1
$\begingroup$

When studying nuclei it is said that spherical nuclei do not rotate, instead rotations are considered for deformed nuclei only. I do not understand why is that. If one can write the hamiltonian of deformed nuclei as $H=H_{rot}+H_{intrinsic}$, with the same coordinate transformation one could do the same for spherical nuclei. The only difference is that now $I_1=I_2=I_3 \equiv I$ and the rotational spectrum is $E_{rot} = \frac{\hbar^{2}}{2I}J(J+1)$.

$\endgroup$

1 Answer 1

3
$\begingroup$

This is colloquial to say that spherical nuclei do not have a rotational spectra.

The nucleus could have in principle rotational energy but we’d have no way of measuring energy differences through quadrupole transitions since all quadrupole moments are $0$. The rotational energy would then appear as a constant offset in any energy calculation.

(Nota: since rotational transitions have the selection rule $\Delta L=\pm 2$, they must arise as a result of quadrupole transitions.)

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.