Table 2.

1S–2P transition frequencies

	Sample spin polarization	Antihydrogen fres(exp) (MHz)	Hydrogen fres(th) (MHz)	Difference fres(exp) − fres(th) (MHz)
1Scd→2Pc±	Single	2,466,051,659(62)	2,466,051,625	34
1Scd→2Pf±	Single	2,466,036,611(88)	2,466,036,642	−31
1Sd→2Pc−	Double	2,466,051,189(76)	2,466,051,270	−81
1Sd→2Pf−	Double	2,466,036,395(81)	2,466,036,287	108

The experimentally determined transition frequencies for antihydrogen f_res(exp) (with 1σ errors in parentheses) are compared with the theoretically expected values for hydrogen f_res(th) at a magnetic field of 1.0329 T. For the singly spin-polarized data, the centroid of the hyperfine states is given. The transition frequencies for hydrogen were calculated to a precision better than 1 MHz (Methods).