RESUMO
We investigated mu(+) decays at rest produced at the ISIS beam stop target. Lepton flavor (LF) conservation has been tested by searching for nu(e) via the detection reaction p(nu(e),e(+))n. No nu(e) signal from LF violating mu(+) decays was identified. We extract upper limits of the branching ratio (BR) for the LF violating decay mu(+)-->e(+)+nu(e)+nu(-) compared to the standard model (SM) mu(+)-->e(+)+nu(e)+nu(mu) decay: BR<0.9(1.7) x 10(-3) (90% C.L.) depending on the spectral distribution of nu(e) characterized by the Michel parameter rho=0.75(0.0). These results improve earlier limits by one order of magnitude and restrict extensions of the SM in which nu(e) emission from mu(+) decay is allowed with considerable strength. The decay mu(+)-->e(+)+nu(e)+nu(mu) often proposed as a potential source for the nu(e) signal observed in the LSND experiment can be excluded.
RESUMO
Excitation functions A(N)(p(p),Theta(c.m.)) of the analyzing power in pp--> elastic scattering have been measured with a polarized atomic hydrogen target for projectile momenta p(p) between 1000 and 3300 MeV/ c. The experiment was performed for scattering angles 30 degrees
RESUMO
In an air gap of 10 centimeters of width lying over a U-shaped iron core, a magnetic field with an intensity of B greater than or equal to 0,069 Tesla is produced by two permanent magnetic plates. This field is arranged behind the diaphragm unit of a Co-60 gammatron at right angle to the direction of radiation, so the surface dose can be reduced until a depth of 3 millimeters. This magnetic field diffracts the secondary electrons emanating from the diaphragms of the gammatron in such a manner that they cannot contribute to the surface dose within or beyond the irradiation field. Depending on the size of the irradiation field, the magnet allows to reduce the dose by 30% at most in a tissue depth of 5 to 10 mg/cm2. Measures were taken by means of a soft radiation chamber for different tissue depths within and beyond the irradiation field.
