Production of prompt charmonia in e(+)e(-) annihilation at square root of s approximately equals 0.6 GeV

The production of prompt J/psi, psi(2S), chi(c1), and chi(c2) is studied using a 32.4 fb(-1) data sample collected with the Belle detector at Upsilon(4S) and at 60 MeV below the resonance. The yield of prompt J/psi mesons in the Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Upsilon(4S)-->J/psiX) < 1.9 x 10(-4) at the 95% confidence level, and find sigma(e(+)e(-)-->J/psiX) = 1.47 plus/minus 0.10 plus/minus 0.13 pb. The cross sections for prompt psi(2S) and direct J/psi are measured. The J/psi momentum spectrum, production angle distribution, and polarization are studied.     

Retention of structure in microemulsion polymerization: formation of nanolatices

Polymerization of styrene-in-water microemulsions by photoinitiation using the initiator 2,2'-dimethoxy-2-phenyl acetophenone (DMPA) produces small nanolatices of the same size as the parent microemulsion (radius = 24-31 angstroms). This behavior is distinct from previously applied methods where significant particle growth accompanies the polymerization reaction. NMR measurements confirmed that polymerization is complete in under an hour and small-angle neutron scattering established the microemulsion structure before and after polymerization. The approach may be of more general application where retention of structure is sought in microemulsion-based polymer templating procedures.     

Turbulent boundary layers on axially-inclined cylinders. II. Circumferentially averaged wall-pressure wavenumber–frequency spectra

The boundary layer on a long cylinder with its axis at small inclinations to the freestream (an idealisation of “streamers” used in underwater seismic surveys) has been studied experimentally. For the range of incidence 0–6°, there is no evidence of vortex shedding at typical Reynolds numbers. The circumferentially averaged fluctuating wall pressure decreases with increasing incidence, showing that increases in extraneous noise in seismic measurements when the streamer is at incidence are not caused by the changes in boundary layer structure. Wavenumber–frequency spectra of the circumferentially averaged wall pressure show a convective ridge that persists for the range of incidences studied. Received: 10 June 2000/Accepted: 4 July 2001     

Stabilization of CeO(2) nanoparticles in a CO(2) rich solvent

Here it is shown that the chemical nature of outer organic surfactant layers, used to stabilize inorganic nanoparticles (NPs), is a key factor controlling solubility in a mixed liquid CO(2)-heptane (10% vol) solvent.     

Studies of the decay B+/- -->D(CP)K+/-

We report studies of the Cabibbo-suppressed decay B+/--->D(CP)K+/-, where D(CP) denotes CP eigenstates of the D0-D0; system. The analysis is based on a 29.1 fb(-1) sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) storage ring. We measure ratios of branching fractions, relative to Cabibbo-favored B+/--->D(CP)pi(+/-), of B(B--->D1K-)/B(B--->D1pi(-))=0.125+/-0.036+/-0.010 and B(B--->D2K-)/B(B--->D2pi(-))=0.119+/-0.028+/-0.006; the index 1 (2) denotes the CP=+1 (-1) eigenstate. We also extract the partial rate asymmetries for B+/--->D(CP)K+/-, finding A(1)=0.29+/-0.26+/-0.05 and A(2)=-0.22+/-0.24+/-0.04.     

A photo-responsive organogel

A photo-responsive organogel has been made by addition of a novel stilbene-containing photo-surfactant to toluene: exposure to UV light led to a gel-to-sol transition with spatial control.     

Photo-stabilised microemulsions

Light-induced stabilisation of water-in-heptane microemulsions has been achieved with a UV-sensitive gemini photo-surfactant.     

Observation of double cć production in e+e- annihilation at squareroot[s] approximately 10.6 GeV

We report the observation of prompt J/psi via double cc; production from the e+e- continuum. In this process one cc; pair fragments into a J/psi meson while the remaining pair either produces a charmonium state or fragments into open charm. Both cases have been experimentally observed. We find cross sections of sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) pb and infer sigma(e+e- -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These results are obtained from a 46.2 fb(-1) data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB collider.