# Precise measurement of the decay $K_{L} \to\pi^{0}\gamma\gamma$

Abstract : The decay rate of $\klpgg$ has been measured with the NA48 detector at the CERN SPS. A total of $2558$ $\klpgg$ candidates have been observed with a residual background of $3.2\%$. The branching ratio is determined to be $(1.36 \pm0.03_{(stat)} \pm0.03_{(syst)}\pm 0.03_{(norm)})\times10^{-6}$ and the vector coupling constant $a_v = -0.46 \pm0.03_{(stat)} \pm0.04_{(syst)}$. This result suggests that the CP-violation effects are dominating in the $\klpee$ decay. An upper limit for the $\klpgg$ decay rate in the two photon mass region $m_{\gamma\gamma} m_{\pi^0}$ is also given
Document type :
Journal articles
Complete list of metadata

Cited literature [7 references]

http://hal.in2p3.fr/in2p3-00011740
Contributor : Hélène Kerec <>
Submitted on : Tuesday, June 25, 2002 - 2:56:58 PM
Last modification on : Saturday, January 2, 2021 - 11:26:02 PM
Long-term archiving on: : Tuesday, March 30, 2010 - 5:01:05 PM

### Identifiers

• HAL Id : in2p3-00011740, version 1

### Citation

A. Lai, D. Marras, J R. Batley, A. Bevan, R S. Dosanjh, et al.. Precise measurement of the decay $K_{L} \to\pi^{0}\gamma\gamma$. Physics Letters B, Elsevier, 2002, 536, pp.229-240. ⟨in2p3-00011740⟩

Record views