We propose and investigate a novel, minimal, and experimentally testable framework for baryogenesis, dubbed dexiogenesis, using baryon number violating effective interactions of right-handed Majorana neutrinos responsible for the seesaw mechanism. The distinct LHC signature of our framework is same-sign top quark final states, possibly originating from displaced vertices. The region of parameters relevant for LHC phenomenology can also yield concomitant signals in nucleon decay experiments. We provide a simple ultraviolet origin for our effective operators, by adding a color-triplet scalar, which could ultimately arise from a grand unified theory.

We present a class of models in which dark matter (DM) is a fermionic singlet under the Standard Model (SM) gauge group but is charged under a symmetry of flavor that acts as well on the SM fermions. Interactions between DM and SM particles are mediated by the scalar fields that spontaneously break the flavor symmetry, the so-called flavons. In the case of gauged flavor symmetries, the interactions are also mediated by the flavor gauge bosons. We first discuss the construction and the generic features of this class of models. Then a concrete example with an Abelian flavor symmetry is considered. We compute the complementary constraints from the relic abundance, direct detection experiments and flavor observables, showing that wide portions of the parameter space are still viable. Other possibilities like non-Abelian flavor symmetries can be analyzed within the same framework.

In this paper we analyze Yukawa unification in a three family SO(10) SUSY GUT. We perform a global ${\chi }^2$ analysis and show that supersymmetry (SUSY) effects do not decouple even though the universal scalar mass parameter at the grand unified theory (GUT) scale, $m_{16}$, is found to lie between 15 and 30 TeV with the best fit given for $m_{16}\approx 25\mathrm{TeV}$. Note, SUSY effects do not decouple since stops and bottoms have mass of order 5 TeV, due to renormalization group running from $M_{\mathrm{GUT}}$. The model has many testable predictions. Gauginos are the lightest sparticles and the light Higgs boson is very much standard model-like. The model is consistent with flavor and $CP$ observables with the $\mathrm{BR}(\mu \to e\gamma )$ close to the experimental upper bound. With such a large value of $m_{16}$ we clearly cannot be considered “natural” SUSY nor are we “split” SUSY. We are thus in the region in between or “SUSY on the edge.”

Production and decays of doubly charged Higgs bosons at the LHC and future hadron colliders triggered by a vector boson fusion mechanism are discussed in the context of the minimal left-right symmetric model. Our analysis is based on the Higgs boson mass spectrum compatible with available constraints which include flavor changing neutral current (FCNC) effects and vacuum stability of the scalar potential. Though the parity breaking scale $v_R$ is large ($\sim$ few TeV) and scalar masses which contribute to FCNC effects are even larger, a consistent Higgs boson mass spectrum still allows us to keep doubly charged scalar masses below 1 TeV which is an interesting situation for LHC and future circular collider (FCC). We have shown that the allowed Higgs boson mass spectrum constrains the splittings ($M_{H_1^{\pm \pm }}-M_{H_1^{\pm }}$), closing the possibility of $H_1^{\pm \pm }\to W_1^{\pm }{H}_1^{\pm }$ decays. Assuming that doubly charged Higgs bosons decay predominantly into a pair of same-sign charged leptons through the process $pp\to H_{1/2}^{\pm \pm }{H}_{1/2}^{\mp \mp }jj\to {\ell }^{\pm }{\ell }^{\pm }{\ell }^{\mp }{\ell }^{\mp }jj$, we find that for the LHC operating at $\sqrt{s}=14\mathrm{TeV}$ with an integrated luminosity at the level of $3000{\mathrm{fb}}^{-1}$ (HL-LHC), there is practically no chance to detect such particles at the reasonable significance level through this channel. However, at 33 TeV HE-LHC and (or) 100 TeV FCC-hh, a wide region opens up for exploring the doubly charged Higgs boson mass spectrum. In FCC-hh, the doubly charged Higgs bosons mass up to 1 TeV can be easily probed.

At very high energies scattering amplitudes in a spontaneously broken gauge theory into multiparticle final states are known to grow factorially with the number of particles produced. Using simple scalar field theory models with and without the vacuum expectation value, we compute total cross sections with up to seven particles in the final state at the leading order in perturbation theory with MadGraph. By exploring the known scaling properties of the multiparticle rates with the number of particles, we determine from these the general $n$-point cross sections in the large-$n$ limit. In the high-multiplicity regime we are considering, $n\gg 1$ and $\lambda n=\mathrm{fixed}$, the perturbation theory becomes strongly coupled with the higher-order loop effects contributing increasing powers of $\lambda n$. In the approximation where only the leading loop effects are included, we show that the corresponding perturbative cross sections grow exponentially and ultimately violate perturbative unitarity. This occurs at surprisingly low energy scales $\sim 40–50\mathrm{TeV}$ with multiplicities above $\sim 150$. It is expected that a repair mechanism or an extension of the theory has to set-in before these scales are reached, possibly involving a novel nonperturbative dynamics in the a priori weakly coupled theory.

