HELL

High Energy Large Logarithms

A small-x resummation code


Authors: Marco Bonvini, Tiziano Peraro
Developers: Marco Bonvini
Contributors: Simone Marzani, Claudio Muselli, Luca Rottoli, Federico Silvetti

HELL is a code which resums the dominant small-x logarithms in DGLAP splitting functions (at LL and NLL) and in coefficient functions (at relative LL only, which is absolute NLL in DIS).
The processes for which the resummation of coefficient functions is already included in HELL are
For both speed and size issues, a light version of HELL, called HELL-x, bases on pre-tabulated resummed splitting and coefficient functions, is also available.
We suggest the use of HELL-x for all applications. HELL-x has also been interfaced to APFEL (for DGLAP evolution and DIS structure functions).

We provide the code and the interpolation tables in separate tarballs. Code version X.Y should use tables version X.

HELL-x (recommended for applications)

Latest version: HELL-x v3.0
Latest tables: HELL-x-data v3

Instructions: Download the tarballs above, or wget them directly:
> wget https://www.roma1.infn.it/~bonvini/hell/downloads/HELLx.v3.0.tgz
> wget https://www.roma1.infn.it/~bonvini/hell/downloads/HELLx-data.v3.tgz
then untar them, make and run
> tar xzf HELLx.v3.0.tgz
> tar xzf HELLx-data.v3.tgz
> cd HELLx
> make -j
> ./examples/test_hellx

Version history



HELL (for advanced users only)

Latest version: HELL v3.1
Latest tables: HELL-data v3
Latest auxiliary tables: HELL-data-aux v3.1 (these can be computed with HELL itself, and are needed for the resummation of coefficient functions)

Instructions: Download the tarballs above, or wget them directly:
> wget https://www.roma1.infn.it/~bonvini/hell/downloads/HELL.v3.0.1.tgz
> wget https://www.roma1.infn.it/~bonvini/hell/downloads/HELL-data.v3.tgz
> wget https://www.roma1.infn.it/~bonvini/hell/downloads/HELL-data-aux.v3.tgz   (optional)
then untar them, make (some adjustments to the makefile may be needed, e.g. the path to CUBA) and run
> tar xzf HELL.v3.0.1.tgz
> tar xzf HELL-data.v3.tgz
> tar xzf HELL-data-aux.v3.tgz
> cd HELL
> make -j
> ./examples/test_hell                            (needs aux data)
> ./examples/create_deltaP_tables -a 0.2 -n 4     (does not need aux data)
Note: To understand the workflow of HELL, better dropping me an email...

Version history




Dependencies

HELL-x has only standard dependencies.
HELL depends on the following libraries:

Citation Policy

When you use the HELL and/or HELL-x code, please cite this webpage and the original publications:
\cite{Bonvini:2016wki,Bonvini:2017ogt,Bonvini:2018xvt,Bonvini:2018iwt}


Contacts

For any problem, request or suggestion, contact us