We investigate some phenomenological aspects of the holographic models based on the tachyon Dirac-Born-Infeld action in anti–de Sitter space-time. These holographic theories model strongly interacting fermions and feature dynamical mass generation and symmetry breaking. We show that they can be viewed as models of holographic walking technicolor and compute the Peskin-Takeuchi $S$ parameter and masses of lightest technimesons for a variety of tachyon potentials. We also investigate the phase structure at finite temperature and charge density. Finally, we comment on the holographic Wilsonian renormalization group in the context of holographic tachyon Dirac-Born-Infeld models.

We extend the maximal-unitarity method at two loops to double-box basis integrals with up to three external massive legs. We use consistency equations based on the requirement that integrals of total derivatives vanish. We obtain unique formulas for the coefficients of the master double-box integrals. These formulas can be used either analytically or numerically.

We extend previous results on the reflection and transmission of self-gravitating dust shells across the apparent horizon during quantum dust collapse to nonmarginally-bound dust collapse in arbitrary dimensions with a negative cosmological constant. We show that the Hawking temperature is independent of the energy function and that the wave functional describing the collapse is well behaved at the Hawking-Page transition point. Thermal radiation from the apparent horizon appears as a generic result of nonmarginal collapse in AdS spacetime owing to the singular structure of the Hamiltonian constraint at the apparent horizon.

The primordial inflation dilutes all matter except the quantum fluctuations which we see in the cosmic microwave background radiation. Therefore the last phases of inflation must be embedded within a beyond the Standard Model sector where the inflaton can directly excite the Standard Model quarks and leptons. In this paper we consider two inflaton candidates $\tilde{L}\tilde{L}\tilde{e}$ and $\tilde{u}\tilde{d}\tilde{d}$ whose decay can naturally excite all the relevant degrees of freedom besides thermalizing the lightest supersymmetric particle (LSP) during and after reheating. In particular, we present the regions of the parameter space which can yield successful inflation with the right temperature anisotropy in the cosmic microwave background, the observed relic density for the neutralino LSP, and the recent Higgs mass constraints from LHC within the minimal supersymmetric Standard Model with nonuniversal Higgs masses—referred to as the NUHM2 model. We found that in most scenarios the LSP seems strongly mass degenerated with the next to lightest LSP and the branching ratio $B_s\to {\mu }^{+}{\mu }^{-}$ very close to the present bound, thus leading to falsifiable predictions. Also the dark matter interactions with XENON nuclei would fall within the projected range for the XENON1T experiment. In the case of a positive signal of low-scale supersymmetry at the LHC, one would be able to potentially pin down the inflaton mass by using the associated values for the mass of the stau, the stop, and the neutralino.

Local scale invariant theory leads to the existence of a new particle called the Weyl vector meson. We study a generalized Standard Model, which displays local scale invariance. The model contains a real scalar field besides the Higgs multiplet. For a certain range of coupling parameters, the Weyl-Higgs coupling leads to an interesting phenomenon in particle colliders as well as in cosmology. Here we study the signature of the Weyl meson in particle colliders and determine the range of coupling parameters for which it can solve the dark matter problem.

We describe the electroproduction of the $N(1440)$ Roper resonance in soft-wall anti–de Sitter/quantum chromodynamics. The Roper resonance is identified as the first radially excited state of the nucleon, where higher Fock states in addition to the three-quark ($3q$) component are included. The main conclusion is that the leading $3q$ component plays the dominant role in the description of electroproduction properties of this resonance: form factors, helicity amplitudes, and charge densities. The obtained results are in good agreement with the recent results of the CLAS Collaboration at JLab.

The breakdown of $E_6$ gauge symmetry at high energies may lead to supersymmetric models based on the standard model gauge group together with extra $U(1{)}_{\psi }$ and $U(1{)}_{\chi }$ gauge symmetries. To ensure anomaly cancellation the particle content of these $E_6$ inspired models involves extra exotic states that generically give rise to nondiagonal flavor transitions and rapid proton decay. We argue that a single discrete ${\tilde{Z}}_2^H$ symmetry can be used to forbid tree-level flavor changing transitions, as well as the most dangerous baryon and lepton number violating operators. We present $5D$ and $6D$ orbifold grand unified theory constructions that lead to the $E_6$ inspired supersymmetric models of this type. The breakdown of $U(1{)}_{\psi }$ and $U(1{)}_{\chi }$ gauge symmetries that preserves $E_6$ matter parity assignment guarantees that ordinary quarks and leptons and their superpartners, as well as the exotic states which originate from 27 representations of $E_6$, survive to low energies. These $E_6$ inspired models contain two dark matter candidates and must also include additional TeV scale vectorlike lepton or vectorlike down-type quark states to render the lightest exotic quark unstable. We examine gauge coupling unification in these models and discuss their implications for collider phenomenology and cosmology.

