At any time within 20 days after the service of any findings of fact by the Workers’ Compensation Appeals Board under this part, any party aggrieved thereby, or the board, may petition for a rehearing upon one or more of the following grounds, and no other:
(a)
That the Workers’ Compensation Appeals Board acted without or in excess of its powers.
(b)
That the findings of fact were procured by fraud.
(c)
That the evidence does not justify the findings of fact.
(d)
That the petitioner has discovered new evidence material to him or her, that he or she could not, with reasonable diligence, have discovered and produced at the hearing.