Search for charged Higgs bosons through the violation of lepton universality in $t\bar{t}$ events using $pp$ collision data at $\sqrt{s}=7$ TeV with the ATLAS experiment

In several extensions of the Standard Model, the top quark can decay into a bottom quark and a light charged Higgs boson H (+), t → bH (+), in addition to the Standard Model decay t → bW. Since W bosons decay to the three lepton generations equally, while H (+) maypredominantlydecayinto τν, charged Higgs bosons can be searched for using the violation of lepton universality in top quark decays. The analysis in this paper is based on 4.6 fb(−1) of proton-proton collision data at TeV collected by the ATLAS experiment at the Large Hadron Collider. Signatures containing leptons (e or μ) and/or a hadronically decaying τ (τ (had)) are used. Event yield ratios between e + τ (had) and e + μ, as well as between μ + τ (had) andμ + e, final states are measured in the data and compared to predictions from simulations. This ratio-based method reduces the impact of systematic uncertainties in the analysis. No significant deviation from the Standard Model predictions is observed. With the assumption that the branching fraction (H (+) → τν) is 100%, upper limits in the range 3.2%–4.4% can be placed on the branching fraction (t → bH (+)) for charged Higgs boson masses m ( )H(+) in the range 90–140 GeV. After combination with results from a search for charged Higgs bosons in decays using the τ (had) + jets final state, upper limits on (t → bH (+)) can be set in the range 0.8%–3.4%, for m ( )H(+) in the range 90-160 GeV.

Note:

20 pages plus author list (43 pages total), 7 figures, 6 tables, submitted to JHEP, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2012-22/ Revision corresponds to published version

p p: interaction
Higgs particle: charged particle: search for
lepton: universality: violation
top: pair production
top: rare decay
top: branching ratio: upper limit
Higgs particle: leptonic decay
dilepton: final state
final state: (muon electron)
final state: (tau lepton)

References(47)

Figures(12)

[1]

A Theory of Spontaneous T Violation

T.D. Lee
(
- Columbia U.
)

- Phys.Rev.D 8 (1973) 1226-1239,
- In *Lee, T.D.: Selected papers, vol. 2*, 516-529
•
DOI:
- 10.1103/PhysRevD.8.1226

[2]

Supersymmetry and Weak, Electromagnetic and Strong Interactions

Pierre Fayet
(
- Ecole Normale Superieure
)

- Phys.Lett.B 64 (1976) 159,
- Physics Letters B64 (1976) 159-162 and Paris Ecole Normale Superieure - PTENS 76-14 (76,REC.SEP) 11p
•
DOI:
- 10.1016/0370-2693(76)90319-1

[3]

Spontaneously Broken Supersymmetric Theories of Weak, Electromagnetic and Strong Interactions

Pierre Fayet
(
- Ecole Polytechnique
)

- Phys.Lett.B 69 (1977) 489,
- IN *FERRARA, S. (ED.): SUPERSYMMETRY, VOL. 1*, 666-671. (PHYS. LETT. B69 (1977) 489-494)
•
DOI:
- 10.1016/0370-2693(77)90852-8

[4]

Phenomenology of the Production, Decay, and Detection of New Hadronic States Associated with Supersymmetry

Glennys R. Farrar
(
- Caltech
)
,
Pierre Fayet
(
- Caltech
)

- Phys.Lett.B 76 (1978) 575-579
•
DOI:
- 10.1016/0370-2693(78)90858-4

[5]

Relations Between the Masses of the Superpartners of Leptons and Quarks, the Goldstino Couplings and the Neutral Currents

Pierre Fayet
(
- Caltech
)

- Phys.Lett.B 84 (1979) 416,
- IN *FERRARA, S. (ED.): SUPERSYMMETRY, VOL. 1*, 672-676. (PHYS. LETT. B84 (1979) 416-420) AND CALTECH PASADENA - CALT-68-0692 (REC.MAY 79) 11 P. (SEE BOOK INDEX)
•
DOI:
- 10.1016/0370-2693(79)91229-2

[6]

Softly Broken Supersymmetry and SU(5)

Savas Dimopoulos
(
- Stanford U., ITP and
- Santa Barbara, KITP and
- Michigan U.
)
,
Howard Georgi
(
- Harvard U.
)

- Nucl.Phys.B 193 (1981) 150-162
•
DOI:
- 10.1016/0550-3213(81)90522-8

[7]

Search for charged Higgs bosons: Preliminary combined results using LEP data collected at energies up to 209-GeV

LEP Higgs Working Group for Higgs boson searches and
ALEPH and
DELPHI and
L3 and
OPAL

Collaborations

e-Print:
- hep-ex/0107031

[8]

Search for charged Higgs bosons decaying via $H^{+} \to \tau \nu$ in top quark pair events using $pp$ collision data at $\sqrt{s}=7$ TeV with the ATLAS detector

ATLAS

Collaboration

•

Georges Aad
(
- Freiburg U.
)

et al.

