I have two maven based java projects, project A and project B. Project A is managed by a team and B by another team. Project A is a base project whose library and classes are consumed in project B. Currently, Project A's team sends a jar of their project to team B whenever they make any change to their project and team B has to replace the old jar with the new one.
Since our projects are maven based projects and managed as git repositories, I believe that there will be a much better way to do it automatically, so that whenever there is a change in project A, team B need not to worry about it and the latest changes should automatically reflect to the team B.
Seeing as you're using Maven, Team A should publish Project A to a repository (probably a private one). Team B and then depend on Project A (via their POM) and the rest will take care of itself, ie. no more manually copying of libraries.
As a bonus, Team B can always specify exactly which version of Project A they wish to depend on.
(Setting up your own private repository is not difficult. Apache's web server can host it or you can use a tool such as Nexus. Some build tools (eg. gradle) will generate a POM and publish your library to a site for you.)