master defense 2015
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Search for Supersymmetry in the
Higgs Sector Master’s thesis
Mohammed El Amine BENAICHOUCHE
Under the supervision of Prof. Ulrich GOERLACH
Outline Goal: Generate events of p-p collision with neutral Higgs bosons in
Supersymmetry using the event generator MadGraph5
1. Introduction
2. Standard Model Higgs Boson production via gluon-gluon fusion
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
4. Conclusions and perspectives
Search for SUSY in the Higgs sector 2
1. Introduction: The Standard Model and Supersymmetry
Relativistic Quantum Mechanics
Quantum Field Theory
Gauge Theories
The Standard Model
The Higgs mechanism
The discovery of the Higgs Boson (2012) at CERN
Shortcomings of the Standard Model
What is Supersymmetry?
Search for SUSY in the Higgs sector 3
1. Introduction:
The Higgs sector in the SM and Supersymmetric Models
The Higgs Mechanism in the SM
The Higgs Mechanism version in Supersymmetry
The Higgs sector in the MSSM: h, H, A, H±
The MSSM superpotential
The µ-problem in the MSSM and the dynamical solution in the NMSSM
How do we obtain NMSSM from MSSM
The Higgs sector in the NMSSM
Search for SUSY in the Higgs sector 4
1. Introduction:
The Higgs sector in the SM and Supersymmetric Models
The Higgs Mechanism in the SM
The Higgs Mechanism version in Supersymmetry
The Higgs sector in the MSSM: h, H, A, H±
The MSSM superpotential
The µ-problem in the MSSM and the dynamical solution in the NMSSM
How do we obtain NMSSM from MSSM
The Higgs sector in the NMSSM: h, Hs, H, As, A, H±
Search for SUSY in the Higgs sector 5
2. Standard Model Higgs Boson production via gluon-gluon fusion
Search for SUSY in the Higgs sector 6
MadGraph5_aMC@NLO performs computations at tree-level and
one loop QCD amplitudes for arbitrary processes
Such computations are then used to predict physical observables
like the x-sections.
Delphes Detector events
Pythia Shower/Hadronize events
MadGraph Description of proton using pdf
Matrix-element
Parton level
2. Standard Model Higgs Boson production via gluon-gluon fusion
The importance of Gluon-Gluon fusion process of production of
the Higgs boson via Top-Quark loop at the LHC
Search for SUSY in the Higgs sector 7
2. Standard Model Higgs Boson production via gluon-gluon fusion
The Higgs effective field theory(HEFT)
Using the HEFT model, I got for the
125.09 GeV SM Higgs boson effective
coupling to the Gluon 𝑔ℎ = 5.11 × 10−5
The graph illustrates the effective
couplings of the Gluon with the
Higgs Boson in function of the Higgs
mass
Search for SUSY in the Higgs sector 8
2. Standard Model Higgs Boson production via gluon-gluon fusion
1) Study of 𝑔𝑙𝑢𝑜𝑛 − 𝑔𝑙𝑢𝑜𝑛 𝑓𝑢𝑠𝑖𝑜𝑛 → 𝐻𝑖𝑔𝑔𝑠 𝐵𝑜𝑠𝑜𝑛 → 𝑑𝑖𝑝ℎ𝑜𝑡𝑜𝑛 (a1, a2 are two photons)
(Delphes CMS level) ; at 13 TeV
2) Study of 𝑔𝑙𝑢𝑜𝑛 − 𝑔𝑙𝑢𝑜𝑛 𝑓𝑢𝑠𝑖𝑜𝑛 → 𝐻𝑖𝑔𝑔𝑠 𝐵𝑜𝑠𝑜𝑛 → 𝑍 𝑍∗ → 𝑚𝑢 + 𝑚𝑢 − 𝑚𝑢 + 𝑚𝑢 − using MadAnalysis5 (Delphes CMS level) ; at 13 TeV
Search for SUSY in the Higgs sector 9
← 𝑍 𝑚𝑎𝑠𝑠 − 𝑝𝑒𝑎𝑘
Z−𝑝𝑒𝑎𝑘 →
𝐻 − 𝑝𝑒𝑎𝑘 →
𝑍 𝑍 − 𝑝𝑒𝑎𝑘 →
𝑀 𝛾 𝛾 (𝐺𝑒𝑉
𝑐2 ) 𝑀 𝛾 𝛾 (
𝐺𝑒𝑉
𝑐2 )
𝑃𝑡 > 35𝐺𝑒𝑉; 𝜂 < 2.7
𝐻 → 𝑍 𝑍∗ → 𝑚𝑢 + 𝑚𝑢 − 𝑚𝑢 + 𝑚𝑢 −
𝑃 𝑃 → 𝑚𝑢 + 𝑚𝑢 − 𝑚𝑢 + 𝑚𝑢 −
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
They scanned all the parameters space of NMSSM relevant for the Higgs sector in the 13 TeV run2 of the LHC taking into account experimental limits
from LHC run1, Tevatron and LEP
One of the 5 NMSSM Neutral Higgs bosons has always to be SM-Like
They presented a series of benchmark scenarios for run2 of the LHC at 13 TeV compatible with the experimental constraints
Search for SUSY in the Higgs sector 10
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
We have chosen the scenario B.1 to start with because it has low
masses and interesting topologies of decays
Indirect production channels:
Higgs-to-Higgs decays and Higgs-to-Higgs + Gauge-boson decays
Search for SUSY in the Higgs sector 11
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
I have used two fortran codes to calculate the Higgs masses:
NMSSMTools and NMSSMCALC which calculate the Higgs
masses, couplings and decay widths in the NMSSM
NMSSMTools performs computation of the spectrum includes
leading two loop terms, electroweak corrections and propagator
corrections whilst NMSSMCALC performs only a computation of
the full one loop corrections.
