-
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of the mass difference between top ($t$) and
anti-top ($\bar{t}$) quarks using $t\bar{t}$ candidate events reconstructed in
the final state with one lepton and multiple jets. We use the full data set of
Tevatron $\sqrt{s} = 1.96$ TeV proton-antiproton collisions recorded by the CDF
II detector, corresponding to an integrated luminosity of 8.7 fb$^{-1}$. We
estimate event-by-event the mass difference to construct templates for
top-quark signal events and background events. The resulting mass difference
distribution of data compared to signal and background templates using a
likelihood fit yields $\Delta M_{top} = {M}_{t} - {M}_{\bar{t}} = -1.95 $pm$
1.11 (stat) $pm$ 0.59 (syst)$ and is in agreement with the standard model
prediction of no mass difference.
10/2012;
-
CDF Collaboration,
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: This paper reports the result of a search for the standard model Higgs boson
in events containing four reconstructed jets associated with quarks. For masses
below 135GeV/c2, Higgs boson decays to bottom-antibottom quark pairs are
dominant and result primarily in two hadronic jets. An additional two jets can
be produced in the hadronic decay of a W or Z boson produced in association
with the Higgs boson, or from the incoming quarks that produced the Higgs boson
through the vector-boson fusion process. The search is performed using a sample
of \sqrt{s} = 1.96 TeV proton-antiproton collisions corresponding to an
integrated luminosity of 9.45 fb-1 recorded by the CDF II detector. The data
are in agreement with the background model and 95% credibility level upper
limits on Higgs boson production are set as a function of the Higgs boson mass.
The median expected (observed) limit for a 125GeV/c2 Higgs boson is 11.0 (9.0)
times the predicted standard model rate.
08/2012;
-
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a precision measurement of the top-quark mass using the full
sample of Tevatron $\sqrt{s}=1.96$ TeV proton-antiproton collisions collected
by the CDF II detector, corresponding to an integrated luminosity of 8.7
$fb^{-1}$. Using a sample of $t\bar{t}$ candidate events decaying into the
lepton+jets channel, we obtain distributions of the top-quark masses and the
invariant mass of two jets from the $W$ boson decays from data. We then compare
these distributions to templates derived from signal and background samples to
extract the top-quark mass and the energy scale of the calorimeter jets with
{\it in situ} calibration. The likelihood fit of the templates from signal and
background events to the data yields the single most-precise measurement of the
top-quark mass, $\mtop = 172.85 $\pm$ 0.71 (stat) $\pm$ 0.85 (syst) GeV/c^{2}.$
07/2012;
-
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: An inclusive search for the standard model Higgs boson using the four-lepton
final state in proton-antiproton collisions produced by the Tevatron at sqrt(s)
= 1.96 TeV is conducted. The data are recorded by the CDF II detector and
correspond to an integrated luminosity of 9.7 /fb. Three distinct Higgs decay
modes, namely ZZ, WW, and tau-tau, are simultaneously probed. Nine potential
signal events are selected and found to be consistent with the background
expectation. We set a 95% credibility limit on the production cross section
times the branching ratio and subsequent decay to the four lepton final state
for hypothetical Higgs boson masses between 120 GeV/c^2 and 300 GeV/c^2.
07/2012;
-
T. Aaltonen,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report a set of measurements of inclusive invariant pT differential cross sections of Λ0, Λ̅ 0, Ξ±, and Ω± hyperons reconstructed in the central region with pseudorapidity |η|<1 and pT up to 10 GeV/c. Events are collected with a minimum-bias trigger in pp̅ collisions at a center-of-mass energy of 1.96 TeV using the CDF II detector at the Tevatron Collider. As pT increases, the slopes of the differential cross sections of the three particles are similar, which could indicate a universality of the particle production in pT. The invariant differential cross sections are also presented for different charged-particle multiplicity intervals.
Phys. Rev. D. 07/2012; 86(1).
-
T Aaltonen,
B Álvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
Phys. Rev. D. 07/2012; 86(1):012002.
-
T Aaltonen,
B Álvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report on a search for the standard model Higgs boson decaying into pairs of τ leptons in pp collisions produced by the Tevatron at sqrt[s]=1.96 TeV. The analyzed data sample was recorded by the CDFII detector and corresponds to an integrated luminosity of 6.0 fb(-1). The search is performed in the final state with one τ decaying leptonically and the second one identified through its semihadronic decay. Since no significant excess is observed, a 95% credibility level upper limit on the production cross section times branching ratio to the ττ final state is set for hypothetical Higgs boson masses between 100 and 150 GeV/c2. For a Higgs boson of 120 GeV/c2 the observed (expected) limit is 14.6 (15.3) the predicted value.
