Rear scubbing on my right rear brakes

Ok thks for the caliper answer but I have one more ? before I take my car bk to the shop I had just my front brakes n rotors replaced n then when I dive now when I com ro a slow stop with my foot on the brake theirs a scubbing sound in the rear right wheel even so the man said my bk brakes look fine the soundcould be the hub cap im a woman so still a littleweary to go bk to the same place, but its weard if I sundly I hear know sound at all only when im braking n slowing down at the same time if I stop suddly it makes no sound now is that crazy or what could it be my hub cap or still could it be the caliper I mean I never had this problem till they fix my front brakes n chk the bk im just puzzled,why dose it do it slowing down but not at a sudden stop,im use to braking at ease whe I come up to stop lights not slow down then stop with fast pressure but that's how the mechanic drove it,im close to getting new hubcaps n then see just my hub caps were exspensive and I cant afford the same I got,but heck all the lug caps r broke off anyway wear thet take the off with them power tools,i call them the capsn cover lugs,the were the lock on type so now really their all loose except one set I still have,help me one more time and ill ask this crazy ? no more im just a single mom n terrified of mechanic shops