The MOMENT to search for CP violation

Journal of High Energy Physics, Mar 2016

In this letter, we analyze for the first time the physics reach in terms of sensitivity to leptonic CP violation of the proposed MuOn-decay MEdium baseline NeuTrino beam (MOMENT) experiment, a novel neutrino oscillation facility that would operate with neutrinos from muon decay. Apart from obtaining a sufficiently intense flux, the bottlenecks to the physics reach of this experiment will be achieving a high enough suppression of the atmospheric background and, particularly, attaining a sufficient level of charge identification. We thus present our results as a function of these two factors. As for the detector, we consider a very massive Gd-doped Water Cherenkov detector. We find that MOMENT will be competitive with other currently planned future oscillation experiments if a charge identification of at least 80 % can be achieved at the same time that the atmospheric background can be suppressed by at least a factor of ten. We also find a large synergy of MOMENT with the current generation of neutrino oscillation experiments, T2K and NOvA, which significantly enhances its final sensitivity.

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The MOMENT to search for CP violation

JHE The MOMENT to search for CP violation Mattias Blennow 0 1 2 5 6 7 8 Pilar Coloma 0 1 2 3 6 7 8 Enrique Fernandez-Mart nez 0 1 2 4 6 7 8 0 P. O. Box 500, Batavia, IL 60510 , U.S.A 1 106 91 Stockholm , Sweden 2 KTH Royal Institute of Technology, Albanova University Center 3 Theoretical Physics Department, Fermi National Accelerator Laboratory 4 Departamento de F sica Teorica, Universidad Autonoma de Madrid 5 Department of Theoretical Physics, School of Engineering Sciences 6 nd a large synergy 7 Calle Nicolas Cabrera 13-15 , Cantoblanco E-28049 Madrid , Spain 8 Cantoblanco E-28049 Madrid , Spain In this letter, we analyze for the rst time the physics reach in terms of sensitivity to leptonic CP violation of the proposed MuOn-decay MEdium baseline NeuTrino beam (MOMENT) experiment, a novel neutrino oscillation facility that would operate with neutrinos from muon decay. Apart from obtaining a su ciently intense necks to the physics reach of this experiment will be achieving a high enough suppression of the atmospheric background and, particularly, attaining a su cient level of charge identi - cation. We thus present our results as a function of these two factors. As for the detector, we consider a very massive Gd-doped Water Cherenkov detector. We nd that MOMENT will be competitive with other currently planned future oscillation experiments if a charge identi cation of at least 80 % can be achieved at the same time that the atmospheric background can be suppressed by at least a factor of ten. We also of MOMENT with the current generation of neutrino oscillation experiments, T2K and NOvA, which signi cantly enhances its nal sensitivity. CP violation; Neutrino Physics 1 Introduction 2 Implementation 3 Results and conclusions 1 Introduction PMNS matrix element Ue3 provided by accelerator and reactor neutrino experiments [11{ 15], it is plausible that CP-violation in the lepton sector may be found in the not so distant future. The current hints of maximal lepton CP-violation [16{18] provide further indication that this discovery may be right around the corner. In the next generation of neutrino oscillation experiments, the front runners in the hunt for leptonic CP-violation are the proposed Deep Underground Neutrino Experiment (DUNE) [19] and the Tokai to Hyper-Kamiokande (T2HK) experiment [20]. Both of them propose to use conventional accelerator neutrino beams from pion decay. In contrast, the MuOn-decay MEdium baseline NeuTrino beam facility (MOMENT) [21] proposes to observe a neutrino beam produced from decaying muons at relatively low energies. By { 1 { using this type of beam, some of the technical di culties related to the construction of the more futuristic neutrino factory could be avoided [22{24]. The aim of this letter is to study the capabilities of the MOMENT experiment and put it into context in the global experimental e ort in neutrino physics. 