Pass a variable from a running process to another process (alfresco - activiti)

Question

Greetings to the community, I am using Alfresco 6.0.0 (Community Edition) and I am wondering if the following scenario would be possibly achieved.

Step 1

Start a process through the alfresco workflow console with definition = 'process1'

Step 2

Start a second process through the alfresco workflow console with definition = 'process2'

I wonder if I somehow could "interact" with the process1 from process2

(for example, update a variable that exists in the process1 from process2)

In case the above scenario is feasible, I would prefer to do that either inside the .bpmn file of my process2 or maybe using a serviceTask extending a custom JavaDelegate method.

Any help would be greatly appreciated, thanks :)