VA1 - Automated perturbative NLO calculations for heavy ions and quarkonia (NLOAccess)

NLOAccess gives access to automated tools generating scientific codes allowing anyone to evaluate observables-such as production rates or kinematical properties - of scatterings involving hadrons. The automation and the versatility of these tools are such that these scatterings need not to be pre-coded. In other terms, it is possible that a random user may request for the first time the generation of a code to compute characteristics of a reaction which nobody thought of before. NLOAccess will allow the user to test the code and then to download to run it on its own computer. It essentially gives access to a dynamical library. As it stands, the automated tools on which NLOAccess is based are (i) the MADGRAPH ensemble heavily used by the high-energy physics (HEP) community, but extended to deal with meson and heavy-ion beams and (ii) the HELACONIA code allowing the computation of cross section for heavy-quark bound states, the quarkonia. The portal NLOAccess is conceived such as to deal with additional automated tools; its scope can thus be later extended. It is based on the portal of MADGRAPH@UCLouvain with the necessary additions to deal with heavy-ion collisions and quarkonium production. As of today, in contrast to HEP, no such place exists for hadronic physics where interested colleagues can go test their ideas and turn them into concrete realisation with automated Monte Carlo tools. In addition, the available tools are limited to a reduced class of applications. For each, one needs to install them one by one, sometimes along with dedicated libraries and one needs to get familiar with their syntax. A single portal for hadron physics will not only ease the task of the community but will give a much higher visibility to the codes included in it as well as to the hadron physics models on which they are based. Services currently offered by the infrastructure: MADGRAPH is an ensemble of tools developed since early 2000’s allowing for the simulation of any elementary particle scatterings where perturbation theory is applicable. It is massively used by the community of physicists working on high-energy colliders, in particular the CERN-LHC community and in the past that of the Fermilab-Tevatron. It is widely tested and runs at the state-of-the-art accuracy for such tools, namely NLO, and is versatile enough to be extended to scatterings relevant for hadronic physics, for instance the study of perturbative reactions in nucleus-nucleus collisions. On the other hand, HELAC-ONIA is the most advanced automated tool to deal with quarkonium production as it can deal with several of them with an improved algorithm rendering its usage very fast. Whereas the original version of MADGRAPH for HEP has been used for hundred of LHC studies (with a yearly citation rate of 400~600 since the publication of its latest version at NLO), we expect its hadronic physics counterpart and an online version of HELAC-ONIA to become essential tools for a significant fraction of the heavy-ion physics community (2000+ physicists worldwide), that of heavy-quark production at colliders and that of spin physics at colliders and highenergy fixed-target experiments. More than 20 research groups in Europe have already marked their firm interest for the access as they are ready to test and improve it. We expect yearly several hundreds of recurrent users, namely a significant part of the targeted researchers.