We study how observables of the neutrino mixing matrix can link up with those in the quark sector. The deviation from the bimaximal flavor mixing is parametrized using a $3\times 3$ unitary matrix. The neutrino mixings are investigated supposing this unitary matrix to be hierarchical like the quark mixing matrix. We obtain the remarkable prediction $|U_{e3\mathrm{}}|>~0.03$ from the experimentally allowed range ${\tan }^2{\theta }_{\mathrm{sol}}=0.24\mathrm{}–\mathrm{0.89.}$ The $\mathrm{CP}$ violation in neutrino oscillations is expected to be very small.

We propose a statistical formulation to estimate possible errors in long baseline neutrino oscillation experiments caused by uncertainties in the Earth matter density. A quantitative investigation of the effect is made using the $\mathrm{CP}$ asymmetry in future experiments at the neutrino factory and superbeam.

We discuss a consistent treatment of the light-front gauge-boson and meson wave functions in analyses of the generalized parton distributions (GPDs) and the scattering amplitudes in deeply virtual Compton scattering (DVCS) for the pion. The continuity of the GPDs at the crossover where the longitudinal momentum fraction of the probed quark is equal to the skewedness parameter and the finiteness of the DVCS amplitude are ensured if the same light-front radial wave function as that of the meson bound state is used for the gauge boson bound state arising from the pair-creation (or nonvalence) diagram. The frame independence of our model calculation is also guaranteed by the constraint from the sum rule between the GPDs and the form factors.

We present a thorough analysis of the current solar neutrino data, in the context of two-flavor active neutrino oscillations. We aim at performing an accurate and exhaustive statistical treatment of both the input and the output information. Concerning the input information, we analyze 81 observables, including the total event rate from the chlorine experiment, the total gallium event rate and its winter-summer difference, the 44 bins of the Super-Kamiokande (SK) energy-nadir electron spectrum, and the 34 day-night energy spectrum bins from the Sudbury Neutrino Observatory (SNO) experiment. We carefully evaluate and propagate the effects of 31 sources of correlated systematic uncertainties, including 12 standard solar model (SSM) input errors, the ${}^8\mathrm{B}$ neutrino energy spectrum uncertainty, as well as 11 and 7 systematics in SK and SNO, respectively. Concerning the output information, we express the ${\chi }^2$ analysis results in terms of “pulls,” embedding the single contributions to the total ${\chi }^2$ coming from both the observables and the systematics. It is shown that the pull method, as compared to the (numerically equivalent) covariance matrix approach, is not only simpler and more advantageous, but also includes useful indications about the preferred variations of the neutrino fluxes with respect to their SSM predictions. Our final results confirm the current best-fit solution at large mixing angle (LMA), but also allow, with acceptable statistical significance, other solutions in the low-mass (LOW) or in the quasivacuum oscillation (QVO) regime. Concerning the LMA solution, our analysis provides conservative bounds on the oscillation parameters, and shows that the contribution of correlated systematics to the total ${\chi }^2$ is rather modest. In addition, within the LMA solution, the allowed variations from SSM neutrino fluxes are presented in detail. Concerning the LOW and QVO solutions, the analysis of the pull distributions clearly shows that they are still statistically acceptable, while the small mixing angle (SMA) solution could be recovered only by ad hoc “recalibrations” of several SSM and experimental systematics. A series of Appendixes elucidate various topics related to the ${\chi }^2$ statistics, the winter-summer difference in GALLEX-GNO, the treatment of the SK and SNO spectra, and a quasi-model-independent comparison of the SK and SNO total rates.

The radiation at the collision of high-energy particles is formed over a rather long distance and therefore is sensitive to the environment. In particular, the smallness of the transverse dimensions of the colliding beams leads to suppression of the bremsstrahlung cross section for soft photons. This beam-size effect was discovered and investigated at INP, Novosibirsk. At that time an incomplete expression for the bremsstrahlung spectrum was calculated and used. This is because a subtraction associated with the extraction of the pure fluctuation process was not performed. Here this procedure is done. The complete expression for the spectral-angular distribution of incoherent bremsstrahlung probability is obtained. The case of the Gaussian colliding beams is investigated in detail. In the case of flat beams the expressions for the bremsstrahlung spectrum are essentially simplified. The comparison shows quite reasonable agreement between the theory and the VEPP-4 and DESY HERA data. The possible application to the tuning of beams in a linear $e^{+}{e}^{-}$ collider is discussed.

