Abstract
Observables of neutrino oscillations in matter have, in general, contributions from the effective matter potential. It contaminates the CP violation asymmetry adding a fake effect that has been recently disentangled from the genuine one by their different behavior under T and CPT. Is the genuine T-odd CPT-invariant component of the CP asymmetry coincident with the T asymmetry? Contrary to CP, matter effects in uniform matter cannot induce by themselves a non-vanishing T asymmetry; however, the question of the title remained open. We demonstrate that, in the presence of genuine CP violation, there is a new non-vanishing CP-even, and so CPT-odd, component in the T asymmetry in matter, which is of odd-parity in both the phase δ of the flavor mixing and the matter parameter a. The two disentangled components, genuine A T;CP αβ and fake A T;CPT αβ , could be experimentally separated by the measurement of the two T asymmetries in matter (να ↔ νβ) and (\( {\overline{\nu}}_{\alpha}\leftrightarrow {\overline{\nu}}_{\beta } \)). For the (νμ ↔ νβ) transitions, the energy dependence of the new A T;CPT μe component is like the matter-induced term A CP;CPT μe of the CP asymmetry which is odd under a change of the neutrino mass hierarchy. We have thus completed the physics involved in all observable asymmetries in matter by means of their disentanglement into the three independent components, genuine A CP;T αβ and fake A CP;CPT αβ and A T;CPT αβ .
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References
J. Bernabéu and A. Segarra, Disentangling genuine from matter-induced CP-violation in neutrino oscillations, Phys. Rev. Lett. 121 (2018) 211802 [arXiv:1806.07694] [INSPIRE].
J. Bernabéu and A. Segarra, Signatures of the genuine and matter-induced components of the CP-violation asymmetry in neutrino oscillations, JHEP 11 (2018) 063 [arXiv:1807.11879] [INSPIRE].
N. Cabibbo, Time Reversal Violation in Neutrino Oscillation, Phys. Lett. 72B (1978) 333 [INSPIRE].
S.M. Bilenky, J. Hosek and S.T. Petcov, On Oscillations of Neutrinos with Dirac and Majorana Masses, Phys. Lett. 94B (1980) 495 [INSPIRE].
J. Arafune and J. Sato, CP and T violation test in neutrino oscillation, Phys. Rev. D 55 (1997) 1653 [hep-ph/9607437] [INSPIRE].
S.M. Bilenky, C. Giunti and W. Grimus, Long baseline neutrino oscillation experiments and CP-violation in the lepton sector, Phys. Rev. D 58 (1998) 033001 [hep-ph/9712537] [INSPIRE].
J. Bernabeu, CP, T violation in neutrino oscillations, in Neutrino mixing. Festschrift in honour of Samoil Bilenky’s 70th birthday. Proceedings, International Meeting, Turin, Italy, March 25–27, 1999, pp. 41–49 (1999) [hep-ph/9904474] [INSPIRE].
P.F. Harrison and W.G. Scott, CP and T violation in neutrino oscillations and invariance of Jarlskog’s determinant to matter effects, Phys. Lett. B 476 (2000) 349 [hep-ph/9912435] [INSPIRE].
Z.-z. Xing, New formulation of matter effects on neutrino mixing and CP-violation, Phys. Lett. B 487 (2000) 327 [hep-ph/0002246] [INSPIRE].
J. Bernabeu and M.C. Banuls, CP and T violation in neutrino oscillations, Nucl. Phys. Proc. Suppl. 87 (2000) 315 [hep-ph/0003299] [INSPIRE].
M. Freund, Analytic approximations for three neutrino oscillation parameters and probabilities in matter, Phys. Rev. D 64 (2001) 053003 [hep-ph/0103300] [INSPIRE].
E.K. Akhmedov, P. Huber, M. Lindner and T. Ohlsson, T violation in neutrino oscillations in matter, Nucl. Phys. B 608 (2001) 394 [hep-ph/0105029] [INSPIRE].
H. Minakata, H. Nunokawa and S.J. Parke, CP and T violation in neutrino oscillations, AIP Conf. Proc. 670 (2003) 132 [hep-ph/0306221] [INSPIRE].
E.M. Henley, M.B. Johnson and L.S. Kisslinger, Time Reversal in Neutrino Oscillations, Int. J. Mod. Phys. E 20 (2011) 2463 [Erratum ibid. E 21 (2012) 1292001] [arXiv:1205.6430] [INSPIRE].
S.T. Petcov and Y.-L. Zhou, On Neutrino Mixing in Matter and CP and T Violation Effects in Neutrino Oscillations, Phys. Lett. B 785 (2018) 95 [arXiv:1806.09112] [INSPIRE].
L. Wolfenstein, Neutrino Oscillations in Matter, Phys. Rev. D 17 (1978) 2369 [INSPIRE].
S.P. Mikheyev and A. Yu. Smirnov, Resonance Amplification of Oscillations in Matter and Spectroscopy of Solar Neutrinos, Sov. J. Nucl. Phys. 42 (1985) 913 [INSPIRE].
V.D. Barger, K. Whisnant, S. Pakvasa and R.J.N. Phillips, Matter Effects on Three-Neutrino Oscillations, Phys. Rev. D 22 (1980) 2718 [INSPIRE].
T.-K. Kuo and J.T. Pantaleone, Neutrino Oscillations in Matter, Rev. Mod. Phys. 61 (1989) 937 [INSPIRE].
H.W. Zaglauer and K.H. Schwarzer, The Mixing Angles in Matter for Three Generations of Neutrinos and the MSW Mechanism, Z. Phys. C 40 (1988) 273 [INSPIRE].
P.I. Krastev, Searching for the MSW effect with neutrino beams from next generation accelerators, Nuovo Cim. A 103 (1990) 361 [INSPIRE].
R.H. Bernstein and S.J. Parke, Terrestrial long baseline neutrino oscillation experiments, Phys. Rev. D 44 (1991) 2069 [INSPIRE].
Hyper-Kamiokande collaboration, Hyper-Kamiokande Design Report, arXiv:1805.04163 [INSPIRE].
DUNE collaboration, Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE), arXiv:1512.06148 [INSPIRE].
IDS-NF collaboration, International Design Study for the Neutrino Factory, Interim Design Report, arXiv:1112.2853 [INSPIRE].
P.F. de Salas, D.V. Forero, C.A. Ternes, M. Tortola and J.W.F. Valle, Status of neutrino oscillations 2018: 3σ hint for normal mass ordering and improved CP sensitivity, Phys. Lett. B 782 (2018) 633 [arXiv:1708.01186] [INSPIRE].
T. Ohlsson and S. Zhou, Extrinsic and Intrinsic CPT Asymmetries in Neutrino Oscillations, Nucl. Phys. B 893 (2015) 482 [arXiv:1408.4722] [INSPIRE].
M.C. Banuls, G. Barenboim and J. Bernabeu, Medium effects for terrestrial and atmospheric neutrino oscillations, Phys. Lett. B 513 (2001) 391 [hep-ph/0102184] [INSPIRE].
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Bernabéu, J., Segarra, A. Do T asymmetries for neutrino oscillations in uniform matter have a CP-even component?. J. High Energ. Phys. 2019, 103 (2019). https://doi.org/10.1007/JHEP03(2019)103
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DOI: https://doi.org/10.1007/JHEP03(2019)103