• P S Goel

Articles written in Proceedings – Section A

• Analysis of τ-mesons

We describe in this paper measurements made on the decay products of 11 τ-mesons observed in large nuclear emulsion block detectors. Out of the 33 charged decay products; 27 have been arrested in the block, and were identified as π-mesons. The charge of the τ-meson was found to be positive in 6 cases. In one case the charge of the τ-meson is possibly negative and in 4 cases it could not be determined. Omitting one τ-meson in which a high energy γ-ray is emitted and which has been reported earlier1 the weighted mean Q-value of the remaining 10 τ-mesons is:$$Q_\tau = 76 \cdot 3 \pm 0 \cdot 3 MeV$$ which gives the mass of the τ-meson as:$$m_\tau = 968 \cdot 7 \pm 0 \cdot 6 m_e$$ This value is slightly higher than the mean value 965·5±0·7me compiled by Amaldiet al.2 from measurements of various laboratories.

• Ground water recharge in Western Uttar Pradesh

The downward movement of water in the soil due to 1971 monsoon precipitation and supplemental surface irrigation has been traced at about forty-five sites in Western Uttar Pradesh, using a thin layer of moisture tagged with tritiated water. The tritiated layer was found to move down to different depths at different sites. The movement, averaged over the forty sites is found to be 96 cm, indicating that the average recharge for the year 1971 (a year of normal monsoon) was 21.5 cm of water.

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