We search for conceptually simple extensions of the standard model, and describe here a candidate model which we find attractive. Our starting point is the assumption that off-diagonal CKM mixing matrix elements are directly related by lowest order perturbation theory to the quark mass matrices. This appears to be most easily and naturally implemented by assuming that all off-diagonal elements reside in the down-quark mass matrix. This assumption is in turn naturally realized by introducing three generations of heavy, electroweak-singlet down quarks which couple to the Higgs sector diagonally in flavor, while mass mixing off-diagonally with the light down quarks. Anomaly cancellation then naturally leads to inclusion of electroweak vector-doublet leptons. It is then only a short step to completing the extension to three generations of fundamental $\underset{¯}{27}$ representations of $E\left(6\right).$ Consequences of this picture include (1) the hypothesis of “Stech texture” for the down-quark mass matrix (imaginary off-diagonal elements) leads to an approximate right unitarity triangle $(\gamma \approx \pi /2),$ and a value of $\sin 2\beta$ between 0.64 and 0.80. (2) Assuming only that the third generation B couples to the Higgs sector at least as strongly as does the top quark, the mass of the B is roughly estimated to lie between 1.7 TeV and 10 TeV, with lower-generation quarks no heavier. The corresponding guess for the new leptons is a factor two lower, 0.8 TeV to 5 TeV. (3) Within the validity of the model, flavor and $\mathrm{CP}$ violation are “infrared” in nature, induced by semi-soft mass mixing terms, not Yukawa couplings. (4) The “Mexican hat” structure of the Higgs potential may be radiatively induced by the new heavy down-quark one-loop contributions to the potential. (5) A subset of the precision electroweak experiments are sensitive to the physics induced by the heavy quarks and/or leptons. (6) If the Higgs couplings of the new quarks are flavor symmetric, then there necessarily must be at least one “oasis” in the desert, induced by new radiative corrections to the top quark and Higgs coupling constants, and roughly at ${10}^3\mathrm{TeV}.$ (7) If the Higgs couplings of the new down quarks are hierarchical and equal to the usual Higgs couplings to right-handed up quarks, then, in the limit in which gauge coupling constants are set to zero, parity violation is also “infrared,” induced by semi-soft mass terms.

We report on measurements of the branching ratios of the decays $B^{+}\to {\chi }_{c1\mathrm{}}^0{\mathrm{}\left(1P\right)K}^{+}$ and $B^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-},$ where ${\chi }_{c1\mathrm{}}^0\mathrm{}\left(1P\right)\mathrm{}\to J/\psi \gamma$ and $J/\overrightarrow{\psi }{\mu }^{+}{\mu }^{-}$ in $p\overline{p}$ collisions at $\sqrt{s}=1.8\mathrm{}\mathrm{TeV}.$ Using a data sample from an integrated luminosity of $110{\mathrm{pb}}^{-1}$ collected by the Collider Detector at Fermilab we measure the branching ratios to be ${BR(B}^{+}\to {\chi }_{c1\mathrm{}}^0{\mathrm{}\left(1P\right)K}^{+})=15.5\mathrm{}\pm 5.4(\mathrm{stat})\pm 1.5(\mathrm{syst})\pm 1.3(\mathrm{br})\times {10}^{-4}$ and ${BR(B}^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-})=6.9\mathrm{}\pm 1.8(\mathrm{stat})\pm 1.1(\mathrm{syst})\pm 0.4(\mathrm{br})\times {10}^{-4}$ where $\left(\mathrm{br}\right)$ is due to the finite precision on ${BR(B}^{+}\to J/\psi K^{+}),$ $BR\left({\chi }_{c1\mathrm{}}^0\mathrm{}\right(1P)\mathrm{}\to J/\psi \gamma )$ is used to normalize the signal yield, and $\left(\mathrm{syst}\right)$ encompasses all other systematic uncertainties.

We observed atmospheric gamma rays around 10 GeV at balloon altitudes (15–25 km) and at a mountain (2770 m a.s.l). The observed results were compared with Monte Carlo calculations to find that an interaction model (Lund FRITIOF1.6) used in an old neutrino flux calculation was not good enough for describing the observed values. Instead, we found that two other nuclear interaction models, Lund FRITIOF7.02 and DPMJET3.03, gave much better agreement with the observations. Our data will serve for examining nuclear interaction models and for deriving a reliable absolute atmospheric neutrino flux in the GeV region.