- JHEP 06 (2012) 039
•
e-Print:
- 1204.2760
•
DOI:
- 10.1007/JHEP06(2012)039

[9]

Search for a Light Charged Higgs Boson in Top Quark Decays in $pp$ Collisions at $\sqrt{s}=7$ TeV

CMS

Collaboration

•

Serguei Chatrchyan
(
- Yerevan Phys. Inst.
)

et al.

- JHEP 07 (2012) 143
•
e-Print:
- 1205.5736
•
DOI:
- 10.1007/JHEP07(2012)143

[10]

Combination of t anti-t cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons

D0

Collaboration

•

V.M. Abazov
(
- Dubna, JINR
)

et al.

- Phys.Rev.D 80 (2009) 071102
•
e-Print:
- 0903.5525
•
DOI:
- 10.1103/PhysRevD.80.071102

[11]

Suggestions for Benchmark Scenarios for MSSM Higgs Boson Searches at Hadron Colliders

Marcela Carena
(
- Fermilab
)
,
S. Heinemeyer
(
- Brookhaven
)
,
C.E.M. Wagner
(
- Argonne and
- Chicago U., EFI
)
,
G. Weiglein
(
- Durham U., IPPP
)

- Eur.Phys.J.C 26 (2003) 601-607
•
e-Print:
- hep-ph/0202167
•
DOI:
- 10.1140/epjc/s2002-01084-3

[12]

The ATLAS Experiment at the CERN Large Hadron Collider

ATLAS

Collaboration

•

G. Aad
(
- Marseille, CPPM
)

et al.

- JINST 3 (2008) S08003
•
DOI:
- 10.1088/1748-0221/3/08/S08003

[13]

The anti- $k_t$ jet clustering algorithm

- JHEP 04 (2008) 063
•
e-Print:
- 0802.1189
•
DOI:
- 10.1088/1126-6708/2008/04/063

[14]

Dispelling the $N^{3}$ myth for the $k_t$ jet-finder

Matteo Cacciari
(
- Paris, LPTHE
)
,
Gavin P. Salam
(
- Paris, LPTHE
)

- Phys.Lett.B 641 (2006) 57-61
•
e-Print:
- hep-ph/0512210
•
DOI:
- 10.1016/j.physletb.2006.08.037

[15]

Measurement of the $p \bar{p} \to t \bar{t}$ production cross section at $\sqrt{s}$ = 1.96-TeV in the fully hadronic decay channel.

D0

Collaboration

•

V.M. Abazov
(
- Dubna, JINR
)

et al.

- Phys.Rev.D 76 (2007) 072007
•
e-Print:
- hep-ex/0612040
•
DOI:
- 10.1103/PhysRevD.76.072007

[16]

Commissioning of the ATLAS high-performance b-tagging algorithms in the 7 TeV collision data

ATLAS

Collaboration

[17]

Performance of the Reconstruction and Identification of Hadronic Tau Decays in ATLAS with 2011 Data

ATLAS

Collaboration

[18]

Luminosity Determination in pp Collisions at sqrt(s) = 7 TeV using the ATLAS Detector in 2011

ATLAS

Collaboration

[19]

Luminosity Determination in $pp$ Collisions at $\sqrt{s}=7$ TeV Using the ATLAS Detector at the LHC

ATLAS

Collaboration

•

Georges Aad
(
- Freiburg U.
)

et al.

- Eur.Phys.J.C 71 (2011) 1630
•
e-Print:
- 1101.2185
•
DOI:
- 10.1140/epjc/s10052-011-1630-5

[20]

PYTHIA 6.4 Physics and Manual

Torbjorn Sjostrand
(
- Lund U., Dept. Theor. Phys.
)
,
Stephen Mrenna
(
- Fermilab
)
,
Peter Z. Skands
(
- Fermilab
)

- JHEP 05 (2006) 026
•
e-Print:
- hep-ph/0603175
•
DOI:
- 10.1088/1126-6708/2006/05/026

[21]

TAUOLA as tau Monte Carlo for future applications

Z. Was
(
- CERN and
- Cracow, INP
)
,
P. Golonka
(
- CERN and
- AGH-UST, Cracow
)

- Nucl.Phys.B Proc.Suppl. 144 (2005) 88-94,
•
e-Print:
- hep-ph/0411377
•
DOI:
- 10.1016/j.nuclphysbps.2005.02.012

[22]

PHOTOS: A Universal Monte Carlo for QED radiative corrections in decays

- Comput.Phys.Commun. 66 (1991) 115-128,
- Comput. Phys. Commun. 66 (1991) 115-128 and CERN Geneva - TH. 5857 (90,rec.Oct.) 21 p
•
DOI:
- 10.1016/0010-4655(91)90012-A