[hibernate-users] When does reattachment occur?

[Robert Nicholson]

So, if I have the following scenario when using Ehcache.

open session a
load object a using criteria query
close session a

open session b
load object  a using criteria query (2nd level cache hit)
close session b

Can anybody tell me is explicit reattachment necessary or is the  
object attached to session b when it's loaded even when it comes out  
of ehcache and what put it in ehcache is the earlier session a.