We introduce an operator depending on the “transverse velocity” $r$ that describes the effect of hadron masses on the leading $1/Q$ power correction to event-shape observables. Here, $Q$ is the scale of the hard collision. This work builds on earlier studies of mass effects by Salam and Wicke [J. High Energy Phys. 05 (2001) 061] and of operators by Lee and Sterman [Phys. Rev. D 75, 014022 (2007)]. Despite the fact that different event shapes have different hadron mass dependence, we provide a simple method to identify universality classes of event shapes whose power corrections depend on a common nonperturbative parameter. We also develop an operator basis to show that at a fixed value of $Q$, the power corrections for many classic observables can be determined by two independent nonperturbative matrix elements at the 10% level. We compute the anomalous dimension of the transverse velocity operator, which is multiplicative in $r$ and causes the power correction to exhibit nontrivial dependence on $Q$. The existence of universality classes and the relevance of anomalous dimensions are reproduced by the hadronization models in Pythia 8 and $\mathrm{Herwig}\text{}+\text{}+$, though the two programs differ in the values of their low-energy matrix elements.

We perform a comprehensive $SU(3)$-flavor analysis of charmed mesons decaying to two pseudoscalar $SU(3)$-octet mesons. Taking into account $SU(3)$-breaking effects induced by the splitting of the quark masses, $m_s\ne m_{u,d}$, we find that existing data can be described by $SU(3)$ breaking of the order 30%. The requisite penguin enhancement to accommodate all data on $CP$ violation tends to be even larger than the one extracted from $\Delta a_{CP}^{\mathrm{dir}}(K^{+}{K}^{-},{\pi }^{+}{\pi }^{-})$ alone, strengthening explanations beyond the standard model. Despite the large number of matrix elements, correlations between $CP$ asymmetries allow one potentially to differentiate between different scenarios for the underlying dynamics, as well as between the standard model and various extensions characterized by $SU(3)$ symmetry and its subgroups. We investigate how improved measurements of the direct $CP$ asymmetries in singly Cabibbo-suppressed decays can further substantiate the interpretation of the data. We show that particularly informative are the asymmetries in $D\to {\pi }^{+}{\pi }^{-}$ versus $D\to K^{+}{K}^{-}$, $D_s\to K_S{\pi }^{+}$ versus $D^{+}\to K_S{K}^{+}$, $D^{+}\to {\pi }^{+}{\pi }^0$, $D\to {\pi }^0{\pi }^0$, and $D\to K_S{K}_S$.

Since the smallest leptonic mixing angle ${\theta }_{13}$ has been measured to be relatively large, it is quite promising to constrain or determine the leptonic Dirac $CP$-violating phase $\delta$ in future neutrino oscillation experiments. Given some typical values of $\delta =\pi /2$, $\pi$, and $3\pi /2$ at the low energy scale, as well as current experimental results of the other neutrino parameters, we perform a systematic study of radiative corrections to $\delta$ by using the one-loop renormalization group equations in the minimal supersymmetric standard model and the universal extra-dimensional model. It turns out that $\delta$ is rather stable against radiative corrections in both models, except for the minimal supersymmetric standard model with a very large value of $\tan \beta$. Both cases of Majorana and Dirac neutrinos are discussed. In addition, we use the preliminary indication of $\delta =({1.08}_{-0.31}^{+0.28})\pi$ or $\delta =({1.67}_{-0.77}^{+0.37})\pi$ from the latest global-fit analyses of data from neutrino oscillation experiments to illustrate how it will be modified by radiative corrections.

We report on the first measurement of the double-spin asymmetry, $A_{LL}$, of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized $p+p$ collisions at $\sqrt{s}=200\mathrm{GeV}$ for $p_T=0.5$ to $3.0\mathrm{GeV}/c$. The asymmetry was measured at midrapidity ($|\eta |<0.35$) with the PHENIX detector at the Relativistic Heavy Ion Collider. The measured asymmetries are consistent with zero within the statistical errors. We obtained a constraint for the polarized gluon distribution in the proton of $|\Delta g/g({log}_{10}x=-{1.6}_{-0.4}^{+0.5},\mu =m_T^c){|}^2<0.030$ ($1\sigma$) based on a leading-order perturbative quantum chromodynamics model, using the measured asymmetry.

