Measurement of the Kinetic Energy Distribution of Pionic Hydrogen Atoms in Liquid Hydrogen

Abstract

In this experiment1’2 time-of-flight distributions of neutrons produced by the charge exchange reaction $${\pi ^ - }p \to {\pi ^0}n $$ (1) π− p → π0 n (1) of π− p atoms in liquid hydrogen were measured. The data were used to determine the pion mass difference mπ — m π o and, as a side result, the kinetic energy distribution of the pionic hydrogen atoms just before the charge exchange reaction.