It seems to be that, every time a new user is created in HANA, a new schema with the same name as the user is created too.
It's the normal behavior of SAP HANA and it's not configurable. https://answers.sap.com/questions/12096524/index.html
Here is the documentation link for SAP HANA user: https://help.sap.com/viewer/4fe29514fd584807ac9f2a04f6754767/2.0.00/en-US/20d5ddb075191014b594f7b11ff08ee2.html
A schema with the user's name is created for each database user: this schema cannot be explicitly dropped. The user's schema is automatically dropped when the user is deleted. The database user owns this schema and it is used as their default schema when they execute a command without explicitly specifying a schema name.