M5-branes with 3/8 supersymmetry in pp-wave background
  We construct M5-branes in pp-wave background and find that they preserve exactly half of the background pp-wave supersymmetries. We explicitly write down the standard as well as supernumerary Killing spinors and find that their respective numbers are also half of those for the pp-wave background. This is in line with the recent work of Dabholkar et.al. which shows half-supersymmetric D-branes can be constructed in Hpp-wave background. 
Harvendra Singh