We consider hard three-loop corrections to hyperfine splitting in muonium and positronium generated by the diagrams with closed electron loops. There are six gauge-invariant sets of such diagrams that generate corrections of order $m{\alpha }^7$. The contributions of these diagrams are calculated for an arbitrary electron-muon mass ratio without expansion in the small mass ratio. We obtain the formulas for contributions to hyperfine splitting that in the case of a small mass ratio describe corrections for muonium and in the case of equal masses describe corrections for positronium. The first few terms of the expansion of hard corrections in the small mass ratio were earlier calculated for muonium analytically. We check numerically that the new results coincide with the sum of the known terms of the expansion in the case of a small mass ratio. In the case of equal masses we obtain hard nonlogarithmic corrections of order $m{\alpha }^7$ to hyperfine splitting in positronium.

A search for the decay of neutral, weakly interacting, long-lived particles using data collected by the ATLAS detector at the LHC is presented. This analysis uses the full data set recorded in 2012: $20.3{\mathrm{fb}}^{-1}$ of proton-proton collision data at $\sqrt{s}=8\mathrm{TeV}$. The search employs techniques for reconstructing decay vertices of long-lived particles decaying to jets in the inner tracking detector and muon spectrometer. Signal events require at least two reconstructed vertices. No significant excess of events over the expected background is found, and limits as a function of proper lifetime are reported for the decay of the Higgs boson and other scalar bosons to long-lived particles and for Hidden Valley $Z^{\prime }$ and Stealth SUSY benchmark models. The first search results for displaced decays in $Z^{\prime }$ and Stealth SUSY models are presented. The upper bounds of the excluded proper lifetimes are the most stringent to date.

We measure absolute branching fractions for six exclusive $D_s$ semileptonic decays. We use data collected in the CLEO-c detector from $e^{+}{e}^{-}$ annihilations delivered by the Cornell Electron Storage Ring with a center-of-mass energy near 4170 MeV. We find $\mathcal{B}(D_s\to \varphi e\nu )=(2.14\pm 0.17\pm 0.08)\%$, $\mathcal{B}(D_s\to \eta e\nu )=(2.28\pm 0.14\pm 0.19)\%$, and $\mathcal{B}(D_s\to {\eta }^{\prime }e\nu )=(0.68\pm 0.15\pm 0.06)\%$ for the largest modes, where the first uncertainties are statistical and the second are systematic. We also obtain $\mathcal{B}(D_s\to K^{0}e\nu )=(0.39\pm 0.08\pm 0.03)\%$, $\mathcal{B}(D_s\to K^{*}e\nu )=(0.18\pm 0.04\pm 0.01)\%$, and $\mathcal{B}(D_s\to f_{0}e\nu ,f_0\to \pi \pi )=(0.13\pm 0.03\pm 0.01)\%$ for $f_0$ masses within 60 MeV of 980 MeV. We use our results to determine the $\eta -{\eta }^{\prime }$ and $f_0$ mixing angles with $s\overline{s}$, and we combine our results with lattice calculations to estimate $|V_{cs}|$. This measurement improves upon the $D_s$ semileptonic branching ratio precision and provides a new approach for future work that eliminates the $D_s^{*}$ daughter photon reconstruction.

Using data samples collected at center-of-mass energies of $\sqrt{s}=4.009$, 4.226, 4.257, 4.358, 4.416, and 4.599 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the isospin violating decay $Y(4260)\to J/\psi \eta {\pi }^0$. No signal is observed, and upper limits on the cross section $\sigma (e^{+}{e}^{-}\to J/\psi \eta {\pi }^0)$ at the 90% confidence level are determined to be 3.6, 1.7, 2.4, 1.4, 0.9, and 1.9 pb, respectively.

