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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title Search for neutral-current induced single photon production at the ND280 near detector in T2K Type Journal Article
Year 2019 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume 46 Issue 8 Pages 08LT01 - 16pp
Keywords T2K; neutrino; neutrino oscillation; neutrino interaction; Mini-BooNE; CP violation
Abstract Neutrino neutral-current (NC) induced single photon production is a sub-leading order process for accelerator-based neutrino beam experiments including T2K. It is, however, an important process to understand because it is a background for electron (anti)neutrino appearance oscillation experiments. Here, we performed the first search of this process below 1 GeV using the fine-grained detector at the T2K ND280 off-axis near detector. By reconstructing single photon kinematics from electron-positron pairs, we achieved 95% pure gamma ray sample from 5.738 x 10(20) protons-on-targets neutrino mode data. We do not find positive evidence of NC induced single photon production in this sample. We set the model-dependent upper limit on the cross-section for this process, at 0.114 x 10(-38) cm(2) (90% C.L.) per nucleon, using the J-PARC off-axis neutrino beam with an average energy of < E-v > similar to 0.6 GeV. This is the first limit on this process below 1 GeV which is important for current and future oscillation experiments looking for electron neutrino appearance oscillation signals.
Address [Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000518888100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4318
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 124 Issue 16 Pages 161802 - 8pp
Keywords
Abstract Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40s and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.
Address [Bravo Berguno, D.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000527135200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4379
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title Constraint on the matter-antimatter symmetry-violating phase in neutrino oscillations Type Journal Article
Year 2020 Publication Nature Abbreviated Journal Nature
Volume 580 Issue 7803 Pages 339-344
Keywords
Abstract The charge-conjugation and parity-reversal (CP) symmetry of fundamental particles is a symmetry between matter and antimatter. Violation of this CP symmetry was first observed in 1964(1), and CP violation in the weak interactions of quarks was soon established(2). Sakharov proposed(3) that CP violation is necessary to explain the observed imbalance of matter and antimatter abundance in the Universe. However, CP violation in quarks is too small to support this explanation. So far, CP violation has not been observed in non-quark elementary particle systems. It has been shown that CP violation in leptons could generate the matter-antimatter disparity through a process called leptogenesis(4). Leptonic mixing, which appears in the standard model's charged current interactions(5,6), provides a potential source of CP violation through a complex phase dCP, which is required by some theoretical models of leptogenesis(7-9). This CP violation can be measured in muon neutrino to electron neutrino oscillations and the corresponding antineutrino oscillations, which are experimentally accessible using accelerator-produced beams as established by the Tokai-to-Kamioka (T2K) and NOvA experiments(10,11). Until now, the value of dCP has not been substantially constrained by neutrino oscillation experiments. Here we report a measurement using long-baseline neutrino and antineutrino oscillations observed by the T2K experiment that shows a large increase in the neutrino oscillation probability, excluding values of dCP that result in a large increase in the observed antineutrino oscillation probability at three standard deviations (3 sigma). The 3 sigma confidence interval for delta(CP), which is cyclic and repeats every 2p, is [-3.41, -0.03] for the so-called normal mass ordering and [-2.54, -0.32] for the inverted mass ordering. Our results indicate CP violation in leptons and our method enables sensitive searches for matter-antimatter asymmetry in neutrino oscillations using accelerator-produced neutrino beams. Future measurements with larger datasets will test whether leptonic CP violation is larger than the CP violation in quarks.
Address [Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain
Corporate Author Thesis
Publisher Nature Publishing Group Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes WOS:000530151300023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4388
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title First combined measurement of the muon neutrino and antineutrino charged-current cross section without pions in the final state at T2K Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 11 Pages 112001 - 44pp
Keywords
Abstract This paper presents the first combined measurement of the double-differential muon neutrino and antineutrino charged-current cross sections with no pions in the final state on hydrocarbon at the off-axis near detector of the T2K experiment. The data analyzed in this work comprise 5.8 x 10(20) and 6.3 x 10(20) protons on target in neutrino and antineutrino mode respectively, at a beam energy peak of 0.6 GeV. Using the two measured cross sections, the sum, difference, and asymmetry were calculated with the aim of better understanding the nuclear effects involved in such interactions. The extracted measurements have been compared with the prediction from different Monte Carlo generators and theoretical models showing that the difference between the two cross sections have interesting sensitivity to nuclear effects.
Address [Bravo Berguno, D.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid 28049, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000537161300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4418
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title First measurement of the charged current (nu)over-bar(mu) double differential cross section on a water target without( )pions in the final state Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 102 Issue 1 Pages 012007 - 16pp
Keywords
Abstract This paper reports the first differential measurement of the charged-current (nu) over bar (mu) interaction cross section on water with no pions in the final state. The unfolded flux-averaged measurement using the T2K off-axis near detector is given in double-differential bins of mu(+) momentum and angle. The integrated cross section in a restricted phase space is sigma = (1.11 +/- 0.18) x 10(-38) cm(2) per water molecule. Comparisons with several nuclear models are also presented.
Address [Abe, K.; Bronner, C.; Hayato, Y.; Ikeda, M.; Kameda, J.; Kataoka, Y.; Kato, Y.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, Y.; Nakayama, S.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Tanaka, H. K.; Yano, T.] Univ Tokyo, Inst Cosm Ray Res, Kamioka Observ, Kamioka, Akita, Japan
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000550579800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4465
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P.
Title Measurement of the charged-current electron (anti-)neutrino inclusive cross-sections at the T2K off-axis near detector ND280 Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 114 - 43pp
Keywords Other experiments
Abstract The electron (anti-)neutrino component of the T2K neutrino beam constitutes the largest background in the measurement of electron (anti-)neutrino appearance at the far detector. The electron neutrino scattering is measured directly with the T2K off-axis near detector, ND280. The selection of the electron (anti-)neutrino events in the plastic scintillator target from both neutrino and anti-neutrino mode beams is discussed in this paper. The flux integrated single differential charged-current inclusive electron (anti-)neutrino cross-sections, d sigma/dp and d sigma/d cos(theta), and the total cross-sections in a limited phase-space in momentum and scattering angle (p 300 MeV/c and theta <= 45 degrees) are measured using a binned maximum likelihood fit and compared to the neutrino Monte Carlo generator predictions, resulting in good agreement.
Address [Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000583585900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4589
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Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Izmaylov, A.; Novella, P.
Title Measurement of inclusive double-differential nu(mu) charged-current cross section with improved acceptance in the T2K off-axis near detector Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 1 Pages 012004 - 18pp
Keywords
Abstract We report a measurement of the flux-integrated cross section for inclusive muon neutrino charged-current 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 x 10(20) protons on target. The total flux-integrated cross section is measured to be (6.950 +/- 0.662) x 10(-39) cm(2) nucleon(-1) and is consistent with our simulation.
Address [Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, E-28049 Madrid, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000440140300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3679
Permanent link to this record
 

