From the measurements of the DS fusion yield with varying US overlayer
thickness (MOD measurements), we have extracted the effective attenuation
Leffatt, which agrees at the 10% level with the
value given by the Monte Carlo using the
elastic cross section
from Ref. :
Our data could alternatively be used to extract information on the scattering
angular distribution. A MC calculation assuming isotropic scattering
with the same total cross section as Ref. 
resulted in the effective attenuation length:
In order to reproduce our experimental attenuation length Leffintusing the isotropic angular distribution, the total cross section needs to be half of the predicted value, which seems rather unlikely (the experimental absolute fusion yield at US thickness zero is reasonably well reproduced by either model). Thus, our results given in Table 8.15 confirm the importance of the p-wave contribution in scattering.
Furthermore, the suggestion of the large p-wave contribution in turn provides indirect yet intriguing experimental evidence for the existence of the J=1 state near the threshold. Note that while for the molecule there is some evidence for its J state from the fusion branching ratio of the two channels (it is predicted to be sensitive to J according to R-matrix calculations ), there has been little direct experimental information of the J state of the loosely bound .
Finally, our analysis presented here suggests that the measurement by Strasser et al. , who assumed an isotropic angular distribution in the simulation of the deceleration in deuterium, may require re-interpretation. Since there is a significant p-wave contribution also in the interaction, neglecting its angular distribution is not justified, as demonstrated in our analysis. Therefore, their conclusion, which stressed the importance of molecular effects, should be taken with caution.