Abstract
The mass of the ηc meson is calculated by means of QCD sum rules. If the spectrum of the 0- states of charmonium contains a single prominent resonance, like the J ψ in the case of vector states, then the ηc mass is 3.0 GeV, not 2.83. There is a possibility however that there are two mixed 0- states with close masses. Then the X(2.83) could be one of them. The other one however has a much larger coupling to the pseudoscalar current of c quarks and is a "true" ηc. The ηc mass in the case of two mixed states is 3.0-3.2 GeV.
Original language | English (US) |
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Pages (from-to) | 80-83 |
Number of pages | 4 |
Journal | Physics Letters B |
Volume | 77 |
Issue number | 1 |
DOIs | |
State | Published - Jul 17 1978 |