Negative points in calculating cross section

I don't see negative points for
    e,E -> h,ne,Ne
at Pcm=4000.
Send me details of your session.
In principle for such process negative points can appear only in result
of lost of numerical precision.
You can improve precision uncommenting
  //#define _LONG_
in file include/nType.h
Use
     make clean
     make
after that.

Best
   Alexander Pukhov

On 07/26/2017 05:03 PM, Feng wrote:
> New question #653537 on CalcHEP:
> https://answers.launchpad.net/calchep/+question/653537
>
> Dear Professor,
>
> I am trying to calculate e- e+ > ve ve~ h process in SM. I include two diagrams but obtain negative points in calculating cross section using both the inside Standard Model and the SM created by FeynRules. Can you help me solve this problem. Thanks a lot.
>
> Best
> Feng
>

Hi Professor,

I just checked it, setting Pcm=4000 there is no problem.

When Pcm is set to 120, even I follow your suggestion and uncomment #define _LONG_,
there is still negative points 0.003%.

Best
Feng

Sorry for so late replay. I was busy. I have decided that 0.002% of
negative points is not so important.

To avoid negative points go to Breit-Wigner and set some large number for
"BreitWigner range", for instance, 1000.

Best
     Alexander Pukhov

On 07/26/2017 05:03 PM, Feng wrote:
> New question #653537 on CalcHEP:
> https://answers.launchpad.net/calchep/+question/653537
>
> Dear Professor,
>
> I am trying to calculate e- e+ > ve ve~ h process in SM. I include two diagrams but obtain negative points in calculating cross section using both the inside Standard Model and the SM created by FeynRules. Can you help me solve this problem. Thanks a lot.
>
> Best
> Feng
>