Stretched states in $^{12,13}$B from the $^{14,15}$C(d,$\alpha)^{12,13}$B reactions

We have studied the $^{14,15}$C(d,$\alpha)^{12,13}$B reactions in inverse kinematics using HELIOS (the HELIcal Orbit Spectrometer) at Argonne National Laboratory. It is known that the (d,$\alpha$) and ($\alpha$,d) reactions are highly selective and strongly populate states where the transferred proton and neutron are transferred from, or to the same shell-model orbitals with aligned spins coupled to the maximum possible angular momentum (``stretched states'') and $T_{np}$=0. For exotic nuclei studied with radioactive beams, this reaction accesses states at high spin and excitation energy otherwise inaccessible with knockout or single-nucleon transfer. Beams of 17.1 MeV/u $^{14}$C, and 15.7 MeV/u $^{15}$C made using the In-Flight production method, bombarded CD$_2$ targets. Alpha particles were detected in the HELIOS position-sensitive silicon-detector array at forward laboratory angles. Heavy beam-like recoils were detected in coincidence using silicon $\Delta$E-E telescopes also at forward angles. Evidence for strongly populated unbound states in $^{12,13}$B with possible fully aligned character will be presented.