Patterns of Voting on Ballot Propositions: A Mixture Model of Voter Types

In this paper we analyze the patterns of behavior voters exhibit over a set of votes. We explore a set of structural estimation problems that involve analyzing several votes at one time and develop estimation techniques for identifying and analyzing patterns. Using the information in these patterns, we introduce a method for studying voter heterogeneity based on a finite mixture model. Finally, we employ data containing actual micro-level vote returns to estimate the mixture model parameters

Collective modes and correlations in one-component plasmas

The static and time-dependent potential and surface charge correlations in a plasma with a boundary are computed for different shapes of the boundary. The case of a spheroidal or spherical one-component plasma is studied in detail because experimental results are available for such systems. Also, since there is some knowlegde both experimental and theoretical about the electrostatic collective modes of these plasmas, the time-dependent correlations are computed using a method involving these modes.Comment: 20 pages, plain TeX, submitted to Phys. Rev.

Dynamic Phase Transitions in Cell Spreading

We monitored isotropic spreading of mouse embryonic fibroblasts on fibronectin-coated substrates. Cell adhesion area versus time was measured via total internal reflection fluorescence microscopy. Spreading proceeds in well-defined phases. We found a power-law area growth with distinct exponents a_i in three sequential phases, which we denote basal (a_1=0.4+-0.2), continous (a_2=1.6+-0.9) and contractile (a_3=0.3+-0.2) spreading. High resolution differential interference contrast microscopy was used to characterize local membrane dynamics at the spreading front. Fourier power spectra of membrane velocity reveal the sudden development of periodic membrane retractions at the transition from continous to contractile spreading. We propose that the classification of cell spreading into phases with distinct functional characteristics and protein activity patterns serves as a paradigm for a general program of a phase classification of cellular phenotype. Biological variability is drastically reduced when only the corresponding phases are used for comparison across species/different cell lines.Comment: 4 pages, 5 figure

Absorption in Ultra-Peripheral Nucleus-Atom Collisions in Crystal

The Glauber theory description of particle- and nucleus-crystal Coulomb interactions at high-energy is developed. The allowance for the lattice thermal vibrations is shown to produce strong absorption effect which is of prime importance for quantitative understanding of the coherent Coulomb excitation of ultra-relativistic particles and nuclei passing through the crystal.Comment: 8 pages, LaTe

Nonperturbative study of generalized ladder graphs in a \phi^2\chi theory

The Feynman-Schwinger representation is used to construct scalar-scalar bound states for the set of all ladder and crossed-ladder graphs in a \phi^2\chi theory in (3+1) dimensions. The results are compared to those of the usual Bethe-Salpeter equation in the ladder approximation and of several quasi-potential equations. Particularly for large couplings, the ladder predictions are seen to underestimate the binding energy significantly as compared to the generalized ladder case, whereas the solutions of the quasi-potential equations provide a better correspondence. Results for the calculated bound state wave functions are also presented.Comment: 5 pages revtex, 3 Postscripts figures, uses epsf.sty, accepted for publication in Physical Review Letter

Di-electron and two-photon widths in charmonium

The vector and pseudoscalar decay constants are calculated in the framework of the Field Correlator Method. Di-electron widths: $\Gamma_{ee}(J/\psi)=5.41$ keV, $\Gamma_{ee}(\psi'(3686))=2.47$ keV, $\Gamma_{ee}(\psi''(3770))=0.248$ keV, in good agreement with experiment, are obtained with the same coupling, $\alpha_s=0.165$, in QCD radiative corrections. We show that the larger $\alpha_s=0.191\pm 0.004$ is needed to reach agreement with experiment for $\Gamma_{\gamma\gamma}(\eta_c)=7.22$ keV, $\Gamma_{\gamma\gamma} (\chi(^3P_0))=3.3$ keV, $\Gamma_{\gamma\gamma}(\chi(^3P_2))= 0.54$ keV, and also for $\Gamma(J/\psi\to 3g)=59.5$ keV, $\Gamma(J/\psi\to \gamma 2g)=5.7$ keV. Meanwhile even larger $\alpha_s=0.238$ gives rise to good description of $\Gamma(\psi'\to 3g)=52.7$ keV, $\Gamma(\psi'\to \gamma 2g)= 3.5$ keV, and provides correct ratio of the branching fractions: $\frac{\mathcal{B}(J/\psi\to light hadrons)}{\mathcal{B}(\psi'\to light hadrons)}=0.24.$Comment: 8 pages, no figure

Decay constants of the heavy-light mesons from the field correlator method

Meson Green's functions and decay constants $f_{\Gamma}$ in different channels $\Gamma$ are calculated using the Field Correlator Method. Both, spectrum and $f_\Gamma$, appear to be expressed only through universal constants: the string tension $\sigma$, $\alpha_s$, and the pole quark masses. For the $S$-wave states the calculated masses agree with the experimental numbers within $\pm 5$ MeV. For the $D$ and $D_s$ mesons the values of $f_{\rm P} (1S)$ are equal to 210(10) and 260(10) MeV, respectively, and their ratio $f_{D_s}/f_D$=1.24(3) agrees with recent CLEO experiment. The values $f_{\rm P}(1S)=182, 216, 438$ MeV are obtained for the $B$, $B_s$, and $B_c$ mesons with the ratio $f_{B_s}/f_B$=1.19(2) and $f_D/f_B$=1.14(2). The decay constants $f_{\rm P}(2S)$ for the first radial excitations as well as the decay constants $f_{\rm V}(1S)$ in the vector channel are also calculated. The difference of about 20% between $f_{D_s}$ and $f_D$, $f_{B_s}$ and $f_B$ directly follows from our analytical formulas.Comment: 37 pages, 10 tables, RevTeX

Baryons in the Field Correlator Method: Effects of the Running Strong Coupling

The ground and P-wave excited states of nnn, nns and ssn baryons are studied in the framework of the Field Correlator Method using the running strong coupling constant in the Coulomb-like part of the three-quark potential. The running coupling is calculated up to two loops in the background perturbation theory. The three-quark problem has been solved using the hyperspherical functions method. The masses of the S- and P-wave baryons are presented. Our approach reproduces and improves the previous results for the baryon masses obtained for the freezing value of the coupling constant. The string correction for the confinement potential of the orbitally excited baryons, which is the leading contribution of the proper inertia of the rotating strings, is estimated.Comment: 13 pages, 1 figure, 5 table

Patterns of Voting on Ballot Propositions: A Mixture Model of Voter Types

In this paper we analyze the patterns of behavior voters exhibit over a set of votes. We explore a set of structural estimation problems that involve analyzing several votes at one time and develop estimation techniques for identifying and analyzing patterns. Using the information in these patterns, we introduce a method for studying voter heterogeneity based on a finite mixture model. Finally, we employ data containing actual micro-level vote returns to estimate the mixture model parameters