Physical Review Letters 05/2012; 108(18):181804. · 7.37 Impact Factor
-
The CDF Collaboration,
T. Aaltonen,
B. ÁlvarezGonzález,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We use a new method to estimate with 5% accuracy the contribution of pion and kaon in-flight-decays to the dimuon data set
acquired with the CDF detector. Based on this improved estimate, we show that the total number and the properties of the collected
dimuon events are not yet accounted for by ordinary sources of dimuons which also include the contributions, as measured in
the data, of heavy flavor, ϒ, and Drell–Yan production in addition to muons mimicked by hadronic punchthrough. The number of unaccounted events corresponds
to (12.8±3.2)% of the b[`(b)]b\bar{b} production. We find that (23±6)% of the unaccounted events contain additional muon candidates. For comparison, this fraction
is (6.9±0.4)% for events due to b[`(b)]b\bar{b} production.
European Physical Journal C 05/2012; 71(8):1-14. · 3.63 Impact Factor
-
CDF Collaboration,
T. Aaltonen,
J. Adelman,
T. Akimoto,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos, [......],
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
L. Zanello,
A. Zanetti,
X. Zhang,
Y. Zheng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report a search for narrow resonances, produced in
p[`(p)]p\bar{p}
collisions at
Ös=1.96\sqrt{s}=1.96
TeV, that decay into muon pairs with invariant mass between 6.3 and 9.0GeV/c
2. The data, collected with the CDFII detector at the Fermilab Tevatron collider, correspond to an integrated luminosity of
630pb−1. We use the dimuon invariant mass distribution to set 90% upper credible limits of about 1% to the ratio of the production
cross section times muonic branching fraction of possible narrow resonances to that of the ϒ(1S) meson.
European Physical Journal C 04/2012; 62(2):319-326. · 3.63 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report an indirect search for nonstandard model physics using the flavor-changing neutral current decays B→K(*)μ(+)μ(-). We reconstruct the decays and measure their angular distributions, as a function of q(2)=M(μμ)(2)c(2), where M(μμ) is the dimuon mass, in pp¯ collisions at √s=1.96 TeV using a data sample corresponding to an integrated luminosity of 6.8 fb(-1). The transverse polarization asymmetry A(T)(2) and the time-reversal-odd charge-and-parity asymmetry A(im) are measured for the first time, together with the K* longitudinal polarization fraction F(L) and the muon forward-backward asymmetry A(FB) for the decays B(0)→K(*0)μ(+)μ(-) and B(+)→K(*+)μ(+)μ(-). The B→K*μ(+)μ(-) forward-backward asymmetry in the most sensitive kinematic regime, 1≤q(2)<6 GeV(2)/c(2), is measured to be A(FB)=0.29(-0.23)(+0.20)(stat)±0.07(syst), the most precise result to date. No deviations from the standard model predictions are observed.
Physical Review Letters 02/2012; 108(8):081807. · 7.37 Impact Factor
-
T. Aaltonen,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the rare radiative decay W±→π±γ using data corresponding to an integrated luminosity of 4.3 fb-1 of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF experiment at Fermilab. As no statistically significant signal is observed, we set a 95%-confidence-level upper limit on the relative branching fraction Γ(W±→π±γ)/Γ(W±→e±ν) at 6.4×10-5, a factor of 10 improvement over the previous limit.
Phys. Rev. D. 02/2012; 85(3).
-
T. Aaltonen,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: A search is performed for heavy metastable particles that decay into jet pairs with a macroscopic lifetime (cτ∼1 cm) in pp̅ collisions at √s=1.96 TeV using data from the CDF II detector at Fermilab corresponding to an integrated luminosity of 3.2 fb-1. To estimate the standard model background, a data-driven approach is used. Probability-density functions are constructed to model secondary vertices from known processes. No statistically significant excess is observed above the background. Limits on the production cross section in a hidden valley benchmark phenomenology are set for various Higgs boson masses as well as metastable particle masses and lifetimes.
Phys. Rev. D. 01/2012; 85(1).
-
CDF Collaboration,
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report on a search for the standard model Higgs boson decaying into pairs
of tau leptons in $p\bar{p}$ collisions produced by the Tevatron at $\sqrt{s}$
= 1.96 TeV. The analyzed data sample was recorded by the CDFII detector and
corresponds to an integrated luminosity of 6.0 fb$^{-1}$. The search is
performed in the final state with one tau decaying leptonically and the second
one identified through its semi-hadronic decay.Since no significant excess is
observed, a 95% credibility level upper limit on the production cross section
times branching ratio to the tau-tau final state is set for hypothetical Higgs
boson masses between 100 and 150 GeV/$c^2$. For a Higgs boson of 120 GeV/$c^2$
the observed (expected) limit is 14.6 (15.3) the predicted value.