We study the rare hadronic transitions ${\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S})\eta$ and ${\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^0$ using a sample of $158\times {10}^6{\rm Y}(2\mathrm{S})$ decays collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. We measure the ratios of branching fractions $(\mathcal{B})\frac{\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S})\eta )}{\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^{+}{\pi }^{-})}=(1.99\pm 0.14(\mathrm{stat})\pm 0.11(\mathrm{syst}))\times {10}^{-3}$ and $\frac{\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^0)}{\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^{+}{\pi }^{-})}<2.3\times {10}^{-4}$ at the 90% confidence level (CL). Assuming the value $\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^{-}{\pi }^{+})=(17.92\pm 0.26)\%$, we obtain $\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S})\eta )=(3.57\pm 0.25(\mathrm{stat})\pm 0.21(\mathrm{syst}))\times {10}^{-4}$ and $\mathcal{B}({\rm Y}(2\mathrm{S})\to {\rm Y}(1\mathrm{S}){\pi }^0)<4.1\times {10}^{-5}(90\%\mathrm{CL})$.

Usually alternative theories of gravity imply deviations from the well-known Kerr space-time, a model of an isolated black hole in general relativity. In the dominant order, the deformed Kerr metric, free of closed timelike curves outside the event horizon, has been suggested recently by Johannsen and Psaltis. It has a single deformation parameter which is not constrained by the current observations, allowing, thereby, for a kind of unified and simple phenomenological description of black holes in various theories of gravity. Here we consider a number of classical and quantum phenomena of radiation in the vicinity of such deformed Schwarzschild-like and Kerr-like black holes: spiralling of particles into black holes, decay of fields propagating in the black hole’s background, Hawking radiation. In particular, we calculate some quantitative characteristics of the above phenomena, such as the binding energy of particles, quasinormal modes, late-time tails of fields of various spin, intensity of Hawking radiation. The binding energy released when a particle goes over from a given stable orbit in the equatorial plane to the innermost stable one is calculated for such non-Kerr black holes. Due to apparent inseparability of variables in the perturbation equations in the general case, the perturbations and stability of scalar, Dirac, and electromagnetic fields are analyzed for vanishing rotation only. The dependence of the radiation phenomena on the deformation parameter is discussed.

We study the dynamics of the homogeneous and isotropic universe with a scalar field and an SU(2) non-Abelian gauge (Yang-Mills) field. The scalar field has an exponential potential and the Yang-Mills field is coupled to the scalar field with an exponential function of the scalar field. We find that the magnetic component of the Yang-Mills field assists acceleration of the cosmic expansion and a power-law inflation becomes possible even if the scalar field potential is steep, which may be expected from some compactification of higher-dimensional unified theories of fundamental interactions. This power-law inflationary solution is a stable attractor in a certain range of coupling parameters. Unlike the case with multiple Abelian gauge fields, the power-law inflationary solution with the dominant electric component is unstable because of the existence of nonlinear coupling of the Yang-Mills field. We also analyze the dynamics for the noninflationary regime, and find several attractor solutions.

In this paper, we explain how moments of the thermal Sunyaev-Zel’dovich (tSZ) effect can constrain both cosmological parameters and the astrophysics of the intracluster medium. As the tSZ signal is strongly non-Gaussian, higher moments of tSZ maps contain useful information. We first calculate the dependence of the tSZ moments on cosmological parameters, finding that higher moments scale more steeply with ${\sigma }_8$ and are sourced by more massive galaxy clusters. Taking advantage of the different dependence of the variance and skewness on cosmological and astrophysical parameters, we construct a statistic, $|⟨T^3⟩|/⟨T^2{⟩}^{1.4}$, which cancels much of the dependence on cosmology (i.e., ${\sigma }_8$) yet remains sensitive to the astrophysics of intracluster gas (in particular, to the gas fraction in low-mass clusters). Constraining the intracluster medium astrophysics using this statistic could break the well-known degeneracy between cosmology and gas physics in tSZ measurements, allowing for tight constraints on cosmological parameters. Although detailed simulations will be needed to fully characterize the accuracy of this technique, we provide a first application to data from the Atacama Cosmology Telescope and the South Pole Telescope. We estimate that a Planck-like full-sky tSZ map could achieve a $\lesssim 1\%$ constraint on ${\sigma }_8$ and a $1\sigma$ error on the sum of the neutrino masses that is comparable to the existing lower bound from oscillation measurements.

