Abstract
Neutrino mass hierarchy, CP-violation, and octant of θ 23 are the fundamental unknowns in neutrino oscillations. In order to address all these three unknowns, we study the physics reach of a setup, where we replace the antineutrino run of T2HK with antineutrinos from muon decay at rest (μ-DAR). This approach has the advantages of having higher statistics in both neutrino and antineutrino modes, and lower beam-on backgrounds for antineutrino run with reduced systematics. We find that a hybrid setup consisting of T2HK (ν) and μ-DAR \( \left(\overline{\nu}\right) \) in conjunction with full exposure from T2K and NOνA can resolve the issue of mass hierarchy at greater than 3σ C.L. irrespective of the choices of hierarchy, δ CP, and θ 23. This hybrid setup can also establish the CP-violation at 5σ C.L. for ∼ 55% choices of δ CP, whereas the same for conventional T2HK \( \left(\nu + \overline{\nu}\right) \) setup along with T2K and NOνA is around 30%. As far as the octant of θ 23 is concerned, this hybrid setup can exclude the wrong octant at 5σ C.L. if θ 23 is at least 3° away from maximal mixing for any δ CP.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
ATLAS collaboration, Observation of a new particle in the search for the standard model Higgs boson with the ATLAS detector at the LHC, Phys. Lett. B 716 (2012) 1 [arXiv:1207.7214] [INSPIRE].
CMS collaboration, Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Phys. Lett. B 716 (2012) 30 [arXiv:1207.7235] [INSPIRE].
Super-Kamiokande collaboration, Y. Fukuda et al., Evidence for oscillation of atmospheric neutrinos, Phys. Rev. Lett. 81 (1998) 1562 [hep-ex/9807003] [INSPIRE].
SNO collaboration, Q.R. Ahmad et al., Direct evidence for neutrino flavor transformation from neutral current interactions in the Sudbury Neutrino Observatory, Phys. Rev. Lett. 89 (2002) 011301 [nucl-ex/0204008] [INSPIRE].
KamLAND collaboration, K. Eguchi et al., First results from KamLAND: evidence for reactor anti-neutrino disappearance, Phys. Rev. Lett. 90 (2003) 021802 [hep-ex/0212021] [INSPIRE].
S.F. King, Unified models of neutrinos, flavour and CP-violation, Prog. Part. Nucl. Phys. 94 (2017) 217 [arXiv:1701.04413] [INSPIRE].
S.F. King, Models of neutrino mass, mixing and CP-violation, J. Phys. G 42 (2015) 123001 [arXiv:1510.02091] [INSPIRE].
A. de Gouvêa, Neutrino mass models, Ann. Rev. Nucl. Part. Sci. 66 (2016) 197 [INSPIRE].
G. Altarelli, Status of neutrino mass and mixing, Int. J. Mod. Phys. A 29 (2014) 1444002 [arXiv:1404.3859] [INSPIRE].
J. Gehrlein, A. Merle and M. Spinrath, Predictivity of neutrino mass sum rules, Phys. Rev. D 94 (2016) 093003 [arXiv:1606.04965] [INSPIRE].
I. Girardi, S.T. Petcov, A.J. Stuart and A.V. Titov, Leptonic Dirac CP-violation predictions from residual discrete symmetries, Nucl. Phys. B 902 (2016) 1 [arXiv:1509.02502] [INSPIRE].
P. Ballett, S.F. King, C. Luhn, S. Pascoli and M.A. Schmidt, Testing solar lepton mixing sum rules in neutrino oscillation experiments, JHEP 12 (2014) 122 [arXiv:1410.7573] [INSPIRE].
I. Girardi, S.T. Petcov and A.V. Titov, Determining the Dirac CP-violation phase in the neutrino mixing matrix from sum rules, Nucl. Phys. B 894 (2015) 733 [arXiv:1410.8056] [INSPIRE].
C.H. Albright and M.-C. Chen, Model predictions for neutrino oscillation parameters, Phys. Rev. D 74 (2006) 113006 [hep-ph/0608137] [INSPIRE].
