Britain retained heavy-gun knowledge after 1945

Did Britain stop large-calibre naval-gun research after the Second World War?

No; research continued, but the navy needed carriers and other ships more than new battleships.

British research on large-calibre naval guns continued after 1945 even though no new battleships were ordered. The technical base remained strong enough that Lion-class construction could probably have resumed quickly if required. Wartime pauses in carrier and cruiser construction left more urgent demands elsewhere in the fleet. Once those priorities were considered, additional battleships offered too little value to justify construction.