Supersymmetric theories that can allow for a 125 GeV Higgs mass and also solve the naturalness and supersymmetry flavor problems now require a fair degree of complexity. Here we consider the simplest possibility for supersymmetry near the weak scale, but with the requirement of naturalness dropped. In “pure gravity mediation,” all supersymmetric particles except for the gauginos lie at tens to thousands of TeV, with the gauginos obtaining loop suppressed masses automatically by anomaly mediation and Higgsino threshold corrections. The gauginos are the lightest superpartners, and we investigate the current collider constraints on their masses, as well as the future reach of the Large Hadron Collider (LHC). We consider gluino pair production with a $\mathrm{\text{jets}}+\mathrm{\text{missing}}$ energy signature, as well as events with disappearing charged tracks caused by charged winos decaying into their neutral partners. We show that presently, gluino masses less than about 1 TeV and wino masses less than about 300 GeV are excluded, and that the 14 TeV LHC can probe gluino masses up to about 2 TeV and wino masses up to 1 TeV.

In this work we make a systematic analysis of the correlated processes $J/\psi \to \gamma \eta (1440)/f_1(1420)$ with $\eta (1440)/f_1(1420)\to K\overline{K}\pi$, $\eta \pi \pi$ and $3\pi$, where the role played by the so-called “triangle singularity mechanism” (TSM) is clarified. Our results agree well with the experimental data and suggest a small fraction of $f_1(1420)$ contributions in these processes. This study confirms our conclusion [Wu et al. Phys. Rev. Lett. 108, 081803 (2012)] that the dynamic feature of the TSM can be recognized by the strong narrow peak observed in the $\pi \pi$ invariant mass spectrum of $\eta (1440)\to 3\pi$ with anomalously large isospin violations. Nevertheless, we explicitly demonstrate that the TSM can produce obvious peak position shifts for the same $\eta (1440)$ or $f_1(1420)$ state in different decay channels. This is strong evidence that the $\eta (1405)$ and $\eta (1475)$ are actually the same state, i.e., $\eta (1440)$. We also make an analysis of the radiative decays of $\eta (1440)\to \gamma V$ ($V=\varphi$, ${\rho }^0$, or $\omega$), which shows that such a one-state prescription seems not to have a conflict with the so-far existing experimental data. Our analysis may shed light on the long-standing puzzling question about the nature of $\eta (1405)$ and $\eta (1475)$.

According to extensive theoretical studies of the high-energy limit of QCD, inelastic interactions are dominated by the multi-Regge final states. The appropriate gauge-invariant objects, which simultaneously incorporate the transverse momentum degrees of freedom, are Reggeized gluons, quarks and antiquarks. In the present communication we extend parton Reggeization approach to Drell-Yan production of massive lepton pairs. The basic ingredient is a process of Reggeized quark-antiquark annihilation, $\mathcal{Q}\overline{\mathcal{Q}}\to {\gamma }^{\star }\to l^{+}{l}^{-}$, which is described by the Reggeon-Reggeon-photon effective vertex ${\Gamma }_{\mathcal{Q}\overline{\mathcal{Q}}}^{\gamma }$. We calculate transverse-momentum and invariant-mass distributions of Drell-Yan lepton pairs measured at the CERN SPS, FNAL Tevatron and CERN LHC in the different ranges of energy and rapidity. We focus on angular distributions of Drell-Yan leptons in different kinematical ranges. The obtained results are compared with the existing data and a good agreement is found. The predictions for future experiments for Drell-Yan lepton pair production at the CERN LHC have been made.

The null radiation zone theorem states that, when special kinematical conditions are satisfied, all the helicity amplitudes of a parton-level subprocess where a vector current is emitted vanish due to destructive interference among different diagrams. We study the manifestation of the theorem in $pp$ collisions at the $\sqrt{s}=8\mathrm{TeV}$ LHC. The theorem predicts that the cross section for $pp\to jj\gamma$ events is suppressed when the transverse momenta of the two jets are similar and when the rapidity difference between the photon and the cluster of the jets is nearly zero, because the $uu\to uu\gamma$ subprocess, which dominates in events with large $jj\gamma$ invariant mass, has strong destructive interference in this region. We confirm this prediction by the calculation with MadGraph 5, and show that the suppression on the $pp\to jj\gamma$ cross section is observable at the LHC.