High power,single frequency operation of a Q-switched TEM00 Mode NdYAG laser

An actively Q-switched NdYAG laser, using a telescopic resonator configuration has produced single longitudinal mode, TEM₀₀ outputs of 100 mJ with output pulses free from any observable mode-beating.     

Cryoscopy on sulfuric acid solutions of a heterocyclic polymer (BBB) and related compounds

Cryoscopic measurements have been carried out on solutions in sulfuric acid of a heterocyclic polymer, its monomers, and certain of its oligomers. The polymer, BBB, is prepared by the polycondensation of 1,4,5,8-naphthalenetetracarboxylic acid (NTC) with 3,3′-diaminobenzidine (DAB). The results show that the polymer, its oligomers and one of its monomers, DAB, are all extensively protonated in sulfuric acid, whereas its other monomer is not. The degree of protonation appears to be greater for the polymer than for its low molecular weight oligomers.     

Correlation diagram for rigid and nonrigid three-body systems

We consider the relation between energy level patterns of rigid structures and those of systems in which the particle motions are uncorrelated. Defining an ideal model system of the non-rigid limit for N identical particles, we exhibit the correlation diagram connecting this limit to an ideal rigid system for N = 3. States of the two limits are related in a simple manner. Vibration-rotation levels for three identical spin-0 and spin-1/2 particles are classified explicitly, according to their quantum numbers in both limits.     

Stokes’ phenomenon; smoothing a victorian discontinuity

Summary Small exponentials in asymptotic representations of functionsy(k; X) (k → ∞) can appear and disappear across sets of codimension 1 in the space of variables X. These changes are not discontinuous but happen smoothly and according to a universal law. Dedicated to René Thom.     

The influence of subglottal acoustics on laboratory models of phonation

Many previous laboratory investigations of phonation involving physical models, excised larynges, and in vivo canine larynges have failed to fully specify the subglottal system. Many of these same studies have reported a variety of nonlinear phenomena, including bifurcations (e.g., various classes of phonation onset and offset, register changes, frequency jumps), subharmonics, and chaos, and attributed such phenomena to the biomechanical properties of the larynx. However, such nonlinear phenomena may also be indicative of strong coupling between the voice source and the subglottal tract. Consequently, in such studies, it has not been clear whether the underlying mechanisms of such nonlinear phenomena were acoustical, biomechanical, or a coupling of the acoustical and biomechanical systems. Using a physical model of vocal fold vibration, and tracheal tube lengths which have been commonly reported in the literature, it is hypothesized and subsequently shown that such nonlinear phenomena may be replicated solely on the basis of laryngeal interactions with the acoustical resonances of the subglottal system. Recommendations are given for ruling out acoustical resonances as the source of nonlinear phenomena in future laboratory studies of phonation.     

Observation of Bs(0)-Bs(0) oscillations

We report the observation of Bs(0)-Bs(0) oscillations from a time-dependent measurement of the Bs(0)-Bs(0) oscillation frequency Deltams. Using a data sample of 1 fb(-1) of pp collisions at square root of s=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic Bs decays, 3100 partially reconstructed hadronic Bs decays, and 61,500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for Bs(0)-Bs(0) oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10(-8), which exceeds 5sigma significance. We measure Deltams=17.77 +/- 0.10(stat) +/- 0.07(syst) ps(-1) and extract /V(td)/V(ts)/=0.2060+/-0.0007(Deltams)(-0.0060)(+0.008)(Deltamd+theor).     

Observation of B(s)0-->K+ K- and measurements of branching fractions of charmless two-body decays of B0 and B(s)0 mesons in pp collisions at square root of s = 1.96 TeV

We search for decays of the type B(s)0-->h+ h'- (where h,h' = K or pi) in 180 pb(-1) of pp collisions collected at the Tevatron by the upgraded Collider Detector at Fermilab. We report the first observation of the new mode B(s)0-->K+ K- with a yield of 236+/-32 events, corresponding to (fs/fd) x B(B(s)0-->K+ K-)/B(B0-->K+ pi-) = 0.46+/-0.08stat+/-0.07syst, where fs/fd is the ratio of production fractions of B(s)0 and B0. We find results in agreement with world averages for the B0 modes, and set the following new limits at 90% C.L.: B(B(s)0-->K- pi+) < 5.6 x 10(-6) and B(B(s)0-->pi+ pi-) < 1.7 x 10(-6).