-
The CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
J. Leonard,
R. Loveless,
A. Mohapatra,
F. Palmonari,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The first measurement of inclusive Z → τ
+
τ
− production in pp collisions at the LHC is presented, in the final states μ + hadrons, e + hadrons, e + μ, and μ + μ. The data sample corresponds to an integrated luminosity of 36 pb−1 collected with the CMS detector. The measured cross section is σ (pp → ZX) × B (Z → τ
+
τ
−) = 1.00 ± 0.05(stat.) ± 0.08(syst.) ± 0.04(lumi.)nb, which is in good agreement with the next-to-next-to-leading order QCD prediction and improves on previous measurements
in the Z → e+e− and μ
+
μ
− channels. The reconstruction efficiency for hadronic τ decays is determined with a precision of 7%.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(8):1-32. · 5.83 Impact Factor
-
The CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
J. Leonard,
R. Loveless,
A. Mohapatra,
F. Palmonari,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment
at the CERN LHC, using pp collision data recorded at Ös = 7 \sqrt {s} = 7 TeV. The event samples correspond to integrated luminosities of 40 pb−1 in the dimuon channel and 35 pb−1 in the dielectron channel. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z′) or
as Kaluza-Klein graviton excitations (GKK) in the Randall-Sundrum model. Upper limits on the inclusive cross section of Z′(GKK) → ℓ
+
ℓ
− relative to Z → ℓ
+
ℓ
− are presented. These limits exclude at 95% confidence level a Z′ with standard-model-like couplings below 1140GeV, the superstring-inspired
Z
ψ
′ below 887 GeV, and, for values of the coupling parameter
k /
[`(M)] \textPl {{k} \left/ {{{{\overline M }_{\text{Pl}}}}} \right.} of 0.05 (0.1), Kaluza-Klein gravitons below 855 (1079) GeV.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(5):1-35. · 5.83 Impact Factor
-
The CMS Collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
D. Lomidze,
R. Loveless,
A. Mohapatra,
W. Parker,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The production of J/ψ mesons is studied in pp collisions at Ös = 7\sqrt{s} = 7TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity
of 314nb−1. The J/ψ differential cross section is determined, as a function of the J/ψ transverse momentum, in three rapidity ranges. Afit to the decay length distribution is used to separate the prompt from
the non-prompt (b hadron toJ/ψ) component. Integrated over J/ψ transverse momentum from6.5 to 30GeV/c and over rapidity in the range |y|<2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9±2.1(stat.)±3.0(syst.)±7.8(luminosity)nb
for prompt J/ψ mesons assuming unpolarized production and 26.0±1.4(stat.)±1.6(syst.)±2.9(luminosity)nb for J/ψ mesons from b-hadron decays.
European Physical Journal C 04/2012; 71(3):1-26. · 3.63 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Bose-Einstein correlations between identical particles are measured in samples of proton-proton collisions at 0.9 and 7 TeV
centre-of-mass energies, recorded by the CMS experiment at the LHC. The signal is observed in the form of an enhancement of
number of pairs of same-sign charged particles with small relative momentum. The dependence of this enhancement on kinematic
and topological features of the event is studied. Anticorrelations between same-sign charged particles are observed in the
region of relative momenta higher than those in the signal region.
KeywordHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(5):1-29. · 5.83 Impact Factor
-
The CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
J. Leonard,
R. Loveless,
A. Mohapatra,
F. Palmonari,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The results of searches for new physics in events with two same-sign isolated leptons, hadronic jets, and missing transverse
energy in the final state are presented. The searches use an integrated luminosity of 35 pb−1 of pp collision data at a centre-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. The observed numbers
of events agree with the standard model predictions, and no evidence for new physics is found. To facilitate the interpretation
of our data in a broader range of new physics scenarios, information on our event selection, detector response, and efficiencies
is provided.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(6):1-47. · 5.83 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
D. Lomidze,
R. Loveless,
A. Mohapatra,
W. Parker,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton
collisions at centre-of-mass energies of Ös = 0.9 \sqrt {s} = 0.9 , 2.36, and 7 TeV, in five pseudorapidity ranges from |η| < 0.5 to |η| < 2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and
the 7 TeV run in 2010. The multiplicity distribution at
Ös = 0.9\textTeV \sqrt {s} = 0.9\;{\text{TeV}} is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with Ös \sqrt {s} is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented.
