-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present the first direct measurement of the top-quark mass using tt[over ¯] events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2 fb^{-1} collected by the CDF II detector in pp[over ¯] collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron, we measure the tt[over ¯] cross section, σ_{tt[over ¯]}, and the top-quark mass, M_{top}. We extract M_{top} from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σ_{tt[over ¯]}=8.8±3.3(stat)±2.2(syst) pb and M_{top}=172.7±9.3(stat)±3.7(syst) GeV/c^{2}.
Physical Review Letters 11/2012; 109(19):192001. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: A search is presented for the standard model Higgs boson produced in association with top quarks using the full Run II proton-antiproton collision data set, corresponding to 9.45 fb^{-1}, collected by the Collider Detector at Fermilab. No significant excess over the expected background is observed, and 95% credibility-level upper bounds are placed on the cross section σ(tt[over ¯]H→lepton+missing transverse energy+jets). For a Higgs boson mass of 125 GeV/c^{2}, we expect to set a limit of 12.6 and observe a limit of 20.5 times the standard model rate. This represents the most sensitive search for a standard model Higgs boson in this channel to date.
Physical Review Letters 11/2012; 109(18):181802. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of the bottom-strange meson mixing phase β_{s} using the time evolution of B_{s}^{0}→J/ψ(→μ^{+}μ^{-})ϕ(→K^{+}K^{-}) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt[s]=1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb^{-1} of integrated luminosity. We report confidence regions in the two-dimensional space of β_{s} and the B_{s}^{0} decay-width difference ΔΓ_{s} and measure β_{s}∈[-π/2,-1.51]∪[-0.06,0.30]∪[1.26,π/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of β_{s}, we also determine ΔΓ_{s}=0.068±0.026(stat)±0.009(syst) ps^{-1} and the mean B_{s}^{0} lifetime τ_{s}=1.528±0.019(stat)±0.009(syst) ps, which are consistent and competitive with determinations by other experiments.
Physical Review Letters 10/2012; 109(17):171802. · 7.37 Impact Factor
-
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;
-
[show abstract]
[hide abstract]
ABSTRACT: STUDY QUESTION: Does the use of a digital home ovulation test have any effect on the level of stress in women seeking to conceive? SUMMARY ANSWER: No difference was found in levels of stress between women using digital ovulation tests to time intercourse compared with women who were trying to conceive without any additional aids: in addition, their use did not negatively impact time to conception in users but may provide additional benefits, including an increased understanding of the menstrual cycle, reassurance and confidence in focusing conception attempts to the correct time in the cycle. WHAT IS KNOWN ALREADY: It has been suggested that timing of intercourse in such a way that it coincides with ovulation by using ovulation tests can lead to emotional distress; however, no study has been conducted to investigate this hypothesis specifically, until now. STUDY DESIGN, SIZEAND DURATION: The study was performed over two complete menstrual cycles as a prospective, randomized, controlled trial including quantitative and qualitative methods. The intervention (test) group were given digital ovulation tests to time intercourse to the most fertile time of the cycle and the control group were provided with the current National Institute for Health and Clinical Excellence guidelines for increasing the chances of conception (intercourse every 2-3 days) and asked not to use any additional methods to time when ovulation occurs. PARTICIPANTS/MATERIALS, SETTING AND METHODS: A total of 210 women who were seeking to conceive were recruited from the general UK population. A total of 115 women were randomized to the test group and 95 to the control group through block randomization. The positive and negative affect schedule (PANAS) and the Perceived Stress Scale (PSS) were used to measure subjective stress levels, the Short-Form 12 health survey was used as a measure of general health and well-being and urine samples were measured for biochemical markers of stress including urinary cortisol. Qualitative data were collected in the form of a telephone interview upon study completion. MAIN RESULTS AND THE ROLE OF CHANCE: There was no evidence for a difference either in total stress as measured using the PSS or in total positive or negative affect using the PANAS questionnaire between the test and control groups at any time point for the duration of the study. During cycle 1, for example, on Day 6, the difference in total stress score (test-control) was -0.62 [95% confidence interval (CI) -2.47 to 1.24] and on the day of the LH surge, it was 0.53 (95% CI -1.38 to 2.44). In addition, no correlation was observed between time trying to conceive and levels of stress, or between age and levels of stress, and no evidence was found to show that stress affected whether or not a pregnancy was achieved. There is also no evidence that the biochemistry measurements are related to whether a pregnancy was achieved or of a difference in biochemistry between the treatment groups. The use of digital ovulation tests did not negatively affect time to conception and with an adequately sized study, could potentially show improvement. To ensure that the results of this study were not affected by chance, we used a number of different methods for measuring stress, each of which had been independently validated. LIMITATIONS AND REASONS FOR CAUTION: Randomization occurred before the start of the study because of the need to provide the ovulation tests in readiness for Day 6 of the first cycle. As a consequence, a number of women fell pregnant during this period (22 and 13 in the test and control groups, respectively). A further 15 women were either lost to follow-up or withdrew consent prior to study start. Pregnancy rate was higher overall in the test group, so to ensure that there were sufficient data from women who failed to become pregnant in the test group, we implemented an additional biased recruitment. This second cohort may have been different from the first, although no significant differences were observed between the two phases of recruitment for any of the information collected upon admission to the study. WIDER IMPLICATIONS OF THE FINDINGS: Women who seek medical advice while trying to conceive should not be discouraged by health care professionals from using digital ovulation tests in order to time intercourse. The cohort of women recruited to this study initially had no evidence of infertility and were looking to conceive in a non-medical setting. A separate study to assess the impact of home ovulation tests in a subfertile population would be of interest and complementary to the present study. STUDY FUNDING/COMPETING INTERESTS: This study was funded by SPD Swiss Precision Diagnostics, GmbH, manufacturer of Clearblue(®) pregnancy and ovulation tests. SPD Development Company Ltd is a wholly owned subsidiary of SPD Swiss Precision Diagnostics GmbH; together referred to as SPD. TRIAL REGISTRATION NUMBER: NCT01084304 (www.clinicaltrials.gov).
