-
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker,
P. R. Burchat, [......],
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
S. M. Yang,
D. Yi,
S. Yoshida,
R. Zaliznyak,
C. Zhang,
W. M. Dunwoodie
Physical review D: Particles and fields 08/2006; 74(5):59901.
-
E M Aitala,
S Amato,
J C Anjos,
J A Appel,
D Ashery,
S Banerjee,
I Bediaga,
G Blaylock,
S B Bracker,
P R Burchat, [......],
S Watanabe,
R Weiss-Babai,
J Wiener,
N Witchey,
E Wolin,
S M Yang,
D Yi,
S Yoshida,
R Zaliznyak,
C Zhang
[show abstract]
[hide abstract]
ABSTRACT: We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.
Physical Review Letters 09/2002; 89(12):121801. · 7.37 Impact Factor
-
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker,
P. R. Burchat, [......],
S. Watanabe,
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
S. M. Yang,
D. Yi,
S. Yoshida,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: Using data from the E791 fixed-target hadroproduction experiment at Fermilab, we have studied the Cabibbo-favored but phase-space-suppressed decay D0→K-K-K+π+. We find the decay rate for this mode to be (0.54±0.16±0.08)×10-2 times that for the normalization mode D0→K-π-π+π+. We observe a clear signal for D0→φK-π+ which is consistent with producing 0.7±0.3 of the D0→K-K-K+π+ signal. In the context of simple models, we use our measurements to estimate the importance of decay amplitudes that produce extra quark-antiquark pairs from the vacuum relative to those that do not.
Phys. Rev. D. 11/2001; 64(11).
-
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker,
P. R. Burchat, [......],
S. Watanabe,
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
S.M. Yang,
D. Yi,
S. Yoshida,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: We present a study of correlations between D and
[`(D)]{\overline D}
mesons produced in 500 GeV/cπ−-nucleon interactions, based on data from experiment E791 at Fermilab. We have fully reconstructed 791 44 charm meson pairs to study correlations between the transverse and longitudinal momenta of the two D mesons and the relative production rates for different types of D meson pairs. We see slight correlations between the longitudinal momenta of the D and the
[`(D)]{\bar D}
, and significant correlations between the azimuthal angle of the D and the
[`(D)]{\bar D}
. The experimental distributions are compared to a next-to-leading-order QCD calculation and to predictions of the PYTHIA/JETSET Monte Carlo event generator. We observe less correlation between transverse momenta and different correlations between longitudinal momenta than these models predict for the default values of the model parameters. Better agreement between data and theory might be achieved by tuning the model parameters or by adding higher order perturbative terms, thus contributing to a better understanding of charm production.The relative production rates for the four sets of charm pairs,
D0[`(D)]0, D0 D-, D+[`(D)]0, D+ D-D^0{{\overline D}^0}, D^0 D^{-}, D^+{{\overline D}^0}, D^+ D^{-}
as calculated in the PYTHIA/JETSET event generator with the default parameters, agree with data as far as the relative ordering, but predict too many
D+ [`(D)]0D^+ {{\overline D}^0}
pairs and too few
D+ D-D^+ D^{-}
pairs.
EPJ direct 11/2000; 1(1):1-67.
-
Fermilab Collaboration,
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker, [......],
S. Watanabe,
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
S. M. Yang,
D. Yi,
S. Yoshida,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: We have searched for evidence of the production and decay of a neutral
bound-state pentaquark, one of a predicted doublet of states:
P0c¯s=c¯suud> and
P-c¯s=c¯sddu>. Specifically, we have
searched for the decay
P0c¯s-->K*0K-p in
data from Fermilab experiment E791, in which a 500 GeV/c
π- beam interacted with nuclear targets. We find
mass-dependent upper limits at the 90% confidence level for the ratio of
cross section times branching fraction of this decay relative to that
for the decay
Ds--->K*0K-. The upper
limits vary between 0.016 and 0.036 for
M(P0c¯s) between 2.75 and 2.91
GeV/c2, assuming a pentaquark lifetime of 0.4 ps.
