The possibility of $X(1835)$ discovered by BESII as a $0^{-+}$ glueball is studied in this paper. The decay rates of $X(1835)\to p\overline{p}$, $VV$ are associated with the gluon spin contents of proton and vector mesons, respectively. Estimations of the decay rates of $X(1835)\to VV$, $\gamma V$, $\gamma \gamma$ and the cross sections of $\gamma \gamma \to X(1835)\to f$ and $h_1+h_2\to X(1835)+\dots$ are presented. It predicts that as a glueball $X(1835)$ is unlikely to be produced in $J/\psi$ hadronic decays but as a $p\overline{p}$ it is likely.

In this note we study the adiabatic perturbation spectrum of N-flation with power law potential. We show that the scalar spectrum of N-flation is generally redder than that of its corresponding single field. The result obtained for that with unequal massive fields is consistent with the recent numerical investigation of Kim and Liddle.

Slowly evolving horizons are trapping horizons that are “almost” isolated horizons. This paper reviews their definition and discusses several spacetimes containing such structures. These include certain Vaidya and Tolman-Bondi solutions as well as (perturbatively) tidally distorted black holes. Taking into account the mass scales and orders of magnitude that arise in these calculations, we conjecture that slowly evolving horizons are the norm rather than the exception in astrophysical processes that involve stellar-scale black holes.

A new method of calculating the energy spectrum of neutrinos and antineutrinos produced in the electron-positron annihilation processes in hot stellar plasma is presented. Detection of these neutrinos, produced copiously in the presupernova, which is an evolutionary advanced neutrino-cooled star, may serve in the future as a trigger of a precollapse early warning system. Also, observation of neutrinos will probe final stages of thermonuclear burning in the presupernova. The spectra obtained with the new method are compared to Monte Carlo simulations. To achieve high accuracy in the energy range of interest, determined by neutrino detector thresholds, a differential cross section for production of the antineutrino, previously unknown in an explicit form, is calculated as a function of energy in the plasma rest frame. The neutrino spectrum is obtained as a 3-dimensional integral, computed with the use of the Cuhre algorithm of at least 5% accuracy. Formulas for the mean neutrino energy and its dispersion are given as a combination of Fermi-Dirac integrals. Also, useful analytical approximations of the whole spectrum are shown.

We construct quasiequilibrium sequences of black-hole–neutron-star binaries for arbitrary mass ratios by solving the constraint equations of general relativity in the conformal thin-sandwich decomposition. We model the neutron star as a stationary polytrope satisfying the relativistic equations of hydrodynamics and account for the black hole by imposing equilibrium boundary conditions on the surface of an excised sphere (the apparent horizon). In this paper we focus on irrotational configurations, meaning that both the neutron star and the black hole are approximately nonspinning in an inertial frame. We present results for a binary with polytropic index $n=1$, mass ratio $M_{\mathrm{irr}}^{\mathrm{BH}}/M_{\mathrm{B}}^{\mathrm{NS}}=5$, and neutron star compaction $M_{\mathrm{ADM},0}^{\mathrm{NS}}/R_0=0.0879$, where $M_{\mathrm{irr}}^{\mathrm{BH}}$ is the irreducible mass of the black hole, $M_{\mathrm{B}}^{\mathrm{NS}}$ the neutron star baryon rest mass, and $M_{\mathrm{ADM},0}^{\mathrm{NS}}$ and $R_0$ the neutron star Arnowitt-Deser-Misner mass and areal radius in isolation, respectively. Our models represent valid solutions to Einstein’s constraint equations and may therefore be employed as initial data for dynamical simulations of black-hole–neutron-star binaries.

This paper presents the first study of mesons with a quark and an antiquark with different and finite masses in a simple confining and chiral invariant quark-antiquark interaction, leading to spontaneous chiral symmetry breaking and to constituent quarks. In the false chiral invariant vacuum, the chiral partners are degenerate, and tachyons occur in the light-light spectrum. In the true vacuum, most of the standard nonrelativistic quark-model spectra should be recovered except for the pion and other particular constraints. The calibration problem of chiral quark models is also addressed here. The detailed inspection of the different contributions to the $D$ and $D_s$ masses suggests that the challenging recently observed $D_s^{*}(2317)$ and $D_s^{*}(2460)$ mesons might not fit as global chirally rotated quark-antiquark $D_s$ mesons.