F. Capozzi et al., Global constraints on absolute neutrino masses and their ordering, arXiv:1703.04471 [INSPIRE].
I. Esteban, M.C. Gonzalez-Garcia, M. Maltoni, I. Martinez-Soler and T. Schwetz, Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity, JHEP 01 (2017) 087 [arXiv:1611.01514] [INSPIRE].
T2K collaboration, Y. Itow et al., The JHF-Kamioka neutrino project, hep-ex/0106019 [INSPIRE].
T2K collaboration, K. Abe et al., The T2K experiment, Nucl. Instrum. Meth. A 659 (2011) 106 [arXiv:1106.1238] [INSPIRE].
D. Ayres et al., Letter of intent to build an off-axis detector to study ν μ → ν e oscillations with the NuMI neutrino beam, hep-ex/0210005 [INSPIRE].
NOvA collaboration, D.S. Ayres et al., NOvA: proposal to build a 30 kiloton off-axis detector to study ν μ → ν e oscillations in the NuMI beamline, hep-ex/0503053 [INSPIRE].
NOvA collaboration, D.S. Ayres et al., The NOvA technical design report, FERMILAB-DESIGN-2007-01 (2007) [INSPIRE].
P. Huber, M. Lindner, T. Schwetz and W. Winter, First hint for CP-violation in neutrino oscillations from upcoming superbeam and reactor experiments, JHEP 11 (2009) 044 [arXiv:0907.1896] [INSPIRE].
S. Prakash, S.K. Raut and S.U. Sankar, Getting the best out of T2K and NOvA, Phys. Rev. D 86 (2012) 033012 [arXiv:1201.6485] [INSPIRE].
S.K. Agarwalla, S. Prakash, S.K. Raut and S.U. Sankar, Potential of optimized NOvA for large θ 13 & combined performance with a LArTPC & T2K, JHEP 12 (2012) 075 [arXiv:1208.3644] [INSPIRE].
M. Ghosh, P. Ghoshal, S. Goswami and S.K. Raut, Can atmospheric neutrino experiments provide the first hint of leptonic CP-violation?, Phys. Rev. D 89 (2014) 011301 [arXiv:1306.2500] [INSPIRE].
P.A.N. Machado, H. Minakata, H. Nunokawa and R. Zukanovich Funchal, What can we learn about the lepton CP phase in the next 10 years?, JHEP 05 (2014) 109 [arXiv:1307.3248] [INSPIRE].
M. Ghosh, P. Ghoshal, S. Goswami and S.K. Raut, Evidence for leptonic CP phase from NOνA, T2K and ICAL: a chronological progression, Nucl. Phys. B 884 (2014) 274 [arXiv:1401.7243] [INSPIRE].
T2K collaboration, K. Abe et al., Neutrino oscillation physics potential of the T2K experiment, Prog. Theor. Exp. Phys. 2015 (2015) 043C01 [arXiv:1409.7469] [INSPIRE].
S.K. Agarwalla, S.S. Chatterjee, A. Dasgupta and A. Palazzo, Discovery potential of T2K and NOvA in the presence of a light sterile neutrino, JHEP 02 (2016) 111 [arXiv:1601.05995] [INSPIRE].
S.K. Agarwalla, S. Prakash and S.U. Sankar, Resolving the octant of θ 23 with T2K and NOvA, JHEP 07 (2013) 131 [arXiv:1301.2574] [INSPIRE].
A. Chatterjee, P. Ghoshal, S. Goswami and S.K. Raut, Octant sensitivity for large θ 13 in atmospheric and long-baseline neutrino experiments, JHEP 06 (2013) 010 [arXiv:1302.1370] [INSPIRE].
G.J. Feldman, J. Hartnell and T. Kobayashi, Long-baseline neutrino oscillation experiments, Adv. High Energy Phys. 2013 (2013) 475749 [arXiv:1210.1778] [INSPIRE].
