(a) The Superior Court may grant a new trial of any action that may come before it, for mispleading, the discovery of new evidence or want of actual notice of the action to any defendant or of a reasonable opportunity to appear and defend, when a just defense in whole or part existed, or the want of actual notice to any plaintiff of the entry of a nonsuit for failure to appear at trial or dismissal for failure to prosecute with reasonable diligence, or for other reasonable cause, according to the usual rules in such cases. The judges of the Superior Court may in addition provide by rule for the granting of new trials upon prompt request in cases where the parties or their counsel have not adequately protected their rights during the original trial of an action.
(b) An affidavit signed by any party or his or her attorney shall be presumptive evidence of want of actual notice.