We study extensions of the standard model with additional colored scalar fields which can couple directly to quarks. Natural suppression of flavor changing neutral currents implies minimal flavor violation, and fixes the scalars to transform as $(\mathbf{8},\mathbf{2}{)}_{1/2}$ under the $SU(3)\times SU(2)\times U(1)$ gauge symmetry. We explore the phenomenology of the standard model with one additional $(\mathbf{8},\mathbf{2}{)}_{1/2}$ scalar, and discuss how this extension can modify flavor physics and the Higgs boson production rate at the LHC. Custodial $SU(2)$ symmetry can be implemented for the octet scalars since they transform as a real color representation. Additional weak scale degrees of freedom needed for gauge unification are discussed.

I demonstrate that the chiral properties of domain wall fermions (DWF) in the large to intermediate lattice spacing regime of QCD, 1 to 2 GeV, are significantly improved by adding to the action two standard Wilson fermions with supercritical mass equal to the negative DWF five-dimensional mass. Using quenched DWF simulations I show that the eigenvalue spectrum of the transfer matrix Hamiltonian develops a substantial gap and that the residual mass decreases appreciatively. Furthermore, I confirm that local topology changing remains active and that the hadron spectrum of the added Wilson fermions is above the lattice cutoff and therefore is irrelevant. I argue that this result should also hold for dynamical DWF and furthermore that it should improve the chiral properties of related fermion methods.

In this paper we present a proof for automatic $O(a)$ improvement in twisted mass lattice QCD at maximal twist, which uses only the symmetries of the leading part in the Symanzik effective action. In the process of the proof we clarify that the twist angle is dynamically determined by vacuum expectation values in the Symanzik theory. For maximal twist according to this definition, we show that scaling violations of all quantities which have nonzero values in the continuum limit are even in $a$. In addition, using Wilson chiral perturbation theory, we investigate this definition for maximal twist and compare it to other definitions which were already employed in actual simulations.

We discuss the implementation and properties of the quenched approximation in the calculation of the left-right, strong penguin contributions (i.e. $Q_6$) to ${ϵ}^{\prime }/ϵ$. The coefficient of the new chiral logarithm, discovered by Golterman and Pallante, which appears at leading order in quenched chiral perturbation theory is evaluated using both the method proposed by those authors and by an improved approach which is free of power divergent corrections. The result implies a large quenching artifact in the contribution of $Q_6$ to ${ϵ}^{\prime }/ϵ$. This failure of the quenched approximation affects only the strong penguin operators and so does not affect the $Q_8$ contribution to ${ϵ}^{\prime }/ϵ$ nor $\mathrm{Re}{A}_0$, $\mathrm{Re}{A}_2$ and thus, the $\Delta I=1/2$ rule at tree level in chiral perturbation theory.

We present new parameterizations of energy spectra of secondary particles, $\pi$ mesons, gamma rays, electrons, and neutrinos produced in inelastic proton-proton collisions. The simple analytical approximations based on simulations of proton-proton interactions using the public available SIBYLL code provide very good accuracy for energy distributions of secondary products in the energy range above 100 GeV. Generally, the recommended analytical formulas deviate from the simulated distributions within a few percent over a large range of $x=E_i/E_p$—the fraction of energy of the incident proton transferred to the secondaries. Finally, we describe an approximate procedure of continuation of calculations towards low energies, down to the threshold of $\pi$-meson production.

Bose-Einstein condensation of composite diquarks in quark matter (the color superconductor phase) is discussed using the quasichemical equilibrium theory at a relatively low-density region near the deconfinement phase transition, where dynamical quark-pair fluctuations are assumed to be described as bosonic degrees of freedom (diquarks). A general formulation is given for the diquark formation and particle-antiparticle pair-creation processes in the relativistic framework, and some interesting properties are shown, which are characteristic for the relativistic many-body system. Behaviors of transition temperature and phase diagram of the quark-diquark matter are generally presented in model parameter space, and their asymptotic behaviors are also discussed. As an application to the color superconductivity, the transition temperatures and the quark and diquark density profiles are calculated in case with constituent/current quarks, where the diquark is in the bound/resonant state. We obtained $T_C\sim 60–80\mathrm{MeV}$ for constituent quarks and $T_C\sim 130\mathrm{MeV}$ for current quarks at a moderate density (${\rho }_b\sim 3{\rho }_0$). The method is also developed to include interdiquark interactions into the quasichemical equilibrium theory within a mean-field approximation, and it is found that a possible repulsive diquark-diquark interaction lowers the transition temperature by $\sim 50\%$.

