it is permissible for a man to see/touch/embrace his dead wife?

I'd like to know if it is permissible for a man to see/touch/embrace his dead wife? Also, if it is permissible for a woman to see/touch/embrace her dead husband? I have seen some people not even allowing the wife to see the face of her dead husband and also, not allowing the husband to see the face of her wife, saying it is not permissible? Also, it is said that after the death of a husband or wife, the Nikah is invalidated. Is it true? Can the husband give his dead wife ghusl for burial? Can the wife give her dead husband ghusl for burial? Please enlighten me with the proper knowledge, from The Holy Qur'aan and Hadith? Awaiting your expert comments. Jazaakumullaahu Khhair.