12 research outputs found
Measurement of the single pi(0) production rate in neutral current neutrino interactions on water
The single Ï0 production rate in neutral current neutrino interactions on water in a neutrino beam with a peak neutrino energy of 0.6 GeV has been measured using the PĂD, one of the subdetectors of the T2K near detector. The production rate was measured for data taking periods when the PĂD contained water (2.64Ă10(20) protons-on-target) and also periods without water (3.49Ă10(20) protons-on-target). A measurement of the neutral current single Ï0 production rate on water is made using appropriate subtraction of the production rate with water in from the rate with water out of the target region. The subtraction analysis yields 106 ± 41 ± 69 signal events where the uncertainties are statistical (stat.) and systematic (sys.) respectively. This is consistent with the prediction of 157 events from the nominal simulation. The measured to expected ratio is 0.68 ± 0.26 (stat) ± 0.44 (sys) ± 0.12 (flux). The nominal simulation uses a flux integrated cross section of 7.63Ă10(â39)cm(2) per nucleon with an average neutrino interaction energy of 1.3 GeV
Characterization of nuclear effects in muon-neutrino scattering on hydrocarbon with a measurement of final-state kinematics and correlations in charged-current pionless interactions at T2K
This paper reports measurements of final-state proton multiplicity, muon and proton kinematics, and
their correlations in charged-current pionless neutrino interactions, measured by the T2K ND280 near
detector in its plastic scintillator (C8H8) target. The data were taken between years 2010 and 2013,
corresponding to approximately 6 Ă 1020 protons on target. Thanks to their exploration of the proton
kinematics and of imbalances between the proton and muon kinematics, the results offer a novel probe of
the nuclear-medium effects most pertinent to the (sub-)GeV neutrino-nucleus interactions that are used in
accelerator-based long-baseline neutrino oscillation measurements. These results are compared to many
neutrino-nucleus interaction models which all fail to describe at least part of the observed phase space.
In case of events without a proton above a detection threshold in the final state, a fully consistent
implementation of the local Fermi gas model with multinucleon interactions gives the best description of
the data. In the case of at least one proton in the final state, the spectral function model agrees well with the
data, most notably when measuring the kinematic imbalance between the muon and the proton in the plane
transverse to the incoming neutrino. Within the models considered, only the existence of multinucleon
interactions are able to describe the extracted cross section within regions of high transverse kinematic
imbalance. The effect of final-state interactions is also discussed
Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2 x 10(21) Protons on Target
The T2K experiment measures muon neutrino disappearance and electron neutrino
appearance in accelerator-produced neutrino and antineutrino beams. With an
exposure of protons on target in neutrino
(antineutrino) mode, 89 candidates and 7 anti- candidates were
observed while 67.5 and 9.0 are expected for and normal mass
ordering. The obtained confidence interval for the violating
phase, , does not include the -conserving cases
(). The best-fit values of other parameters are
and .Comment: 9 pages, 6 figure
Search for heavy neutrinos with the T2K near detector ND280
International audienceThis paper reports on the search for heavy neutrinos with masses in the range 140<MN<493ââMeV/c2 using the off-axis near detector ND280 of the T2K experiment. These particles can be produced from kaon decays in the standard neutrino beam and then subsequently decay in ND280. The decay modes under consideration are Nââα±Ïâ and Nââα+âÎČ-Îœ(â)(α,ÎČ=e,ÎŒ). A search for such events has been made using the Time Projection Chambers of ND280, where the background has been reduced to less than two events in the current dataset in all channels. No excess has been observed in the signal region. A combined Bayesian statistical approach has been applied to extract upper limits on the mixing elements of heavy neutrinos to electron-, muon- and tau- flavored currents (Ue2, UÎŒ2, UÏ2) as a function of the heavy neutrino mass, e.g., Ue2<10-9 at 90% C.L. for a mass of 390ââMeV/c2. These constraints are competitive with previous experiments
Electroweak parameters of the z0 resonance and the standard model
Contains fulltext :
124399.pdf (publisher's version ) (Open Access
Measurement of inclusive double-differential ΜΌ charged-current cross section with improved acceptance in the T2K off-axis near detector
We report a measurement of the flux-integrated cross section for inclusive muon neutrino chargedcurrent interactions on carbon. The double-differential measurements are given as a function of the muon momentum and angle. Relative to our previous publication on this topic, these results have an increased angular acceptance and higher statistics. The data sample presented here corresponds to 5.7 Ă 1020 protons on target. The total flux-integrated cross section is measured to be Ă°6.950 0.662Ă Ă 10â39 cm2 nucleonâ1 and is consistent with our simulation
Search for heavy neutrinos with the T2K near detector ND280
This paper reports on the search for heavy neutrinos with masses in the range 140 < M_N < 493 MeV/c using the off-axis near detector ND280 of the T2K experiment. These particles can be produced from kaon decays in the standard neutrino beam and then subsequently decay in ND280. The decay modes under consideration are and (). A search for such events has been made using the Time Projection Chambers of ND280, where the background has been reduced to less than two events in the current dataset in all channels. No excess has been observed in the signal region. A combined Bayesian statistical approach has been applied to extract upper limits on the mixing elements of heavy neutrinos to electron-, muon- and tau- flavoured currents (, , ) as a function of the heavy neutrino mass, e.g. U_e^2 < 10^{-9} at C.L. for a mass of MeV/c. These constraints are competitive with previous experiments
Measurement of the muon neutrino charged-current single Ï+ production on hydrocarbon using the T2K off-axis near detector ND280
We report the measurements of the single and double differential cross section of muon neutrino charged-current interactions on carbon with a single positively charged pion in the final state at the T2K off-axis near detector using 5.56Ă1020 protons on target. The analysis uses data control samples for the background subtraction and the cross section signal, defined as a single negatively charged muon and a single positively charged pion exiting from the target nucleus, is extracted using an unfolding method. The model-dependent cross section, integrated over the T2K off-axis neutrino beam spectrum peaking at 0.6 GeV, is measured to be Ï=(11.76±0.44(stat)±2.39(syst))Ă10-40ââcm2ânucleon-1. Various differential cross sections are measured, including the first measurement of the Adler angles for single charged pion production in neutrino interactions with heavy nuclei target.We report the measurements of single and double differential cross section of muon neutrino charged-current interactions on carbon with a single positively charged pion in the final state at the T2K off-axis near detector using protons on target. The analysis uses data control samples for the background subtraction and the cross section signal, defined as a single negatively charged muon and a single positively charged pion exiting from the target nucleus, is extracted using an unfolding method. The model dependent cross section, integrated over the T2K off-axis neutrino beam spectrum peaking at ~GeV, is measured to be ~. Various differential cross sections are measured, including the first measurement of the Adler angles for single charged pion production in neutrino interactions with heavy nuclei target