Quarkonia g-production in UPC A+A

• HERA: gpVp (V=J/,¡) very sensitive to gluon distrib. at small-x:

• Likewise RHIC,LHC: g+A V+A (V=J/,¡ ) in UPC A+A clean measurement of:

  • Nuclear GA(x,Q2) at small-x: x(J/) ~4·10-4 , x(¡)~10-3 at LHC (y=0)
  • QQbar propagation in cold nuclear matter.