The \(\eta_{c}(2980)\) formation in two-photon collisions at LEP energies

  • The DELPHI Collaboration
experimental physics

Abstract.

\(\eta_{c}(2980)\) production in \(\gamma\gamma\) interactions has been detected via its decays into \(K^{0}_{s}K^{\pm}\pi^{\mp}\),K + K - K + K - and \({K^ + }{K^-}{\pi^ + }{\pi^-}\) in the data taken with the DELPHI detector at LEP1 and LEP2 energies. The two-photon radiative width averaged over all observed decay channels is \(\Gamma_{\gamma\gamma}\) = 13.9 \(\pm\) 2.0 (stat.) \(\pm\) 1.4(syst.) \(\pm\) 2.7 (BR) keV. No direct decay channel \(\eta_c\rightarrow \pi^ + \pi^-\pi^ + \pi^-\) has been observed. An upper limit \(\Gamma_{\gamma\gamma}\) < 5.5 keV at 95% confidence level has been evaluated for this decay mode.

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© Springer-Verlag Berlin/Heidelberg 2003

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  • The DELPHI Collaboration

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