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On the Particle Data Group evaluation of Psi' and chi_c Branching Ratios

Claudia Patrignani
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Abstract

I propose a new evaluation of $ψ'(2S)$ and $χ_c(1P)$ branching ratios which avoids the correlations affecting the current Particle Data Group evaluation. These correlations explain the apparent technique-dependent discrepancies between the available determinations of the ${\cal B}(χ_c(1P)\to p\bar p)$ and $Γ(χ_c(1P)\to γγ)$ under the hypotesis that the current values of the $ψ'(2S)\toχ_c(1P)γ$ branching ratios are overestimated. In the process I also noticed that Particle Data Group has not restated many of the older measurements, when necessary, for the new value of ${\cal B}(J/ψ\to l^+l^-)$, which significantly affects the evaluation of some relevant $ψ'(2S)$ and $χ_c(1P)$ exclusive branching ratios.

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Claudia Patrignani. 2001-05-08. On the Particle Data Group evaluation of Psi' and chi_c Branching Ratios. https://doi.org/10.1103/physrevd.64.034017

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