In his article The Myth of American Meritocracy (archive), Harvard graduate Ron Unz presents data of enrolment in Ivy League universities by ethno-racial background.

The research shows a representation of Jews in Ivy League comparable with whites', despite Jews being 1.8% of the population and non-Hispanic whites being over 60%. At Harvard, Jewish OR reaches over 1300% (against whites' less than 50%, less than blacks); at Yale the figures are exactly the same; and at Cornell it is 1200% (with whites below 100%, but more than blacks and Hispanics).

Despite all of that, Jews don't perform in science competitions as well as whites and Asians. The data used for the charts are from multiple official sources and are listed here (archive)