Uncertainties in the lightest CP even Higgs boson mass prediction in the minimal supersymmetric standard model: fixed order versus effective field theory prediction

B. C. Allanach,A. Voigt

doi:10.1140/epjc/s10052-018-6046-z

Abstract

We quantify and examine the uncertainties in predictions of the lightest CP even Higgs boson pole mass M_h in the Minimal Supersymmetric Standard Model ({text {MSSM}}), utilising current spectrum generators and including some three-loop corrections. There are two broadly different approximations being used: effective field theory (EFT) where an effective Standard Model (text {SM}) is used below a supersymmetric mass scale, and a fixed order calculation, where the {text {MSSM}} is matched to text {QCD}times text {QED} at the electroweak scale. The uncertainties on the M_h prediction in each approach are broken down into logarithmic and finite pieces. The inferred values of the stop mass parameters are sensitively dependent upon the precision of the prediction for M_h. The fixed order calculation appears to be more accurate below a supersymmetry (SUSY) mass scale of M_Sapprox 1.2~text {TeV}, whereas above this scale, the EFT calculation is more accurate. We also revisit the range of the lightest stop mass across fine-tuned parameter space that has an appropriate stable vacuum and is compatible with the lightest CP even Higgs boson h being identified with the one discovered at the ATLAS and CMS experiments in 2012; we achieve a maximum value of sim 10^{11} GeV.

Highlights

The 2012 discovery at Large Hadron Collider experiments [1, 2] of a resonance that has measured properties compatibleB
Provided the sparticle spectrum is not split so that some sparticles are much lighter than mt1, as this would invalidate the assumptions implicit within the effective field theory (EFT) calculation that all sparticles are around MS
We compared the precision of the Higgs boson mass predictions of the state-of-the-art DR fixed-order and EFT spectrum generators SOFTSUSY, FlexibleSUSY and HSSUSY in the Minimal Supersymmetric Standard Model (MSSM)

Summary

Introduction

The 2012 discovery at Large Hadron Collider experiments [1, 2] of a resonance that has measured properties compatible. Untenable unless its value is finely tuned with unrelated contributions cancelling to a suspiciously large degree This technical hierarchy problem can be solved by new physics that appears around the TeV scale, the foremost example being TeV scale supersymmetry. TeV scale supersymmetry predicts that the masses of new hitherto undiscovered sparticles are not much higher than the TeV scale These to date have not been discovered, and the most natural portion of supersymmetry parameter space is being heavily squeezed by experimental constraints. Its mass, which is Mh = MZ cos 2β at tree level in the decoupling limit (MZ being the mass of the Z boson and tan β = vu/vd is the ratio of the two neutral C P-even MSSM Higgs field vacuum expectation values (VEVs)), receives large corrections at the loop level. It has been known for some time that the largest corrections to its mass (squared) come from top/stop corrections, which are enhanced by the large value of the top mass [4]: 573 Page 2 of 10

Z cos2

S at the tree level and therefore is less accurate

Higgs boson mass prediction uncertainties

Upper bound on the lightest stop mass

H2 κ dt

Summary