Name: Rolf Mertig (email_not_shown)
Date: 10/03/00-03:08:40 PM Z


Hi,
I apologize for not checking everything when I rearranged the FC code
for feyncalc.org.

The quick fix is:
Replace this line in FeynCalc.m :

-----------------
diractraceevsimpleplus[x_/;Head[x]=!=Plus,{opt___}] := x;
--------------------
  by this one:
--------------
diractraceevsimpleplus[x_/;Head[x]=!=Plus,{opt___}] := x *
 (TraceOfOne /. {opt} /.Options[Tr] /. Options[DiracTrace] );
---------------

Alternatively you can just execute this:

DownValues[HighEnergyPhysics`FeynCalc`DiracTrace`Private`diractraceevsimpleplus]={
 HoldPattern[
   HighEnergyPhysics`FeynCalc`DiracTrace`Private`diractraceevsimpleplus[
    HighEnergyPhysics`FeynCalc`DiracTrace`Private`x_Plus,
    {HighEnergyPhysics`FeynCalc`DiracTrace`Private`opt___}]] :>
  (HighEnergyPhysics`FeynCalc`DiracTrace`Private`diractraceevsimple[#1,
     {HighEnergyPhysics`FeynCalc`DiracTrace`Private`opt}] & ) /@
   HighEnergyPhysics`FeynCalc`DiracTrace`Private`x,
 HoldPattern[
   HighEnergyPhysics`FeynCalc`DiracTrace`Private`diractraceevsimpleplus[
    HighEnergyPhysics`FeynCalc`DiracTrace`Private`x_ /;
     Head[HighEnergyPhysics`FeynCalc`DiracTrace`Private`x] =!= Plus,
    {HighEnergyPhysics`FeynCalc`DiracTrace`Private`opt___}]] :>
  HighEnergyPhysics`FeynCalc`DiracTrace`Private`x*
   (HighEnergyPhysics`FeynCalc`DiracTrace`Private`TraceOfOne /.
      {HighEnergyPhysics`FeynCalc`DiracTrace`Private`opt} /.
     Options[HighEnergyPhysics`FeynCalc`DiracTrace`Private`Tr] /.
    Options[DiracTrace])}

Rolf

Wojciech Broniowski wrote:
>
> Hi!
>
> The most simple trace: Tr[DiracSlash[p,p]] gives a WRONG!!!!! answer: p^2
> instead of 4p^2.
>
> Wojciech Broniowski broniows@solaris.ifj.edu.pl
>
> Institute of Nuclear Physics Tel:(48)12-6370222 ext. 270 or 431 (Work)
> ul. Radzikowskiego 152 (48)12-6367884 (Home),
> Fax:(48)12-6375441
> PL-31342 Krakow, POLAND



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