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Status of SUSY Higgs Physics
Monoranjan Guchait TIFR, Mumbai
EWSB & Flavors in the light of LHC February 20-22, 2014 IIT Guwahati
Outline
Higgs discovery.
Higgs in Supersymmetry and relatedPhenomenology.
Higgs in non-minimal model
Higgs Properties
)]([
)]([
ihBr
ihBr
hj
observedhji
μ=0.80 ±0.14
� 20% uncertainty.With updgraded LHC, this can come down to 8-10%
Spin 0+ is favored
What it is?
Hence, it is a “125 GeV Boson/new state”….
But it is a Higgs BosonIs it “the SM Higgs Boson” or “a Higgs boson” from some other model..or something else..
Couplings to WW, ZZ and γγ are as expected in SM. Couplings are proportional to Masses as predicted by Higgs mechanism.
Higgs and New PhysicsBut a very serious implications are there for BSMData is compatible with SM , but sensitivity is 15-20% can constrain BSM.Some models are already “closed”: Higgsless model, fermiophobic, gauge phobic, fourth generation, extreme technicolour..
Some models are very much constrained….
Some models are under tension, many other extension of Higgs model, private, portal light technicolor
Is SM can be regarded as Theory of everything?Is the SM a complete theory? Most probably answer is NO.
Many issues(Th+Exp) need to understand, Hierarchy problem.. Neutrino mass, Origin of DM ………………
Beyond SM
Supersymmetry and many of its variations
Extra dimension,
Kaluza Klein,
Composite Higgs
Little Higgs,
Littlest Higgs ………………….
Implication in SUSY
The MSSM: particle content
+ 2 Higgs doublets
100+ parameters
Stabilization of Higgs mass, Hierarchy problem, m(Higgs)<<M(planck)
Bf ||
Supersymmetry is not an exact symmetry
Higgs Masses
At tree level, lightest Higgs mass :
Higgs masses are calculable:d
u
v
vtantan,AM
HAHh ,,,5 Higgsses:
Lightest Higgs masses2222 2cos hZh MMM
)6(0 St MX No(Maximal) mixing
At 1-loop correction , 20-25 GeV for stop ��masses < 1 TeV and no mixing scenario
Upper bound on lightest Higgs Mass2222 2cos hZh MMM
Very strong prediction
M
For MSUSY 1 TeV. �
An upper bound of 135 GeV of lightest higgs can be achieved
135hM GeV
ImplicationsA Higgs of mass 125 ±2 GeV is observed.
•What are the implications In SUSY models?
•What happens to the Higgs sector?
What are the implications of Higgs discovery in other particle searches, in particular stop searches?
Lightest Higgs mass and stop sector
Maximal mixing is favored, otherwise, requires heavy stop
Hall et. al ,12
Lightest Higgs mass and stop sector
In pMSSM Large MS values with moderate mixings and high tanβ are preferred
Djouadi et. al ‘12
Prediction for stops
• For large mixing, stop masses are within the reach of LHC and if it found, then this form of MSSM may be valid.
• If LHC does not find stop, need to think some other form of SUSY models.
Stop searches at the LHC
Stop mass 500-600 GeV excluded depending on LSP mass. �
Improved calculation of Higgs massCodes SoftSUSy, Spheno, and SusPect calculates the Higgs mass full One loop + dominant 2 loop contributions from top/stop loops
Recent calculation taking leading Three loops using DR or a hybrid renormalization scheme for stop sector where is the numerical evaluation Depends on various SUSY hierarchies.
FeynHiggs version 2.10 full one loop + two loop leading and subleading contribution + resummation of leading and next to leading contributions
Allanach, et. Al., Porod et. Al, Djouadi et. Al.
Harlander et. Al.