01/2012;
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 7.0 fb{-1} of integrated luminosity from pp collisions at sqrt[s]=1.96 TeV collected by the CDF experiment. No evidence of such a resonance is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of Higgs boson mass. The limits are interpreted in the context of the standard model and one fermiophobic benchmark model where the data exclude fermiophobic Higgs bosons with masses below 114 GeV/c{2} at a 95% Bayesian credibility level.
Physical Review Letters 01/2012; 108(1):011801. · 7.37 Impact Factor
-
T. Aaltonen,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: Diboson production (WW+WZ+ZZ) has been observed at the Tevatron in hadronic decay modes dominated by the WW process. This paper describes the measurement of the cross section of WZ and ZZ events in final states with large E̸T and using b-jet identification as a tool to suppress WW contributions. Because of the limited energy resolution, we cannot distinguish between partially hadronic decays of WZ and ZZ, and we measure the sum of these processes. The number of signal events is extracted using a simultaneous fit to the invariant mass distribution of the two jets for events with two b-jet candidates and events with fewer than two b-jet candidates. We measure a cross section σ(pp̅ →WZ,ZZ)=5.8-3.0+3.6 pb, in agreement with the standard model.
Phys. Rev. D. 01/2012; 85(1).
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of the B(s)(0) lifetime in fully and partially reconstructed B(s)(0)→D(s)(-)(ϕπ(-))X decays in 1.3 fb(-1) collected in pp ¯ collisions at √s=1.96 TeV by the CDF II detector at the Fermilab Tevatron. We measure τ(B(s)(0))=1.518±0.041(stat)±0.027(syst) ps. The ratio of this result and the world average B(0) lifetime yields τ(B(s)(0))/τ(B(0))=0.99±0.03, which is in agreement with recent theoretical predictions.
Physical Review Letters 12/2011; 107(27):272001. · 7.37 Impact Factor
-
T Aaltonen,
B Álvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present the first measurement of polarization and CP-violating asymmetries in a B(s)(0) decay into two light vector mesons, B(s)(0)→φφ, and an improved determination of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb(-1) of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be f(L)=0.348±0.041(stat)±0.021(syst), and the branching ratio B(B(s)(0)→φφ)=[2.32±0.18(stat)±0.82(syst)]×10(-5). Asymmetries of decay angle distributions sensitive to CP violation are measured to be A(u)=-0.007±0.064(stat)±0.018(syst) and A(v)=-0.120±0.064(stat)±0.016(syst).
Physical Review Letters 12/2011; 107(26):261802. · 7.37 Impact Factor
-
T Aaltonen,
B Álvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
A Apresyan, [......],
J Yoh,
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present the results of a search for pair production of a heavy toplike (t') quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6 fb(-1) collected by the CDF II detector in pp collisions at √s=1.96 TeV. We perform parallel searches for t'→Wb and t'→Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t' quark mass, we set upper limits on the t't' production cross section and exclude a standard model fourth-generation t' quark decaying to Wb (Wq) with mass below 358 (340) GeV/c(2) at 95% C.L.
Physical Review Letters 12/2011; 107(26):261801. · 7.37 Impact Factor
-
CDF Collaboration,
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a search for standard model Higgs boson production in
association with a $W$ boson using events recorded by the CDF experiment in a
dataset corresponding to an integrated luminosity of 5.6 fb-1. The search is
performed using a matrix element technique in which the signal and background
hypotheses are used to create a powerful discriminator. The discriminant output
distributions for signal and background are fit to the observed events using a
binned likelihood approach to search for the Higgs boson signal. We find no
evidence for a Higgs boson, and 95% confidence level (C.L.) upper limits are
set on the Higgs boson production rate. The observed limits range from 3.5 to
37.6 relative to the standard model expectation for Higgs boson masses between
100 and 150 GeV. The 95% C.L. expected limit is estimated from the median of an
ensemble of simulated experiments and varies between 2.9 and 32.7 relative to
the production rate predicted by the standard model over the Higgs boson mass
range studied.
12/2011;
-
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
A. Apresyan, [......],
J. Yoh,
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: In this paper we present a precise measurement of the total ZZ production
cross section in pp collisions at {\surd}s= 1.96 TeV, using data collected with
the CDF II detector corresponding to an integrated luminosity of approximately
6 fb-1. The result is obtained by combining separate measurements in the
four-charged (lll'l'), and two-charged-lepton and two-neutral-lepton (llvv)
decay modes of the Z. The combined measured cross section for pp {\to} ZZ is
1.64^(+0.44)_(-0.38) pb. This is the most precise measurement of the ZZ
production cross section in 1.96 TeV pp collisions to date.
12/2011;