One-loop contributions to the $CP$ even-$CP$ odd Higgs boson mixings arising from contributions due to exchange of a vectorlike multiplet are computed under the Higgs boson mass constraint. The vectorlike multiplet consists of a fourth generation of quarks and a mirror generation. This sector brings in new $CP$ phases which can be large consistent with the electric dipole moment constraints. In this work we compute the contributions from the exchange of quarks and mirror quarks $t_{4L},t_{4R},T_L,T_R$, and their scalar partners, the squarks, and the mirror squarks. The effect of their contributions to the Higgs boson masses and mixings are computed and analyzed. The possibility of measuring the effects of mixing of $CP$ even and $CP$ odd Higgs in experiment is discussed. It is shown that the branching ratios of the Higgs bosons into fermion pairs are sensitive to new physics and specifically to $CP$ phases.

The forward Compton scattering off the proton is determined by substituting the empirical total photoabsorption cross sections into dispersive sum rules. In addition to the spin-independent amplitude evaluated previously [Phys. Rev. D 92, 074031 (2015)], we obtain the spin-dependent amplitude over a broad energy range. The two amplitudes contain all the information about the forward CS process and we hence can reconstruct the observables. The results are compared with predictions of chiral perturbation theory where available. The low-energy expansion of the spin-dependent Compton scattering amplitude yields the Gerasimov-Drell-Hearn (GDH) sum rule and relations for the forward spin polarizabilities (FSPs) of the proton. Our evaluation provides an empirical verification of the GDH sum rule for the proton and yields empirical values of the proton FSPs. For the GDH integral, we obtain $204.5(21.4)\mu \mathrm{b}$, in agreement with the sum rule prediction: $204.784481(4)\mu \mathrm{b}$. For the FSPs, we obtain ${\gamma }_0=-92.9(10.5)\times {10}^{-6}{\mathrm{fm}}^4$ and $\overline{{\gamma }_0}=48.4(8.2)\times {10}^{-6}{\mathrm{fm}}^6$, improving on the accuracy of previous evaluations.

Here we propose a realistic $\mathrm{SU}(3{)}_{\mathrm{c}}\otimes \mathrm{SU}(3{)}_{\mathrm{L}}\otimes \mathrm{U}(1{)}_{\mathrm{X}}$ electroweak gauge model with enlarged Higgs sector. The scheme allows for the natural implementation of a type II seesaw mechanism for Dirac neutrinos, while charged lepton and quark masses are reproduced in a natural way thanks to the presence of new scalars. The new $\mathrm{SU}(3{)}_{\mathrm{c}}\otimes \mathrm{SU}(3{)}_{\mathrm{L}}\otimes \mathrm{U}(1{)}_{\mathrm{X}}$ energy scale characterizing neutrino mass generation could be accessible to the current LHC experiments.

Evidence of the $K^{+}\to {\mu }^{+}\nu \overline{\nu }\nu$ decay was searched for using E949 (Brookhaven National Laboratory, USA) experimental data with an exposure of $1.70\times 10^{12}$ stopped kaons. The data sample is dominated by the background process $K^{+}\to {\mu }^{+}{\nu }_{\mu }\gamma$. An upper limit on the decay rate $\mathrm{\Gamma }(K^{+}\to {\mu }^{+}\nu \overline{\nu }\nu )<2.4\times {10}^{-6}\mathrm{\Gamma }(K^{+}\to \text{all})$ at 90% confidence level was set assuming the standard model muon spectrum. The data are presented in such a way as to allow calculation of rates for any assumed ${\mu }^{+}$ spectrum.

Searches for exclusively produced $W$ boson pairs in the process $pp(\gamma \gamma )\to p{W}^{+}{W}^{-}p$ and an exclusively produced Higgs boson in the process $pp(gg)\to pHp$ have been performed using $e^{\pm }{\mu }^{\mp }$ final states. These measurements use $20.2{\mathrm{fb}}^{-1}$ of $pp$ collisions collected by the ATLAS experiment at a center-of-mass energy $\sqrt{s}=8\mathrm{TeV}$ at the LHC. Exclusive production of $W^{+}{W}^{-}$ consistent with the Standard Model prediction is found with $3.0\sigma$ significance. The exclusive $W^{+}{W}^{-}$ production cross section is determined to be $\sigma (\gamma \gamma \to W^{+}{W}^{-}\to e^{\pm }{\mu }^{\mp }X)=6.9\pm 2.2(\mathrm{stat})\pm 1.4(\mathrm{sys})\mathrm{fb}$, in agreement with the Standard Model prediction. Limits on anomalous quartic gauge couplings are set at 95% confidence level as $-1.7\times {10}^{-6}<a_0^W/{\mathrm{\Lambda }}^2<1.7\times {10}^{-6}{\mathrm{GeV}}^{-2}$ and $-6.4\times {10}^{-6}<a_C^W/{\mathrm{\Lambda }}^2<6.3\times {10}^{-6}{\mathrm{GeV}}^{-2}$. A 95% confidence-level upper limit on the total production cross section for an exclusive Higgs boson is set to 1.2 pb.