2 Implementation The MOMENT design is still not fully developed and is therefore subject to large uncertainties. As a rst step towards studying its physics potential and the requirements it would need to meet to reach a competitive performance with respect to other future neutrino oscillation experiments, some assumptions regarding both the beam and detector performance have to be made. However, in our analysis we leave the most relevant parameters free in order to explore their impact on the expected sensitivities. The MOMENT facility would employ a proton linac (either continuous or pulsed) of 1.5 GeV, as well as a 10 mA proton driver. The aim of its design is to deliver a beam of extremely high power, up to 15 MW. Reaching such a high intensity already represents a major technological challenge. In addition, if such a high intensity is eventually achieved, a suitable target that is able to withstand it would need to be identi ed. Further issues have been pointed out related to the focusing system for the pions, heat mitigation and the radiation levels at the target station. These points are already being investigated, and we refer the interested reader to ref. [21]. In this work we will start from the muon and electron neutrino uxes presented in refs. [21, 25] (at 150 km from the source), and we will assume that alternating between muon polarities with a similar ux intensity is possible. In order to assess the importance of achieving the demanding goal of 15 MW, we will also show how our results scale with the total luminosity of the experiment. The neutrino uxes used in this work have their maximum at energies around 150 MeV with maximum intensity of 109 MeV 1 m 2 year 1, and have been taken from ref. [25]. Five years of running time per polarity are assumed. In principle, the MOMENT setup would allow the study of the e ! e , e ! and ! oscillation channels as well as their corresponding CP-conjugate partners. However, since the original ux is composed of and e from decay, both good avour and charge identi cation capabilities are needed in order to be sensitive to a possible CP-violating signal. The neutrino ux for this facility would peak at low energies around 150-200 MeV. Therefore, a very massive detector would be required in order to compensate the low interaction cross section at these energies and reach large enough statistics. The detector technology for MOMENT has not yet been decided, but a massive Water Cherenkov detector has been suggested due to its excellent avour identi cation capabilities and performance at low energies. The drawback of using a Water Cherenkov in combination with the MOMENT beam is its inability to distinguish neutrinos and antineutrinos. Nevertheless, this problem may be solved (at least partially) by doping the water with Gd [26] at the 0.1-0.2% level. We will thus adopt a Mton class (500 kton ducial) Gd-doped Water Cherenkov detector as baseline detector for our analysis. { 2 { In this study, the detector response has been implemented following ref. [ 27 ]. Migration matrices, describing both the detection e ciencies and energy reconstruction, are used for all four relevant oscillation channels (and their CP-conjugates). The most relevant backgrounds come from charge mis-identi cation (charge mis-ID) of events coming from the intrinsic contamination of the beam, avour mis-identi cation and neutral current (NC) backgrounds mis-identi ed as charged current (CC) events. Since charge mis-ID will be one of the bottlenecks for the physics performance of the facility, our results will be presented as a function of this parameter. In ref. [28] it was estimated that Gd-doping alone (at the 0.1-0.2 % level) could bring charge separation up to the 80 % level. Besides Gddoping, some statistical neutrino/antineutrino discrimination could be achieved from other distinctive features [28], such as the angular distribution between the charged lepton and the incident neutrino/antineutrino, or the di erent lifetimes of the outgoing muons/antimuons produced in / interactions. Since it is uncertain how much extra charge-identi cation e ciency these extra handles would eventually bring to the table,1 we will show how much the performance of the setup would improve if the total charge-identi cation e ciency surpasses the 70 % level, which is taken as a (conservative) lower threshold [ 30 ]. Another important limiting factor could be the potentially large atmospheric-induced background. By placing the detector deep underground all such background, except the contribution from atmospheric neutrinos, can be e ciently suppressed: at a depth of 2500 m of water equivalent, the muon ux would be reduced by almost two and a half orders of magnitude (see, e.g., gure 3 in ref. [ 31 ]). We will therefore consider the background coming from particles interacting in the atmosphere to be