How to set the future permissions of content in folder

Let's say I am the user Alice and I have a publicly accessible folder /samba/public The permissions of the public Samba folder (/samba/public/) are nobody:nogroup and 0777. When Alice tries to copy over something from her home folder to the shared public drive (e.g cp ~/Downloads/* /samba/public), Alice wants the newly copied files to be editable/deletable by all guests who have access to the public Samba share. I want the copied files to be owned by nobody:nogroup and set to 0777. Instead, what happens is that the newly copied files are owned by alice:alice and guest users on the public drive can't edit or delete the files. How can I ensure that future copy/move operations of content from Alice's home folder to the shared/public Samba folder will be owned by nobody:nogroup so that guest users aren't then prevented from deleting/editing the files themselves?