The effects of nonlinear vacuum electrodynamics are most clearly pronounced in a strong electromagnetic field close to Schwinger limit. Electromagnetic fields of such intensity can be obtained in laboratory conditions only on very few extreme laser facilities and during a short time interval. At the same time, the astrophysical compact objects with a strong electromagnetic field such as pulsars and magnetars are the best suited to study the effects of nonlinear vacuum electrodynamics. We present analytical calculations for pulsar proper radiation in parametrized post-Maxwellian nonlinear vacuum electrodynamics. Based on the obtained solutions, the effect of nonlinear vacuum corrections to pulsar spin down is being investigated. The analysis of torque functions show that the nonlinear vacuum electrodynamics corrections to the electromagnetic radiation for some pulsars may be comparable to the energy loss by gravitational radiation.

We find clear numerical evidence for a bilinear condensate in three-dimensional QCD in the ’t Hooft limit. We use a nonchiral random matrix model to extract the value of the condensate $\mathrm{\Sigma }$ from the low-lying eigenvalues of the massless anti-Hermitian overlap Dirac operator. We estimate $\mathrm{\Sigma }/{\lambda }^2=0.0042\pm 0.0004$ in units of the physical ’t Hooft coupling.

In a recent Letter [Sanchis-Gual et al., Phys. Rev. Lett. 116, 141101 (2016)], we presented numerical relativity simulations, solving the full Einstein–Maxwell–Klein-Gordon equations, of superradiantly unstable Reissner-Nordström black holes (BHs), enclosed in a cavity. Low frequency, spherical perturbations of a charged scalar field trigger this instability. The system’s evolution was followed into the nonlinear regime, until it relaxed into an equilibrium configuration, found to be a hairy BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. Here, we investigate the impact of adding self-interactions to the scalar field. In particular, we find sufficiently large self-interactions suppress the exponential growth phase, known from linear theory, and promote a nonmonotonic behavior of the scalar field energy. Furthermore, we discuss in detail the influence of the various parameters in this model: the initial BH charge, the initial scalar perturbation, the scalar field charge, the mass, and the position of the cavity’s boundary (mirror). We also investigate the “explosive” nonlinear regime previously reported to be akin to a bosenova. A mode analysis shows that the “explosions” can be interpreted as the decay into the BH of modes that exit the superradiant regime.

We study the generation of a magnetic field in primordial plasma of standard model particles at a temperature $T>80\mathrm{TeV}$—much higher than the electroweak scale. It is assumed that there is an excess number of right-handed electrons compared to left-handed positrons in the plasma. Using the Berry-curvature modified kinetic theory to incorporate the effect of the Abelian anomaly, we show that this chiral imbalance leads to the generation of a hypermagnetic field in the plasma in both the collision dominated and collisionless regimes. It is shown that, in the collision dominated regime, the chiral-vorticity effect can generate finite vorticity in the plasma together with the magnetic field. Typical strength of the generated magnetic field is $10^{27}\mathrm{G}$ at $T\sim 80\mathrm{TeV}$ with the length scale $10^5/T$, whereas the Hubble length scale is $10^{13}/T$. Furthermore, the instability can also generate a magnetic field of the order $10^{31}\mathrm{G}$ at a typical length scale $10/T$. But there may not be any vorticity generation in this regime. We show that the estimated values of the magnetic field are consistent with the bounds obtained from current observations.

Recently Liang et al. [Phys. Rev. D 93, 103525 (2016)] found a tentative line signal at about 43 GeV in the directions of 16 nearby galaxy clusters. If arising from dark matter annihilation, the mass of the dark matter particles should be $m_{\chi }\sim 43\mathrm{GeV}$ and the annihilation cross section $⟨\sigma v⟩\sim 5\times {10}^{-28}(\overline{\mathrm{BF}}/10^3{)}^{-1}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$ is needed, where $\overline{\mathrm{BF}}$ is the averaged boost factor of the annihilation signal of these galaxy clusters. In this work we discuss several models which could interpret these features and estimate the model parameters. Usually a sizeable coupling parameter is needed. The $2\sigma$ upper limits on the cross section of the dark matter annihilation into various final states such as $b\overline{b}$, ${\mu }^{+}{\mu }^{-}$ and so on are also presented.

