he denominator, unlike the Gaussians 
used to pick <i>(p_x, p_y, p_z)</i>.) 
  

<p/><code>parm&nbsp; </code><strong> Beams:sigmaPxB &nbsp;</strong> 
 (<code>default = <strong>0.</strong></code>; <code>minimum = 0.</code>)<br/>
The width of a Gaussian distribution of the <i>p_x</i> spread of the
second incoming particle.
  

<p/><code>parm&nbsp; </code><strong> Beams:sigmaPyB &nbsp;</strong> 
 (<code>default = <strong>0.</strong></code>; <code>minimum = 0.</code>)<br/>
The width of a Gaussian distribution o