequalities allows experimental studies of quantum and open quantum systems in external fields. In this paper, we study the properties of the time-dependent Wigner inequalities using the time evolution of neutral pseudoscalar mesons with $CP$-violation effects taken into account. It is shown that it is always possible to find a range of parameters to test for violation in an experimentally accessible area. The effect of the relaxation of the inequalities for large time scales is demonstrated.

A simple TeV scale model for baryon and lepton number violation is presented, where neutrino mass arises via a one loop radiative seesaw effect and $B$-violation obeys the $\mathrm{\Delta }B=2$ selection rule, leading to observable neutron-antineutron oscillations. The stability of the proton is connected to the neutrino mass generation. Matter-antimatter asymmetry is generated in this model via a resonant baryogenesis mechanism, which can be realized at either above or below the electroweak scale, independent of the sphaleron processes. A novel six-jet-plus-dilepton signal of this model can be searched for at the LHC.

We study QCD finite energy sum rules (FESR) for the axial-vector current correlator in the presence of a magnetic field, in the weak field limit and at zero temperature. We find that the perturbative QCD and the hadronic contribution to the sum rules get explicit magnetic-field-dependent corrections and that these in turn induce a magnetic field dependence on the deconfinement phenomenological parameter $s_0$ and on the gluon condensate. The leading corrections turn out to be quadratic in the field strength. We find from the dimension $d=2$ first FESR that the magnetic field dependence of $s_0$ is proportional to the absolute value of the light-quark condensate. Hence, it increases with increasing field strength. This implies that the parameters describing chiral symmetry restoration and deconfinement behave similarly as functions of the magnetic filed. Thus, at zero temperature the magnetic field is a catalyzing agent of both chiral symmetry breaking and confinement. From the dimension $d=4$ second FESR we obtain the behavior of the gluon condensate in the presence of the external magnetic field. This condensate also increases with increasing field strength.

In this paper, we argue that an extension of the Standard Model with a single leptoquark and three right-handed neutrinos can explain the excess in the first-generation leptoquark search at the LHC. We also find that when the leptoquark has similarly sized couplings to all three generations, it produces additional signals which will soon be tested in the second- and third-generation leptoquark searches, as well as in decay channels consisting of two mixed flavor leptons and two jets. If the leptoquark only couples to the first generation, on the other hand, two of the right-handed neutrinos need to be fairly degenerate in mass with the leptoquark while the other right-handed neutrinos mass should be much lighter. This hierarchical structure could explain dark matter and the baryon asymmetry of the Universe. These simple models may be regarded as benchmark models for explaining the excess, which can be tested in the next stage of the LHC running.

The Peccei-Quinn (PQ) mechanism provides an elegant solution to the strong charge parity ($CP$) problem. However astrophysical constraints on axions require the PQ breaking scale to be far higher than the electroweak scale. In supersymmetric models the PQ symmetry can be broken at an acceptable scale if the effective potential for the pseudomodulus in the axion multiplet develops a minimum at large enough field values. In this work we classify systematically hadronic axion models in the context of gauge mediation and study their effective potentials at one loop. We find that some models generate a PQ scale comparable to the messenger scale. Our result may prove useful for constructing full realistic models of gauge mediation that address the strong $CP$ problem. We also comment briefly on the cosmological aspects related to the saxion and axino, and on the quality of the PQ symmetry.

Assuming the presence of physics beyond the Standard Model (SM) with a characteristic scale $M\sim \mathcal{O}(10)\mathrm{TeV}$, we investigate the naturalness of the Higgs sector at scales below $M$ using an effective field theory (EFT) approach. We obtain the complete set of higher-dimensional effective operators (at any dimension $n\ge 5$) that give the leading one-loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff and discuss the (fine-) tuning between these terms and the SM one-loop contribution, which is required in order to alleviate the little hierarchy problem. We then show that this tuning can be translated into a condition for naturalness in the underlying new physics, a condition we denote by “EFT naturalness” and which we express as constraints on the corresponding higher-dimensional operator coefficients up to the scale of the effective action $\mathrm{\Lambda }<M$. We also determine the types of physics that can lead to EFT naturalness and discuss the current experimental constraints on the relevant operator coefficients. We show that these types of new physics are best probed in vector-boson and multiple-Higgs production.

