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Beyond Minimal Models at Three Frontiers

Final Report Summary - BMM@3F (Beyond Minimal Models at Three Frontiers)

The project began on 06/03/2013 and the finished on 30/09/2013, and so the initial reporting period is the whole project duration. The project was very successful, in that it produced several high-quality papers and directly contributed to the researcher obtaining a permanent research position – necessitating the early termination.

The aims for the above period were (a) developing and improving the codes to investigate the Higgs properties in Dirac gaugino models (an interesting and important example of a non-minimal supersymmetric scenario which allows for increased naturalness), and (b) begin the computation of missing one-loop corrections to the Kaehler metric in toy string models using CFT techniques (a vital endeavour to determine the masses of the superpartners in certain well-motivated classes of string models). These objectives were achieved and in fact surpassed, as shall be described below. As mentioned above, the project funded work leading to 4 papers already released, with at least two more expected, an impressive return for such a short period. They are

1. P. Anastasopoulos, M. D. Goodsell and R. Richter, “Three- and Four-point correlators of excited bosonic twist fields,” JHEP 1310 (2013) 182 [arXiv:1305.7166 [hep-th]].

2. S. Andreas, M. D. Goodsell and A. Ringwald, “Hidden Photons in connection to Dark Matter,” AIP Conf.Proc. 1563 (2013) 114-117 [arXiv:1306.1168 [hep-ph]].

3. E. Dudas, M. Goodsell, L. Heurtier and P. Tziveloglou, “Flavour models with Dirac and fake gluinos,” to appear in Nucl. Phys. B. [arXiv:1312.2011 [hep-ph]].

4. K. Benakli, M. Goodsell, F. Staub and W. Porod, “The Constrained Minimal Dirac Gaugino Supersymmetric Standard Model,” arXiv:1403.5122 [hep-ph], submitted to Physical Review D.

The paper “Goldstini with Dirac gaugino masses” (in collaboration with P. Tziveloglou and the scientist in charge, E. Dudas) directly related to goal (a) is in preparation, where the researcher completed most of the work during the project period, while a paper related to goal (b) is also in preparation.
Paper (1) was loosely related to goal (b), in that it involves CFT calculations on toy string backgrounds, and so should be regarded as a bonus warm-up paper. Subsequent to that work, the researcher began the full calculation of the Kaehler metric corrections, and encouraging partial results were obtained which were presented in talks at the String Phenomenology 2013 and SUSY conferences. However, the completion of this calculation was not envisaged for the project period, and indeed the termination of the project has led to some delays in the production of the final publication.
Paper (4) is the culmination of the aims of goal (a): the latest LHC data give no clear signs of deviations of the Higgs properties from (minimal-supersymmetric) standard-model-like behaviour,so the challenge now is to understand its mass. In paper (4) the researcher proposed a minimal unified Dirac gaugino scenario – solving a key problem of unification in that class of models and providing a framework for future collider studies. Unification was verified at two-loop order, as illustrated in Figure 1. He also developed codes based on the publically-available SARAH (to which he contributed in the development/testing of adding Dirac gaugino masses) to find viable models in this class with the correct Higgs mass, which required some innovations that have now been incorporated into the public release of the code. The paper then performed a preliminary exploration of the parameter space; further studies are now expected.

Paper (3) was a collaboration with the scientist in charge of the project, and goes beyond the objectives of goal (a). The idea was to examine the flavour constraints in Dirac gaugino models – using experiments other than direct searches at the LHC to constrain the particle properties in these models. This required developing new codes as well as performing new calculations, and led to some important new insights into the properties of this class of models: it was found that naive expectations about the suppression of flavour-violating properties are only true for certain biased regions of the parameter space as illustrated in figure 2; thus the prospects for indirect detection of the models are better than thought. A first examination of the constraints on models to explain the flavour structure of the standard model in this class of models was also performed.

Web address of the scientist in charge: https://www.cpht.polytechnique.fr/?q=fr/node/63