Precision Measurement of the Mass Difference m π − − m π <…
1986; American Physical Society; Volume: 56; Issue: 10 Linguagem: Inglês
10.1103/physrevlett.56.1043
ISSN1092-0145
AutoresJ. F. Crawford, M. Daum, R. Frosch, B. Jost, P.‐R. Kettle, Roger M. Marshall, K. O. H. Ziock,
Tópico(s)Advanced Chemical Physics Studies
ResumoUsing the time-of-flight method to determine the velocity of the neutrons from the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}+n$ at rest we have measured the mass difference ${m}_{{\ensuremath{\pi}}^{\ensuremath{-}}}{m}_{{\ensuremath{\pi}}^{0}}$ to be 4.5930 \ifmmode\pm\else\textpm\fi{} 0.0013 ${\mathrm{M}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$. From the width of the time-of-flight distributions we conclude that the pionic hydrogen atoms have a mean kinetic energy ${\overline{T}}_{\ensuremath{\pi}p}<12$ eV (90% confidence limit) at the time of the charge exchange.
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