K. Abe et al., Letter of intent: the Hyper-Kamiokande experiment — detector design and physics potential, arXiv:1109.3262 [INSPIRE].
Hyper-Kamiokande Working Group, K. Abe et al., A long baseline neutrino oscillation experiment using J-PARC neutrino beam and Hyper-Kamiokande, arXiv:1412.4673 [INSPIRE].
P. Coloma, A. Donini, E. Fernandez-Martinez and P. Hernández, Precision on leptonic mixing parameters at future neutrino oscillation experiments, JHEP 06 (2012) 073 [arXiv:1203.5651] [INSPIRE].
P. Coloma, P. Huber, J. Kopp and W. Winter, Systematic uncertainties in long-baseline neutrino oscillations for large θ 13, Phys. Rev. D 87 (2013) 033004 [arXiv:1209.5973] [INSPIRE].
M. Blennow, P. Coloma and E. Fernandez-Martinez, Reassessing the sensitivity to leptonic CP-violation, JHEP 03 (2015) 005 [arXiv:1407.3274] [INSPIRE].
S. Fukasawa, M. Ghosh and O. Yasuda, Complementarity between Hyper-Kamiokande and DUNE in determining neutrino oscillation parameters, Nucl. Phys. B 918 (2017) 337 [arXiv:1607.03758] [INSPIRE].
P. Ballett, S.F. King, S. Pascoli, N.W. Prouse and T. Wang, Sensitivities and synergies of DUNE and T2HK, arXiv:1612.07275 [INSPIRE].
J. Liao, D. Marfatia and K. Whisnant, Nonstandard neutrino interactions at DUNE, T2HK and T2HKK, JHEP 01 (2017) 071 [arXiv:1612.01443] [INSPIRE].
M. Ghosh and O. Yasuda, Effect of systematics in T2HK, T2HKK and DUNE, arXiv:1702.06482 [INSPIRE].
S.K. Raut, T2HK and T2HKK: does more matter matter?, arXiv:1703.07136 [INSPIRE].
S.K. Agarwalla, P. Huber, J.M. Link and D. Mohapatra, A new approach to anti-neutrino running in long baseline neutrino oscillation experiments, JHEP 04 (2011) 099 [arXiv:1005.4055] [INSPIRE].
J. Alonso et al., Expression of interest for a novel search for CP-violation in the neutrino sector: DAEdALUS, arXiv:1006.0260 [INSPIRE].
J. Evslin, S.-F. Ge and K. Hagiwara, The leptonic CP phase from T2(H)K and μ + decay at rest, JHEP 02 (2016) 137 [arXiv:1506.05023] [INSPIRE].
J.M. Conrad and M.H. Shaevitz, Multiple cyclotron method to search for CP-violation in the neutrino sector, Phys. Rev. Lett. 104 (2010) 141802 [arXiv:0912.4079] [INSPIRE].
Hyper-Kamiokande proto-collaboration, K. Abe et al., Physics potentials with the second Hyper-Kamiokande detector in Korea, arXiv:1611.06118 [INSPIRE].
A. Cervera et al., Golden measurements at a neutrino factory, Nucl. Phys. B 579 (2000) 17 [Erratum ibid. B 593 (2001) 731] [hep-ph/0002108] [INSPIRE].
M. Freund, P. Huber and M. Lindner, Systematic exploration of the neutrino factory parameter space including errors and correlations, Nucl. Phys. B 615 (2001) 331 [hep-ph/0105071] [INSPIRE].
E.K. Akhmedov, R. Johansson, M. Lindner, T. Ohlsson and T. Schwetz, Series expansions for three flavor neutrino oscillation probabilities in matter, JHEP 04 (2004) 078 [hep-ph/0402175] [INSPIRE].
S.K. Agarwalla, Y. Kao and T. Takeuchi, Analytical approximation of the neutrino oscillation matter effects at large θ 13, JHEP 04 (2014) 047 [arXiv:1302.6773] [INSPIRE].