Compensated isocurvature perturbations (CIPs) are modes in which the baryon and dark matter density fluctuations cancel. They arise in the curvaton scenario as well as some models of baryogenesis. While they leave no observable effects on the cosmic microwave background (CMB) at linear order, they do spatially modulate two-point CMB statistics and can be reconstructed in a manner similar to gravitational lensing. Due to the similarity between the effects of CMB lensing and CIPs, lensing contributes nearly Gaussian random noise to the CIP estimator that approximately doubles the reconstruction noise power. Additionally, the cross correlation between lensing and the integrated Sachs-Wolfe effect generates a correlation between the CIP estimator and the temperature field even in the absence of a correlated CIP signal. For cosmic-variance limited temperature measurements out to multipoles $l\le 2500$, subtracting a fixed lensing bias degrades the detection threshold for CIPs by a factor of 1.3, whether or not they are correlated with the adiabatic mode.

We present photometric redshift estimates for galaxies used in the weak lensing analysis of the Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based photometric redshift methods—annz2, bpz calibrated against BCC-Ufig simulations, skynet, and tpz—are analyzed. For training, calibration, and testing of these methods, we construct a catalogue of spectroscopically confirmed galaxies matched against DES SV data. The performance of the methods is evaluated against the matched spectroscopic catalogue, focusing on metrics relevant for weak lensing analyses, with additional validation against COSMOS photo-$z$’s. From the galaxies in the DES SV shear catalogue, which have mean redshift $0.72\pm 0.01$ over the range $0.3<z<1.3$, we construct three tomographic bins with means of $z=\{0.45,0.67,1.00\}$. These bins each have systematic uncertainties $\delta z\lesssim 0.05$ in the mean of the fiducial skynet photo-$z$ $n(z)$. We propagate the errors in the redshift distributions through to their impact on cosmological parameters estimated with cosmic shear, and find that they cause shifts in the value of ${\sigma }_8$ of approximately 3%. This shift is within the one sigma statistical errors on ${\sigma }_8$ for the DES SV shear catalogue. We further study the potential impact of systematic differences on the critical surface density, ${\mathrm{\Sigma }}_{\text{crit}}$, finding levels of bias safely less than the statistical power of DES SV data. We recommend a final Gaussian prior for the photo-$z$ bias in the mean of $n(z)$ of width 0.05 for each of the three tomographic bins, and show that this is a sufficient bias model for the corresponding cosmology analysis.

We study the fermionic dark matter (DM) particle interacting with Standard Model quarks via a light pseudoscalar mediator. We consider separately the scenarios for which the DM-pseudoscalar coupling is $CP$ conserving or $CP$ violating. We show that taking a contact interaction is not suitable, even when the mediator has a mass of the same order of magnitude as the typical momentum transfer at the direct-detection experiments, such that the allowed DAMA region is excluded or considerably modified by the correct relic density requirement. The DAMA result seems to indicate that the $CP$-violating interaction is dominant at direct searches. We find that, if the proton-to-neutron effective coupling ratio is $-60\sim -40$, the exclusion limits set by SuperCDMS, XENON100, and LUX are highly suppressed, and the DAMA signal can thus be easily reconciled with these null measurements. For this model, the allowed region determined by the DAMA signal and correct relic density can successfully satisfy the conditions required by the thermal equilibrium, big bang nucleosynthesis, and DM self-interactions. The results of future measurements on flavor physics will provide important constraints on the related models. Precise measurements performed by COUPP, PICASSO, SIMPLE, and KIMS should be able to test this model in the near future.

We present a determination of the strange, charm, and bottom quark masses as well as the strong coupling constant in $2+1$ flavor lattice QCD simulations using highly improved staggered quark action. The ratios of the charm quark mass to the strange quark mass and the bottom quark mass to the charm quark mass are obtained from the meson masses calculated on the lattice and found to be $m_c/m_s=11.877(91)$ and $m_b/m_c=4.528(57)$ in the continuum limit. We also determine the strong coupling constant and the charm quark mass using the moments of pseudoscalar charmonium correlators: ${\alpha }_s(\mu =m_c)=0.3697(85)$ and $m_c(\mu =m_c)=1.267(12)\mathrm{GeV}$. Our result for ${\alpha }_s$ corresponds to the determination of the strong coupling constant at the lowest energy scale so far and is translated to the value ${\alpha }_s(\mu =M_Z,n_f=5)=0.11622(84)$.

The differential cross section of exclusive diffractive vector meson production in electron proton collisions carries important information on the geometric structure of the proton. More specifically, the coherent cross section as a function of the transferred transverse momentum is sensitive to the size of the proton, while the incoherent or proton dissociative cross section is sensitive to fluctuations of the gluon distribution in coordinate space. We show that at high energies the experimentally measured coherent and incoherent cross sections for the production of $J/\mathrm{\Psi }$ mesons are very well reproduced within the color glass condensate framework when strong geometric fluctuations of the gluon distribution in the proton are included. For $\rho$ meson production, we also find reasonable agreement. We study in detail the dependence of our results on various model parameters, including the average proton shape, analyze the effect of saturation scale and color charge fluctuations and constrain the degree of geometric fluctuations.

