/code>)<br/>
the slope <i>b</i> of the strong-interaction term <i>exp(bt)</i>,
in units of GeV^-2. 
  

<p/><code>parm&nbsp; </code><strong> SigmaElastic:rho &nbsp;</strong> 
 (<code>default = <strong>0.13</strong></code>; <code>minimum = -1.</code>; <code>maximum = 1.</code>)<br/>
the ratio of the real to the imaginary parts of the nuclear scattering
amplitude.
  

<p/><code>parm&nbsp; </code><strong> SigmaElastic:lambda &nbsp;</strong> 
 (<code>default = <strong>0.71</strong></code>; <code>minimum = 0.1</