We present a simple method for analyzing the impact of precision electroweak data above and below the $Z$ peak on flavor-conserving, heavy new physics. We find that experiments have probed about ten combinations of new-physics effects, which to a good approximation can be condensed into the effective oblique parameters $\widehat{S}$, $\widehat{T}$, $\widehat{U}$, $V$, $X$, $W$, $Y$ (we prove positivity constraints $W,Y\ge 0$) and three combinations of quark couplings (including a distinct parameter for the bottom). We apply our method to generic extra $Z^{\prime }$ vectors.

A measurement of the inclusive bottom jet cross section is presented for events containing a $Z$ boson in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ using the Collider Detector at Fermilab. $Z$ bosons are identified in their electron and muon decay modes, and $b$ jets with $E_T>20\mathrm{GeV}$ and $|\eta |<1.5$ are identified by reconstructing a secondary decay vertex. The measurement is based on an integrated luminosity of about $330{\mathrm{pb}}^{-1}$. A cross section times branching ratio of $\sigma (Z+b\mathrm{\text{jets}})\times \mathcal{B}(Z\to {\ell }^{+}{\ell }^{-})=0.93\pm 0.36\mathrm{pb}$ is found, where $\mathcal{B}(Z\to {\ell }^{+}{\ell }^{-})$ is the branching ratio of the $Z$ boson or ${\gamma }^{*}$ into a single flavor dilepton pair ($e$ or $\mu$) in the mass range between 66 and $116\mathrm{GeV}/c^2$. The ratio of $b$ jets to the total number of jets of any flavor in the $Z$ sample, within the same kinematic range as the $b$ jets, is $2.36\pm 0.92\%$. Here, the uncertainties are the quadratic sum of statistical and systematic uncertainties. Predictions made with next-to-leading order QCD agree, within experimental and theoretical uncertainties, with these measurements.

We have studied the Cabibbo-suppressed decay mode $D^0\to K^{+}{K}^{-}{\pi }^0$ using a Dalitz plot technique and find the strong phase difference ${\delta }_D\equiv {\delta }_{K^{*-}{K}^{+}}-{\delta }_{K^{*+}{K}^{-}}=332°\pm 8°\pm 11°$ and relative amplitude $r_D\equiv a_{K^{*-}{K}^{+}}/a_{K^{*+}{K}^{-}}=0.52\pm 0.05\pm 0.04$. This measurement indicates significant destructive interference between $D^0\to K^{+}(K^{-}{\pi }^0{)}_{K^{*-}}$ and $D^0\to K^{-}(K^{+}{\pi }^0{)}_{K^{*+}}$ in the Dalitz plot region where these two modes overlap. This analysis uses $9.0{\mathrm{fb}}^{-1}$ of data collected at $\sqrt{s}\approx 10.58\mathrm{GeV}$ with the CLEO III detector.