M. Ghosh, S. Goswami and S.K. Raut, Implications of δ CP = −90° towards determining hierarchy and octant at T2K and T2K-II, Mod. Phys. Lett. A 32 (2017) 1750034 [arXiv:1409.5046] [INSPIRE].
M. Ghosh, P. Ghoshal, S. Goswami, N. Nath and S.K. Raut, New look at the degeneracies in the neutrino oscillation parameters and their resolution by T2K, NOνA and ICAL, Phys. Rev. D 93 (2016) 013013 [arXiv:1504.06283] [INSPIRE].
M. Ghosh, Reason for T2K to run in dominant neutrino mode for detecting CP-violation, Phys. Rev. D 93 (2016) 073003 [arXiv:1512.02226] [INSPIRE].
P. Huber, J. Kopp, M. Lindner, M. Rolinec and W. Winter, New features in the simulation of neutrino oscillation experiments with GLoBES 3.0: General Long Baseline Experiment Simulator, Comput. Phys. Commun. 177 (2007) 432 [hep-ph/0701187] [INSPIRE].
P. Huber, M. Lindner and W. Winter, Simulation of long-baseline neutrino oscillation experiments with GLoBES (General Long Baseline Experiment Simulator), Comput. Phys. Commun. 167 (2005) 195 [hep-ph/0407333] [INSPIRE].
E.A. Paschos and J.Y. Yu, Neutrino interactions in oscillation experiments, Phys. Rev. D 65 (2002) 033002 [hep-ph/0107261] [INSPIRE].
M.D. Messier, Evidence for neutrino mass from observations of atmospheric neutrinos with Super-Kamiokande, Ph.D. Thesis, Boston University (1999) [INSPIRE].
T2K collaboration, K. Abe et al., Combined analysis of neutrino and antineutrino oscillations at T2K, Phys. Rev. Lett. 118 (2017) 151801 [arXiv:1701.00432] [INSPIRE].
NOvA collaboration, P. Adamson et al., Constraints on oscillation parameters from ν e appearance and ν μ disappearance in NOvA, arXiv:1703.03328 [INSPIRE].
E. Ciuffoli, J. Evslin and X. Zhang, Confidence in a neutrino mass hierarchy determination, JHEP 01 (2014) 095 [arXiv:1305.5150] [INSPIRE].
M. Blennow, P. Coloma, P. Huber and T. Schwetz, Quantifying the sensitivity of oscillation experiments to the neutrino mass ordering, JHEP 03 (2014) 028 [arXiv:1311.1822] [INSPIRE].
M. Blennow, On the Bayesian approach to neutrino mass ordering, JHEP 01 (2014) 139 [arXiv:1311.3183] [INSPIRE].
J. Elevant and T. Schwetz, On the determination of the leptonic CP phase, JHEP 09 (2015) 016 [arXiv:1506.07685] [INSPIRE].
K.N. Abazajian et al., Light sterile neutrinos: a white paper, arXiv:1204.5379 [INSPIRE].
A. Palazzo, Phenomenology of light sterile neutrinos: a brief review, Mod. Phys. Lett. A 28 (2013) 1330004 [arXiv:1302.1102] [INSPIRE].
S. Gariazzo, C. Giunti, M. Laveder, Y.F. Li and E.M. Zavanin, Light sterile neutrinos, J. Phys. G 43 (2016) 033001 [arXiv:1507.08204] [INSPIRE].
C. Giunti, Light sterile neutrinos: status and perspectives, Nucl. Phys. B 908 (2016) 336 [arXiv:1512.04758] [INSPIRE].
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.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1704.06116
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Agarwalla, S.K., Ghosh, M. & Raut, S.K. A hybrid setup for fundamental unknowns in neutrino oscillations using T2HK (ν) and μ-DAR \( \left(\overline{\nu}\right) \) . J. High Energ. Phys. 2017, 115 (2017). https://doi.org/10.1007/JHEP05(2017)115
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP05(2017)115