Abstract
In the vanilla type-I seesaw leptogenesis scenario, CP violation required to generate the lepton asymmetries in the heavy Majorana neutrino decays stem from complex Dirac-type Yukawa couplings. In this paper we explore the case in which that CP violation originates from the vacuum expectation value of a complex scalar singlet at a very high scale. This non-trivial CP-violating phase can be successfully communicated to the low-energy neutrino sector via the heavy neutrino portal. The new scalar-singlet degrees of freedom generate new contributions to the CP asymmetries relevant for leptogenesis not only at the one-loop level but also through tree-level three-body decays. These are computed here for an arbitrary number of heavy neutrinos, Higgs doublets and scalar singlets. We also take into account the new decays and scattering processes that enter the unflavoured Boltzmann equations governing the heavy-neutrino particle densities and the (B – L)-asymmetry evolution. Having established the framework of interest, we present a simple model with two RH neutrinos, two Higgs doublets and a complex scalar singlet, supplemented with a Ƶ8 flavour symmetry. This symmetry minimises the number of free parameters without compromising the possibility of spontaneous CP violation and compatibility with neutrino data. In fact, the only viable Ƶ8 charge assignment shows a preference for a non-trivial spontaneous CP-violating phase, which in turn leads to a non-vanishing CP asymmetry due to the direct link between high- and low-energy CP violation. An interesting feature of this simple setup is that the usual wave and vertex type-I seesaw contributions to the CP asymmetry vanish due to the Ƶ8 symmetry. Thus, the observed baryon-to-photon ratio can be explained thanks to the new couplings among the heavy neutrinos and the new scalar degrees of freedom.
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References
A.B. McDonald, Nobel Lecture: The Sudbury Neutrino Observatory: Observation of flavor change for solar neutrinos, Rev. Mod. Phys. 88 (2016) 030502 [INSPIRE].
T. Kajita, Nobel Lecture: Discovery of atmospheric neutrino oscillations, Rev. Mod. Phys. 88 (2016) 030501 [INSPIRE].
P.F. de Salas et al., 2020 global reassessment of the neutrino oscillation picture, JHEP 02 (2021) 071 [arXiv:2006.11237] [INSPIRE].
I. Esteban, M.C. González-Garcia, M. Maltoni, T. Schwetz and A. Zhou, The fate of hints: updated global analysis of three-flavor neutrino oscillations, JHEP 09 (2020) 178 [arXiv:2007.14792] [INSPIRE].
F. Capozzi, E. Di Valentino, E. Lisi, A. Marrone, A. Melchiorri and A. Palazzo, Unfinished fabric of the three neutrino paradigm, Phys. Rev. D 104 (2021) 083031 [arXiv:2107.00532] [INSPIRE].
U. Rahaman, S. Razzaque and S.U. Sankar, A Review of the Tension between the T2K and NOνA Appearance Data and Hints to New Physics, Universe 8 (2022) 109 [arXiv:2201.03250] [INSPIRE].
DUNE collaboration, Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE): Conceptual Design Report, Volume 1: The LBNF and DUNE Projects, arXiv:1601.05471 [INSPIRE].
Hyper-Kamiokande collaboration, Hyper-Kamiokande Design Report, arXiv:1805.04163 [INSPIRE].
G.C. Branco, R.G. Felipe and F.R. Joaquim, Leptonic CP Violation, Rev. Mod. Phys. 84 (2012) 515 [arXiv:1111.5332] [INSPIRE].
S.M. Bilenky and C. Giunti, Neutrinoless Double-Beta Decay: a Probe of Physics Beyond the Standard Model, Int. J. Mod. Phys. A 30 (2015) 1530001 [arXiv:1411.4791] [INSPIRE].
S. Dell’Oro, S. Marcocci, M. Viel and F. Vissani, Neutrinoless double beta decay: 2015 review, Adv. High Energy Phys. 2016 (2016) 2162659 [arXiv:1601.07512] [INSPIRE].
M.J. Dolinski, A.W.P. Poon and W. Rodejohann, Neutrinoless Double-Beta Decay: Status and Prospects, Ann. Rev. Nucl. Part. Sci. 69 (2019) 219 [arXiv:1902.04097] [INSPIRE].