 
Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Izmaylov, A.; Novella, P.
Title 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 Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 3 Pages 032003 - 46pp
Keywords
Abstract 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 x 10(20) 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.
Address [Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, E-28049 Madrid, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000441235800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3693
Permanent link to this record
 

 
Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Molina Bueno, L.
Title Improved constraints on neutrino mixing from the T2K experiment with 3.13 x 10(21) protons on target Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 11 Pages 112008 - 59pp
Keywords
Abstract The T2K experiment reports updated measurements of neutrino and antineutrino oscillations using both appearance and disappearance channels. This result comes from an exposure of 14.9(16.4) x 10(20) protons on target in neutrino (antineutrino) mode. Significant improvements have been made to the neutrino interaction model and far detector reconstruction. An extensive set of simulated data studies have also been performed to quantify the effect interaction model uncertainties have on the T2K oscillation parameter sensitivity. T2K performs multiple oscillation analyses that present both frequentist and Bayesian intervals for the Pontecorvo-Maki-Nakagawa-Sakata parameters. For fits including a constraint on sin(2)theta(13) from reactor data and assuming normal mass ordering T2K measures sin(2)theta(13) = 0.53(-0.04)(+0.03) and Delta m(32)(2) = (2.45 +/- 0.07) x 10(-3) eV(2) c(-4). The Bayesian analyses show a weak preference for normal mass ordering 89)% posterior probability) and the upper sin(2)theta(13) octant (80% posterior probability), with a uniform prior probability assumed in both cases. The T2K data exclude CP conservation in neutrino oscillations at the 2 sigma level.
Address [Bravo Berguno, D.; Labarga, L.; Marti-Magro, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid 28049, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000663019200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4880
Permanent link to this record
 

 
Author (up) T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Molina Bueno, L.
Title First T2K measurement of transverse kinematic imbalance in the muon-neutrino charged-current single-pi(+) production channel containing at least one proton Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 11 Pages 112009 - 27pp
Keywords
Abstract This paper reports the first T2K measurement of the transverse kinematic imbalance in the single-pi(+) production channel of neutrino interactions. We measure the differential cross sections in the muonneutrino charged-current interaction on hydrocarbon with a single pi(+) and at least one proton in the final state, at the ND280 off axis near detector of the T2K experiment. The extracted cross sections are compared to the predictions from different neutrino-nucleus interaction event generators. Overall, the results show a preference for models that have a more realistic treatment of nuclear medium effects including the initial nuclear state and final-state interactions.
Address [Bravo Berguno, D.; Labarga, L.; Marti-Magro, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid 28049, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000664516000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4883
Permanent link to this record