negligible, with the sole exception of that coming from atmospheric neutrinos. This contribution, on the other hand, could be largely reduced by sending the neutrino ux in short bunches, so that a time cut can be e ciently applied. This is usually parametrized in terms of a suppression factor (SF), i.e., the ratio between the length of each bunch to the distance between bunches. In neutrino oscillation experiments using pion decay beams, the achieved SF is typically around 10 3 [24]. In the current work, we will explicitly consider the atmospheric background, computed as in ref. [32], applying a SF ranging from 1 to 5 10 3 in order to quantify its impact on the nal sensitivities. Finally, we also include an overall 5 % (10 %) normalization systematic error, uncorrelated between all signal (background) channels. All of our numerical simulations have been implemented using the GLoBES software [33, 34]. For convenience, table 1 summarizes the total expected event rates in the energy range between 0 and 1.6 GeV, for all oscillation channels under consideration, after e ciencies are accounted for. The signal and background rates are provided separately for each channel, assuming a charge separation e ciency of 70 % and a suppression factor SF = 10 1 for the atmospheric neutrino background. These number of events have been obtained assuming that the true values of the oscillation parameters correspond to the best- t values from ref. [35], with the sole exception of the CP-violating phase which is set to = 0. A normal ordering of the neutrino masses (m1 < m2 < m3) has also been assumed. Only those 1Very recently, Gd-doping has been approved for the Super-KamiokaNDE detector [29]. Therefore, by CID 1004 3191 7567 124 352 153 448 11 4 9 4 2 5 2 4 Atm. 652 449 399 268 652 449 399 268 suppression factor SF = 10 1 have been assumed. events with reconstructed neutrino energy between 0.1 and 1 GeV are considered for the 2 analysis. 3 Results and conclusions In its most conservative incarnation, with a 70 % charge ID and no suppression of the atmospheric background, we nd that the MOMENT facility, on its own, barely improves over what the presently running experiments T2K and NO A will achieve in the coming years. However, we have found that combining the data from the three facilities can be quite complementary, leading to a signi cant improvement of their individual physics reaches beyond that due to a simple increase in statistics. In the following, we have simulated the sensitivity from the NO A experiment as in ref. [36], using 3 years of data taking per polarity and 6:0 1020 protons on target (PoT) per year. This is then combined with a simulation of T2K data using neutrino data corresponding to approximately 3 The T2K uxes have been taken from ref. [37] and the signal and background e ciencies have been set to approximately match the results from ref. [38] for the same exposure. 1020 PoT. The complementarity between MOMENT and the current generation of neutrino oscillation experiments is shown for a particular point in the 23- parameter space in gure 1. In each panel, the shaded areas show the con dence regions obtained in the 23 plane for the correct neutrino mass ordering, while the dashed lines show the allowed regions for the opposite mass ordering (a.k.a., sign degeneracies [39]). Each panel corresponds to the expected results for a given facility (or combination thereof), as indicated in the legend. As { 4 { -50 -100 -50 -100 -150 -50 -100 -150 the presently running facilities T2K and NO A. In each panel, the shaded areas indicate the allowed con dence regions when the t is done using the correct mass ordering (normal ordering, in this example), while the dashed lines indicate the allowed regions when the t is performed using the wrong mass ordering (sign degeneracies). All regions correspond to 90 % con dence level, for 2 d.o.f.. The black dot indicates the assumed true values for 23 and . can be seen from a comparison between the left and central panels, the sign degeneracies a ect both the T2K+NO A and the MOMENT setup, but appear at completely di erent values of due to the much weaker matter e ects that characterize the latter. Furthermore, the octant degeneracy also plays an important role at MOMENT, while it is solved at T2K+NO A (for this particular point in parameter space). We found that, even though both the e ! and ! e channels are available at MOMENT for running, the former channel dominates the physics reach unless very optimistic charge ID is