John P. Dooher

Single direct photon production in pp collisions at √s = 53.2 GeV in the pt interval 2.3 to 5.7 GeV/c

Abstract We report the results of an experiment made at the CERN ISR to investigate the possible diret production of single photons in pp collisions at √ s = 53.2 GeV at 90° and in the p t interval 2.3 to 5.7 GeV/ c . The value of the ratio R = n γ / n π 0 is compatible with zero for low p t ⪅ 3 GeV/ c but, in spite of the large error, shows a trend to increase for larger p t .

Combustion studies of water/oil emulsion on a commercial boiler using No. 2 oil and low and high sulphur No. 6 oil☆

Abstract The effect of water/oil emulsions on soot reduction and boiler efficiency was studied using a boiler rated at 35 million Btu h −1 (10.3 MW) with steam atomization. These tests represent the first detailed efficiency studies of combustion of emulsions with an accurately instrumented commercial boiler. Water/oil emulsions were generated with 10%, 15%, and 20% water by an in-line ultrasonic emulsifier. Particulate emissions were reduced by as much as 10% and 13% when using emulsions made with low and high sulphur oils, respectively. This reduction is less than that reported elsewhere, which may have resulted in part from the use of a lower preheat temperature in this study. The results of a series of 32 separate 4 h tests showed that there was no significant improvement in thermal efficiencies using water in No. 2 and No. 6 high sulphur oil emulsions. Though there is improvement in combustion, as represented by reducing the excess air, this seems to be compensated for by the additional heat loss due to the vapourization of the added water. In addition, an 8 h test to remove sulphur dioxide from the combustion gases using an emulsion of the high sulphur oil and soda ash in water was conducted. The efficiency of SO 2 removal was very high, approaching 100%.

Three-photon absorption for nanosecond excitation in cadmium selenide quantum dots

We experimentally observe saturable absorption and dra- matic three-photon absorption in various colloidal solutions of cadmium selenide quantum dots, with a strong size dependence witnessed for these properties. We also develop a model for the electronic portion of the nonlinearities that illustrates well the trends exhibited by our experi- mental data. The model incorporates six bands three each in the va- lence and conduction bands.

Multigamma-ray events at the CERN ISR

Abstract Results of a search for multigamma-ray events at √s = 52 GeV in pp collision are reported. The results are compared with a Monte Carlo simulation of the decay of pairs of heavy mass particles by gamma-ray emission, and upper limits for the production cross section are determined.

Two-photon mass spectra produced in p-p collision at √s = 52 GeV

In this paper we repor t on the resul ts obta ined at t i le ISR for ~Js--52 GeV on the react ion p-p -+ 2 y + a n y t h i n g , where the two photons are emi t t ed on opposite sides a round 90 ~ wi th respect to the c i rcula t ing beams. The lay-out of the exper imenta l set up, main ly consist ing of two matr ices of lead glasses (SP, S X ) , has been described in a previous paper (1) on the produc t ion cross-section of the J / ~ observed in the e+e decay mode. The da ta repor ted here correspond to an in tegra ted luminos i ty of 1.15.1037 em 2 and have been obta ined wi th the same t r igger described in ref. (~), i.e. at least one lead glass in each of the two matr ices wi th a deposi ted energy ~ 600 MeV. In the analysis, we look for lead glasses showing re la t ive m a x i m a of the deposi ted energy > 100 MeV, and define as ( the sum of the energies deposi ted in this counter and in the ad jacent lead glasses. A (~ y-ray ,) is defined as an energy cluster wi thou t signal in the scint i l la tor counter in f ront of it. 0 n l y those events have been analyses tha t show in the S P as well as in the S X units at least one (, y-ray ,) wi th energy larger t han 900 MeV. A single cluster somet imes is due to unresolved ~0. Fo r reducing this cont r ibut ion we have in t roduced the following selection requ i rements :

An investigation of high-multiplicity gamma events in pp collisions with c.m. energies between 22 and 62 GeV

Results of an exploratory experiment on the investigation of high multiplicity gamma events, carried out using colliding proton beams, are described. The main objective was to look for multigamma events which could reveal interesting features of

Three-photon absorption in cadmium selenide quantum dots

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Investigation into a catalytically controlled reaction gasifier (CCRG) for coal to hydrogen

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J/ψ production and high-mass electron-pair limit in pp collisions at √s = 52 GeV

multiple production as well as other possible mechanisms of gamma production. Evidence was found for the existence of multiparticle correlations. (JFP)