I would like to upgrade MAUS to ROOT6 for the following reasons:

• maintain our ability to build MAUS on modern systems (ROOT5 and GCC6 don't seem to work together);
• enjoy the latest updates to ROOT which only go in ROOT6;
• generally keep the MAUS code base current.

When I presented this at an analysis meeting a few concern were raised:

1. Will ROOT6 MAUS be able to open our existing processed data?
2. Will it alter any physics results?
3. Will it mess up onrec?
4. Will it work my personal scripts?

I have addressed these questions (at least in part):

1. Yes, checked and no problem
2. I ran an MC of run 8681, 1000 events, and compared results, they were identical (output files attached)
3. I need the onrec code to say for sure, but the test plots look fine, plots in general look identical
4. There may need to be some small tweaks, principally changing . to -> to access pointers

NB: ROOT6 MAUS use slightly more memory than ROOT5, but otherwise the performance seems to be identical

Please let me have any more comments or concerns here.