We argue that an astrophysical solution to the ultrahigh energy cosmic ray (UHECR) problem is viable. The detailed study of UHECR energy spectra is performed. The spectral features of extragalactic protons interacting with the cosmic microwave background (CMB) are calculated in a model-independent way. Using the power-law generation spectrum $\propto E^{-{\gamma }_g}$ as the only assumption, we analyze four features of the proton spectrum: the GZK cutoff, dip, bump, and the second dip. We found the dip, induced by electron-positron production on the CMB, to be the most robust feature, existing in energy range $1\times {10}^{18}–4\times {10}^{19}\mathrm{eV}$. Its shape is stable relative to various phenomena included in calculations: discreteness of the source distribution, different modes of UHE proton propagation (from rectilinear to diffusive), local overdensity or deficit of the sources, large-scale inhomogeneities in the universe, and interaction fluctuations. The dip is well confirmed by observations of the AGASA, HiRes, Fly’s Eye, and Yakutsk detectors. With two free parameters (${\gamma }_g$ and flux normalization constant) the dip describes about 20 energy bins with ${\chi }^2/\mathrm{d}.\mathrm{o}.\mathrm{f}.\approx 1$ for each experiment. The best fit is reached at ${\gamma }_g=2.7$, with the allowed range 2.55–2.75. The dip is used for energy calibration of the detectors. For each detector independently, the energy is shifted by factor $\lambda$ to reach the minimum ${\chi }^2$. We found ${\lambda }_{\mathrm{Ag}}=0.9$, ${\lambda }_{\mathrm{Hi}}=1.2$, and ${\lambda }_{\mathrm{Ya}}=0.75$ for the AGASA, HiRes, and Yakutsk detectors, respectively. Remarkably, after this energy shift the fluxes and spectra of all three detectors agree perfectly, with discrepancy between AGASA and HiRes at $E>1\times {10}^{20}\mathrm{eV}$ being not statistically significant. The excellent agreement of the dip with observations should be considered as confirmation of UHE proton interaction with the CMB. The dip has two flattenings. The high energy flattening at $E\approx 1\times {10}^{19}\mathrm{eV}$ automatically explains ankle, the feature observed in all experiments starting from the 1980s. The low-energy flattening at $E\approx 1\times {10}^{18}\mathrm{eV}$ reproduces the transition to galactic cosmic rays. This transition is studied quantitatively in this work. Inclusion of primary nuclei with a fraction of more than 20% upsets the agreement of the dip with observations, which we interpret as an indication of the acceleration mechanism. We study in detail the formal problems of spectra calculations: energy losses (the new detailed calculations are presented), the analytic method of spectrum calculations, and the study of fluctuations with the help of a kinetic equation. The UHECR sources, AGN and GRBs, are studied in a model-dependent way, and acceleration is discussed. Based on the agreement of the dip with existing data, we make the robust prediction for the spectrum at $1\times {10}^{18}–1\times {10}^{20}\mathrm{eV}$ to be measured in the nearest future by the Auger detector. We also predict the spectral signature of nearby sources, if they are observed by Auger. This paper is long and contains many technical details. For those who are interested only in physical content we recommend the Introduction and Conclusions, which are written as autonomous parts of the paper.

We study the prospects for observing coherent neutrino-nucleus elastic scattering with a noble liquid detector operated in a low-energy beta beam. We compute the expected signal rates and background contamination from different sources. We conclude that, with a one tonne detector, 1 yr of operation will suffice to observe this reaction with a very high statistical significance.

Transport equations can be derived from quantum field theory assuming a loss of information about the details of the initial state and a gradient expansion. While the latter can be systematically improved, the assumption about a memory loss is not known to be controlled by a small expansion parameter. We determine the range of validity of transport equations for the example of a scalar $g^2{\Phi }^4$ theory. We solve the nonequilibrium time evolution using the three-loop 2PI effective action. The approximation includes off-shell and memory effects and assumes no gradient expansion. This is compared to transport equations to lowest order (LO) and beyond (NLO). We find that the earliest time for the validity of transport equations is set by the characteristic relaxation time scale $t_{\mathrm{damp}}=-2\omega /{\Sigma }_{\varrho }^{(\mathrm{eq})}$, where $-{\Sigma }_{\varrho }^{(\mathrm{eq})}/2$ denotes the on-shell imaginary-part of the self-energy. This time scale agrees with the characteristic time for partial memory loss, but is much shorter than thermal equilibration times. For times larger than about $t_{\mathrm{damp}}$ the gradient expansion to NLO is found to describe the full results rather well for $g^2\lesssim 1$.

We study renormalization of Coulomb-gauge QCD within the Lagrangian, second-order, formalism. We derive a Ward identity and the Zinn-Justin equation, and, with the help of the latter, we give a proof of algebraic renormalizability of the theory. Through diagrammatic analysis, we show that, in the strict Coulomb gauge, $g^2{D}^{00}$ is invariant under renormalization. ($D^{00}$ is the time-time component of the gluon propagator.)

We find an unexpected iterative structure within the two-loop five-gluon amplitude in $\mathcal{N}=4$ supersymmetric Yang-Mills theory. Specifically, we show that a subset of diagrams contributing to the full amplitude, including a two-loop pentagon-box integral with nontrivial dependence on five kinematical variables, satisfies an iterative relation in terms of one-loop scalar box diagrams. The implications of this result for the possible iterative structure of the full two-loop amplitude are discussed.