assumed. This can be understood as follows. On one hand, the \wrong sign" electrons from e disappearance completely overwhelm the signal in the e channel. On the other hand, the present in the beam are less of an issue for the ! e ! channel, since most them have already oscillated to when they reach the detector and therefore do not contribute to the muon-like CC sample. Thus, the physics reach from MOMENT and T2K+NO A is dominated by di erent and complementary channels. The right panel of gure 1 shows how the combination of the three facilities is able to solve all degeneracies unambiguously and determine the correct value of 23 and with an allowed region which is signi cantly reduced compared to the individual ts. Since by the time the MOMENT facility is built the T2K and NO A facilities will have already nished taking data, we will present our results for the combination of MOMENT+T2K+NOvA only. Notice that this essentially improves the overall performance for the most conservative choices for the charge ID and SF of MOMENT, while it has little impact in the optimistic scenarios. Similarly, the physics reach of DUNE or T2HK is mildly a ected after combination with T2K+NO A, since their observations are less complementary and do not lead to further degeneracy solving besides a small increase in statistics. For this reason, when comparing the reach of MOMENT to that of T2HK or DUNE, we will take the expected physics reach for the latter from their respective proposals. { 5 { 0.6 0.5 the dot-dashed lines (taken from ref. [43]). We have also explored the e ect of changing the baseline of the MOMENT detector. Indeed, it has been shown that, given the relatively large value of 13, if the neutrino ux is centered around the second oscillation peak, the sensitivity to [40, 41] improves considerably. This has been studied in depth for a similar low-energy neutrino beam, the ESS SB [42], also in combination with a Water Cherenkov detector. In the case of MOMENT, we nd that when the most conservative assumptions are made, the optimal baseline is around L = 150 km. However, when the most optimistic assumptions are adopted, the sensitivity becomes almost independent of the baseline as it is increased from the rst to the second peak. This is mainly due to the strong dependence on at longer baselines, which compensates for the lower statistics. Thus, in the following we will only consider a L = 150 km baseline, since the performance of the detector is still uncertain. Our main results are shown in gure 2, where we show the fraction of possible values of for which the combination of MOMENT+T2K+NO A would allow a 3 (5 ) discovery of leptonic CP violation. Our results are shown as a function of the achievable charge-ID and atmospheric suppression factor. As can be seen, if a 80 % charge-ID can be achieved, a 3 (5) discovery of CP violation would be possible for roughly 60 % (20 %) of the values of , as long as the atmospheric suppression factor remains below SF . 0:1. This is similar to the sensitivity reach expected for DUNE [19] with an exposure of 300 MW kt yr (corresponding to 3:5 years running per polarity). Conversely, if the charge identi cation cannot be improved beyond 70 %, less than 10 % of the values of would lead to a 5 discovery regardless of the value of SF. As a comparison, T2HK [43] with a 10-year run using a beam power of 750 MW would allow to cover 75 % ( 55 %) of the values of for a 3 (5 ) discovery. MOMENT would require a charge ID of 98 % and SF < 5 10 2 to achieve a similar performance. { 6 { a function of the ratio of the considered exposure to the nominal exposure considered in this work Finally, as it was already mentioned, the MOMENT beam will have several technical challenges to meet before reaching its nominal beam intensity. Therefore, we have also studied the impact of the total exposure on the performance of the facility. This is shown in gure 3, where we show the fraction of values of for which CP violation could be observed at the 3 level, as a function of the ratio between the considered exposure to the nominal exposure. Results are shown under two di erent sets of assumptions, as indicated in the gure, for the suppression factor and charge-identi cation capability of the detector. As it can be seen from the gure, the performance of the facility is not limited by statistics and therefore the total exposure can be reduced by a factor of between 5 and 10 before seeing a noticeable reduction in performance. This is due to the fact that