Perspectives on Nuclear Structure and Scattering with the Ab Initio No-Core Shell Model

Nuclear structure and reaction theory are undergoing a major renaissance with advances in many-body methods, strong interactions with greatly improved links to Quantum Chromodynamics (QCD), the advent of high performance computing, and improved computational algorithms. Predictive power, with well-quantified uncertainty, is emerging from non-perturbative approaches along with the potential for new discoveries such as predicting nuclear phenomena before they are measured. We present an overview of some recent developments and discuss challenges that lie ahead. Our focus is on explorations of alternative truncation schemes in the harmonic oscillator basis, of which our Japanese--United States collaborative work on the No-Core Monte-Carlo Shell Model is an example. Collaborations with Professor Takaharu Otsuka and his group have been instrumental in these developments.Comment: 8 pages, 5 figures, accepted for publication in Proceedings of Perspectives of the Physics of Nuclear Structure, JPS Conference Proceedings, Japan (to appear

Measurements of Diffractive Processes at CDF

We review the results of measurements on hard diffractive processes performed by the CDF Collaboration and report preliminary CDF results on two soft diffractive processes with a leading antiproton and a rapidity gap in addition to that associated with the antiproton. All results have been obtained from data collected in Run I of the Fermilab Tevatron $\bar pp$ collider.Comment: 7 pages, Presented at 14$^{th}$ Topical Conference on Hadron Collider Physics, HCP-2002, Karlsruhe, Germany, 29 Sep - 4 Oct 200

Exponents of 2-multiarrangements and multiplicity lattices

We introduce a concept of multiplicity lattices of 2-multiarrangements, determine the combinatorics and geometry of that lattice, and give a criterion and method to construct a basis for derivation modules effectively.Comment: 14 page

Brief Report from the Tevatron

We report on the B physics prospects from the Fermilab Tevatron, summarizing the B physics goals of the CDF and DO experiments using their upgraded detectors. We discuss the time schedule for completion of the detector upgrades and summarize the current measurement of the CP violation parameter sin(2 beta) at CDF.Comment: Final version as it will appear in Proceedings of XIX International Symposium on Lepton and Photon Interactions at High Energies, Stanford University, August 9-14, 1999. 8 pages plus title page; 5 figure

Stability of Tsallis antropy and instabilities of Renyi and normalized Tsallis entropies: A basis for q-exponential distributions

The q-exponential distributions, which are generalizations of the Zipf-Mandelbrot power-law distribution, are frequently encountered in complex systems at their stationary states. From the viewpoint of the principle of maximum entropy, they can apparently be derived from three different generalized entropies: the Renyi entropy, the Tsallis entropy, and the normalized Tsallis entropy. Accordingly, mere fittings of observed data by the q-exponential distributions do not lead to identification of the correct physical entropy. Here, stabilities of these entropies, i.e., their behaviors under arbitrary small deformation of a distribution, are examined. It is shown that, among the three, the Tsallis entropy is stable and can provide an entropic basis for the q-exponential distributions, whereas the others are unstable and cannot represent any experimentally observable quantities.Comment: 20 pages, no figures, the disappeared "primes" on the distributions are added. Also, Eq. (65) is correcte

Hidden gauge structure and derivation of microcanonical ensemble theory of bosons from quantum principles

Microcanonical ensemble theory of bosons is derived from quantum mechanics by making use of a hidden gauge structure. The relative phase interaction associated with this gauge structure, described by the Pegg-Barnett formalism, is shown to lead to perfect decoherence in the thermodynamics limit and the principle of equal a priori probability, simultaneously.Comment: 10 page

Solenoid valve performance characteristics studied

Current and voltage waveforms of a solenoid coil are recorded as the valve opens and closes. Analysis of the waveforms with respect to time and the phase of the valve cycle accurately describes valve performance

Dynamical radion superfield in 5D action

We derive 5D N=1 superspace action including the radion superfield. The radion is treated as a dynamical field and identified as a solution of the equation of motion even in the presence of the radius stabilization mechanism. Our derivation is systematic and based on the superconformal formulation of 5D supergravity. We can read off the couplings of the dynamical radion superfield to the matter superfields from our result. The correct radion mass can be obtained by calculating the radion potential from our superspace action.Comment: 29 pages, no figures, LaTeX, some comments adde

Top-quark decay via R-parity violating interactions at the Tevatron

We consider the top-quark decay $t\to \tilde \tau b$ and $t\to \tau b \tilde{\chi}^0_1$ via explicit R-parity violating interactions in SUSY theories. We discuss the observability of those channels at the Fermilab Tevatron collider. The existing Tevatron data indicate a 95% confidence level upper bound on the coupling to be less than 0.94(0.63) for a long-lived (short-lived) $\tilde{\chi}^0_1$ with $m_{\tilde\tau}=70$ GeV. At Tevatron Run II with an integrated luminosity of 2 (10) fb$^{-1}$, one can obtain a 2$\sigma$ constraint as 0.38 (0.24) for a long-lived $\tilde{\chi}^0_1$ and 0.29(0.19) for a short-lived $\tilde{\chi}^0_1$, beyond the current indirect limit.Comment: 16 pages, 7 eps figures. Using LaTeX with axodraw. LSP decay mode included; more refs.; to appear in PL