P. Minkowski, μ → eγ at a Rate of One Out of 109 Muon Decays?, Phys. Lett. B 67 (1977) 421 [INSPIRE].
M. Gell-Mann, P. Ramond and R. Slansky, Complex Spinors and Unified Theories, Conf. Proc. C 790927 (1979) 315 [arXiv:1306.4669] [INSPIRE].
T. Yanagida, Horizontal Gauge Symmetry and Masses of Neutrinos, in Seesaw 25, World Scientific (2005), pp. 261–264 [DOI].
S.L. Glashow, The Future of Elementary Particle Physics, NATO Sci. Ser. B 61 (1980) 687 [INSPIRE].
R.N. Mohapatra and G. Senjanovic, Neutrino Mass and Spontaneous Parity Nonconservation, Phys. Rev. Lett. 44 (1980) 912 [INSPIRE].
W. Konetschny and W. Kummer, Nonconservation of Total Lepton Number with Scalar Bosons, Phys. Lett. B 70 (1977) 433 [INSPIRE].
T.P. Cheng and L.-F. Li, Neutrino Masses, Mixings and Oscillations in SU(2) × U(1) Models of Electroweak Interactions, Phys. Rev. D 22 (1980) 2860 [INSPIRE].
G. Lazarides, Q. Shafi and C. Wetterich, Proton Lifetime and Fermion Masses in an SO(10) Model, Nucl. Phys. B 181 (1981) 287 [INSPIRE].
J. Schechter and J.W.F. Valle, Neutrino Masses in SU(2) × U(1) Theories, Phys. Rev. D 22 (1980) 2227 [INSPIRE].
R.N. Mohapatra and G. Senjanovic, Neutrino Masses and Mixings in Gauge Models with Spontaneous Parity Violation, Phys. Rev. D 23 (1981) 165 [INSPIRE].
M. Magg and C. Wetterich, Neutrino Mass Problem and Gauge Hierarchy, Phys. Lett. B 94 (1980) 61 [INSPIRE].
P.H. Frampton, S.L. Glashow and T. Yanagida, Cosmological sign of neutrino CP violation, Phys. Lett. B 548 (2002) 119 [hep-ph/0208157] [INSPIRE].
A. Ibarra and G.G. Ross, Neutrino phenomenology: The Case of two right-handed neutrinos, Phys. Lett. B 591 (2004) 285 [hep-ph/0312138] [INSPIRE].
K. Harigaya, M. Ibe and T.T. Yanagida, Seesaw Mechanism with Occam’s Razor, Phys. Rev. D 86 (2012) 013002 [arXiv:1205.2198] [INSPIRE].
T. Rink and K. Schmitz, Perturbed Yukawa Textures in the Minimal Seesaw Model, JHEP 03 (2017) 158 [arXiv:1611.05857] [INSPIRE].
Y. Shimizu, K. Takagi and M. Tanimoto, Towards the minimal seesaw model via CP violation of neutrinos, JHEP 11 (2017) 201 [arXiv:1709.02136] [INSPIRE].
D.M. Barreiros, R.G. Felipe and F.R. Joaquim, Minimal type-I seesaw model with maximally restricted texture zeros, Phys. Rev. D 97 (2018) 115016 [arXiv:1802.04563] [INSPIRE].
D.M. Barreiros, R.G. Felipe and F.R. Joaquim, Combining texture zeros with a remnant CP symmetry in the minimal type-I seesaw, JHEP 01 (2019) 223 [arXiv:1810.05454] [INSPIRE].
D.M. Barreiros, F.R. Joaquim and T.T. Yanagida, New approach to neutrino masses and leptogenesis with Occam’s razor, Phys. Rev. D 102 (2020) 055021 [arXiv:2003.06332] [INSPIRE].
W. Grimus, A.S. Joshipura, L. Lavoura and M. Tanimoto, Symmetry realization of texture zeros, Eur. Phys. J. C 36 (2004) 227 [hep-ph/0405016] [INSPIRE].