Physics Letters B 01/1999; 448:303-310. · 3.95 Impact Factor
-
Fermilab Collaboration,
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker, [......],
S. Watanabe,
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
D. Yi,
S. M. Yang,
S. Yoshida,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: The form factor ratios rV=V(0)/A1(0),
r2=A2(0)/A1(0) and
r3=A3(0)/A1(0) in the decay
D+-->K¯*0l +νl,
K¯*0-->K-π+ have been
measured using data from charm hadroproduction experiment E791 at
Fermilab. From 3034 (595) signal (background) events in the muon
channel, we obtain rV=1.84+/-0.11+/-0.09,
r2=0.75+/-0.08+/-0.09 and, as a first measurement of
r3, we find 0.04+/-0.33+/-0.29. The values of the form factor
ratios rV and r2 measured for the muon channel are
combined with the values of rV and r2 that we have
measured in the electron channel. The combined E791 results for the muon
and electron channels are rV=1.87+/-0.08+/-0.07 and
r2=0.73+/-0.06+/-0.08.
Physics Letters B 10/1998; 440:435-441. · 3.95 Impact Factor
-
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock,
S. B. Bracker,
P. R. Burchat, [......],
A. K. Tripathi,
S. Watanabe,
R. Weiss-Babai,
J. Wiener,
N. Witchey,
E. Wolin,
D. Yi,
S. Yoshida,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of the branching ratio B(D+ ->
ρ0 l+ νl)/B(D+ ->
K*0 l+ νl) from the Fermilab charm
hadroproduction experiment E791. Based on signals of 49 +/- 17 events in
the D+ -> ρ0 e+ νe
mode and 54 +/- 18 events in the D+ -> ρ0
μ+ νμ mode, we measureB(D+
-> ρ0 e+ νe)/B(D+
-> K*0 e) νe) = 0.045 +/- 0.014
+/- 0.009,B(D+ -> ρ0 μ+
νμ)/B(D+ -> K*0
μ+ νμ) = 0.051 +/- 0.015 +/- 0.009.
Combining the results from both the electronic and muonic modes, we
obtainB(D+ -> ρ0 l+
νl)/B(D+ -> K*0 l+
νl) = 0.047 +/- 0.013. This result is compared to
theoretical predictions.
Physics Letters B 01/1997; 397:325-332. · 3.95 Impact Factor
-
E. M. Aitala,
S Amato,
J. C. Anjos,
J A Appel,
M. Aryal,
D. Ashery,
J. Astorga,
S Banerjee,
I. Bediaga,
G Blaylock, [......],
K Thorne,
A K Tripathi,
S Watanabe,
R Weiss-Babai,
J Wiener,
N Witchey,
E Wolin,
D Yi,
R Zaliznyak,
C Zhang
[show abstract]
[hide abstract]
ABSTRACT: We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.
02/1996;
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
C. Baltay,
A. Bean,
R. Ben-David,
T. Bienz,
F. Bird,
D.O. Caldwell, [......],
J. Va'vra,
T. Weber,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
S. Willocq,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: We present the Cherenkov ring imaging detector in the endcap
regions of the SLD detector and report initial performance. The endcap
CRID was completed and commissioned in 1993 and is fully operational for
the 1994 run. First Cherenkov rings have been observed. The endcap CRID
detectors and fluid systems are described and initial operational
experience is discussed
IEEE Transactions on Nuclear Science 09/1995; · 1.45 Impact Factor
-
A. Nguyen,
E. M. Aitala,
S. Amato,
J. C. Anjos,
J. A. Appel,
M. Aryal,
D. Ashery,
S. Banerjee,
I. Bediaga,
G. Blaylock, [......],
K. Thorne,
A. K. Tripathi,
S. Watanabe,
R. Weiss,
J. Wiener,
N. Witchey,
E. Wolin,
D. Yi,
R. Zaliznyak,
C. Zhang
[show abstract]
[hide abstract]
ABSTRACT: Fermilab E791 is a high statistics charm experiment using a 500 GeV/c π− beam incident on a segmented target. We present results based on one third of the 1991‐1992 data, with particular emphasis on a search for the flavor changing neutral current decay D+→π+μ+μ−. © 1995 American Institute of Physics.
AIP Conference Proceedings. 07/1995; 338(1):777-780.