The ratio of charged and neutral B meson production at the ${\rm Y}\mathrm{}\left(4S\right),$ $f_{+-}{/f}_{00},$ is measured through the decays $\overline{B}\to D^{*}{\mathcal{l}}^{-}{\overline{\nu }}_{\mathcal{l}},$ reconstructed using a partial reconstruction method where the $D^{*}$ is detected only through a pion daughter from the decay $D^{*}\to D\pi .$ Using data collected by the CLEO II detector, the charged and neutral B decays are measured in such a way that their ratio is independent of the decay model, limited mainly by the uncertainty in the relative efficiency for detecting neutral and charged pions. This measurement yields the ratio of production fractions times the ratio of semileptonic branching fractions, $f_{+-}{b}_{+}{/f}_{00}{b}_0.$ Assuming that $b_{+}{/b}_0$ is equal to the lifetime ratio ${\tau }_{+}/{\tau }_0$ and using the world average value of ${\tau }_{+}/{\tau }_0$ as input, we obtain $f_{+-}{/f}_{00}=1.058\mathrm{}\pm 0.084\pm \mathrm{0.136.}$

We consider the perturbative description of saturation based on the nonlinear QCD evolution equation of Balitsky and Kovchegov. Although the nonlinear corrections lead to saturation of the scattering amplitude locally in impact parameter space, we show that they do not unitarize the total cross section. The total cross section for the scattering of a strongly interacting probe on a hadronic target is found to grow exponentially with rapidity $t=\ln {(s/s}_0),$ $\sigma \propto \exp \{({\alpha }_s{N}_c/2\mathrm{}\pi )\epsilon t\}$ where $\epsilon$ is a number of order unity. The origin of this violation of unitarity is the presence of long range Coulomb fields away from the saturation region. The growth of these fields with rapidity is not tempered by the nonlinearity of the Balitsky-Kovchegov equation.

Baryon octet magnetic moments when calculated within the chiral quark model, incorporating the orbital angular momentum as well as the quark sea contribution through the Cheng-Li mechanism, not only show improvement over the nonrelativistic quark model results but also give a nonzero value for the right-hand side of the Coleman-Glashow sum rule. When effects due to spin-spin forces between constituent quarks as well as “mass adjustments” due to confinement are added, it leads to an excellent fit for the case of $p,{\Sigma }^{+},$ ${\Xi }^o$ and violation of the Coleman-Glashow sum rule, whereas in almost all the other cases the results are within 5% of the data.

We discuss the phenomenology of a three-family supersymmetric standardlike model derived from the orientifold construction, in which the ordinary chiral states are localized at the intersection of branes at angles. In addition to the standard model group, there are two additional ${U\left(1\right)\mathrm{}}^{\prime }$ symmetries, one of which has family nonuniversal and therefore flavor changing couplings, and a quasihidden non-Abelian sector which becomes strongly coupled above the electroweak scale. The perturbative spectrum contains a fourth family of exotic $\left[\mathrm{SU}\right(2)\mathrm{}$-singlet] quarks and leptons, in which, however, the left-chiral states have unphysical electric charges. It is argued that these decouple from the low energy spectrum due to hidden sector charge confinement, and that anomaly matching requires the physical left-chiral states to be composites. The model has multiple Higgs doublets and additional exotic states. The moduli-dependent predictions for the gauge couplings are discussed. The strong coupling agrees with experiment for reasonable moduli, but the electroweak couplings are too small.

We examine the problem of gauge dependence of the two-particle irreducible (2PI) effective action and its $\Phi$-derivable approximations in gauge theories. The dependence on the gauge-fixing condition is obtained. The result shows that $\Phi$-derivable approximations, defined as truncations of the 2PI effective action at a certain order, have a controlled gauge dependence, i.e. the gauge dependent terms appear at higher order than the truncation order. Furthermore, using the stationary point obtained for the approximation to evaluate the complete 2PI effective action boosts the order at which the gauge dependent terms appear to twice the order of truncation. We also comment on the significance of this controlled gauge dependence.

It is shown that embedding a four-dimensional flipped $\mathrm{SU}\left(5\right)\mathrm{}$ model in a five-dimensional $\mathrm{SO}\left(10\right)\mathrm{}$ model preserves the best features of both flipped $\mathrm{SU}\left(5\right)\mathrm{}$ and $\mathrm{SO}\left(10\right).$ The missing partner mechanism, which naturally achieves both doublet-triplet splitting and suppression of $d=5\mathrm{}$ proton decay operators, is realized as in flipped $\mathrm{SU}\left(5\right),$ while the gauge couplings are unified as in $\mathrm{SO}\left(10\right).$ The masses of down quarks and charged leptons, which are independent in flipped $\mathrm{SU}\left(5\right),$ are related by the $\mathrm{SO}\left(10\right).$ Distinctive patterns of quark and lepton masses can result. The gaugino mass $M_1$ is independent of $M_3$ and $M_2,$ which are predicted to be equal.