Heinemeyer et. Al
MH-mod scenario•mh-max scenario was designed to get large Higgs mass , with sparticle masses set to > 1 TeV.•Now, with the present Higgs mass, relaxing mh-max scenario, possible to obtain desired Higgs mass
Beyond MSSMIn MSSM, getting the correct Higgs mass is not so trivial. Need higher SUSY scales, fine tuning which is not very interesting from phenomenological point of view.
May be LHC data give hints to go beyond MSSM, (M+1) SSM= NMSSM
NMSSM Model
The superpotential,....
3
1 3 SHSHW du
....3
1.|| 322 SAHSHASmV dussoft
Four new parameters : ,
AA ,: dimensionless
: dimension full M � SUSY
Some additional terms are not considered in general MSSM, like tadpole terms etc.
Higgs spectrum
Mass terms :
7 Higgsses
Singlet like CP even: 321 ,, HHH
21 , AACP odd:
H
tan,,,,,, Aeff MAA
NMSSM: μ problem
Seff
A vev <S> of S, of the order of the weak or SUSY breaking scale generates μ-term with
It solves mu problem.
Phenomenological constrained , lighter chargino > 100 GeV,
GeVeff 100/100GeVS
Lightest Higgs MassThe lightest Higgs mass:, the SM like , largest coupling with the gauge boson,
2sin2cos 222222 vMM Zh
Contribution due to the singlet intFor large values of λ, and for small tanβ, the second term grows, possible to achieve larger Higgs mass at tree level.
For λ 0.7 – 0.8, Higgs mass cannot be raised above �125 GeV at tree level.
To recover 125 GeV Higgs mass, we need, another � 25 GeV contribution to the tree level mass.
Higgs Mass at one loop
corrZh vMM 2sin2cos 222222
Loop level contribution make Higgs mass favorable value
Higgs MixingsMixing of CP odd Higgs
2
1
1
2
cossin
cos
P
PSin
A
A
AA
AA
P2 is singlet like , If MA is large, mixing is small, A1 is completely singlet like A2 has finite singlet component.
And for CP even Higgs, jiji SOH
Oij is a diagnolizing matrices and also determine couplings., it controls Couplings.
Higgs couplings•The treel level couplings between charged Higgs and fermions/gauge bosons sams as MSSM
•Couplings A1,2 to SM particles are same as MSSM, but multiplied by a dilution factors, related with mixings
•Coulings for h1 and SM particle can be read off by replacing Cosα and sinβ by the i-th eigen vector of diagonalizing matrices.
•A pure singlet SU(2) components has valising couplingswith fermions and gauge bosons, then it is difficult to search those higgs masses at the the collider.
ZZH reduced couplings
iZZH ig
iZHZee Non observation of Higgs in LEP
12 iLight CP scalars are not ruled out by LEP, because of reduced couplings.For ξ 0, the H � 1 is difficult to produce, H2 is sensitive to Higgs searches, possibility of another lighter Higgs to exist.
NMSSM Higgs at the LHCHiggs discovery is same as MSSM channels, but sensitivity depends on the doublet-singlet mixings.Interestingly, higgs to higgs decays, h→AA decays give rich phenomenology. Gunion et. Al., Poulose, Moretti et. al. ,
Dproy, Drees, MG, ….
If lighter state , possibly below LEP limits, is SM like and strongly mixed, less coupling with b-quarks, enhanced decay rates In photonic channel.
G. Belanger et. al ‘12, ….
There are scenario where the SM like state is H2 and the lightest state is H1(70 – 100 GeV), singlet like.Distinguishing feature of NMSSM
OutlookDiscovery of 125 GeV Higgs open up new era in particle physics. Although, it is very much SM-like, possibility of other BSM are not ruled out. May be , this Higgs is the first piece of BSM, which has been discovered.
In minimal Supersymmetry, it can be confirmed by discovering sparticles, mainly lighter Stop, and non-minimal SUSY model, in addition more lighter states of Higgs are required to be discovered.
A rich phenomenology and experimental program is ahead in the next generation of LHC.