SciPost Submission Page

The $\pi^0$ mass and the first experimental verification of Coulomb de-excitation in pionic hydrogen

by M. Daum and P.-R. Kettle

Submission summary

As Contributors: Manfred Daum
Preprint link: scipost_202105_00042v2
Date accepted: 2021-07-06
Date submitted: 2021-07-05 10:00
Submitted by: Daum, Manfred
Submitted to: SciPost Physics Proceedings
Proceedings issue: Review of Particle Physics at PSI
Academic field: Physics
Specialties:
  • High-Energy Physics - Experiment
Approach: Experimental

Abstract

The most precise value for the $\pi^0$ mass was obtained from the measurement of the mass difference $m_{\pi^-}-m_{\pi^0} = 4.593\,64(48)$\,MeV/c$^2$ in the charge exchange reaction $\pi^-$p $\rightarrow \pi^0$n at PSI. With the most precise charged pion mass value, $m_{\pi^+} = 139.570\,21(14)$\,MeV/c$^2$ and the validity of the CPT theorem ($m_{\pi^-} = m_{\pi^+}$), a value $m_{\pi^0} = 134.976\,57(50)$\,MeV/c$^2$ is obtained. The measurements also revealed, for the first time, evidence of an unexpectedly large contribution from Coulomb de-excitation states during the pionic atom cascade.

Published as SciPost Phys. Proc. 5, 012 (2021)



Submission & Refereeing History

You are currently on this page

Resubmission scipost_202105_00042v2 on 5 July 2021

Login to report or comment