-
K. Abe,
N. Abgrall,
H. Aihara,
T. Akiri,
J. B. Albert,
C. Andreopoulos,
S. Aoki,
A. Ariga,
T. Ariga,
S. Assylbekov, [......],
N. Yershov,
M. Yokoyama,
Ì T. Yuan,
A. Zalewska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
and J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: T2K has performed the first measurement of \nu{\mu} inclusive charged current
interactions on carbon at neutrino energies of ~1 GeV where the measurement is
reported as a flux-averaged double differential cross section in muon momentum
and angle. The flux is predicted by the beam Monte Carlo and external data,
including the results from the NA61/SHINE experiment. The data used for this
measurement were taken in 2010 and 2011, with a total of 10.8 x 10^{19}
protons-on-target. The analysis is performed on 4485 inclusive charged current
interaction candidates selected in the most upstream fine-grained scintillator
detector of the near detector.
The flux-averaged total cross section is <\sigma_CC>_\phi =(6.91 +/- 0.13
(stat) +/- 0.84 (syst)) x10^{-39} cm^2/nucleon for a mean neutrino energy of
0.85 GeV.
02/2013;
-
Collaboration,
K. Abe,
N. Abgrall,
H. Aihara,
T. Akiri,
J. B. Albert,
C. Andreopoulos,
S. Aoki,
A. Ariga,
T. Ariga, [......],
N. Yershov,
M. Yokoyama,
T. Yuan,
A. Zalewska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an
off-axis muon neutrino beam with a peak energy of about 0.6 GeV that originates
at the J-PARC accelerator facility. Interactions of the neutrinos are observed
at near detectors placed at 280 m from the production target and at the far
detector -- Super-Kamiokande (SK) -- located 295 km away. The flux prediction
is an essential part of the successful prediction of neutrino interaction rates
at the T2K detectors and is an important input to T2K neutrino oscillation and
cross section measurements. A FLUKA and GEANT3 based simulation models the
physical processes involved in the neutrino production, from the interaction of
primary beam protons in the T2K target, to the decay of hadrons and muons that
produce neutrinos. The simulation uses proton beam monitor measurements as
inputs. The modeling of hadronic interactions is re-weighted using thin target
hadron production data, including recent charged pion and kaon measurements
from the NA61/SHINE experiment. For the first T2K analyses the uncertainties on
the flux prediction are evaluated to be below 15% near the flux peak. The
uncertainty on the ratio of the flux predictions at the far and near detectors
is less than 2% near the flux peak.
11/2012;
-
Heavy Flavor Averaging Group,
Y. Amhis,
Sw. Banerjee,
R. Bernhard,
S. Blyth,
A. Bozek,
C. Bozzi,
A. Carbone,
A. Oyanguren Campos,
R. Chistov, [......],
O. Schneider,
C. Schwanda,
A. J. Schwartz,
B. Shwartz,
J. G. Smith,
R. Tesarek,
D. Tonelli,
K. Trabelsi,
P. Urquijo,
R. Van Kooten
[show abstract]
[hide abstract]
ABSTRACT: This article reports world averages of measurements of b-hadron, c-hadron,
and tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG)
using results available through the end of 2011. In some cases results
available in the early part of 2012 are included. For the averaging, common
input parameters used in the various analyses are adjusted (rescaled) to common
values, and known correlations are taken into account. The averages include
branching fractions, lifetimes, neutral meson mixing parameters, CP violation
parameters, parameters of semileptonic decays and CKM matrix elements.
07/2012;
-
Breast Cancer Research 04/2012; 10:1-2. · 5.33 Impact Factor
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Collaboration,
K. Abe,
N. Abgrall,
Y. Ajima,
H. Aihara,
J. B. Albert,
C. Andreopoulos,
B. Andrieu,
M. D. Anerella,
S. Aoki, [......],
M. Yokoyama,
T. Yuan,
A. Zalewska,
J. Zalipska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of muon-neutrino disappearance in the T2K experiment.
The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation
of the off-axis technique in a long-baseline neutrino oscillation experiment.
With data corresponding to 1.43 10**20 protons on target, we observe 31
fully-contained single muon-like ring events in Super-Kamiokande, compared with
an expectation of 104 +- 14 (syst) events without neutrino oscillations. The
best-fit point for two-flavor nu_mu -> nu_tau oscillations is sin**2(2
theta_23) = 0.98 and |\Delta m**2_32| = 2.65 10**-3 eV**2. The boundary of the
90 % confidence region includes the points (sin**2(2 theta_23),|\Delta
m**2_32|) = (1.0, 3.1 10**-3 eV**2), (0.84, 2.65 10**-3 eV**2) and (1.0, 2.2
10**-3 eV**2).
