S-Wave Heavy Quarkonium Spectra: Mass, Decays, and Transitions

Table 11

Two-photon decay widths (in keV). The widths calculated with and without QCD corrections are denoted by and .

	Power		Logarithmic		[15]		[8]	[12]	Exp. [43]
State
(1S)	1.10	0.664	1.450	0.869	11.17	6.668	3.69	7.18	7.2 0.7 0.2
(2S)	0.987	0.592	1.291	0.774	8.48	5.08	1.4	1.71
(3S)	0.907	0.543	1.184	0.710	7.57	4.53	0.930	1.21
(4S)	0.847	0.508	1.105	0.662			0.720
(5S)	0.801	0.480	1.044	0.620
(1S)	0.277	0.199	0.277	0.199	0.58	0.42	0.214	0.45
(2S)	0.212	0.153	0.246	0.177	0.29	0.20	0.121	0.11
(3S)	0.195	0.142	0.226	0.162	0.24	0.17	0.09	0.063
(4S)	0.188	0.136	0.211	0.151			0.07
(5S)	0.176	0.129	0.199	0.143
(6S)	0.164	0.116	0.182	0.134