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Higher order corrections and unification in the minimal supersymmetric standard model: SOFTSUSY3.5

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Allanach, BC 
Bednyakov, A 
Ruiz de Austri, R 


We explore the effects of three-loop minimal supersymmetric standard model renormalisation group equation terms and some leading two-loopthreshold corrections on gauge and Yukawa unification: each being one loop higher order than current public spectrum calculators. We also explore the effect of the higher order terms (often 2-3 GeV) on the lightest CP even Higgs mass prediction. We illustrate our results in the constrained minimal supersymmetric standard model. Neglecting threshold corrections at the grand unified scale, the discrepancy between the unification scale αs and the other two unified gauge couplings changes by 0.1% due to the higher order corrections and the difference between unification scale bottom-tau Yukawa couplings neglecting unification scale threshold corrections changes by up to 1%. The difference between unification scale bottom and top Yukawa couplings changes by a few percent. Differences due to the higher order corrections also give an estimate of the size of theoretical uncertainties in the minimal supersymmetric standard model spectrum. We use these to provide estimates of theoretical uncertainties in predictions of the dark matter relic density (which can be of order one due to its strong dependence on sparticle masses) and the LHC sparticle production cross-section (often around 30%). The additional higher order corrections have been incorporated into SOFTSUSY, and we provide details on how to compile and use the program. We also provide a summary of the approximations used in the higher order corrections.



MSSM, Sparticle

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Computer Physics Communications

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Science and Technology Facilities Council (ST/J000434/1)
Science and Technology Facilities Council (ST/L000385/1)
This work has been partially supported by STFC. R. RdA, is supported by the Ramón y Cajal program of the Spanish MICINN and also thanks the support of the Spanish MICINN’s Consolider-Ingenio 2010 Programme under the grant MULTIDARK CSD2209-00064, the Invisibles European ITN project (FP7-PEOPLE-2011-ITN, PITN-GA-2011-289442-INVISIBLES) and the “SOM Sabor y origen de la Materia” (FPA2011-29678) and the “Fenomenologia y Cosmologia de la Fisica mas alla del Modelo Estandar e lmplicaciones Experimentales en la era del LHC” (FPA2010-17747) MEC projects. BCA thanks the Cambridge SUSY working group for useful discussions. We thank P. Slavich for helpful communication and suggestions and D. Kunz and P. Kant for communications regarding the H3M package. AVB is immensely grateful to A. Sheplyakov for providing a program for dealing with GiNaC archives. The work of AVB is supported by the RFBR grants 12-12-02-00412-a, 14-02-00494-a, and the Russian President Grant MK-1001.2014.2.