Tools & Toys
XSummer - Transcendental Functions and Symbolic Summation in
Form
Harmonic sums and their generalizations are extremely useful in the evaluation of higher-order perturbative corrections in quantum field theory. Of particular interest have been the so-called nested sums,where the harmonic sums and their generalizations appear as building blocks, originating for example from the expansion of generalized hypergeometric functions around integer values of the parameters. XSummer implements several algorithms to solve these sums by algebraic means, using the computer algebra system Form.
Written by S. Moch, P. Uwer.
Published in:
Comput.Phys.Commun.174:759-770,2006
e-Print Archive: math-ph/0508008
The package can be downloaded here
AutoDipole - Automated generation of dipole subtraction terms
The package implements the Catani-Seymour subtraction method used to
handle
collinear and soft singularities in real corrections.
Written by K. Hasegawa, S. Moch, P.Uwer
Published in: Comput.Phys.Commun.181:1802-1817,2010
e-Print Archive: arXiv:0911.4371
The AutoDipole package can be downloaded here.
Lectures notes from a presentation at the "Computer Algebra and
Particle Physics 2009"
(CAPP 2009) school can be found
here.
HATHOR - HAdronic Top and Heavy quarks crOss section calculatoR
Hathor calculates the total cross section for top-quark pair production in hadronic collisions.
The program takes into account recent theoretical developments such as approximate
next-to-next-to-leading order perturbative QCD corrections and it allows for studies of
the theoretical uncertainty by separate variations of the factorization and renormalization
scales. In addition it offers the possibility to obtain the cross section as a function of the
running top-quark mass. A GUI to simplify the usage is included as well.
Written by: M. Aliev, H. Lacker, U. Langenfeld, S. Moch, P. Uwer and M. Wiedermann
Published in: – HATHOR – HAdronic Top and Heavy quarks crOss section calculatoR
Comput.Phys.Commun.182:1034-1046,2011
e-Print archive: arXiv: 1007.1327
The latest version of Hathor can be obtained here.
NGluon: A Package to Calculate One-loop Multi-gluon Amplitudes
We present a computer library for the numerical evaluation of colour-ordered n-gluon
amplitudes at one-loop order in pure Yang-Mills theory. The library uses the recently developed
technique of generalised unitarity. Running in double precision the library yields
reliable results for up to 14 gluons with only a small fraction of events requiring a
re-evaluation using extended floating point arithmetic. We believe that the library presented
here provides an important contribution to future LHC phenomenology. The program may also prove
useful in cross checking results obtained by other methods. In addition the code provides a
sample implementation which may serve as a starting point for further developments
Written by: S. Badger, B. Biedermann and P.Uwer
Published in: NGluon: A Package to Calculate One-loop Multi-gluon Amplitudes
Comput.Phys.Commun.182:1674-1692,2011
e-print archive: arXiv1011.2900
NGluon-1.0 can be obtained here (md5sum: 38ffeb1edae261ab35ec01a6d668ded8)
On some operating systems the file system cannot distinguish between files called NGluon.cpp and ngluon.cpp. On these systems version 1.0 will not compile. To address this issue we have renamed in version NGluon-1.1 the source file ngluon.cpp into NGluon-demo.cpp. The corresponding executable is now NGluon-demo.
NGluon-1.1 can be obtained here (md5sum: 69f53091d2f64651ed6d32ad0593c6ff).
EasyNData
EasyNData allows an easy extraction of numerical values from published plots. The EasyNData package can be downloaded here as EasyNData.zip The zip-file includes the program code EasyNData.jar, two examples as well as a short description of the program. The most recent description of the program be found here as pdffile. An older version is available here. The program alone can be obtained also as EasyNData.jar. To run the program call java -jar EasyNData.jar and follow the instructions outlined in the documentation. Note that the installed Java(TM) version has to be 1.5.0 or later.
No warranty on the correctness of the program is given and use is at own risk.