most of the background is beam-related, and therefore the signal to background ratio does not change much when the exposure is reduced. At some point the atmospheric background dominates over the beam-induced and the decrease in sensitivity becomes much more pronounced. This situation is reached earlier for the more conservative assumption as expected as can be seen in the gure. A qualitatively similar behavior is also found at higher con dence levels, although the decrease in the CP coverage takes place sooner as the exposure of the experiment is decreased (as expected). In conclusion, we have studied for the rst time the physics reach attainable at MOMENT in terms of its CP violation discovery potential. We nd that the main limiting factors to its performance are the charge identi cation and atmospheric background suppression. With a conservative assumption of 70 % charge identi cation and no atmospheric background suppression, MOMENT would not improve signi cantly over the results expected at the end of the running period of T2K and NO A, even after a 10 year run with a Mton Water Cherenkov detector. However, its combination with present facilities is able to lift several degeneracies and signi cantly improve the combined physics reach over a simple addition of statistics. { 7 { In order to compete with other future neutrino oscillation facilities, more demanding detection capabilities would be necessary. We nd that the physics reach of MOMENT would be similar to a 7 year run of DUNE if a charge identi cation of 80 % and atmospheric suppression by a factor of 10 is achieved. To compete with 10 years of T2HK with a 750 MW beam, the background suppression factor should improve by a factor 20 keeping charge identi cation capabilities at the level of 98 %. In order to satisfy this requirement, a di erent detector technology would most likely be required in this case. Acknowledgments The work of MB was supported by the Goran Gustafsson Foundation. PC and EFM acknowledge nancial support from the European Union through the ITN INVISIBLES (Marie Curie Actions, PITN-GA-2011-289442-INVISIBLES). EFM also acknowledges support from the EU through the FP7 Marie Curie Actions CIG NeuProbes (PCIG11GA-2012-321582) and the Spanish MINECO through the \Ramon y Cajal" programme (RYC2011-07710) and the project FPA2009-09017. MB and EFM were also supported by the Spanish MINECO through the Centro de excelencia Severo Ochoa Program under grant SEV-2012-0249. MB would also like to thank the Instituto de F sica Teorica, Madrid, for warm hospitality during the time when this work was initiated. PC would like to thank the Mainz Institute for Theoretical Physics for hospitality and partial support during completion of this work. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Open Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. Nauk 161 (1991) 61] [JETP Lett. 5 (1967) 24] [INSPIRE]. [4] M.B. Gavela, P. Hernandez, J. Orlo and O. Pene, Standard model CP-violation and baryon asymmetry, Mod. Phys. Lett. A 9 (1994) 795 [hep-ph/9312215] [INSPIRE]. [5] M.B. Gavela, P. Hernandez, J. Orlo , O. Pene and C. Quimbay, Standard model CP-violation and baryon asymmetry. Part 2: nite temperature, Nucl. Phys. B 430 (1994) 382 [hep-ph/9406289] [INSPIRE]. [6] B. Pontecorvo, Mesonium and anti-mesonium, Sov. Phys. JETP 6 (1957) 429 [Zh. Eksp. Teor. Fiz. 33 (1957) 549] [INSPIRE]. [7] B. Pontecorvo, Inverse beta processes and nonconservation of lepton charge, Sov. Phys. JETP 7 (1958) 172 [Zh. Eksp. Teor. Fiz. 34 (1957) 247] [INSPIRE]. { 8 { HJEP03(216)97 [8] Z. Maki, M. Nakagawa, Y. Ohnuki and S. Sakata, A uni ed model for elementary particles, Prog. Theor. Phys. 23 (1960) 1174 [INSPIRE]. Prog. Theor. Phys. 28 (1962) 870 [INSPIRE]. [10] B. Pontecorvo, Neutrino experiments and the problem of conservation of leptonic charge, Sov. Phys. JETP 26 (1968) 984 [Zh. Eksp. Teor. Fiz. 53 (1967) 1717] [INSPIRE]. [11] Daya Bay collaboration, F.P. An et al., Observation of electron-antineutrino disappearance at Daya Bay, Phys. Rev. Lett. 108 (2012) 171803 [arXiv:1203.1669] [INSPIRE]. [12] RENO collaboration, J.K. Ahn et al., Observation of Reactor Electron Antineutrino Disappearance in the RENO experiment, Phys. Rev. Lett. 108 (2012) 191802 [13] Double CHOOZ collaboration, Y. Abe et al., Reactor electron antineutrino disappearance in the Double CHOOZ experiment, Phys. Rev. D 86 (2012) 052008 [arXiv:1207.6632] [INSPIRE]. [arXiv:1108.0015] [INSPIRE]. [arXiv:1106.2822] [INSPIRE]. [14] MINOS collaboration, P. Adamson