Search for pair production of a new quark that decays to a Z boson and a bottom quark with the ATLAS detector

A search is reported for the pair production of a new quark, b', with at least one b' decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb^-1 of integrated luminosity, were collected from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b' candidates is tested for an enhancement. No evidence for a b' signal is detected in the observed mass distribution, resulting in the exclusion at 95% confidence level of b' quarks with masses m_{b'} < 400 GeV that decay entirely via b' to Z+b. In the case of a vector-like singlet b' mixing solely with the third Standard Model generation, masses m_{b'} < 358 GeV are excluded.

Note:

5 pages plus cover letter and author list (18 pages total), 5 figures, 1 table, revised author list, matches published PRL version

14.65.Jk
14.65.Fy
12.60.-i
p p: interaction
bottom': search for
bottom': pair production
bottom': decay
final state: (Z0 bottom)
Z0: leptonic decay
mass spectrum

References(51)

Figures(6)

[1]

Quarks and leptons beyond the third generation

Paul H. Frampton
(
- North Carolina U.
)
,
P.Q. Hung
(
- Virginia U.
)
,
Marc Sher
(
- William-Mary Coll.
)

- Phys.Rept. 330 (2000) 263
•
e-Print:
- hep-ph/9903387
•
DOI:
- 10.1016/S0370-1573(99)00095-2

[2]

Extra vector-like matter and the lightest Higgs scalar boson mass in low-energy supersymmetry

Stephen P. Martin
(
- Northern Illinois U. and
- Fermilab
)

- Phys.Rev.D 81 (2010) 035004
•
e-Print:
- 0910.2732
•
DOI:
- 10.1103/PhysRevD.81.035004

[3]

Beautiful mirrors and precision electroweak data

D. Choudhury
(
- Argonne and
- Harish-Chandra Res. Inst.
)
,
Timothy M.P. Tait
(
- Argonne
)
,
C.E.M. Wagner
(
- Argonne and
- Chicago U., EFI
)

- Phys.Rev.D 65 (2002) 053002
•
e-Print:
- hep-ph/0109097
•
DOI:
- 10.1103/PhysRevD.65.053002

[3]

K. Kumar

[3]

Beautiful Mirrors at the LHC

Kunal Kumar
(
- Argonne and
- Northwestern U.
)
,
William Shepherd
(
- Northwestern U. and
- UC, Irvine
)
,
Tim M.P. Tait
(
- Argonne and
- Northwestern U. and
- UC, Irvine
)
,
Roberto Vega-Morales
(
- Argonne and
- Northwestern U.
)

- JHEP 08 (2010) 052
•
e-Print:
- 1004.4895
•
DOI:
- 10.1007/JHEP08(2010)052

[4]

The E6 inspired isosinglet quark and the Higgs boson

S. Sultansoy
(
- Baku, Inst. Phys. and
- Gazi U.
)
,
G. Unel
(
- UC, Irvine and
- CERN
)

- Phys.Lett.B 669 (2008) 39-45
•
e-Print:
- hep-ex/0610064
•
DOI:
- 10.1016/j.physletb.2008.09.022

[5]

Identifying top partners at LHC

J.A. Aguilar-Saavedra
(
- Granada U.
)

- JHEP 11 (2009) 030
•
e-Print:
- 0907.3155
•
DOI:
- 10.1088/1126-6708/2009/11/030

[6]

Four generations and Higgs physics

Graham D. Kribs
(
- Oregon U.
)
,
Tilman Plehn
(
- Edinburgh U.
)
,
Michael Spannowsky
(
- Munich U., ASC and
- Munich U.
)
,
Timothy M.P. Tait
(
- Argonne
)

- Phys.Rev.D 76 (2007) 075016
•
e-Print:
- 0706.3718
•
DOI:
- 10.1103/PhysRevD.76.075016

[7]

Source of CP Violation for the Baryon Asymmetry of the Universe

Wei-Shu Hou
(
- Taiwan, Natl. Taiwan U.
)

- Chin.J.Phys. 47 (2009) 134
•
e-Print:
- 0803.1234

[8]

Search for a fourth generation charge -1/3 quark via flavor changing neutral current decay

D0

Collaboration

•

S. Abachi

et al.