The measurement of higher-order moments of the multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling
that has been observed at lower energies.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(1):1-38. · 5.83 Impact Factor
-
CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The spectra of strange hadrons are measured in proton-proton collisions, recorded by the CMS experiment at the CERN LHC, at
centre-of-mass energies of 0.9 and 7 TeV. The
\textK\textS0 {\text{K}}_{\text{S}}^0 , Λ, and Ξ− particles and their antiparticles are reconstructed from their decay topologies and the production rates are measured as
functions of rapidity and transverse momentum, p
T. The results are compared to other experiments and to predictions of the Pythia Monte Carlo program. The p
T distributions are found to differ substantially from the Pythia results and the production rates exceed the predictions by up to a factor of three.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(5):1-40. · 5.83 Impact Factor
-
CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
J. Leonard,
R. Loveless,
A. Mohapatra,
F. Palmonari,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for large extra spatial dimensions via virtual-graviton exchange in the diphoton channel has been carried out with
the CMS detector at the LHC. No excess of events above the standard model expectations is found using a data sample collected
in proton-proton collisions at Ös = 7 \sqrt {s} = 7 TeV and corresponding to an integrated luminosity of 36 pb−
1. New lower limits on the effective Planck scale in the range of 1.6–2.3TeV at the 95% confidence level are set, providing
the most restrictive bounds to date on models with more than two large extra dimensions.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(5):1-28. · 5.83 Impact Factor
-
The CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search is presented for physics beyond the standard model (SM) in final states with opposite-sign isolated lepton pairs
accompanied by hadronic jets and missing transverse energy. The search is performed using LHC data recorded with the CMS detector,
corresponding to an integrated luminosity of 34 pb−1. No evidence for an event yield beyond SM expectations is found. An upper limit on the non-SM contribution to the signal
region is deduced from the results. This limit is interpreted in the context of the constrained minimal supersymmetric model.
Additional information is provided to allow testing the exclusion of specific models of physics beyond the SM.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(6):1-33. · 5.83 Impact Factor
-
The CMS Collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
J. Leonard,
D. Lomidze,
R. Loveless,
A. Mohapatra,
G. Polese,
D. Reeder,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the underlying activity in scattering processes with p
T
scale in the GeV region is performed in proton–proton collisions at Ös = 0.9\sqrt{s} = 0.9TeV, using data collected by the CMS experiment at the LHC. Charged particle production is studied with reference to the
direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several
QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally
predict too little production of charged particles with pseudorapidity |η|<2, p
T
>0.5 GeV/c, and azimuthal direction transverse to that of the leading object.
European Physical Journal C 04/2012; 70(3):555-572. · 3.63 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
D. Lomidze,
R. Loveless,
A. Mohapatra,
W. Parker,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Measurements of inclusive W and Z boson production cross sections in pp collisions at Ös = 7 \sqrt {s} = 7 TeV are presented, based on 2.9 pb−1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are
combined to give
s( \textpp ® \textWX ) B( \textW ® ln ) = 9.95±0.07( \textstat. )±0.28( \textsyst. )±1.09 \sigma \left( {{\text{pp}} \to {\text{W}}X} \right) \times \mathcal{B}\left( {{\text{W}} \to \ell \nu } \right) = 9.95\pm 0.07\left( {{\text{stat}}{.}} \right)\pm 0.28\left( {{\text{syst}}{.}} \right)\pm 1.09 (lumi.) nb and
s( \textpp ® \textZX ) B( Z ® l+ l- ) = 0.931±0.026( \textstat. )±0.023( \textsyst. )±0.102 \sigma \left( {{\text{pp}} \to {\text{Z}}X} \right) \times \mathcal{B}\left( {Z \to {\ell^{+} }{\ell^{-} }} \right) = 0.931\pm 0.026\left( {{\text{stat}}{.}} \right)\pm 0.023\left( {{\text{syst}}{.}} \right)\pm 0.102 (lumi.) nb, where ℓ stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions,
are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty
of less than 4%, are also reported.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(1):1-40. · 5.83 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the b-hadron production cross section in proton-proton collisions at
Ös = 7\textTeV \sqrt {s} = 7\;{\text{TeV}} is presented. The dataset, corresponding to 85 nb−1, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence
of a muon with transverse momentum $ p_T^\mu > 6\;{\text{GeV}} $ p_T^\mu > 6\;{\text{GeV}} with respect to the beam direction and pseudorapidity |η
μ
| < 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from
background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity.