Human Reproduction 10/2012; · 4.47 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
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 tt[over ¯] 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 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, M_{top}=172.85±0.71(stat)±0.85(syst) GeV/c^{2}.
Physical Review Letters 10/2012; 109(15):152003. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at sqrt[s]=1.96 TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb^{-1}. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a b quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and 150 GeV/c^{2}. For a Higgs boson mass of 125 GeV/c^{2}, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.
Physical Review Letters 09/2012; 109(11):111805. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the standard model Higgs boson produced in association with a W boson in sqrt[s]=1.96 TeV pp[over ¯] collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45 fb^{-1}. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H→bb[over ¯] branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^{2}, we observe (expect) a limit of 4.9 (2.8) times the standard model value.
Physical Review Letters 09/2012; 109(11):111804. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb^{-1}. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H→bb[over ¯] branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^{2}, we observe (expect) a limit of 7.1 (3.9) times the standard model value.
Physical Review Letters 09/2012; 109(11):111803. · 7.37 Impact Factor
-
T Aaltonen,
B Alvarez González,
S Amerio,
D Amidei,
A Anastassov,
A Annovi,
J Antos,
G Apollinari,
J A Appel,
T Arisawa, [......],
K Yorita,
T Yoshida,
G B Yu,
I Yu,
S S Yu,
J C Yun,
A Zanetti,
Y Zeng,
C Zhou,
S Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We combine the results of searches for the standard model (SM) Higgs boson based on the full CDF Run II data set obtained from sqrt[s]=1.96 TeV pp[over ¯] collisions at the Fermilab Tevatron corresponding to an integrated luminosity of 9.45 fb^{-1}. The searches are conducted for Higgs bosons that are produced in association with a W or Z boson, have masses in the range 90-150 GeV/c^{2}, and decay into bb[over ¯] pairs. An excess of data is present that is inconsistent with the background prediction at the level of 2.5 standard deviations (the most significant local excess is 2.7 standard deviations).
Physical Review Letters 09/2012; 109(11):111802. · 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 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. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
T. Arisawa, [......],
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
C. Zhou,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the standard model Higgs boson produced in association with a W± boson. This search uses data corresponding to an integrated luminosity of 7.5 fb-1 collected by the CDF detector at the Tevatron. We select WH→ℓνbb̅ candidate events with two jets, large missing transverse energy, and exactly one charged lepton. We further require that at least one jet be identified to originate from a bottom quark. Discrimination between the signal and the large background is achieved through the use of a Bayesian artificial neural network. The number of tagged events and their distributions are consistent with the standard model expectations. We observe no evidence for a Higgs boson signal and set 95% C.L. upper limits on the WH production cross section times the branching ratio to decay to bb̅ pairs, σ(pp̅ →W±H)×B(H→bb̅ ), relative to the rate predicted by the standard model. For the Higgs boson mass range of 100 to 150 GeV/c2 we set observed (expected) upper limits from 1.34 (1.83) to 38.8 (23.4). For 115 GeV/c2 the upper limit is 3.64 (2.78). The combination of the present search with an independent analysis that selects events with three jets yields more stringent limits ranging from 1.12 (1.79) to 34.4 (21.6) in the same mass range. For 115 and 125 GeV/c2 the upper limits are 2.65 (2.60) and 4.36 (3.69), respectively.
Phys. Rev. D. 08/2012; 86(3).