Euclidean $d=3\mathrm{}$ $\mathrm{SU}\left(2\right)\mathrm{}$ Yang-Mills-Chern-Simons (YMCS) theory may have solitons in the presence of appropriate mass terms, including Georgi-Glashow (GGCS) theory. For integral CS level k and for solitons carrying integral CS number $N_{\mathrm{CS}},$ YMCS theory is gauge invariant and consistent, and the CS integral describes the compact Hopf map $S^3\to S^2.$ However, typical solitons include sphalerons and linked center vortices ${(N}_{\mathrm{CS}}=1/2)$ as well as writhing center vortices with arbitrary real $N_{\mathrm{CS}},$ and compactness may be lost. We study various forms of the non-compact theory in the dilute-gas approximation, including k as an odd integer or non-integral, treating the parameters of non-compact large gauge transformations as collective coordinates. Among our conclusions are the following. (1) YMCS theory dynamically compactifies; a putative non-compact YMCS theory has infinitely higher vacuum energy $\int d^{3}x{\epsilon }_{\mathrm{vac}}$ than compact YMCS theory. (2) For sphalerons with $N_{\mathrm{CS}}=1/2\mathrm{}$ compactification arises through a domain-wall sphaleron, a pure-gauge configuration lying on a closed surface carrying the right amount of $N_{\mathrm{CS}}$ to compactify. (3) We can interpret the domain-wall sphaleron in terms of fictitious closed Abelian field lines, associated with an Abelian potential and magnetic field derived from the non-Abelian CS term. In this language, sphalerons are under- and over-crossings of knots in the field lines; a domain-wall sphaleron acts as a superconducting surface which confines these knots to a compact domain. (4) Analogous results hold for the linking and writhing of center vortices and nexuses. (5) If we induce a CS term with an odd number of fermion doublets, domain-wall sphalerons are related to non-normalizable fermion zero modes of solitons. (6) The GGCS theory with monopoles is explicitly compactified with center-vortex-like strings.

We have considered the structure of the fundamental symmetry violating part of the photon refractive index in vacuum in the presence of constant electric and magnetic fields. This part of the refractive index can, in principle, contain $\mathrm{CPT}$ symmetry breaking terms. Some of the terms violate Lorentz invariance, whereas the others violate locality and causality. Estimates of these effects, using laser experiments are considered.

The gravitational radiation degrees of freedom are described in the framework of the $3+1$ decomposition of spacetime. The relationship with the eigenfields of the Kidder-Scheel-Teukolsky (KST) equations is established. This relationship is used to fix a parameter in the KST equations which is related to the ordering ambiguity of space derivatives in the Ricci tensor, which is inherent to first order evolution systems, such as the ones currently used in numerical relativity applications.

We present a fully nonlinear calculation of the waveform of the gravitational radiation emitted in the fission of a vacuum white hole. At early times, the waveforms agree with close approximation perturbative calculations but they reveal dramatic time and angular dependence in the nonlinear regime. The results pave the way for a subsequent computation of the radiation emitted after a binary black hole merger.

We present a numerical study of critical phenomena (including the Lue-Weinberg phenomenon) arising for gravitating monopoles in a global monopole spacetime. The equations of this model have been recently studied by Spinelly, de Freitas, and Bezerra in a domain of parameter space away from the critical points.

A direct relation between two types of topological field theories, Chern-Simons theory and $\mathrm{BF}$ theory, is presented by using “generalized differential calculus,” which extends an ordinary p-form to an ordered pair of p and $\mathrm{}(p+1\mathrm{})\mathrm{}$-form. We first establish the generalized Chern-Weil homomormism for generalized curvature invariant polynomials in general even dimensional manifolds, and then show that $\mathrm{BF}$ gauge theory can be obtained from the action which is the generalized second Chern class with gauge group G. Particularly when G is taken as $\mathrm{SL}(2,C)\mathrm{}$ in four dimensions, general relativity with a cosmological constant can be derived by constraining the topological $\mathrm{BF}$ theory.