We present the results of a lattice study of the second moment of the light-cone pion distribution amplitude using two flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to $m_{\pi }\sim 150\mathrm{MeV}$. At lattice spacings between 0.06 and 0.08 fm we find for the second Gegenbauer moment the value $a_2=0.1364(154)(145)$ at the scale $\mu =2\mathrm{GeV}$ in the $\overline{\mathrm{MS}}$ scheme, where the first error is statistical including the uncertainty of the chiral extrapolation, and the second error is the estimated uncertainty coming from the nonperturbatively determined renormalization factors. The error due to the continuum extrapolation cannot be quantified yet and is the only remaining significant source of uncertainty.

The strong coupling form factors related to the strong vertices of the positive and negative parity nucleons with the heavy ${\mathrm{\Lambda }}_{b[c]}[{\mathrm{\Sigma }}_{b[c]}]$ baryons and heavy $B^{*}[D^{*}]$ vector mesons are calculated using a three-point correlation function. Using the values of the form factors at $Q^2=-m_{\text{meson}}^2$, we compute the strong coupling constants among the participating particles.

We study leptonic $CP$ violation from a new perspective. For Majorana neutrinos, a new parametrization for leptonic mixing of the form $V=O_{23}{O}_{12}{K}_a^i·O$ reveals interesting aspects that are less clear in the standard parametrization. We identify several important scenario cases with mixing angles in agreement with experiment and leading to large leptonic $CP$ violation. If neutrinos happen to be quasidegenerate, this new parametrization might be very useful, e.g., in reducing the number of relevant parameters of models.

Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of a ${\chi }^2$ analysis employing realistic nuclear structure calculations in the context of the quasiparticle random phase approximation. We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for standard model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge radius. We illustrate our results for various choices of experimental setup and target material.

The Dalitz plot distribution of $B^0\to {\overline{D}}^0{K}^{+}{\pi }^{-}$ decays is studied using a data sample corresponding to $3.0{\mathrm{fb}}^{-1}$ of $pp$ collision data recorded by the LHCb experiment during 2011 and 2012. The data are described by an amplitude model that contains contributions from intermediate $K^{*}(892{)}^0$, $K^{*}(1410{)}^0$, $K_2^{*}(1430{)}^0$ and $D_2^{*}(2460{)}^{-}$ resonances. The model also contains components to describe broad structures, including the $K_0^{*}(1430{)}^0$ and $D_0^{*}(2400{)}^{-}$ resonances, in the $K\pi$ S-wave and the $D\pi$ S- and P-waves. The masses and widths of the $D_0^{*}(2400{)}^{-}$ and $D_2^{*}(2460{)}^{-}$ resonances are measured, as are the complex amplitudes and fit fractions for all components included in the amplitude model. The model obtained will be an integral part of a future determination of the angle $\gamma$ of the Cabibbo-Kobayashi-Maskawa quark mixing matrix using $B^0\to D{K}^{+}{\pi }^{-}$ decays.

The process $e^{+}{e}^{-}\to \gamma {\chi }_{cJ}$ ($J=1$, 2) is studied via initial state radiation using $980{\mathrm{fb}}^{-1}$ of data at and around the $\mathrm{\Upsilon }(nS)$ ($n=1$, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. No significant signal is observed except from $\psi (2S)$ decays. Upper limits on the cross sections between $\sqrt{s}=3.80$ and 5.56 GeV are determined at the 90% credibility level, which range from a few pb to a few tens of pb. We also set upper limits on the decay rate of the vector charmonium [$\psi (4040$), $\psi (4160)$, and $\psi (4415)$] and charmoniumlike [$Y(4260)$, $Y(4360)$, and $Y(4660)$] states to $\gamma {\chi }_{cJ}$.