-
T. Aaltonen,
M. Albrow,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel, [......],
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
C. Zhou,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report on a study of diffractive dijet production in p̅ p collisions at √s=1.96 TeV using the CDF II detector at the Fermilab Tevatron p̅ p collider. A data sample from 310 pb-1 of integrated luminosity collected by triggering on a high transverse energy jet, ETjet, in coincidence with a recoil antiproton detected in a Roman pot spectrometer is used to measure the ratio of single-diffractive to inclusive-dijet event rates as a function of xp̅ of the interacting parton in the antiproton, the Bjorken-x, xBjp̅ , and a Q2≈(ETjet)2 in the ranges 10-3<xBjp̅ <10-1 and 102<Q2<104 GeV2, respectively. Results are presented for the region of p̅ -momentum-loss fraction 0.03<ξp̅ <0.09 and a four-momentum transfer squared tp̅ >-4 GeV2. The tp̅ dependence is measured as a function of Q2 and xBjp̅ and compared with that of inclusive single diffraction dissociation. We find weak xBjp̅ and Q2 dependencies in the ratio of single diffractive to inclusive event rates, and no significant Q2 dependence in the diffractive tp̅ distributions.
Phys. Rev. D. 08/2012; 86(3).
-
T. Aaltonen,
B. Álvarez González,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel,
T. Arisawa, [......],
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
C. Zhou,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of time-integrated CP-violation asymmetries in the resonant substructure of the three-body decay D0→KS0π+π- using CDF II data corresponding to 6.0 fb-1 of integrated luminosity from Tevatron pp̅ collisions at √s=1.96 TeV. The charm mesons used in this analysis come from D*+(2010)→D0π+ and D*-(2010)→D̅ 0π-, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely, a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the D0 and D̅ 0 Dalitz plots. We find no CP-violation effects and measure an asymmetry of ACP=(-0.05±0.57(stat)±0.54(syst))% for the overall integrated CP-violation asymmetry, consistent with the standard model prediction.
Phys. Rev. D. 08/2012; 86(3).
-
M. Battaglia,
C. Da Via,
D. Bortoletto,
R. Brenner, M. Campbell,
P. Collins,
G. F. Dalla Betta,
P. Denes,
H. Graafsma,
I. M. Gregor,
A. Kluge,
V. Manzari,
C. Parkes,
V. Re,
P. Riedler,
G. Rizzo,
W. Snoeys,
M. Winter
[show abstract]
[hide abstract]
ABSTRACT: This report reviews current trends in the R&D of semiconductor pixellated
sensors for vertex tracking and radiation imaging. It identifies requirements
of future HEP experiments at colliders, needed technological breakthroughs and
highlights the relation to radiation detection and imaging applications in
other fields of science.
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).
-
The CDF,
collaborations,
T. Aaltonen,
V. M. Abazov,
B. Abbott,
B. S. Acharya,
M. Adams,
T. Adams,
G. D. Alexeev,
G. Alkhazov, [......],
J. Zennamo,
T. Zhao,
T. G. Zhao,
B. Zhou,
C. Zhou,
J. Zhu,
M. Zielinski,
D. Zieminska,
L. Zivkovic,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: The top quark is the heaviest known elementary particle, with a mass about 40
times larger than the mass of its isospin partner, the bottom quark. It decays
almost 100% of the time to a $W$ boson and a bottom quark. Using top-antitop
pairs at the Tevatron proton-antiproton collider, the CDF and {\dzero}
collaborations have measured the top quark's mass in different final states for
integrated luminosities of up to 5.8 fb$^{-1}$. This paper reports on a
combination of these measurements that results in a more precise value of the
mass than any individual decay channel can provide. It describes the treatment
of the systematic uncertainties and their correlations. The mass value
determined is $173.18 \pm 0.56 \thinspace ({\rm stat}) \pm 0.75 \thinspace
({\rm syst})$ GeV or $173.18 \pm 0.94$ GeV, which has a precision of $\pm
0.54%$, making this the most precise determination of the top quark mass.
07/2012;
-
CDF Collaboration,
T. Aaltonen,
B. Alvarez Gonzalez,
S. Amerio,
D. Amidei,
A. Anastassov,
A. Annovi,
J. Antos,
G. Apollinari,
J. A. Appel, [......],
K. Yorita,
T. Yoshida,
G. B. Yu,
I. Yu,
S. S. Yu,
J. C. Yun,
A. Zanetti,
Y. Zeng,
C. Zhou,
S. Zucchelli
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of time-integrated CP-violation asymmetries in the
resonant substructure of the three-body decay D0 to Ks pi+ pi- using CDF II
data corresponding to 6.0 invfb of integrated luminosity from Tevatron ppbar
collisions at sqrt(s) = 1.96 TeV. The charm mesons used in this analysis come
from D*+(2010) to D0 pi+ and D*-(2010) to D0bar pi-, where the production
flavor of the charm meson is determined by the charge of the accompanying pion.
We apply a Dalitz-amplitude analysis for the description of the dynamic decay
structure and use two complementary approaches, namely a full Dalitz-plot fit
employing the isobar model for the contributing resonances and a
model-independent bin-by-bin comparison of the D0 and D0bar Dalitz plots. We
find no CP-violation effects and measure an asymmetry of ACP = (-0.05 +- 0.57
(stat) +- 0.54 (syst))% for the overall integrated CP-violation asymmetry,
consistent with the standard model prediction.
07/2012;
