L. Dodd, U. Wisconsin 11/13/15 2015 US LUA

Search for MSSM Heavy Higgs

Bosons with Decays to 125 GeV Higgs Bosons with τ Final States in CMS

Laura Margaret Dodd

1

USLUA 2015 University of Wisconsin-Madison

arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

MotivationWe’ve found a higgs!

•Is it the SM higgs?

•Use Higgs as tool for discovery!

Taus are a good handle for probing physics beyond the standard model

•CMS can reconstruct taus well

•higgs → ττ valuable!2

arXiv:1401.5041 [hep-ex]

arXiv:1501.04943v3

L. Dodd, U. Wisconsin 11/13/152015 US LUA

MSSM HiggsMSSM Higgs

•5 Higgs

•h, H, A, H+/-

•Two main parameters

•tanβ=ratio of the two v.e.v.’s

•MA, mass of the pseudoscalar A

2012 Limits

•h,H,A → ττ search

Low tanβ regime still needs to be explored, to further narrow MA-tanβ possibilities

•Hard to probe part of the phase-space

3

arXiv:1304.1787

L. Dodd, U. Wisconsin 11/13/152015 US LUA

Analysis MotivationWe can search A,H in low tanβ regime

•At ~250 GeV

•Heavy H decay to two 125 GeV Higgs

•At 215 GeV

•A decay to Z and one 125 GeV Higgs

•At 350 ttbar dominates

Examine mass range

•hh: 260 GeV-350 GeV

•Zh: 220-350 GeV

4

Lewis, Ian M., arXiv:1308.1742

tanβ=2.5arXiv:1304.1787

L. Dodd, U. Wisconsin 11/13/152015 US LUA

Analysis HighlightsTau reconstruction algorithm

•Hadron-plus-strips algorithm

•Strip in φ from π0 plus an extra hadron

In both H → hh and A → Zh, one h can decay to taus

•Taus can decay leptonically or hadronically

•Use lepton and triggered by an electron or muon

•Use hadron+strips algorithm and triggered by a tau object defined in trigger

Second object reconstructed by di-lepton invariant mass or di-jet invariant mass.

•Z → ll and h → bb

A search is performed using the reconstructed mass of the MSSM A, H as the discriminating variable

5

φ

η

Δη=.05

ΔΦ=.2

π0

γ

γγγ

π+

arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

Analysis Backgrounds

6

W+jets, Z+jets, Zττ, QCD use data-driven

methods

QCD is additionally

scaled based on prior MSSM

h->ττ studies*

*arXiv:1408.3316 [hep-ex]

Zee(μμ), TTbar yields are based

on prior MSSM h->ττ studies*.

Shape from Drell Yan Monte Carlo.

(GeV)ττM0 50 100 150 200 250 300 350

(1/G

eV)

ττdN

/dm

0

5

10

15

20

25

30

ττbb→hh→H

, 2jet-1taghτe

Observed

Bkg. uncertainty

=2)β=300,tanH

hh(m→ H×10

ττ→Z

ee→Z

Electroweak

QCD

tt

CMSUnpublished

(8 TeV)-119.7 fb

arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

H → hh3 Final States, 3 categories

•h → ττ → eτ, μτ, ττ

•h →bb with 2-jet 0-tag, 2-jet 1-tag, 2-jet 2-tag

Signal extraction

•Kinematic Fit applied to reconstruct, H

•Constrain h to be on-shell at 125 GeV

•Mass cuts: 90<Mττ <150 GeV and 70<Mbb<150 GeV

7 [GeV]Hm

260 280 300 320 340

bb) [

pb]

ττ→

hh→

BR

(H×

(ggH

)σ

95%

CL

limit

on

0.2

0.4

0.6

0.8

1.0

1.2

1.4ObservedExpected

Expectedσ 1± Expectedσ 2±

CMS (8 TeV)-119.7 fb

hτhτ+hτµ+hτe

bbττ→hh→H

arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

A → Zh8 final states

•h → ττ → eτ, μτ, ττ, eμ

•Z → ee, μμ

Signal extraction

•Low statistics in each final state

•Reconstructed di-tau mass

•Input τ 4-vectors, MET, and MET resolution

•Kinematics of tau decay are under-constrained

•Outputs most likely di-tau mass

8 [GeV]Am250 300 350

) [fb

]ττ

ll→

Zh

→(g

gA) x

BR

(Aσ

95%

CL

limit

on

0

10

20

30

40

50

60

70

80

90

100ObservedExpected

Expectedσ 1± Expectedσ 2±

hτhτll +

CMS

(8 TeV)-119.7 fb

arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

[GeV]Am250 300 350

βtan

1.5

2.0

2.5

3.0

3.5

4.0

95% CL Excluded:

Observed Expectedσ 1±

Expected Expectedσ 2±

Mass constraint:

3 GeV± 125≠ hMSSMm

-high scenarioβMSSM low-tan

(8 TeV)-1, 19.7 fbττll→Zh→bb + Aττ→hh→ Preliminary,HCMS

progress

Closing the WedgeWith both A and H, we can scan tanβ and contribute to the limits previously set by CMS in a difficult phase space to search.

9arXiv:1510.01181v1

L. Dodd, U. Wisconsin 11/13/152015 US LUA

2HDM Limit InterpretationObserved limits can be set in the generic 2 Higgs Doublet Model (2HDM) interpretation.

10

+ =

arXiv:1510.01181v1

Hhh AZh+ = Cmb

L. Dodd, U. Wisconsin 11/13/152015 US LUA

ConclusionsTargeted low tanβ in MSSM MA-tanβ phase space

•A/H feasible searches in that region

Searches for MSSM A, H were completed with decays to 125 GeV Higgs with tau final states.

•Procedure inspired from 2013 H → ττ paper

•H → hh → ττbb was examined

•A → Zh → llττ was examined

Observed limits are set within 95% of the expected limit

Limits were interpreted in the 2HDM Model

11arXiv:1510.01181v1