- Phys.Rev.Lett. 78 (1997) 3818-3823
•
e-Print:
- hep-ex/9611021
•
DOI:
- 10.1103/PhysRevLett.78.3818

[9]

Search for New Particles Leading to $Z +$ jets Final States in $p \bar{p}$ Collisions at $\sqrt{s}$ = 1.96-TeV

CDF

Collaboration

•

T. Aaltonen
(
- Helsinki Inst. of Phys. and
- Helsinki U.
)

et al.

- Phys.Rev.D 76 (2007) 072006
•
e-Print:
- 0706.3264
•
DOI:
- 10.1103/PhysRevD.76.072006

[9]

CDF Collaboration

Collaboration

[9]

Search for a fourth-generation quark more massive than the Z0 boson in $p \bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV

CDF

Collaboration

•

T. Affolder
(
- LBL, Berkeley
)

et al.

- Phys.Rev.Lett. 84 (2000) 835-840
•
e-Print:
- hep-ex/9909027
•
DOI:
- 10.1103/PhysRevLett.84.835

[10]

Longlived quarks?

Paul H. Frampton
(
- North Carolina U.
)
,
Pham Quang Hung
(
- Virginia U.
)

- Phys.Rev.D 58 (1998) 057704
•
e-Print:
- hep-ph/9711218
•
DOI:
- 10.1103/PhysRevD.58.057704

[11]

Search for long-lived particles decaying into electron or photon pairs with the D0 detector

D0

Collaboration

•

V.M. Abazov
(
- Dubna, JINR
)

et al.

- Phys.Rev.Lett. 101 (2008) 111802
•
e-Print:
- 0806.2223
•
DOI:
- 10.1103/PhysRevLett.101.111802

[12]

Search for Heavy Bottom-Like Quarks Decaying to an Electron or Muon and Jets in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

CDF

Collaboration

•

T. Aaltonen
(
- Helsinki Inst. of Phys.
)

et al.

- Phys.Rev.Lett. 106 (2011) 141803
•
e-Print:
- 1101.5728
•
DOI:
- 10.1103/PhysRevLett.106.141803

[12]

CDF Collaboration

Collaboration

[12]

Search for New Bottomlike Quark Pair Decays Q\Qbar \to (\t\Wmp)(\tbar\Wpm) in Same-Charge Dilepton Events

CDF

Collaboration

•

T. Aaltonen
(
- Helsinki Inst. of Phys.
)

et al.

- Phys.Rev.Lett. 104 (2010) 091801
•
e-Print:
- 0912.1057
•
DOI:
- 10.1103/PhysRevLett.104.091801

[13]

Search for a Heavy Bottom-like Quark in $pp$ Collisions at $\sqrt{s} = 7$ TeV

CMS

Collaboration

•

Serguei Chatrchyan
(
- Yerevan Phys. Inst.
)

et al.

- Phys.Lett.B 701 (2011) 204-223
•
e-Print:
- 1102.4746
•
DOI:
- 10.1016/j.physletb.2011.05.074

[14]

Search for down-type fourth generation quarks with the ATLAS detector in events with one lepton and hadronically decaying $W$ bosons

ATLAS

Collaboration

•

Georges Aad
(
- Freiburg U.
)

et al.

- Phys.Rev.Lett. 109 (2012) 032001
•
e-Print:
- 1202.6540
•
DOI:
- 10.1103/PhysRevLett.109.032001

[14]

ATLAS Collaboration

Collaboration

[14]

Inclusive search for same-sign dilepton signatures in $pp$ collisions at $\sqrt{s}=7$ TeV with the ATLAS detector

ATLAS

Collaboration

•

Georges Aad
(
- Freiburg U.
)

et al.

- JHEP 10 (2011) 107
•
e-Print:
- 1108.0366
•
DOI:
- 10.1007/JHEP10(2011)107

[15]

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

[16]

ATLAS uses a right-handed coordinate system with its origin at the nominal interaction point (IP) in the center of the detector and the z-axis coinciding with the axis of the beam pipe. The x-axis points from the IP to the center of the LHC ring, and the y-axis points upward. Cylindrical coordinates (r,φ) used in the transverse plane, φ being the azimuthal angle around the beam pipe. The pseudorapidity is defined in terms of the polar angle, θ as η = -lntan(θ/2)

[17]

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

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