A Dhaka court here on Monday sentenced expelled Jubo Mohila League leader Shamima Nur Papia and her husband Mofizur Rahman Sumon to 27 years imprisonment each to in an arms case.   Dhaka Metropolitan Sessions Judge KM Imrul Kayesh handed down the verdict when police produced them before a crowded courtroom in the afternoon.   On September 27, the court fixed today for delivering verdict in the case.   Investigation officer Arifuzzaman, sub-inspector of Rapid Action Battalion (Rab), submitted charge sheet in the case on June 29. Charges were framed on August 23.   Twelve people were named as witnesses in the case.