Dear All, 
     Most of events in low energy dAu collisions have not the VpdVz. As shown in these
two plots below, most events with reasonable mVertexZ have not the mVpdVz in 39GeV dAu
https://www.star.bnl.gov/protected/lfsupc/slhuang/picodAu/Mudst-mVertexZ.gif
https://www.star.bnl.gov/protected/lfsupc/slhuang/picodAu/Mudst-mVpdVz.gif

So after the cut of VpdVz, the picDST only contains around 5% of total events.

https://www.star.bnl.gov/protected/lfsupc/slhuang/picodAu/pico-vzvpd.gif

This cut need to be removed. Otherwise, the picDst for dAu low energy will be useless.