Allena K. Opper

Charge symmetry breaking in np-->dpi(0).

The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Charge Symmetry Breaking innp→dπ0

The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Optical design and performance of the SASP spectrometer at TRIUMF

Abstract A new Q–Q-Clamshell magnetic spectrometer called SASP has been commissioned in the proton hall at TRIUMF. The principal optical characteristics are: a solid angle acceptance of 13.5xa0msr, a momentum bite of 25%, a momentum resolution of Δ p / p =2×10 −4 , and a maximum central momentum of 720xa0MeV/ c . We describe the optical design, the magnetostatic design, the magnetic field mapping procedure, and the performance of this instrument.

Apparatus for a measurement of charge symmetry breaking in np→dπ0☆

Abstract TRIUMF experiment E704 is a study of Charge Symmetry Breaking in the reaction np→dπ 0 . The observable is the forward–backward asymmetry in the centre-of-mass differential cross-section, predicted to be −0.0035 at 5 MeV above threshold. As a check on the understanding of certain systematic effects the reaction pp→dπ + , which cannot have an asymmetry, is measured also. Similarly, neutron–proton elastic scattering is used to verify spectrometer acceptance. We describe the beams, target, and detectors developed for this experiment.

Reaction mechanisms in {sup 12}C({gamma},{ital pp}) near 200 MeV

Inclusive {sup 12}C({gamma},{ital pp}) cross sections have been measured with tagged photons in the range {ital E}{sub {gamma}}=187{endash}227 MeV using the Saskatchewan-Alberta Large Acceptance Detector (SALAD). The large angular acceptance allowed the measurement of noncoplanar {ital pp} emission. The cross sections were compared to a Monte Carlo intranuclear cascade calculation. Agreement was reasonable for the shapes of the cross sections but the calculated total cross section was 3.9 times larger than the data. {copyright} {ital 1996 The American Physical Society.}

Measurements of the neutron electric to magnetic form factor ratio G{sub En}/G{sub Mn} via the {sup 2}H(e{yields},e{sup '}n{yields}){sup 1}H reaction to Q{sup 2}=1.45 (GeV/c){sup 2}

We report values for the neutron electric tomagnetic form factor ratio,G_(En)/G_(Mn), deduced frommeasurements nof the neutron’s recoil polarization in the quasielastic ^2H(e, en)^1H reaction, at three Q^2 values of 0.45, 1.13, nand 1.45 (GeV/c)^2. The data at Q^2 = 1.13 and 1.45 (GeV/c)^2 are the first direct experimental measurements of nG_(En) employing polarization degrees of freedom in the Q^2 > 1 (GeV/c)^2 region and stand as the most precise ndeterminations of G_(En) for all values of Q^2.