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[Licence| Download | New Version Template] aeib_v2_1.tar.gz(3835 Kbytes)
Manuscript Title: Full 1-loop calculation of BR(B0s,dllbar) in models beyond the MSSM with SARAH and SPheno
Authors: H. Dreiner, K. Nickel, W. Porod, F. Staub
Program title: SARAH
Catalogue identifier: AEIB_v2_1
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 184(2013)2604
Programming language: Mathematica, Fortran.
Computer: All computers which can run Mathematica and SPheno.
Operating system: Linux, MacOS.
Keywords: Supersymmetry, Neutral B-Meson decays, SPheno.
PACS: 14.40.Nd, 13.20.He.
Classification: 11.1, 11.6.

Does the new version supersede the previous version?: Yes, the new version includes all known features of previous versions but provides also the new features mentioned below.

Nature of problem:
Models beyond the SM can have new contributions to the decays of neutral B-mesons. For a precise prediction of the corresponding branching ratios a full 1-loop calculation including all possible wave, penguin and box diagrams is necessary. This usually requires a big effort and public codes for these calculations so far only support a few selected models.

Solution method:
The implementation of a new model in SARAH is easy and straightforward. In addition, SARAH is already delivered with many different supersymmetric and a few non-supersymmetric models. As a first step, SARAH derives the analytical expressions for masses, interactions and renormalization group equations for the given model. Furthermore, SARAH checks for all possible tree- and 1-loop diagrams which can contribute to the B-meson decays into two leptons. This information is exported to Fortran source code which can afterwards be compiled with SPheno. This generates a fully functional spectrum generator: besides the mass spectrum, sparticle and Higgs decays the new SPheno modules also calculate precision observables like the B-meson decays based on the parameters chosen by the user.

Reasons for new version:
The possible decays of neutral B-mesons into two leptons are constraining models beyond the Standard Model. SARAH allows, in the new version, the production of SPheno source code to calculate those decays at full 1-loop for a large variety of models.

Summary of revisions:
Full 1-loop calculation of B0s,dllbar for any model which can be implemented in SARAH.

SARAH can only calculate the renormalization group equations for a supersymmetric model. Hence, for non-supersymmetric model it is not possible to calculate the running parameters which enter the calculation. These have to be provided by the user as input. In addition, the effects of chiral resummation as well as next-to-leading order QCD corrections known for the MSSM are not included.

Unusual features:
This is the first public tool which allows a full 1-loop calculation of B-meson decays in more complicated models than the minimal or next-to-minimal supersymmetric standard model. Any new contribution in a renormalizable model stemming from an extended matter content or gauge sector is taken into account.

Running time:
Measured CPU time for the evaluation of the MSSM using a Lenovo Thinkpad X220 with i7 processor (2.53 GHz). Calculating the complete Lagrangian: 9 seconds. Calculating all vertices: 51 seconds. Output of the UFO model files: 49 seconds.