Determination Of Upper Limits Research Articles

Test of Charge Conjugation Invariance

We report on the first determination of upper limits on the branching ratio (BR) of eta decay to pi0pi0gamma and to pi0pi0pi0gamma. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(eta-->pi0pi0gamma)<5 x 10(-4) at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(eta-->pi0pi0pi0gamma)<6 x 10(-5) at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.

Stochastic aspects of lung dosimetry for radon decay products at low dose levels

The determination of upper limits for the amount of inhaled radon decay products needs detailed information on the resulting radiation dose in different organs and tissues, particularly in the respiratory tract. The common procedure of theoretical lung dosimetry is characterized by applying simple analytical techniques to a data base consisting of mean values for all anatomical and physiological parameters involved. However, it is well known that great inter- as well as intrasubject variabilities of lung dimensions and clearance processes could be observed, questioning, therefore, the applicability of simplified anatomical and clearance models. Substituting the mean values by probability distributions and applying Monte Carlo techniques a dosimetric method for determining lung doses is presented, taking into consideration these variabilities.

Determination of upper limits to the abundance of carbon 13 in normal red giant stars.

Determination of upper limits to the abundance of carbon 13 in normal red giant stars.