Using a sample of $1.31\times {10}^9$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider, the decays $J/\psi \to \varphi {\pi }^{+}{\pi }^{-}{\pi }^0$ and $J/\psi \to \varphi {\pi }^0{\pi }^0{\pi }^0$ are investigated. The isospin-violating decay $J/\psi \to \varphi {\pi }^0{f}_0(980)$ with $f_0(980)\to \pi \pi$ is observed for the first time. The width of the $f_0(980)$ obtained from the dipion mass spectrum is found to be much smaller than the world average value. In the ${\pi }^0{f}_0(980)$ mass spectrum, there is evidence of $f_1(1285)$ production. By studying the decay $J/\psi \to \varphi {\eta }^{\prime }$, the branching fractions of ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\pi }^0$ and ${\eta }^{\prime }\to {\pi }^0{\pi }^0{\pi }^0$, as well as their ratio, are also measured.

Motivated by the dark matter and the baryon asymmetry problems, we analyze a complex singlet extension of the Standard Model with a ${\mathbb{Z}}_2$ symmetry (which provides a dark matter candidate). After a detailed two-loop calculation of the renormalization group equations for the new scalar sector, we study the radiative stability of the model up to a high energy scale (with the constraint that the 126 GeV Higgs boson found at the LHC is in the spectrum) and find it requires the existence of a new scalar state mixing with the Higgs with a mass larger than 140 GeV. This bound is not very sensitive to the cutoff scale as long as the latter is larger than ${10}^{10}\mathrm{GeV}$. We then include all experimental and observational constraints/measurements from collider data, from dark matter direct detection experiments, and from the Planck satellite and in addition force stability at least up to the grand unified theory scale, to find that the lower bound is raised to about 170 GeV, while the dark matter particle must be heavier than about 50 GeV.

We study the cylinder-plate and the cylinder-cylinder Casimir interaction in the $(D+1)$-dimensional Minkowski spacetime due to the vacuum fluctuations of massless scalar fields. Different combinations of Dirichlet (D) and Neumann (N) boundary conditions are imposed on the two interacting objects. For the cylinder-cylinder interaction, we consider the case where one cylinder is inside the other and the case where the two cylinders are outside each other. By computing the transition matrices of the objects and the translation matrices that relate different coordinate systems, the explicit formulas for the Casimir interaction energies are derived. From these formulas, we compute the large separation and small separation asymptotic behaviors of the Casimir interaction. For the cylinder-plate interaction with $R\ll L$, where $R$ is the radius of the cylinder and $L$ is the distance from the center of the cylinder to the plate, the order of decay of the Casimir interaction only depends on the boundary conditions imposed on the cylinder. The orders are $L^{-D+1}/\ln (L)$ and $L^{-D-1}/\ln L$, respectively, for the Dirichlet and Neumann boundary conditions on the cylinder. For two cylinders with radii $R_1$ and $R_2$ lying parallelly outside each other, the orders of decay of the Casimir interaction energies when $R_1+R_2\ll L$ are $L^{-D+1}/(\ln L{)}^2$, $L^{-D-1}/\ln L$, and $L^{-D-3}$, respectively, for DD, DN/ND, and NN boundary conditions, where $L$ is the distance between the centers of the cylinders. The more interesting and important characteristic of Casimir interaction appears at small separation. Using the perturbation technique, we compute the small separation asymptotic expansions of the Casimir interaction energies up to the next-to-leading-order terms. The leading terms coincide with the respective results obtained using the proximity force approximation, which is of order $d^{-D+1/2}$, where $d$ is the distance between the two objects. The results on the next-to-leading-order terms are more interesting and important. We find some universal behaviors. It is also noticed that for the case of Dirichlet–Dirichlet cylinder-plate interaction the next-to-leading-order term agrees with that obtained using the derivative expansion. Hence, based on our results on other boundary conditions and on the cylinder-cylinder interaction, we postulate a formula for the derivative expansion to expand the Casimir interaction energy up to the next-to-leading-order terms for DD, DN, ND, and NN boundary conditions, for the interaction between two curved surfaces in $(D+1)$-dimensional Minkowski spacetime. It is found that the postulate agrees with our previous results on the sphere-sphere interactions except when $D=4$.

