feyncalc / feynhelpers

FeynHelpers is a collection of intefaces that allow you to use other HEP-related tools from your FeynCalc session

FeynHelpers

FeynHelpers is a collection of interfaces that allow you to use other HEP-related tools from your FeynCalc session.

Requirements

FeynHelpers is designed as an add-on for FeynCalc. To use it you need at least FeynCalc 9.2 and Mathematica 8.

The development version of FeynHelpers requires the latest development version of FeynCalc and Mathematica 10.

Manual

FeynHelpers manual is still work in progress but is already mature enough to be useful for normal users.

The PDF version of the manual can be found here. If you prefer the web version, please visit this website.

For usage information see also the accompanying paper arXiv:1611.06793 and the supplied examples.

Notice that the current manual applies to the development version of FeynHelpers. Hence, it may describe functionality that is not available in the stable version.

Installation

The installation instructions can be found here

Acknowledgments

If you use FeynHelpers in you work, please have a look here.

License

• The code of FeynHelpers is covered by the GNU General Public License 3.
• This does not apply to the packages for which FeynHelpers provides an interface to FeynCalc. For the licensing of those packages please check the informations provided by the respective authors.

feynhelpers's Issues

MajoranaSpinor support in FCFAConvert

Dear FeynCalc Authors,
Using FCFAConvert with a Feynarts model file that contains Majorana Fermions does not work.
It appears that MajoranaSpinor is not recognized by FeynCalc.

please advise,
best,

Kirtimaan

LToolsEvaluate gives different result from example

I execute the function LToolsEvaluate to test the relevant examples, but I obtain a wrong result. My code is as follows:

Out[6] gives a wrong result different from both FeynHelpers manual and Package-X. I am using Ubuntu 22.04 and Mathematica 13.3, with FeynCalc 10.0.0. Does the mistake involve these software versions? Or are there any specific considerations I should be aware of?

var2 sign in FIREBurn result

When I use the following orders to calculate oneloop feynman integral by FIREBurn, the result contains a strange sign "var2". And I calculate the same integral by FIRE5, confirm that var2=MC. What's more, the configure file "FIREp1.m" show that var2=MC.

Exit[]
$LoadAddOns = {"FeynHelpers"};
<< FeynCalc`;
ScalarProduct[p1, p1] = 4 MB^2;
ScalarProduct[p2, p2] = 0;
ScalarProduct[p1, p2] = 2 (MB^2 - MC^2);
fad = FAD[{q, MC, 2}, {q - p1, MC}, {q - p2, MC, 2}]
FIREBurn[fad, {q}, {p1, p2}]

-(((D-2) (D^2 MB^2+D^2 MC^2-11 D MB^2-10 D MC^2+31 MB^2+24 MC^2))/(64 (D-5) MC^4 (MC-MB)^3 (MB+MC)^3 ((q-p1)^2-MC^2)))-((D-2) (2 D^2 MB^4+4 D^2 MB^2 MC^2-16 D MB^4-25 D MB^2 MC^2-D MC^4+32 MB^4+26 MB^2 MC^2+4 MC^4))/(128 MC^6 (MC-MB)^3 (MB+MC)^3 (q^2-MC^2))+((D-2) (4 D^3 MB^2 var2^2+2 D^3 MC^4+4 D^2 MB^4-51 D^2 MB^2 MC^2-29 D^2 MC^4-36 D MB^4+209 D MB^2 MC^2+141 D MC^4+80 MB^4-272 MB^2 MC^2-228 MC^4))/(128 (D-5) MC^6 (MC-MB)^3 (MB+MC)^3 ((q-p2)^2-MC^2))-((D-4) (2 D MB^2-11 MB^2+MC^2))/(8 MC^2 (MC-MB)^2 (MB+MC)^2 ((q-p2)^2-MC^2).(q^2-MC^2).((q-p1)^2-MC^2))-((D-3) (2 D-11) MB^2)/(16 MC^2 (MB-MC)^3 (MB+MC)^3 (q^2-MC^2).((q-p1)^2-MC^2))

There is some directory issues on Windows system

When I used FIREBurn on Windows system, some errors occurred. Here is my code:

$LoadAddOns = {"FeynHelpers"};
<< FeynCalc`
FAD[{q, m, 4}]
FIREBurn[%, {q}, {}]

And my errors are:

Syntax::stresc :  Unknown string escape \U.
Syntax::stresc :  Unknown string escape \g.
Syntax::stresc :  Unknown string escape \A.
Syntax::stresc :  Unknown string escape \R.
Syntax::stresc :  Unknown string escape \M.
Syntax::stresc :  Unknown string escape \A.
Syntax::stresc :  Unknown string escape \F.
Syntax::sntx: Invalid syntax in or before "Get["C:\Users\guoji\AppData\Roaming\Mathematica\Applications\FIRE5\FIRE5.m"];"
                                                  ^
     (line 3 of "C:\Users\guoji\AppData\Roaming\Mathematica\Applications\FeynCalc\Database\FIREp1-int1.m").

As you can see, every unknown string comes from the first letter of every directory. I tried to fix this issue. I came into file 'FIREp1-int1.m' and rewrite every directory like '"C:\Users\guoji\AppData\...' and then it give me right answers with little warning.

I tried same code on Mac and Linux system. It worked well and there was not error.

Maybe you can fix this problem. Or tell me how to deal with it. Thx!!!

Add an interface to Singular

The new partial fractioning library presented in https://arxiv.org/pdf/2008.13194.pdf
seems like a good motivation to add an interface to Singular CAS

In fact, such an interface for older Mma versions already exists

https://www3.risc.jku.at/research/combinat/software/Singular/

and is open source, so that one could fork it and keep only the needed functionality.