Search for SUSY in the Higgs sector 12
PDG
code
Particle Mass (GeV)
NMSSMTools
Mass (GeV)
NMSSMCALC
25 Lightest neutral scalar h 125.37 124.42
35 Second neutral scalar Hs 181.72 188.40
45 Third neutral scalar H 322.64 361.11
36 Lightest pseudoscalar As 72.40 75.04
46 Second pseudoscalar A 311.65 344.32
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
Using Translator2.2 ( written by B. Fuks) :
To get the Higgs bosons events generated one needs to do the proper calculations of the Gluon-Higgs couplings for all 5 Higgses
We need to make the HEFT working in MG5 for the NMSSM
I modified the C++ code translator 2.2 to translate the reduced couplings from NMSSMTools output file
Then I calculated the effective couplings using the HEFT formula to get the couplings for the 5 neutral Higgses of the NMSSM with the gluon
Search for SUSY in the Higgs sector 13
NMSSMTools output file containing
The Reduced-Couplings
Modified translator 2.2
with the HEFT
formula
LHE file compatible with MG5 containing
the Effective-couplings
MadGraph5
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒 𝑐𝑜𝑢𝑝𝑙𝑖𝑛𝑔𝑠 = 𝑅𝑒𝑑𝑢𝑐𝑒𝑑 𝑐𝑜𝑢𝑝𝑙𝑖𝑛𝑔𝑠 × 𝑔ℎ 𝑐𝑜𝑢𝑝𝑙𝑖𝑛𝑔(SM)
After that, heft type term could be implemented in MadGraph5 (by B. Fuks)
Search for SUSY in the Higgs sector 14
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
Using SusHi:
Another tool to install and learn
SusHi stands for Supersymmetric Higgs, it is a computer code which calculates the cross sections in gluon fusion and bottom-quark annihilation in the SM and (N)MSSM for any neutral Higgs boson.
Using Hsushi script
I calculated the x-sections with MG5_aMCSushi at NLO for all the 5 Higgses and produced event samples
Search for SUSY in the Higgs sector 15
Delphes
Detector events
Pythia
Shower/Hadronize events
MadGraph Descripti
on of proton
using pdf
Matrix-element
Parton level
• Hsushi script
• SusHi NMSSM model at NLO
SusHi
• Run card
• Parameters card New
process directories
Decays table
3. Neutral Higgs Bosons in the NMSSM (Next-to-the-Minimal-
Supersymmetric-Standard-Model)
This was produced in the B.1 scenario:
Mass of h = 124.6 GeV
Mass of Hs = 181.7 GeV
Mass of H = 322.6 GeV
Mass of As = 72.5 GeV
Mass of A = 311.7 GeV
Search for SUSY in the Higgs sector 16
MG5_aMCSusHi
4. Conclusions and perspectives
The chain of tools has been installed and closed to generate the
NMSSM Higgs events with MadGraph5 using SusHi
(MG5_aMCSusHi)
Now the real work can start to evaluate the benchmark points
In a future work, automatic transformation of the NMSSMTools
output file to MG5_aMCSusHi needs to be done; there is no script
available, another translate-type tool has to be created
SusHi doesn’t include the Higgs decays.
But decays can be done with Pythia using the decay-tables from
NMSSMtools
We will have to analyze larger data samples of NMSSM and SM-
background
Search for SUSY in the Higgs sector 17
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