The Electroweak Phase Transition within natural GNMSSM models Presenter: Christopher Harman...
Transcript of The Electroweak Phase Transition within natural GNMSSM models Presenter: Christopher Harman...
The Electroweak Phase Transition within natural GNMSSM models
Presenter: Christopher HarmanSupervisor: Dr. Stephan Huber
University of Sussex
Image courtesy of: http://www.symmetrymagazine.org/article/october-2012/what-else-could-the-higgs-be
What is supersymmetry?
SUSYSUSYSTANSTAN
SUPERSYMMETRY INVARIANT THEORYSUPERSYMMETRY INVARIANT THEORY
What is supersymmetry?
SUSYSUSY
STANSTAN
SUPERSYMMETRY INVARIANT THEORYSUPERSYMMETRY INVARIANT THEORY
What is natural supersymmetry?
FESTIVE EDITIONFESTIVE EDITION
What is natural supersymmetry?
natural
unnatural
What is natural supersymmetry?
natural
unnatural excluded
What is the MSSM?
MSSM: Minimal Supersymmetric Standard Model
Motivation: To address deviations (?) and physics not addressed by the Standard ModelTheory: A type II 2HDM with supersymmetry invariance at the high-scale and soft SUSY broken terms to describe the low energy scales
What is the NMSSM?
NMSSM: Next-to-MSSM
Motivation: To resolve the μ-problemTheory: Include a singlet chiral superfield into the Higgs sector of the MSSM
GNMSSM: Generalised NMSSM
Motivation: Include all possible renormalisable terms in the superpotential
What is the GNMSSM?
Not in the scale-invariant NMSSM
Aim of the project
Aim of the project
The (effective) potential is given by
with CP violating phases ``switched off’’.
It contains the following free parameters
The one loop zero temperature potential
Parameter point scan
Randomly assign a (natural) value
Parameter point scan
Randomly assign a (natural) valueEnsure: 1.No linear term in S at the zero field value2.Zero field minimum and EW broken minimum are degenerate (CHOICE!)
Parameter point scan
Randomly assign a (natural) valueEnsure: 1.No linear term in S at the zero field value2.Zero field minimum and EW broken minimum are degenerate (CHOICE!)Record parameter points satisfying certain criteria, e.g.: stable potential, physical masses.
Parameter point scan
At tree level
At tree level, we find
but this is insufficient for a 125 GeV Higgs…
… go to one-loop level!
Aim of the project
Aim of the project
Parameter point scan
Choose a specific stop structure:1.No gauge eigenstate mixing:2.Stop soft mass deviation:
Parameter point scan
Choose a specific stop structure:1.No gauge eigenstate mixing:2.Stop soft mass deviation:Assign a value to Δm3 and scan over natural values of mQ3 until a 125 GeV Higgs is obtained
Parameter point scan
Parameter point scan (two distinct potential shapes)
TYPE 1
Tree
1 loop
Parameter point scan (two distinct potential shapes)
TYPE 1
1 loop
Parameter point scan (two distinct potential shapes)
TYPE 2
Tree
1 loop
Parameter point scan (two distinct potential shapes)
TYPE 2
1 loop
Aim of the project
Aim of the project
One loop finite temperature potential
Include to the potential the following term:
We implement this into our program and obtain values for the critical temperature and critical VEV by numerical means
One loop level (finite temperature)
We implement this into our program and obtain values for the critical temperature and critical VEV by numerical means Tree
1 loop (0T)1 loop (finite T)TYPE 1
TYPE 2
Aim of the project
Aim of the project
Aim of the project
Outlook
CONCLUSIONS:•Can have a 125 GeV Higgs in the GNMSSM•EWPT is found to be rather strongly first order for around 200 natural parameter points
FUTURE WORK:•Relax some of our choices:– Tree-level minima degeneracy (Aλ choice);– No stop mixing (At choice);– Stop soft mass deviation (Δm3 choice)
•Repeat the analysis
Thank you!
S. Martin, A SUSY Primer: http://arxiv.org/abs/hep-ph/9709356U. Ellwanger, The NMSSM: http://arxiv.org/abs/arXiv:0910.1785G. Ross et al., The GNMSSM at one loop: fine tuning and phenomenologyG. Anderson and L. Hall, The Electroweak phase transition and baryogenesis
• Gauge eigenstate basis:
• Mass eigenstate basis:CP-even partCP-even part CP-odd partCP-odd part
Charged partCharged part
The tree-level potential
One-loop level (zero temperature)Green – Exact solution with degenerate stopsRed – Naïve solution with non-degenerate stops
One-loop level (finite temperature)
Include to the potential the following term:
Piece-wise analytic function can be constructed
Finite temperature potential (analytic)
Parameter scan statistics
Models with an unstable singlet potential only: 17.9477 %Models with at least one unphysical mass only: 6.40353 %Models with both of the above issues: 73.7124 %Models with none of the above issues: 1.93641 %
Runs: 20192 Successes: 20192