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
R. Ben-David,
T. Bienz,
F. Bird,
D.O. Caldwell,
M. Cavalli-Sforza, [......],
J. Turk,
J. Va'vra,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
S. Willocq,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: We report on operational experience with and experimental
performance of the SLD barrel Cherenkov Ring Imaging Detector from the
1992 and 1993 physics runs. The liquid (C<sub>6</sub>F<sub>14</sub>) and
gas (C<sub>5</sub>F<sub>12</sub>) radiator recirculation systems have
performed well, and the drift gas supply system has operated
successfully with TMAE for three years. Cherenkov rings have been
observed from both the liquid and gas radiators. The number and angular
resolution of Cherenkov photons have been measured, and found to be
close to design specifications
IEEE Transactions on Nuclear Science 09/1994; · 1.45 Impact Factor
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
R. Ben-David,
T. Bienz,
F. Bird,
D.O. Caldwell,
M. Cavalli-Sforza, [......],
N. Toge,
J. Turk,
J. Va'vra,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: The SLD is an e<sup>+</sup>e<sup>-</sup> spectrometer designed for
Z<sup>0</sup> physics. The SLD Cherenkov Ring Imaging Detector (CRID)
has been designed to provide charged particle identification that allows
π/K/p separation up to 30 GeV/c and e/π separation up to 6 GeV/c.
The detector was fully operational in the 1992 physics data run. The
electron drift velocity and magnetic field deflection of electron
trajectories have been measured. Cherenkov rings have been observed from
both the liquid and gas radiators. The number and the resolution of the
angle of Cherenkov photons have been determined to be approximately
equal to design specifications
IEEE Transactions on Nuclear Science 09/1993; · 1.45 Impact Factor
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
R. Ben-David,
T. Bienz,
F. Bird,
D.O. Caldwell,
M. Cavalli-Sforza, [......],
J. Va'vra,
R. Watt,
T. Weber,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: The design and operation of the fluid delivery, monitor, and
control systems for the SLD barrel Cherenkov Ring Imaging Detector
(CRID) are described. The systems deliver drift gas
(C<sub>2</sub>H<sub>6</sub>+TMAE), radiator gas (C<sub>5</sub>F<sub>12
</sub>+N<sub>2</sub>), and radiator liquid
(C<sub>6</sub>F<sub>14</sub>). Measured critical quantities such as
electron lifetime in the drift gas and ultraviolet (UV) transparencies
of the radiator fluids, together with the operational experience, are
reported
IEEE Transactions on Nuclear Science 09/1993; · 1.45 Impact Factor
-
P Antilogus,
D Aston,
T Bienz,
F Bird,
S Dasu,
S. Dolinsky,
W Dunwoodie,
G. Hallewell,
H Kawahara,
Y Kwon, [......],
K Baird,
P Jacques,
M Kalelkar,
R Plano,
P Stamer,
G. Word,
K Abe,
K Hasegawa,
F Suekane,
H Yuta
[show abstract]
[hide abstract]
ABSTRACT: Summary form only. The performance of the Cherenkov Ring Imaging Detector (CRID) of the SLD experiment at the SLAC linear collider during the 1992 physics data run is discussed. The barrel CRID is complete and fully operational. Cherenkov rings have been observed from both the liquid and the gas radiators. The rings are associated with particle tracks measured in the central drift chamber and the radius of the ring together with the momentum measurement is used to identify particles. Work is in progress to improve the resolution by better determining the position of the drift boxes, the mirrors, and the central drift chamber relative to one other using data from cosmic rays and Z <sup>0 </sup> chambers
Nuclear Science Symposium and Medical Imaging Conference, 1992., Conference Record of the 1992 IEEE; 11/1992
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
T. Bienz,
F. Bird,
D. Caldwell,
M. Cavalli-Sforza,
P. Coyle, [......],
N. Toge,
J. Va'vra,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
M. Witherell,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: The front-end electronics and data acquisition system for the SLD
barrel Cherenkov ring imaging detector (CRID) are described. The
specifications for this system require a 1% charge division measurement
on single e<sup>-</sup> pulses from a wire chamber in the presence of
much larger signals. Fast recovery from saturating pulses and noise
levels below 2000 electrons root-mean-square for single electron pulses
are required. Noise and system performance results are presented for the
initial SLD engineering run data
IEEE Transactions on Nuclear Science 09/1992; · 1.45 Impact Factor
-
J. Va’vra,
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
R. Ben‐David,
T. Bienz,
F. Bird,
D. O. Caldwell, [......],
F. Suekane,
N. Toge,
J. Turk,
J. S. Whitaker,
D. A. Williams,
S. H. Williams,
R. J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: We report first results from the initial physics run of the Cherenkov Ring Imaging Detector (CRID) in the SLD experiment at the SLC. We describe the experimental conditions, show liquid and gas rings, report the number of photoelectrons per ring, and comment on resolution.
