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J Cahoon

Publications and source records attributed to J Cahoon.

5 recordsLinked to original sources
PubMed2006

Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon.

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.

Journal Article↗
PubMed2005

Precision measurement of the weak mixing angle in Møller scattering.

We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Møller) scattering: A(PV) = [-131 +/- 14(stat) +/- 10(syst)] x 10(-9), leading to the determination of the weak mixing angle sin2(thetaW(eff) = 0.2397 +/- 0.0010(stat) +/- 0.0008(syst), evaluated at Q2 = 0.026 GeV2. Combining this result with the measurements of sin2(thetaW(eff) at the Z0 pole, the running of the weak mixing angle is observed with over 6sigma significance. The measurement sets constraints on new physics effects at the TeV scale.

Journal Article↗
PubMed1982

Preparation of 11C-methyl iodide and L-[S-methyl-11C]methionine by an automated continuous flow process.

A continuous flow procedure has been developed for the synthesis of 11C-methyl iodide and L-[S-methyl-11C]methionine from 11CO2. The preparation can be completed in 20 min after the end of bombardment. This procedure results in the production of approximately 44 mCi 11C-methyl methionine with a specific activity of 3.3 Ci/mmol. Radiochemical purity is greater than 96%. The procedure has been automated so that the preparation can be carried out remotely, thus minimizing exposure of personnel to radiation.

Carbon Radioisotopes↗