A. Dighe and N. Sahu, Texture zeroes and discrete flavor symmetries in light and heavy Majorana neutrino mass matrices: a bottom-up approach, arXiv:0812.0695 [INSPIRE].
B. Adhikary, A. Ghosal and P. Roy, mu tau symmetry, tribimaximal mixing and four zero neutrino Yukawa textures, JHEP 10 (2009) 040 [arXiv:0908.2686] [INSPIRE].
S. Dev, S. Gupta and R.R. Gautam, Zero Textures of the Neutrino Mass Matrix from Cyclic Family Symmetry, Phys. Lett. B 701 (2011) 605 [arXiv:1106.3451] [INSPIRE].
R. González Felipe and H. Serôdio, Abelian realization of phenomenological two-zero neutrino textures, Nucl. Phys. B 886 (2014) 75 [arXiv:1405.4263] [INSPIRE].
L.M. Cebola, D. Emmanuel-Costa and R.G. Felipe, Confronting predictive texture zeros in lepton mass matrices with current data, Phys. Rev. D 92 (2015) 025005 [arXiv:1504.06594] [INSPIRE].
R. Samanta and A. Ghosal, Probing maximal zero textures with broken cyclic symmetry in inverse seesaw, Nucl. Phys. B 911 (2016) 846 [arXiv:1507.02582] [INSPIRE].
T. Kobayashi, T. Nomura and H. Okada, Predictive neutrino mass textures with origin of flavor symmetries, Phys. Rev. D 98 (2018) 055025 [arXiv:1805.07101] [INSPIRE].
M.H. Rahat, P. Ramond and B. Xu, Asymmetric tribimaximal texture, Phys. Rev. D 98 (2018) 055030 [arXiv:1805.10684] [INSPIRE].
N. Nath, μ – τ reflection symmetry and its explicit breaking for leptogenesis in a minimal seesaw model, Mod. Phys. Lett. A 34 (2019) 1950329 [arXiv:1808.05062] [INSPIRE].
S.S. Correia, R.G. Felipe and F.R. Joaquim, Dirac neutrinos in the 2HDM with restrictive Abelian symmetries, Phys. Rev. D 100 (2019) 115008 [arXiv:1909.00833] [INSPIRE].
H.B. Camara, R.G. Felipe and F.R. Joaquim, Minimal inverse-seesaw mechanism with Abelian flavour symmetries, JHEP 05 (2021) 021 [arXiv:2012.04557] [INSPIRE].
Planck collaboration, Planck 2018 results. VI. Cosmological parameters, Astron. Astrophys. 641 (2020) A6 [arXiv:1807.06209] [INSPIRE].
A.D. Sakharov, Violation of CP Invariance, C asymmetry, and baryon asymmetry of the universe, Pisma Zh. Eksp. Teor. Fiz. 5 (1967) 32 [INSPIRE].
M.B. Gavela, P. Hernandez, J. Orloff and O. Pene, Standard model CP violation and baryon asymmetry, Mod. Phys. Lett. A 9 (1994) 795 [hep-ph/9312215] [INSPIRE].
M.B. Gavela, M. Lozano, J. Orloff and O. Pene, Standard model CP violation and baryon asymmetry. Part I: Zero temperature, Nucl. Phys. B 430 (1994) 345 [hep-ph/9406288] [INSPIRE].
M.B. Gavela, P. Hernandez, J. Orloff, O. Pene and C. Quimbay, Standard model CP violation and baryon asymmetry. Part II: Finite temperature, Nucl. Phys. B 430 (1994) 382 [hep-ph/9406289] [INSPIRE].
M. Fukugita and T. Yanagida, Baryogenesis Without Grand Unification, Phys. Lett. B 174 (1986) 45 [INSPIRE].
W. Buchmuller, P. Di Bari and M. Plümacher, Leptogenesis for pedestrians, Annals Phys. 315 (2005) 305 [hep-ph/0401240] [INSPIRE].
S. Davidson, E. Nardi and Y. Nir, Leptogenesis, Phys. Rept. 466 (2008) 105 [arXiv:0802.2962] [INSPIRE].
C.S. Fong, E. Nardi and A. Riotto, Leptogenesis in the Universe, Adv. High Energy Phys. 2012 (2012) 158303 [arXiv:1301.3062] [INSPIRE].
