Display:

$\stackrel{\^}{x}\text{versus}\stackrel{\^}{x}$

Source:

<mrow>
     <mover accent="true">
          <mi> x </mi>
          <mo> &Hat; </mo>
     </mover>
     <mtext> versus </mtext>
     <mover accent="false">
          <mi> x </mi>
          <mo> &Hat; </mo>
     </mover>
</mrow>