The measured total cross section in the kinematic acceptance is σ(pp → b + X → μ + X′) = 1.32 ± 0.01(stat) ± 0.30(syst) ± 0.15(lumi)μb.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(3):1-29. · 5.83 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
J. Leonard,
D. Lomidze,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The result of a search at the LHC for heavy stable charged particles produced in pp collisions at
Ös = 7\textTeV \sqrt {s} = 7\;{\text{TeV}} is described. The data sample was collected with the CMS detector and corresponds to an integrated luminosity of 3.1 pb−1. Momentum and ionization-energy-loss measurements in the inner tracker detector are used to identify tracks compatible with
heavy slow-moving particles. Additionally, tracks passing muon identification requirements are also analyzed for the same
signature. In each case, no candidate passes the selection, with an expected background of less than 0.1 events. A lower limit at the 95% confidence level on the mass of a stable gluino is set at 398GeV/c
2, using a conventional model of nuclear interactions that allows charged hadrons containing this particle to reach the muon
detectors. A lower limit of 311 GeV/c
2 is also set for a stable gluino in a conservative scenario of complete charge suppression, where any hadron containing this
particle becomes neutral before reaching the muon detectors.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(3):1-29. · 5.83 Impact Factor
-
The CMS collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
J. Leonard,
R. Loveless,
A. Mohapatra,
F. Palmonari,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the lepton charge asymmetry in inclusive pp → WX production at
Ös = 7\textTeV \sqrt {s} = 7\;{\text{TeV}} is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. This high precision measurement of the lepton charge asymmetry, performed in both the W → eν and W → μν channels, provides new insights into parton distribution functions.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(4):1-31. · 5.83 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the angular correlations between beauty and anti-beauty hadrons (
\textB[`(\textB)] {\text{B}}\overline {\text{B}} ) produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the
region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their
decays. The B hadron angular separation is reconstructed from the decay vertices and the primary-interaction vertex. The differential
\textB[`(\textB)] {\text{B}}\overline {\text{B}} production cross section, measured from a data sample collected by CMS and corresponding to an integrated luminosity of 3.1 pb−1, shows that a sizable fraction of the
\textB[`(\textB)] {\text{B}}\overline {\text{B}} pairs are produced with small opening angles. These studies provide a test of QCD and further insight into the dynamics of
\textb[`(\textb)] {\text{b}}\overline {\text{b}} production.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2011(3):1-35. · 5.83 Impact Factor
-
The CMS Collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
J. Leonard,
D. Lomidze,
R. Loveless,
A. Mohapatra,
G. Polese,
D. Reeder,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: The first LHC pp collisions at centre-of-mass energies of 0.9 and 2.36TeV were recorded by the CMS detector in December 2009.
The trajectories of charged particles produced in the collisions were reconstructed using the all-silicon Tracker and their
momenta were measured in the 3.8T axial magnetic field. Results from the Tracker commissioning are presented including studies
of timing, efficiency, signal-to-noise, resolution, and ionization energy. Reconstructed tracks are used to benchmark the
performance in terms of track and vertex resolutions, reconstruction of decays, estimation of ionization energy loss, as well
as identification of photon conversions, nuclear interactions, and heavy-flavour decays.
European Physical Journal C 04/2012; 70(4):1165-1192. · 3.63 Impact Factor
-
The CMS collaboration,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan,
M. Friedl, [......],
D. Lomidze,
R. Loveless,
A. Mohapatra,
W. Parker,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies
of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (ϕ). Short-range correlations in Δη, which are studied in minimum bias events, are characterized using a simple “independent cluster” parametrization in order
to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity
and particle transverse momentum using a 980 nb−1 data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function
for particle pairs with intermediate p
T
of 1–3 GeV/c, 2.0 < |Δη| < 4.8 and Δϕ ≈ 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or p[`(p)] p\overline p collisions.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2010(9):1-38. · 5.83 Impact Factor
-
CMS Collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for pair-produced bottom-like quarks in pp collisions at s=7
TeV is conducted with the CMS experiment at the LHC. The decay
b′→tW is considered in this search. The
b′b¯→tW-t¯W+
process can be identified by the distinctive signature of trileptons and
same-sign dileptons. With a data sample corresponding to an integrated
luminosity of 34 pb-1, no excess above the standard model
background predictions is observed and a b′ quark with
a mass between 255 and 361 GeV/c2 is excluded at the 95%
confidence level.
Physics Letters B 06/2011; 701:204-223. · 3.95 Impact Factor
-
CMS Collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A new heavy gauge boson, W′, decaying to a muon and a
neutrino, is searched for in pp collisions at a centre-of-mass energy of
7 TeV. The data, collected with the CMS detector at the LHC, correspond
to an integrated luminosity of 36 pb-1. No significant excess
of events above the standard model expectation is found in the
transverse mass distribution of the muon-neutrino system. Masses below
1.40 TeV are excluded at the 95% confidence level for a sequential
standard-model-like W′. The W′ mass
lower limit increases to 1.58 TeV when the present analysis is combined
with the CMS result for the electron channel.
Physics Letters B 06/2011; 701:160-179. · 3.95 Impact Factor
-
CMS Collaboration,
S. Chatrchyan,
V. Khachatryan,
A. M. Sirunyan,
A. Tumasyan,
W. Adam,
T. Bergauer,
M. Dragicevic,
J. Erö,
C. Fabjan, [......],
C. Lazaridis,
J. Leonard,
R. Loveless,
A. Mohapatra,
D. Reeder,
I. Ross,
A. Savin,
W. H. Smith,
J. Swanson,
M. Weinberg
[show abstract]
[hide abstract]
ABSTRACT: A search for pair-produced bottom-like quarks in pp collisions at s=7
TeV is conducted with the CMS experiment at the LHC. The decay
b′→tW is considered in this search. The
b′b¯→tW-t¯W+
process can be identified by the distinctive signature of trileptons and
same-sign dileptons. With a data sample corresponding to an integrated
luminosity of 34 pb-1, no excess above the standard model
background predictions is observed and a b′ quark with
a mass between 255 and 361 GeV/c2 is excluded at the 95%
confidence level.
Physics Letters B 06/2011; 701:204-223. · 3.95 Impact Factor