AIP Conference Proceedings. 02/1992; 272(2):1664-1670.
-
K. Abe,
P. Antilogus,
D. Aston,
K. Baird,
A. Bean,
T. Bienz,
F. Bird,
D. Caldwell,
M. Cavalli-Sforza,
P. Coyle, [......],
N. Toge,
J. Va'vra,
J.S. Whitaker,
D.A. Williams,
S.H. Williams,
M. Witherell,
R.J. Wilson,
G. Word,
S. Yellin,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: All of the major subsystems for the barrel Cerenkov Ring Imaging Detector (CRID) in the SLAC Large Detector (SLD) at Stanford Linear Accelerator Center (SLAC) have now been commissioned. The CRID participated in the SLD engineering run of June-August 1991. In a cosmic ray test at the end of the run, Cerenkov rings were observed for the first time. Initial data for the CRID, including Cerenkov rings, studies of minimum ionizing particles, and data from the fiber optics calibration system are presented. The SLD engineering run and the ensuing dedicated CRID test runs have demonstrated that the system behaves as expected. It has been possible to track particles using ionization in the drift boxes and to reconstruct single electron coordinates very well. The runs have also enabled debugging of this complex system.< >
Nuclear Science Symposium and Medical Imaging Conference, 1991., Conference Record of the 1991 IEEE; 12/1991
-
P Antilogus,
D Aston,
T Bienz,
F Bird,
S Dasu,
S. Dolinsky,
W Dunwoodie,
G. Hallewell,
H Kawahara,
Y Kwon, [......],
K Baird,
P Jacques,
M Kalelkar,
R Plano,
P Stamer,
G. Word,
K Abe,
K Hasegawa,
F Suekane,
H Yuta
[show abstract]
[hide abstract]
ABSTRACT: Summary form only given. The SLAC Large Detector (SLD) barrel Cerenkov ring imaging detector (CRID) is now complete and has participated in SLD data runs. Performance tests of the drift boxes and detectors both in the SLD and in separate test stands have been performed. Tests in SLD with the fiber-optic calibration system include the demonstration and measurement of electron drift paths, checks of the anode wire calibration, and the performance of the fiber-optic system in general. Other tests include measurements of the uniformity of TMAE concentration in a drift box and measurements of single electron diffusion and photon feedback in three drift gases
Nuclear Science Symposium and Medical Imaging Conference, 1991., Conference Record of the 1991 IEEE; 12/1991
-
P. Antilogus,
D. Aston,
T. Bienz,
F. Bird,
S. Dasu,
W. Dunwoodie,
G. Hallewell,
H. Kawahara,
Y. Kwon,
D. Leith, [......],
M. Nussbaum, A.K.S. Santha,
A. Shoup,
I. Stockdale,
P. Jacques,
R. Plano,
P. Stamer,
K. Abe,
K. Hasegawa,
H. Yuta
[show abstract]
[hide abstract]
ABSTRACT: The front-end electronics of the Cerenkov Ring Imaging Detector
(CRID) used in the Stanford Large Detector (SLD) spectrometer at the
Stanford Linear Accelerator Center (SLAC) Linear Collider is described.
The Plessey process provides a straightforward and low-cost path toward
system miniaturization. System tests show good noise performance,
calibration precision, system linearity, and signal shape uniformity
over the full dynamic range
IEEE Transactions on Nuclear Science 05/1991; · 1.45 Impact Factor
-
P. Antilogus,
D. Aston,
T. Bienz,
F. Bird,
S. Dasu,
W. Dunwoodie,
G. Hallewell,
H. Kawahara,
Y. Kwon,
D. Leith, [......],
M. Nussbaum, A.K.S. Santha,
A. Shoup,
I. Stockdale,
P. Jacques,
R. Plano,
P. Stamer,
K. Abe,
K. Hasegawa,
H. Yuta
Nuclear Science Symposium, 1990. Conference record : Including Sessions on Nuclear Power Systems and Medical Imaging Conference, 1990 IEEE; 11/1990
