Utah Const. art. VIII, § 2

The Supreme Court shall be the highest court and shall consist of at least five justices. The number of justices may be changed by statute, but no change shall have the effect of removing a justice from office. A chief justice shall be selected from among the justices of the Supreme Court as provided by statute. The chief justice may resign as chief justice without resigning from the Supreme Court. The Supreme Court by rule may sit and render final judgment either en banc or in divisions. The court shall not declare any law unconstitutional under this constitution or the Constitution of the United States, except on the concurrence of a majority of all justices of the Supreme Court. If a justice of the Supreme Court is disqualified or otherwise unable to participate in a cause before the court, the chief justice, or in the event the chief justice is disqualified or unable to participate, the remaining justices, shall call an active judge from an appellate court or the district court to participate in the cause.