GLoBES: General Long Baseline Experiment Simulator

Abstract

GLoBES (General Long Baseline Experiment Simulator) is a flexible software package to simulate neutrino oscillation long baseline and reactor experiments. On the one hand, it contains a comprehensive abstract experiment definition language (AEDL), which allows to describe most classes of long baseline experiments at an abstract level. On the other hand, it provides a C-library to process the experiment information in order to obtain oscillation probabilities, rate vectors, and Δ χ 2 -values. Currently, GLoBES is available for GNU/Linux. Since the source code is included, the port to other operating systems is in principle possible. GLoBES is an open source code that has previously been described in Computer Physics Communications 167 (2005) 195 and in Ref. [7]). The source code and a comprehensive User Manual for GLoBES v3.0.8 is now available from the CPC Program Library as described in the Program Summary below. The home of GLobES is http://www.mpi-hd.mpg.de/~globes/. Program summary Program title: GLoBES version 3.0.8 Catalogue identifier: ADZI_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADZI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 145 295 No. of bytes in distributed program, including test data, etc.: 1 811 892 Distribution format: tar.gz Programming language: C Computer: GLoBES builds and installs on 32bit and 64bit Linux systems Operating system: 32bit or 64bit Linux RAM: Typically a few MBs Classification: 11.1, 11.7, 11.10 External routines: GSL—The GNU Scientific Library, www.gnu.org/software/gsl/ Nature of problem: Neutrino oscillations are now established as the leading flavor transition mechanism for neutrinos. In a long history of many experiments, see, e.g., [1], two oscillation frequencies have been identified: The fast atmospheric and the slow solar oscillations, which are driven by the respective mass squared differences. In addition, there could be interference effects between these two oscillations, provided that the coupling given by the small mixing angle θ 13 is large enough. Such interference effects include, for example, leptonic CP violation. In order to test the unknown oscillation parameters, i.e. the mixing angle θ 13 , the leptonic CP phase, and the neutrino mass hierarchy, new long-baseline and reactor experiments are proposed. These experiments send an artificial neutrino beam to a detector, or detect the neutrinos produced by a nuclear fission reactor. However, the presence of multiple solutions which are intrinsic to neutrino oscillation probabilities [2–5] affect these measurements. Thus optimization strategies are required which maximally exploit complementarity between experiments. Therefore, a modern, complete experiment simulation and analysis tool does not only need to have a highly accurate beam and detector simulation, but also powerful means to analyze correlations and degeneracies, especially for the combination of several experiments. The GLoBES software package is such a tool [6,7]. Solution method: GLoBES is a flexible software tool to simulate and analyze neutrino oscillation long-baseline and reactor experiments using a complete three-flavor description. On the one hand, it contains a comprehensive abstract experiment definition language (AEDL), which makes it possible to describe most classes of long baseline and reactor experiments at an abstract level. On the other hand, it provides a C-library to process the experiment information in order to obtain oscillation probabilities, rate vectors, and Δ χ 2 -values. In addition, it provides a binary program to test experiment definitions very quickly, before they are used by the application software. Restrictions: Currently restricted to discrete sets of sources and detectors. For example, the simulation of an atmospheric neutrino flux is not supported. Unusual features: Clear separation between experiment description and the simulation software. Additional comments: To find information on the latest version of the software and user manual, please check the author's web site, http://www.mpi-hd.mpg.de/~globes Running time: The examples included in the distribution take only a few minutes to complete. More sophisticated problems can take up to several days.