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Author |
T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P. |
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Title |
Search for neutral-current induced single photon production at the ND280 near detector in T2K |
Type |
Journal Article |
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Year |
2019 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
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Volume |
46 |
Issue |
8 |
Pages |
08LT01 - 16pp |
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Keywords |
T2K; neutrino; neutrino oscillation; neutrino interaction; Mini-BooNE; CP violation |
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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. |
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Address |
[Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain |
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Publisher |
Iop Publishing Ltd |
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Language |
English |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0954-3899 |
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Conference |
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Notes |
WOS:000518888100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4318 |
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Permanent link to this record |
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Author |
T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P. |
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Title |
Measurement of the muon neutrino charged-current single pi(+) production on hydrocarbon using the T2K off-axis near detector ND280 |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
101 |
Issue |
1 |
Pages |
012007 - 19pp |
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Keywords |
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Abstract |
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 5.56 x 10(20) 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 sigma = (11.76 +/- 0.44(stat) +/- 2.39(syst)) x 10(-40) cm(2) nucleon(-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. |
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Address |
[Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, E-28049 Madrid, Spain |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Series Issue |
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Edition |
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ISSN |
2470-0010 |
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Conference |
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Notes |
WOS:000508453600002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4266 |
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Author |
NEXT Collaboration (Fernandes, A.F.M. et al); Alvarez, V.; Benlloch-Rodriguez, J.M.; Carcel, S.; Carrion, J.V.; Diaz, J.; Felkai, R.; Herrero, P.; Kekic, M.; Lopez-March, N.; Martinez-Lema, G.; Muñoz Vidal, J.; Novella, P.; Palmeiro, B.; Querol, M.; Renner, J.; Romo-Luque, C.; Sorel, M.; Uson, A.; Yahlali, N. |
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Title |
Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield |
Type |
Journal Article |
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Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
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Volume |
04 |
Issue |
4 |
Pages |
034 - 18pp |
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Keywords |
Particle correlations and fluctuations; Photon production; Dark Matter and Double Beta Decay (experiments); Rare decay |
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Abstract |
High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe-He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by similar to 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures. |
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Address |
[Hauptman, J.] Iowa State Univ, Dept Phys & Astron, 12 Phys Hall, Ames, IA 50011 USA, Email: cristinam@uc.pt |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Editor |
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ISSN |
1029-8479 |
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Conference |
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Notes |
WOS:000525257400001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4366 |
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Permanent link to this record |
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Author |
T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P. |
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Title |
Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam |
Type |
Journal Article |
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Year |
2020 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
124 |
Issue |
16 |
Pages |
161802 - 8pp |
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Keywords |
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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. |
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Address |
[Bravo Berguno, D.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000527135200004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4379 |
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Permanent link to this record |
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Author |
T2K Collaboration (Abe, K. et al); Antonova, M.; Cervera-Villanueva, A.; Fernandez, P.; Izmaylov, A.; Novella, P. |
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Title |
Constraint on the matter-antimatter symmetry-violating phase in neutrino oscillations |
Type |
Journal Article |
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Year |
2020 |
Publication |
Nature |
Abbreviated Journal |
Nature |
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Volume |
580 |
Issue |
7803 |
Pages |
339-344 |
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Keywords |
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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. |
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Address |
[Berguno, D. Bravo; Ishii, T.; Labarga, L.] Univ Autonoma Madrid, Dept Theoret Phys, Madrid, Spain |
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Corporate Author |
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Thesis |
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Publisher |
Nature Publishing Group |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0028-0836 |
ISBN |
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Conference |
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Notes |
WOS:000530151300023 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4388 |
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Permanent link to this record |