We start with an $SU(\mathcal{N})$ Yang-Mills theory on a manifold $\mathcal{M}$, suitably coupled to scalar fields in the adjoint representation of $SU(\mathcal{N})$, which are forming a doublet and a triplet, respectively, under a global $SU(2)$ symmetry. We show that a direct sum of fuzzy spheres $S_F^{2\mathrm{Int}}≔S_F^2(\ell )\oplus S_F^2(\ell )\oplus S_F^2(\ell +\frac{1}{2})\oplus S_F^2(\ell -\frac{1}{2})$ emerges as the vacuum solution after the spontaneous breaking of the gauge symmetry and paves the way for us to interpret the spontaneously broken model as a $U(n)$ gauge theory over $\mathcal{M}\times S_F^{2\mathrm{Int}}$. Focusing on a $U(2)$ gauge theory, we present complete parametrizations of the $SU(2)$-equivariant, scalar, spinor and vector fields characterizing the effective low energy features of this model. Next, we direct our attention to the monopole bundles $S_F^{2\pm }≔S_F^2(\ell )\oplus S_F^2(\ell \pm \frac{1}{2})$ over $S_F^2(\ell )$ with winding numbers $\pm 1$, which naturally come forth through certain projections of $S_F^{2\mathrm{Int}}$, and give the parametrizations of the $SU(2)$-equivariant fields of the $U(2)$ gauge theory over $\mathcal{M}\times S_F^{2\pm }$ as a projected subset of those of the parent model. Referring to our earlier work [1], we explain the essential features of the low energy effective action that ensues from this model after dimensional reduction. Replacing the doublet with a $k$-component multiplet of the global $SU(2)$, we provide a detailed study of vacuum solutions that appear as direct sums of fuzzy spheres as a consequence of the spontaneous breaking of $SU(\mathcal{N})$ gauge symmetry in these models and obtain a class of winding number $\pm (k-1)\in \mathbb{Z}$ monopole bundles $S_F^{2,\pm (k-1)}$ over $S_F^2(\ell )$ as certain projections of these vacuum solutions and briefly discuss their equivariant field content. We make the observation that $S_F^{2\mathrm{Int}}$ is indeed the bosonic part of the $N=2$ fuzzy supersphere with $OSP(2,2)$ supersymmetry and construct the generators of the $osp(2,2)$ Lie superalgebra in two of its irreducible representations using the matrix content of the vacuum solution $S_F^{2\mathrm{Int}}$. Finally, we show that our vacuum solutions are stable by demonstrating that they form mixed states with nonzero von Neumann entropy.

We investigate the anti-de Sitter (AdS) counterpart to the well-studied de Sitter (dS) model for energy-momentum space, viz “$\kappa$-momentum space” space (with a structure based on the properties of the $\kappa$-Poincaré Hopf algebra). On the basis of previous preliminary results one might expect the two models to be complementary: dS exhibiting an invariant maximal spatial momentum but unbounded energy, AdS a maximal energy but unbounded momentum. If that were the case AdS momentum space could be used to implement a principle of maximal Planck-scale energy, just as several studies use dS momentum space to postulate of maximal Planck-scale spatial momentum. However, several unexpected features are uncovered in this paper, which limit the scope of the expected complementarity, and interestingly they take different forms in different coordinatizations of AdS momentum space. “Cosmological” AdS coordinates mimic the dS construction used for $\kappa$-momentum space, and produce a Carrol limit in the ultraviolet. However, unlike the $\kappa$-momentum space, the boundary of the covered patch breaks Lorentz invariance, thereby introducing a preferred frame. In “horospherical” coordinates we achieve full consistency with frame independence as far as boost transformations are concerned, but find that rotational symmetry is broken, leading to an anisotropic model for the speed of light. Finally, in “static” coordinates we find a way of deforming relativistic transformations that successfully enforces frame invariance and isotropy, and produces a Carrol limit in the ultraviolet. Our results are also relevant for a long-standing debate on whether or not coordinate redefinitions in momentum space lead to physically equivalent theories: our three proposals are evidently physically inequivalent, leading to alternative models of Planck-scale effects. As a corollary we study the UV running of the Hausdorff dimension of momentum space in the first and third model, obtaining different results.

In this paper we present a new scenario where massive primordial black holes (PBHs) are produced from the collapse of large curvature perturbations generated during a mild-waterfall phase of hybrid inflation. We determine the values of the inflaton potential parameters leading to a PBH mass spectrum peaking on planetarylike masses at matter-radiation equality and producing abundances comparable to those of dark matter today, while the matter power spectrum on scales probed by cosmic microwave background (CMB) anisotropies agrees with Planck data. These PBHs could have acquired large stellar masses today, via merging, and the model passes both the constraints from CMB distortions and microlensing. This scenario is supported by Chandra observations of numerous BH candidates in the central region of Andromeda. Moreover, the tail of the PBH mass distribution could be responsible for the seeds of supermassive black holes at the center of galaxies, as well as for ultraluminous x-ray sources. We find that our effective hybrid potential can originate e.g. from D-term inflation with a Fayet-Iliopoulos term of the order of the Planck scale but sub-Planckian values of the inflaton field. Finally, we discuss the implications of quantum diffusion at the instability point of the potential, able to generate a Swiss-cheese-like structure of the Universe, eventually leading to apparent accelerated cosmic expansion.

