Coulomb dissociation of one- and two-neutron halos in halo EFT

In neutron halo nuclei the neutron distribution extends significantly beyond the region occupied by the nuclear``core.'' Halo effective field theory (Halo-EFT) exploits the consequent separation of scales in order to predict relationships between low-energy observables in these systems as a systematic expansion in $R_{core}/R_{halo}$. This talk will discuss results for the Coulomb dissociation of neutron halo nuclei in this framework. In particular, we consider the Coulomb dissociation of ${}^{19}$C~[1]. We compute the reduced transition probability $(\mathrm{d} B(E1)/\mathrm{d}E)$ for excitation of the bound-state neutrons to the continuum up to N$^2$LO in the Halo-EFT expansion. By comparing the predcition with data from RIKEN~[2] we are able to extract accurate results for $^{19}$C's one-neutron separation energy and asymptotic normalization coefficient. Good agreement between data and Halo-EFT is also found for the longitudinal momentum distribution of $^{19}$C. Results from ongoing work to extend ths calculation to two-neutron halos will also be presented~[3]. \\[4pt] [1] B Acharya and D R Phillips, Nucl.~Phys.~A.~{\bf 913},~103~(2013).\\[0pt] [2] T Nakamura et al., Phys.~Rev.~Lett.~{\bf 83},~1112~(1999).\\[0pt] [3] B Acharya, P Hagen, H -W Hammer and D R Phillips, in preparation.