New correlations induced by nuclear supersymmetry

We show that the nuclear supersymmetry model (n-susy) in its extended version, predicts correlations in the nuclear structure matrix elements which characterize transfer reactions between nuclei that belong to the same supermultiplet. These correlations are related to the fermionic generators of the superalgebra and if verified experimentally can provide a direct test of the model.Comment: Invited talk at "Nuclear Physics: Large and Small", April 19-22, 2004, Hacienda Cocoyoc, Mexic

Everything you always wanted to know about SUSY, but were afraid to ask

New experimental tests of nuclear supersymmetry are suggested. They involve the measurement of one- and two-nucleon transfer reactions between nuclei that belong to the same supermultiplet. These reactions provide a direct test of the `fermionic' sector, i.e. of the operators that change a boson into a fermion or vice versa. We present some theoretical predictions for the supersymmetric quartet of nuclei: 194Pt, 195Pt, 195Au and 196Au.Comment: 8 pages, 2 figures, proceedings of `Symmetries in Nuclear Structure', March 23-29, 2003, Erice, Ital

The experimental determination of tyre model parameters

SUMMARY This report describes the analysis of a series of experiments on pneumatic tyres which were designed to test the various hypotheses: regarding the deformed shape of a tyre during the steering process. The experiments consisted of several separate tests first described in Ref. 1 and 2. a) The application of a point lateral force or a moment at one position on the tread band which is restrained at the centre of the wheel, and the measurement of the resulting lateral deflection of each point of the tyre perimeter. b) The application of a uniform force around the tyre perimeter on a hollow cylindrical former and applying a load at the centre of the wheel. c) Direct determination of tread band tension by cutting the tread band and bridging the cut by a dynamometer. d) Estimation of the bending modulus of the tread band by test on sections cut from the tread band. The analysis of the experiments is carried out by first transforming the test results into a Fourier series and determining the spectral content of the bending line with an harmonic analysis. Transfer functions of beam and string models are derived and applied to the test results. A method of considering a three parameter model is described

High temperature alloy

Molybdenum is substituted for tungsten on an atomic basis in a cobalt-based alloy, S-1, thus enabling the alloy to be formed into various mill products, such as tubing and steels. The alloy is weldable, has good high temperature strength and is not subject to embrittlement produced by high temperature aging

Tidal scattering of stars on supermassive black holes in galactic centers

Some of the mass that feeds the growth of a massive black hole (BH) in a galactic center is supplied by tidal disruption of stars that approach it on unbound, low angular momentum orbits. For each star that is disrupted, others narrowly escape after being subjected to extreme tidal distortion, spin-up, mixing and mass-loss, which may affect their evolution and appearance. We show that it is likely that a significant fraction of the stars around massive BHs in galactic centers have undergone such extreme tidal interactions and survived subsequent total disruption, either by being deflected off their orbit or by missing the BH due to its Brownian motion. We discuss possible long-term observable consequences of this process, which may be relevant for understanding the nature of stars in galactic centers, and may provide a signature of the existence of massive BHs there.Comment: 5 pages 4 figures. ApJL in press, minor changes to reflect journal version including redifinition of unbound tidally disturbed stars and additional reference

The Quark Beam Function at Two Loops

In differential measurements at a hadron collider, collinear initial-state radiation is described by process-independent beam functions. They are the field-theoretic analog of initial-state parton showers. Depending on the measured observable they are differential in the virtuality and/or transverse momentum of the colliding partons in addition to the usual longitudinal momentum fraction. Perturbatively, the beam functions can be calculated by matching them onto standard quark and gluon parton distribution functions. We calculate the inclusive virtuality-dependent quark beam function at NNLO, which is relevant for any observables probing the virtuality of the incoming partons, including N-jettiness and beam thrust. For such observables, our results are an important ingredient in the resummation of large logarithms at N3LL order, and provide all contributions enhanced by collinear t-channel singularities at NNLO for quark-initiated processes in analytic form. We perform the calculation in both Feynman and axial gauge and use two different methods to evaluate the discontinuity of the two-loop Feynman diagrams, providing nontrivial checks of the calculation. As part of our results we reproduce the known two-loop QCD splitting functions and confirm at two loops that the virtuality-dependent beam and final-state jet functions have the same anomalous dimension.Comment: 27 pages, 3 figures; v2: journal versio

The Dual Effects of Intellectual Property Regulations: Within- and Between- Patent Competition in the US Pharmaceuticals Industry

A patent only protects an innovator from others producing the same product, but it does not protect him from others producing better products under new patents. Therefore, one may divide up the source of competition facing an innovator into within-patent competition, which results from production of the same product, and betweenpatent competition, which results from production of products on other patents. Previous theoretical and empirical micro -based analyses have emphasized the effects of intellectual property regulations on within -patent competition by showing how protecting innovative returns from imitators raises R&D incentives. However, between-patent competition affects innovative returns, particularly through creative destruction in the many high-tech industries that seem central to overall economic progress. This suggests that a fuller understanding of IP-regulations take into account its effects on between-patent competition. We find that the total effects of intellectual property regulations depend heavily on whether these unexplored effects are present. We attempt to estimate the relative magnitudes of the two sources of competition in limiting innovative returns in the U.S. pharmaceuticals market. In this market within -patent competition from so-called generic producers has been analyzed relatively more compared to competition between-patents through so called therapeutic competition. We estimate that between-patent competition, most of which occurs while a drug is under patent, costs the innovator at least as much as within-patent competition, which cannot occur until a drug is off patent. The reduction in the present discounted value of the innovator's return from between-patent competition appears to be at least as large as the reduction from competition within -patents, and may be much larger.