1 Left-Right Symmetry and the Charged Higgs Bosons at the LHC Gulab Bambhaniya Theoretical Physics Division Physical Research Laboratory, Ahmedabad December 10, 2014 XXI DAE-BRNS High Energy Physics Symposium 2014 Based on JHEP 1405, 033 (2014), in collaboration with J. Chakrabortty, J. Gluza, M. Kordiaczyska and R. Szafron Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Left-Right Symmetry and the Charged Higgs Bosons … Left-Right Symmetry and the Charged Higgs Bosons at the LHC Gulab Bambhaniya Theoretical Physics Division Physical Research Laboratory,
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Left-Right Symmetry and the Charged HiggsBosons at the LHC
Gulab BambhaniyaTheoretical Physics Division
Physical Research Laboratory, Ahmedabad
December 10, 2014
XXI DAE-BRNS High Energy Physics Symposium 2014
Based on JHEP 1405, 033 (2014), in collaboration withJ. Chakrabortty, J. Gluza, M. Kordiaczyska and R. Szafron
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
invariant under the symmetry ∆L ↔ ∆R, Φ ↔ Φ†, βi = 0.Deshpande, Gunion, Kayser, Olness, 1991
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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After Symmetry breaking
Physical scalars are
4 neutral scalars: H00 , H
01 , H
02 , H
03 ,
(the first can be considered to be the light Higgs of the SM),
2 neutral pseudo-scalars: A01, A
02,
2 singly-charged scalars: H±1 , H±
2 ,
2 doubly-charged scalars: H±±1 , H±±
2 .
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Strategy
Already now MW2> 2.8 TeV, it means vR > 5 TeV, for such a high
scale most of effects connected with heavy gauge bosons decouples.
We choose conservatively:
vR = 8 TeV (MW2≥ 3.5 TeV, expected limit in the next LHC
run)
masses of neutral Higgs particles ≃ 15 TeV (to suppress FCNC)
charged Higgs particles with masses testable by LHC
In such a scenario there is a chance to pin down charged Higgs bosonsignals
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Strategy (contd..)
124.7 GeV < MH00< 126.2 GeV
µ1, µ2, µ3, ρ1, ρ2, ρ3, ρ4,α1,α2,α3, λ1,λ2,λ3,λ4
Minimization conditions are used to get values of dimensionfulmass parameters µ1, µ2 and µ3 which can be arbitrarily large, allother parameters are considered as free, but limited to theperturbative limit.
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Mass relations
M2H0
1≃
1
2α3v
2R,
M2A0
1≃
1
2α3v
2R − 2κ2
+ (2λ2 − λ3) ,
M2
H±1
≃1
2v2R (ρ3 − 2ρ1) +
1
4α3κ
21, M2
H±2
≃1
2α3
(
v2R +1
2κ21
)
,
M2
H±±1
≃1
2
*
v2R (ρ3 − 2ρ1) + α3κ21
+
, M2
H±±2
≃ 2ρ2v2R +
1
2α3κ
21.
MH01,MA0
1are large to suppress FCNC =⇒ MH±
2is also large
But other charged scalars (MH±±1
,MH±±2
and MH±1) can be light
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Neutral - charged Higgs mass splitting
Neutral Single Charged Double Charged
0 5 10 15 20100
500
1000
5000
1! 104
M!GeV"
Neutral Single Charged Double Charged
5000 10000 15000 20000
0.2
0.4
0.6
0.8
1.0
One example of mass spectra for charged scalar is
MH±±1
= 483 GeV, MH±±2
= 527 GeV, MH±1
= 355 GeV, MH±2
=15066 GeV.
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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MLRSM processes at the LHC
Primary production Secondary production Signal
I. H+1
H−1
ℓ+ℓ−νLνL ℓ+ℓ− ⊕ MET
– ℓ+ℓ−NRNR depends on NR decay modes
– ℓ+ℓ−νLNR depends on NR decay modes
II. H+2
H−2
ℓ+ℓ−νLνL ℓ+ℓ− ⊕ MET
– ℓ+ℓ−NRNR depends on NR decay modes
– ℓ+ℓ−νLNR depends on NR decay modes
III. H++1
H−−1
– ℓ+ℓ+ℓ−ℓ−
– H+1
H+1
H−1
H−1
See I
– H±1
H±1
H∓2
H∓2
See I & II
– H+2
H+2
H−2
H−2
See II
– W+i
W+i
W−j
W−j
depends on W ’s decay modes
IV. H++2
H−−2
– ℓ+ℓ+ℓ−ℓ−
– H+2
H+2
H−2
H−2
See II
– H±1
H±1
H∓2
H∓2
See I & II
– H+1
H+1
H−1
H−1
See I
– W+i
W+i
W−j
W−j
depends on W ’s decay modes
V. H±±1
H∓1
– ℓ±ℓ±ℓ∓νL
VI. H±±2
H∓2
– ℓ±ℓ±ℓ∓νL
VII. H±1
Zi, H±1
Wi – See I & Zi,Wi decay modes
VIII. H±2
Zi, H±2
Wi – See II & Zi,Wi decay modes
IX. H±1
γ – See I
X. H±2
γ – See II
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Signal Processes
pp → (H++
1/2H−−1/2 ) → ℓi
+ℓi+ℓj
−ℓj− and
pp → (H±±1/2H
∓1/2) → ℓi
±ℓi±ℓj
∓νℓ
q
q
H++1/2
H−−1/2
ℓ+
ℓ+
ℓ−
ℓ−
q
q′
H±±1/2
H∓1/2
ℓ±
ℓ±
ℓ∓
νℓ
So final signals are: 4ℓ and 3ℓ+MET
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Significance of signals over background
We have estimated the SM backgrounds for both the signals atLHC14TeV
4ℓ signal has better significance than 3ℓ+MET signal
MLRSM can be probed up to 600 GeV in 4ℓ channel atLHC14TeV with 300 fb−1 integrated luminosity.
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Conclusion
We discussed charged Higgs boson sector within classicalMLRSM.
Though different low energy data and the LHC exclusion plotsconstrain already W2 and Z2 very much, still the charged scalarscan be relatively light.
We have chosen the benchmark points in such a way that signalsconnected with doubly charged scalars can dominate overnon-standard signals coming from both heavy gauge and neutralHiggs bosons.
If planed integrated luminosity in the next LHC run at√s = 14
TeV is about 10 times larger than present values, clear signalswith four-leptons and tri-lepton signals can be detected.
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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Conclusion (contd..)
These multi lepton final states posses very small SM background.We have shown that MLRSM model can give such signals fordoubly charged masses up to approximately 600 GeV.
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC
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THANK YOU
Gulab Bambhaniya LR Symmetry and the Charged Higgs Bosons at LHC