Aristotelian electrodynamics (AE) describes the regime of a plasma with a very strong electric field that is not shorted out, with the charge current determined completely by pair production and the balance of the Lorentz 4-force against the curvature radiation reaction. Here it is shown how the principal null directions and associated eigenvalues of the field tensor govern AE, and how force-free electrodynamics arises smoothly from AE when the eigenvalues (and therefore the electric field in some frame) vanish. A criterion for validity of AE and force-free electrodynamics is proposed in terms of a pair of “field curvature scalars” formed from the first derivative of the principal null directions.

The Casimir-Polder interaction between an anisotropic particle and a surface is orientation dependent. We study novel orientational effects that arise due to curvature of the surface for distances much smaller than the radii of curvature by employing a derivative expansion. For nanoparticles we derive a general short distance expansion of the interaction potential in terms of their dipolar polarizabilities. Explicit results are presented for nano-spheroids made of ${\mathrm{SiO}}_2$ and gold, both at zero and at finite temperatures. The preferred orientation of the particle is strongly dependent on curvature, temperature, as well as material properties.

We compute dilepton production from the deconfined phase of the quark-gluon plasma using leading-order ($3+1$)-dimensional anisotropic hydrodynamics. The anisotropic hydrodynamics equations employed describe the full spatiotemporal evolution of the transverse temperature, spheroidal momentum-space anisotropy parameter, and the associated three-dimensional collective flow of the matter. The momentum-space anisotropy is also taken into account in the computation of the dilepton production rate, allowing for a self-consistent description of dilepton production from the quark-gluon plasma. For our final results, we present predictions for high-energy dilepton yields as a function of invariant mass, transverse momentum, and pair rapidity. We demonstrate that high-energy dilepton production is extremely sensitive to the assumed level of initial momentum-space anisotropy of the quark-gluon plasma. As a result, it may be possible to experimentally constrain the early-time momentum-space anisotropy of the quark-gluon plasma generated in relativistic heavy-ion collisions using high-energy dilepton yields.

A quark model with running coupling and running strange quark mass, which is thermodynamically self-consistent at both high and lower densities, is presented and applied to study properties of strange quark matter and structure of compact stars. An additional term to the thermodynamic potential density is determined by meeting the fundamental differential equation of thermodynamics. It plays an important role in comparatively lower density and ignorable at extremely high density, acting as a chemical-potential dependent bag constant. In this thermodynamically enhanced perturbative QCD model, strange quark matter still has the possibility of being absolutely stable, while the pure quark star has a sharp surface with a maximum mass as large as about 2 times the solar mass and a maximum radius of about 11 kilometers.

We consider a recently proposed nonminimal matter coupling in massive gravity and multigravity. We argue that, when formulated in terms of unconstrained vielbeins, this matter coupling contains the primary constraints necessary to remove the Boulware–Deser ghost to all orders away from the decoupling limit.

It has been established in Schwarzschild spacetime (and more generally in Kerr spacetime) that pairs of geometrically different timelike geodesics with the same radial and azimuthal frequencies exist in the strong-field regime. The occurrence of this so-called isofrequency pairing is of relevance in view of gravitational-wave observations. In this paper we generalize the results on isofrequency pairing in two directions. Firstly, we allow for a (positive) cosmological constant, i.e., we replace the Schwarzschild spacetime with the Schwarzschild–de Sitter spacetime. Secondly, we consider not only spinless test particles (i.e., timelike geodesics) but also test particles with spin. In the latter case we restrict to the case that the motion is in the equatorial plane with the spin perpendicular to this plane. We find that the cosmological constant as well as the spin have distinct impacts on the description of bound motion in the frequency domain.

The Fermi bubbles have been imaged in sub-TeV gamma rays at Fermi-LAT, and, if their origin is hadronic, they might have been seen with low statistics in $\sim 0.1–1\mathrm{PeV}$ neutrinos at IceCube. We discuss the detectability of these objects at the new High Altitude Water Cherenkov (HAWC) gamma-ray detector. HAWC will view the north bubble for $\sim 2–3$ hours a day and will map its spectrum at 0.1–100 TeV. For the hard primary proton spectrum required to explain five events at IceCube, a high significance detection at HAWC will be achieved in less than 30 days. The combination of results at HAWC and IceCube will substantiate the hadronic model, or constrain its spectral parameters.