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Questions tagged [mssm]

MSSM stands for the Minimal Supersymmetric Standard Model.

The MSSM is the minimal extension of the Standard Model of particle physics necessary to accommodate supersymmetry. It includes all Standard Model particles plus superpartners to each that differ in spin by 1/2. In Addition, the Higgs sector needs to be extended, leading to a Type-I two-Higgs-doublet model.

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Why is the lightest Higgs not a free parameter in SUSY?

In the Standard Model, the Higgs mass doesn't really have any theoretical constraints. It could have basically any value and nothing 'breaks'. However, in MSSM models, we often see the tree level constraint $$m_h < m_z \cos(2\beta)$$ which is…
user788171
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Which is the coupling between the photon and the SU(2)xU(1) gauginos, before symmetry breaking?

The photon field is the non chiral piece of SU(2)xU(1), independently of symmetry breaking or not, isn't it? But before symmetry breaking, each gauge boson has only a chiral gaugino as superpartner. Is it still possible, and correct, to arrange…
user135
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Where does the hidden supersymmetric sector of the MSSM come from?

At the end of Chapter 14 of the "Supersymmetry Demystified book" from Patrick Labelle it is mentioned that to constrain the number of allowed softly SUSY breaking terms, a shadow or hidden supersymmetric sector can be assumed. In this hidden sector,…
Dilaton
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Status of the little hierarchy problem

What is the current thinking on the little hierarchy problem in light of a potential Higgs mass above 120 GeV? A few years ago, at least, I remember various phenomenologists saying that this at least makes life rather difficult for the MSSM.
Aaron
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Feynman rules for SUSY

This might be an incredibly naive question, but I'm wondering if there are a set of rules for "translating" between Standard Model and SUSY. For instance, if I want want to go from a Standard Model feynman diagram to a SUSY diagram, can one write…
user788171
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Is a 125 GeV Higgs large (or small) for the MSSM?

As far I as I know, and from naturalness considerations, a 125 GeV Higgs mass is rather large for the MSSM. This is because in the MSSM $$m_h^2 \lesssim M_z^2 \cos^22\beta + \Delta$$ where $\Delta$ represents top/stop loop corrections to the Higgs.…
stupidity
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mSUGRA boundary conditions and the MSSM

I read that in the MSSM with mSUGRA boundary conditions, the mass spectrum of the model is determined by five parameters at the GUT scale: $m_0$ (universal scalar mass), $m_{1/2}$ (universal gaugino mass), $A_0$ (universal trilinear coupling), $\tan…
stupidity
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Questions about "A Quadrillion Standard Models from F-theory"

This afternoon, I tried to read through this paper claiming to "present $\mathcal{O}(10^{15})$ string compactifications with the exact chiral spectrum of the Standard Model of particle physics". As someone still learning the very basics of string…
tomdodd4598
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Does the Photino have mass or is it mass-less like the photon

Does the photino in super-symmetry have a mass, Or is this different in different super symmetric models?
kaj dijkstra
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How can we use Majorana spinors for charged fermions in MSSM?

According to "Supersymmetry in Particle Physics" by Ian Aitchison (see e.g. p62 of arXiv), in the Minimal Supersymmetric Standard Model (MSSM) we can use Majorana language to build supermultiplets: [There is] a possible alternative formalism, in…
Kosm
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Matching bosonic and fermionic degrees of freedom in Wess-Zumino Lagrangian

In Wess-Zumino model, supersymmetric Lagrangian in addition to the ordinary complex scalar field $\phi$ contains auxiliary field $F$ (also complex scalar) to match the degrees of freedom of the Weyl (or Majorana) spinor, meaning 4. But from…
Kosm
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Why does the $\tilde\chi^0_2 \,\tilde\chi^\pm_1$ cross section increase in the focus point region?

The focus point is an interesting region of the cMSSM parameter space at high $m_0$ and low $m_{1/2}$. Features are high scalar masses (> 1-2 TeV), light charginos / neutralinos (which are higgsino-like), and fairly low fine-tuning. One can also…
jdm
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How did Supersymmetry (incorrectly) predict the mass of the Higgs Boson?

In an article by CERN states The minimal version of supersymmetry predicts that the Higgs boson mass should be less than 120-130 GeV How was this conclusion reached? I could not find any answers on the web.
seaseal
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In MSSM, are the higgs fields eaten by Z,W scalars or pseudoscalars?

I am very puzzled by the quintet of Higgs bosons in the MSSM: two charged, two scalars and a pseudoscalar. I wonder if they could be understood better if they were considered jointly with the three "bosons" that are "eaten" by the Higgs mechanism.…
arivero
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Soft SUSY breaking fermion mass terms in MSSM for matter fields

In the Minimal Supersymmetric Standard Model, the chiral fermion fields (the Higgsinos) don't have any soft SUSY breaking mass terms and soft SUSY breaking trilinear interactions while their scalar superpartners (the Higgs bosons) have so, whereas…
Bruce Lee
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