Two factors can help explain this discrepancy: first, the relatively higher share that US firms have invested ICT capital, and second, the efficiency with which they have turned that investment into productivity gains. And it is structural factors which, at least in part, account for these two differences.
First, while there is variance within the euro area, on the whole there is a relatively higher proportion of micro and small firms in Europe than in the US. European firms are also more static, in the sense that they do not grow or shrink over time.