We investigate the potential of the higher multipole power spectra of the galaxy distribution in redshift space as a cosmological probe on halo scales. Based on the fact that a halo model explains well the multipole power spectra of the luminous red galaxy sample in the Sloan Digital Sky Survey, we focus our investigation on the random motions of the satellite luminous red galaxies that determine the higher multipole spectra at large wave numbers. We show that our theoretical model fits the higher multipole spectra at large wave numbers from N-body numerical simulations, and we apply these results for testing the gravity theory and the velocity structure of galaxies on the halo scales. In this analysis, we use the multipole spectra $P_4(k)$ and $P_6(k)$ on the small scales of the range of wave number $0.3\le k/[h{\mathrm{Mpc}}^{-1}]\le 0.6$, which is in contrast to the usual method of testing gravity by targeting the linear growth rate on very large scales. We demonstrate that our method could be useful for testing gravity on the halo scales.

The direct detection of dark matter constituents, in particular the weakly interacting massive particles (WIMPs), is central to particle physics and cosmology. In this paper we study transitions to the excited states, possible in some nuclei, which have sufficiently low lying excited states. Examples considered previously were the first excited states of ${}^{127}\mathrm{I}$ and ${}^{129}\mathrm{Xe}$. We examine here ${}^{83}\mathrm{Kr}$, which offers some kinematical advantages and is a possible target. We estimate appreciable rates for the inelastic scattering mediated by the spin cross sections, with an inelastic event rate of $4.4\times {10}^{-4}{\mathrm{kg}}^{-1}{\mathrm{d}}^{-1}$. So, the extra signature of the gamma ray following the de-excitation of these states can, in principle, be exploited experimentally. A brief discussion of the experimental feasibility is given.

We study the properties of the $X(4260)$ resonance by reanalyzing all experimental data available, especially the $e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-}$, $\omega {\chi }_{c0}$ cross section data. The final-state interactions of the $\pi \pi$, $K\overline{K}$ coupled-channel system are also taken into account. A sizable coupling between $X(4260)$ and $\omega {\chi }_{c0}$ is found. The inclusion of the $\omega {\chi }_{c0}$ data indicates a small value of ${\mathrm{\Gamma }}_{e^{+}{e}^{-}}=23.30\pm 3.55\mathrm{eV}$.

We calculate the equation of state at nonzero temperature and density from first principles in two-, three-, and four-color QCD with two fermion flavors in the fundamental and two-index, antisymmetric representation. By matching low-energy results (from a “hadron resonance gas”) to high-energy results from (resummed) perturbative QCD, we obtain results for the pressure and trace anomaly that are in quantitative agreement with full lattice-QCD studies for three colors at zero chemical potential. Our results for nonzero chemical potential at zero temperature constitute predictions for the equation of state in QCD-like theories that can be tested by traditional lattice studies for two-color QCD with two fundamental fermions and four-color QCD with two two-index, antisymmetric fermions. We find that the speed of sound squared at zero temperature can exceed $1/3$, which may be relevant for the phenomenology of high-mass neutron stars.

The neutrinos emitted from the proto-neutron star created in a core-collapse supernova must run through a significant amount of turbulence before exiting the star. Turbulence can modify the flavor evolution of the neutrinos imprinting itself upon the signal detected here at Earth. The turbulence effect upon individual neutrinos, and the correlation between pairs of neutrinos, might exhibit sensitivity to the power spectrum of the turbulence, and recent analysis of the turbulence in a two-dimensional hydrodynamical simulation of a core-collapse supernova indicates the power spectrum may not be the Kolmogorov $5/3$ inverse power law as has been previously assumed. In this paper we study the effect of non-Kolmogorov turbulence power spectra upon neutrinos from a point source as a function of neutrino energy and turbulence amplitude at a fixed postbounce epoch. We find the two effects of turbulence upon the neutrinos—the distorted phase effect and the stimulated transitions—both possess strong and weak limits in which dependence upon the power spectrum is absent or evident, respectively. Since neutrinos of a given energy will exhibit these two effects at different epochs of the supernova each with evolving strength, we find there is sensitivity to the power spectrum present in the neutrino burst signal from a Galactic supernova.