There is no official or standard JPA API jar available from the expert group in either Maven Central or the java.net Maven repo that both JPA users & implementors can utilize. Users are left to search for implementations' groupId, artifactId, & version values, which is inconvenient.
Please upload a binary jar (including class files and relevant resource files), a source jar, and a javadoc jar, under the groupId "javax.persistence", artifact id "jpa-api" and version "2.1". A minimal target Maven repository would be Maven Central, but others like java.net might be nice, too.
Bonus points for including OSGi bundle metadata (pretty easy if using Apache Felix's Maven Bundle Plugin, org.apache.felix:maven-bundle-plugin:2.3.7)!