Evidence for tetrahedral symmetry in 16O

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We derive the rotation-vibration spectrum of a 4-alpha configuration with tetrahedral symmetry, T_d, and show evidence for the occurrence of this symmetry in the low-lying spectrum of 16O.

• All vibrational states with A, E and F symmetry appear to have been observed, as well as the rotational bands with L(P)=0(+), 3(-), 4(+), 6(+) on the A states, and part of the rotational bands built on the E, F states.
• We derive analytic expressions for the form factors and B(EL) values of the ground state rotational band and show that the measured values support the tetrahedral symmetry of this band.