et al., Improved search for muon-neutrino to electron-neutrino oscillations in MINOS, Phys. Rev. Lett. 107 (2011) 181802 [15] T2K collaboration, K. Abe et al., Indication of electron neutrino appearance from an accelerator-produced o -axis muon neutrino beam, Phys. Rev. Lett. 107 (2011) 041801 [16] T2K collaboration, K. Abe et al., Observation of electron neutrino appearance in a muon neutrino beam, Phys. Rev. Lett. 112 (2014) 061802 [arXiv:1311.4750] [INSPIRE]. [17] NOvA collaboration, R. Patterson, First oscillation results from NOvA, talk given at the Fermilab Joint Experimental-Theoretical Physics Seminar, available at http://nova-docdb.fnal.gov/cgi-bin/ShowDocument?docid=13883, August 2015. [18] A. Palazzo, 3- avor and 4- avor implications of the latest T2K and NOvA electron (anti-)neutrino appearance results, arXiv:1509.03148 [INSPIRE]. [19] DUNE collaboration, R. Acciarri et al., Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) conceptual design report, available in 4 volumes at http://lbne2-docdb.fnal.gov/cgi-bin/ShowDocument?docid=10688&asof=2015-7-14, (2015). [INSPIRE]. [20] K. Abe et al., Letter of intent: the Hyper-Kamiokande experiment | detector design and physics potential, arXiv:1109.3262 [INSPIRE]. Beams 17 (2014) 090101 [arXiv:1401.8125] [INSPIRE]. [21] J. Cao et al., Muon-decay medium-baseline neutrino beam facility, Phys. Rev. ST Accel. [22] S. Geer, Neutrino beams from muon storage rings: characteristics and physics potential, Phys. Rev. D 57 (1998) 6989 [Erratum ibid. D 59 (1999) 039903] [hep-ph/9712290] [23] A. De Rujula, M.B. Gavela and P. Hernandez, Neutrino oscillation physics with a neutrino factory, Nucl. Phys. B 547 (1999) 21 [hep-ph/9811390] [INSPIRE]. [24] ISS Physics Working Group collaboration, A. Bandyopadhyay, Physics at a future neutrino factory and super-beam facility, Rept. Prog. Phys. 72 (2009) 106201 [arXiv:0710.4947] [INSPIRE]. [25] Y. Wang, Current status and future prospects of neutrino oscillation, plenary talk at Invisibles 015, Madrid Spain June 24 2015. { 9 { water-Cherenkov detector (MEMPHYS), JCAP 01 (2013) 024 [arXiv:1206.6665] [INSPIRE]. at the International Workshop for the Next Generation Nucleon Decay and Neutrino Detector (NNN), Stony Brook U.S.A. October 2015. [arXiv:0912.3804] [INSPIRE]. HJEP03(216)97 experiments with GLoBES (General Long Baseline Experiment Simulator), Comput. Phys. Commun. 167 (2005) 195 [hep-ph/0407333] [INSPIRE]. of neutrino oscillation experiments with GLoBES 3:0: General Long Baseline Experiment disappearance channels by the T2K experiment with 6:6 JHEP 10 (2001) 001 [hep-ph/0108085] [INSPIRE]. 1020 protons on target, Phys. Rev. large 13, JHEP 04 (2012) 089 [arXiv:1110.4583] [INSPIRE]. [42] ESSnuSB collaboration, E. Baussan et al., A very intense neutrino super beam experiment for leptonic CP-violation discovery based on the European spallation source linac, Nucl. long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and [1] J.H. Christenson , J.W. Cronin , V.L. Fitch and R. Turlay , Evidence for the 2 decay of the k20 meson , Phys. Rev. Lett . 13 ( 1964 ) 138 [INSPIRE]. interaction, Prog. Theor. Phys . 49 ( 1973 ) 652 [INSPIRE]. [2] M. Kobayashi and T. Maskawa , CP violation in the renormalizable theory of weak [3] A.D. Sakharov, Violation of CP invariance, c asymmetry and baryon asymmetry of the universe , Sov. Phys. Usp . 34 ( 1991 ) 392 [Pisma Zh . Eksp. Teor. Fiz . 5 ( 1967 ) 32] [Usp. Fiz. [9] Z. Maki , M. Nakagawa and S. Sakata , Remarks on the uni ed model of elementary particles , [26] J.F. Beacom and M.R. Vagins , GADZOOKS! Anti-neutrino spectroscopy with large water Cherenkov detectors , Phys. Rev. Lett . 93 ( 2004 ) 171101 [ hep -ph/0309300] [INSPIRE]. [27] MEMPHYS collaboration, L. Agostino et al., Study of the performance of a large scale [28] P. Huber and T. Schwetz , A low energy neutrino factory with non-magnetic detectors , Phys. [30] M. Vagins , private communication. [31] F.E. Gray , C. Ruybal , J. Totushek , D.-M. Mei , K. Thomas and C. Zhang , Cosmic ray muon ux at the Sanford Underground Laboratory at homestake , Nucl. Instrum. Meth. A 638 [32] E. Fernandez-Martinez , The = 100 -beam revisited, Nucl. Phys. B 833 ( 2010 ) 96 [33] P. Huber , M. Lindner and W. Winter , Simulation of long-baseline neutrino oscillation


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Mattias Blennow, Pilar Coloma, Enrique Fernández-Martínez. The MOMENT to search for CP violation, Journal of High Energy Physics, 2016, 197, DOI: 10.1007/JHEP03(2016)197