We propose a simple and predictive model of fermion masses and mixing in a warped extra dimension, with the smallest discrete non-Abelian group $S_3$ and the discrete symmetries $Z_2\otimes Z_4$. Standard Model fields propagate in the bulk, and the mass hierarchies and mixing angles are accounted for the fermion zero modes localization profiles, similar to the Randall-Sundrum model. To the best of our knowledge, this model is the first implementation of an $S_3$ flavor symmetry in this type of warped extra dimension framework. Our model successfully describes the fermion masses and mixing pattern and is consistent with the current low energy fermion flavor data. The discrete flavor symmetry in our model leads to predictive mixing inspired textures, where the Cabibbo mixing arises from the down-type quark sector, whereas the up-type quark sector contributes to the remaining mixing angles.

Via gauge-gravity duality, relaxation of far-from-equilibrium initial states in a strongly coupled gauge theory has been investigated. In the system we consider in this paper there are two ways where the state under study can deviate from its equilibrium: anisotropic pressure and time-dependent expectation value of a scalar operator with $\mathrm{\Delta }=3$. In the gravity theory, this system corresponds to Einstein’s general relativity with a nontrivial metric, including the anisotropy function, coupled to a massive scalar matter field. We study the effect of different initial configurations for the scalar field and anisotropy function on physical processes such as thermalization, i.e., time evolution of an event horizon; equilibration of the expectation value of a scalar operator; and isotropization. We also discuss time ordering of these time-scales.

We consider violation of Lorentz invariance in QED induced by a very high frequency background wave. An effective theory is obtained by averaging observables over the rapid field oscillations. This preserves Ward identities and restores translation invariance below the high-frequency scale, but only partial Lorentz invariance: we show that the effective theory is C-invariant SIM(2)–QED in very special relativity. Averaging leads to the nonlocal terms familiar from SIM(2) theories, while the short-distance behavior of the background field fermion propagator generates the infinite number of higher-order vertices of SIM(2)-QED.

We construct and analyze the Standard Model of electroweak and strong interactions in multiscale spacetimes with (i) weighted derivatives and (ii) $q$-derivatives. Both theories can be formulated in two different frames, called fractional and integer picture. By definition, the fractional picture is where physical predictions should be made. (i) In the theory with weighted derivatives, it is shown that gauge invariance and the requirement of having constant masses in all reference frames make the Standard Model in the integer picture indistinguishable from the ordinary one. Experiments involving only weak and strong forces are insensitive to a change of spacetime dimensionality also in the fractional picture, and only the electromagnetic and gravitational sectors can break the degeneracy. For the simplest multiscale measures with only one characteristic time, length and energy scale $t_{*}$, ${\ell }_{*}$ and $E_{*}$, we compute the Lamb shift in the hydrogen atom and constrain the multiscale correction to the ordinary result, getting the absolute upper bound $t_{*}<{10}^{-23}\mathrm{s}$. For the natural choice ${\alpha }_0=1/2$ of the fractional exponent in the measure, this bound is strengthened to $t_{*}<{10}^{-29}\mathrm{s}$, corresponding to ${\ell }_{*}<{10}^{-20}\mathrm{m}$ and $E_{*}>28\mathrm{TeV}$. Stronger bounds are obtained from the measurement of the fine-structure constant. (ii) In the theory with $q$-derivatives, considering the muon decay rate and the Lamb shift in light atoms, we obtain the independent absolute upper bounds $t_{*}<{10}^{-13}\mathrm{s}$ and $E_{*}>35\mathrm{MeV}$. For ${\alpha }_0=1/2$, the Lamb shift alone yields $t_{*}<{10}^{-27}\mathrm{s}$, ${\ell }_{*}<{10}^{-19}\mathrm{m}$ and $E_{*}>450\mathrm{GeV}$.

A relativistic Bose gas at finite density suffers from a sign problem that makes direct numerical simulations infeasible. One possible solution to the sign problem is to reexpress the path integral in terms of Lefschetz thimbles. Using this approach we study the relativistic Bose gas both in the symmetric phase (low density) and the spontaneously broken phase (high density). In the high-density phase we break explicitly the symmetry and determine the dependence of the order parameter on the breaking. We study the relative contributions of the dominant and subdominant thimbles in this phase. We find that the subdominant thimble only contributes substantially when the explicit symmetry breaking is small, a regime that is dominated by finite volume effects. In the regime relevant for the thermodynamic limit, this contribution is negligible.