01/2012;
-
K Abe,
N. Abgrall,
Y. Ajima,
H. Aihara,
J. B. Albert,
C. Andreopoulos,
B Andrieu,
M. D. Anerella,
S Aoki,
O. Araoka, [......],
M Yokoyama,
T Yuan,
A Zalewska,
J. Zalipska,
L. Zambelli,
K Zaremba,
M Ziembicki,
E. D. Zimmerman,
M Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: Precise measurement of neutrino beam direction and intensity was achieved
based on a new concept with modularized neutrino detectors. INGRID (Interactive
Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino
oscillation experiment. INGRID consists of 16 identical modules arranged in
horizontal and vertical arrays around the beam center. The module has a
sandwich structure of iron target plates and scintillator trackers. INGRID
directly monitors the muon neutrino beam profile center and intensity using the
number of observed neutrino events in each module. The neutrino beam direction
is measured with accuracy better than 0.4 mrad from the measured profile
center. The normalized event rate is measured with 4% precision.
11/2011;
-
K Abe,
N Abgrall,
Y Ajima,
H Aihara,
J B Albert,
C Andreopoulos,
B Andrieu,
S Aoki,
O Araoka,
J Argyriades, [......],
N Yershov,
M Yokoyama,
A Zalewska,
J Zalipska,
L Zambelli,
K Zaremba,
M Ziembicki,
E D Zimmerman,
M Zito,
J Żmuda
[show abstract]
[hide abstract]
ABSTRACT: The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.
Physical Review Letters 07/2011; 107(4):041801. · 7.37 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Future giant liquid argon (LAr) time projection chambers (TPCs) require a
purity of better than 0.1 parts per billion (ppb) to allow the ionised
electrons to drift without significant capture by any electronegative
impurities. We present a comprehensive study of the effects of electronegative
impurity on gaseous and liquid argon scintillation light, an analysis of the
efficacy of various purification chemicals, as well as the Liverpool LAr setup,
which utilises a novel re-circulation purification system. Of the impurities
tested - Air, O_2, H_2O, N_2 and CO_2 in the range of between 0.01 ppm to 1000
ppm - H_2O was found to have the most profound effect on gaseous argon
scintillation light, and N_2 was found to have the least. Additionally, a
correlation between the slow component decay time and the total energy
deposited with 0.01 ppm - 100 ppm O_2 contamination levels in liquid argon has
been established. The superiority of molecular sieves over anhydrous complexes
at absorbing Ar gas, N_2 gas and H_2O vapour has been quantified using BET
isotherm analysis. The efficiency of Cu and P_2O5 at removing O_2 and H_2O
impurities from 1 bar N6 argon gas at both room temperature and -130 ^oC was
investigated and found to be high. A novel, highly scalable LAr re-circulation
system has been developed. The complete system, consisting of a motorised
bellows pump operating in liquid and a purification cartridge, were designed
and built in-house. The system was operated successfully over many days and
achieved a re-circulation rate of 27 litres/hour and high purity.
06/2011;
-
Collaboration,
N. Abgrall,
H. Aihara,
Y. Ajima,
J. B. Albert,
D. Allan,
P. -A. Amaudruz,
C. Andreopoulos,
B. Andrieu,
M. D. Anerella, [......],
S. Yen,
N. Yershov,
M. Yokoyama,
A. Zalewska,
J. Zalipska,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: The T2K experiment is a long-baseline neutrino oscillation experiment. Its
main goal is to measure the last unknown lepton sector mixing angle
{\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also
aims to make a precision measurement of the known oscillation parameters,
{\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance
studies. Other goals of the experiment include various neutrino cross section
measurements and sterile neutrino searches. The experiment uses an intense
proton beam generated by the J-PARC accelerator in Tokai, Japan, and is
composed of a neutrino beamline, a near detector complex (ND280), and a far
detector (Super-Kamiokande) located 295 km away from J-PARC. This paper
provides a comprehensive review of the instrumentation aspect of the T2K
experiment and a summary of the vital information for each subsystem.
06/2011;
-
ArDM Collaboration,
A. Marchionni,
C Amsler,
A. Badertscher,
V. Boccone,
A. Bueno,
M. C. Carmona-Benitez, J Coleman,
W. Creus,
A. Curioni, [......],
J Rochet,
L Romero,
E Rondio,
A. Rubbia,
L. Scotto Lavina,
N. J. C. Spooner,
T. Strauss,
C Touramanis,
J Ulbricht,
T. Viant
[show abstract]
[hide abstract]
ABSTRACT: The Argon Dark Matter (ArDM-1t) experiment is a ton-scale liquid argon (LAr) double-phase time projection chamber designed for direct Dark Matter searches. Such a device allows to explore the low energy frontier in LAr with a charge imaging detector. The ionization charge is extracted from the liquid into the gas phase and there amplified by the use of a Large Electron Multiplier in order to reduce the detection threshold. Direct detection of the ionization charge with fine spatial granularity, combined with a measurement of the amplitude and time evolution of the associated primary scintillation light, provide powerful tools for the identification of WIMP interactions against the background due to electrons, photons and possibly neutrons if scattering more than once. A one ton LAr detector is presently installed on surface at CERN to fully test all functionalities and it will be soon moved to an underground location. We will emphasize here the lessons learned from such a device for the design of a large LAr TPC for neutrino oscillation, proton decay and astrophysical neutrinos searches. Comment: To appear in Proceedings 1st International Workshop towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba, March 2010
12/2010;
-
The Heavy Flavor Averaging Group,
D. Asner,
Sw Banerjee,
R Bernhard,
S Blyth,
A. Bozek,
C Bozzi,
D. G. Cassel,
G Cavoto,
G Cibinetto, [......],
O. Schneider,
C. Schwanda,
A. J. Schwartz,
B. Shwartz,
J G Smith,
R Tesarek,
D Tonelli,
K. Trabelsi,
P. Urquijo,
R Van Kooten
[show abstract]
[hide abstract]
ABSTRACT: This article reports world averages for measurements of b-hadron, c-hadron,
and tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG)
using results available at least through the end of 2009. Some of the world
averages presented use data available through the spring of 2010. For the
averaging, common input parameters used in the various analyses are adjusted
(rescaled) to common values, and known correlations are taken into account. The
averages include branching fractions, lifetimes, neutral meson mixing
parameters, CP violation parameters, and parameters of semileptonic decays.
