Cal. PROB § 103

Except as provided by Section 224, if spouses die leaving community or quasi-community property and it cannot be established by clear and convincing evidence that one spouse survived the other: (a) One-half of the community property and one-half of the quasi-community property shall be administered or distributed, or otherwise dealt with, as if one spouse had survived and as if that one-half belonged to that spouse. (b) The other one-half of the community property and the other one-half of the quasi-community property shall be administered or distributed, or otherwise dealt with, as if the other spouse had survived and as if that one-half belonged to that spouse.