10/2010;
-
A. Curioni,
L. Epprecht,
A. Gendotti,
L. Knecht,
D. Lussi,
A. Marchionni,
G. Natterer,
F. Resnati,
A. Rubbia, J Coleman,
M. Lewis,
K. Mavrokoridis,
K. McCormick,
C Touramanis
[show abstract]
[hide abstract]
ABSTRACT: In this paper we present a successful experimental test of filling a volume
of 6 m$^3$ with argon gas, starting from normal ambient air and reducing the
impurities content down to few parts per million (ppm) oxygen equivalent. This
level of contamination was directly monitored measuring the slow component of
the scintillation light of the Ar gas, which is sensitive to {\it all} sources
of impurities affecting directly the argon scintillation.
09/2010;
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We search for a light Higgs boson A0 in the radiative decay Upsilon(3S)-->gammaA(0), A(0)-->tau+tau-, tau+-->e+nu(e)nu(tau), or tau+-->mu+nu(mu)nu(tau). The data sample contains 122x10(6) Upsilon(3S) events recorded with the BABAR detector. We find no evidence for a narrow structure in the studied tau+tau- invariant mass region of 4.03<m(tau+tau-)<10.10 GeV/c2. We exclude at the 90% confidence level (C.L.) a low-mass Higgs boson decaying to tau+tau- with a product branching fraction B(Upsilon(3S)-->gammaA(0))xB(A(0)-->tau+tau-)>(1.5-16)x10(-5) across the m(tau+tau-) range. We also set a 90% C.L. upper limit on the tau+tau- decay of the eta(b) at B(eta(b)-->tau+tau-)<8%.
Physical Review Letters 10/2009; 103(18):181801. · 7.37 Impact Factor
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B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We report an analysis of tau;{-} decaying into omegapi;{-}nu_{tau} with omega --> pi;{+}pi;{-}pi;{0} using a data sample containing nearly 320 x 10;{6}tau pairs collected with the BABAR detector at the PEP-II B-Factory. We find no evidence for second-class currents, and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this decay mode.
Physical Review Letters 07/2009; 103(4):041802. · 7.37 Impact Factor
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B Aubert,
M Bona,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges, [......],
G B Mohanty,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
M Pierini,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: In a search for B-->cc[over ]gammaK decays with the BABAR detector, where cc[over ] includes J/psi and psi(2S), and K includes K(+/-), K(S)(0), and K(*)(892), we find evidence for X(3872)-->J/psigamma and X(3872)-->psi(2S)gamma with 3.6sigma and 3.5sigma significance, respectively. We measure the product of branching fractions B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->J/psigamma)=[2.8+/-0.8(stat)+/-0.1(syst)]x10(-6) and B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->psi(2S)gamma)=[9.5+/-2.7(stat)+/-0.6(syst)]x10(-6).
Physical Review Letters 05/2009; 102(13):132001. · 7.37 Impact Factor
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Bju International. 01/2009; 103:45-45.
-
Bju International. 01/2009; 103:18-18.
-
Bju International. 01/2009; 103:3-3.
-
B Aubert,
M Bona,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges, [......],
G B Mohanty,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
M Pierini,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We report a measurement of the branching fractions of B-->D**(l) nu(l), decays based on 417 fb(-1) of data collected at the Y(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are selected by full reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D(*) pi)- m(D(*)) is performed to extract the signal yields of the different D** states. We observe the B-->D**l(-1)nu(l) decay modes corresponding to the four D states predicted by heavy quark symmetry with a significance greater than 5 standard deviations including systematic uncertainties.
Physical Review Letters 12/2008; 101(26):261802. · 7.37 Impact Factor
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B Aubert,
M Bona,
Y Karyotakis,
J P Lees,
V Poireau,
X Prudent,
V Tisserand,
A Zghiche,
J Garra Tico,
E Grauges, [......],
H R Band,
X Chen,
S Dasu,
K T Flood,
P E Kutter,
Y Pan,
M Pierini,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We perform a measurement of the CP asymmetry in b-->sgamma decays using a sample of 383 x 10(6) B[over] B events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X_(s) containing an s quark. We measure the CP asymmetry to be -0.011+/-0.030(stat)+/-0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c(2).
Physical Review Letters 10/2008; 101(17):171804. · 7.37 Impact Factor