T. Hambye, Leptogenesis: beyond the minimal type I seesaw scenario, New J. Phys. 14 (2012) 125014 [arXiv:1212.2888] [INSPIRE].
R. González Felipe, F.R. Joaquim and B.M. Nobre, Radiatively induced leptogenesis in a minimal seesaw model, Phys. Rev. D 70 (2004) 085009 [hep-ph/0311029] [INSPIRE].
F.R. Joaquim, Radiative leptogenesis in minimal seesaw models, Nucl. Phys. B Proc. Suppl. 145 (2005) 276 [hep-ph/0501221] [INSPIRE].
G.C. Branco, M.N. Rebelo and J.I. Silva-Marcos, Leptogenesis, Yukawa textures and weak basis invariants, Phys. Lett. B 633 (2006) 345 [hep-ph/0510412] [INSPIRE].
A. Abada, S. Davidson, A. Ibarra, F.X. Josse-Michaux, M. Losada and A. Riotto, Flavour Matters in Leptogenesis, JHEP 09 (2006) 010 [hep-ph/0605281] [INSPIRE].
J. Zhang and S. Zhou, A Further Study of the Frampton-Glashow-Yanagida Model for Neutrino Masses, Flavor Mixing and Baryon Number Asymmetry, JHEP 09 (2015) 065 [arXiv:1505.04858] [INSPIRE].
K. Siyeon, Seesaw Scale and CP Phases in a Minimal Model of Leptogenesis, J. Korean Phys. Soc. 69 (2016) 1638 [arXiv:1611.04572] [INSPIRE].
T. Geib and S.F. King, Comprehensive renormalization group analysis of the littlest seesaw model, Phys. Rev. D 97 (2018) 075010 [arXiv:1709.07425] [INSPIRE].
A. Achelashvili and Z. Tavartkiladze, Texture Zero Neutrino Models and Their Connection with Resonant Leptogenesis, Nucl. Phys. B 929 (2018) 21 [arXiv:1710.10955] [INSPIRE].
Y. Shimizu, K. Takagi and M. Tanimoto, Neutrino CP violation and sign of baryon asymmetry in the minimal seesaw model, Phys. Lett. B 778 (2018) 6 [arXiv:1711.03863] [INSPIRE].
L. Covi, E. Roulet and F. Vissani, CP violating decays in leptogenesis scenarios, Phys. Lett. B 384 (1996) 169 [hep-ph/9605319] [INSPIRE].
S. Antusch, P. Di Bari, D.A. Jones and S.F. King, Leptogenesis in the Two Right-Handed Neutrino Model Revisited, Phys. Rev. D 86 (2012) 023516 [arXiv:1107.6002] [INSPIRE].
V.A. Kuzmin, V.A. Rubakov and M.E. Shaposhnikov, On the Anomalous Electroweak Baryon Number Nonconservation in the Early Universe, Phys. Lett. B 155 (1985) 36 [INSPIRE].
Y. Chikashige, R.N. Mohapatra and R.D. Peccei, Spontaneously Broken Lepton Number and Cosmological Constraints on the Neutrino Mass Spectrum, Phys. Rev. Lett. 45 (1980) 1926 [INSPIRE].
Y. Chikashige, R.N. Mohapatra and R.D. Peccei, Are There Real Goldstone Bosons Associated with Broken Lepton Number?, Phys. Lett. B 98 (1981) 265 [INSPIRE].
G.B. Gelmini and M. Roncadelli, Left-Handed Neutrino Mass Scale and Spontaneously Broken Lepton Number, Phys. Lett. B 99 (1981) 411 [INSPIRE].
A. Pilaftsis, Electroweak Resonant Leptogenesis in the Singlet Majoron Model, Phys. Rev. D 78 (2008) 013008 [arXiv:0805.1677] [INSPIRE].
D. Aristizabal Sierra, M. Tortola, J.W.F. Valle and A. Vicente, Leptogenesis with a dynamical seesaw scale, JCAP 07 (2014) 052 [arXiv:1405.4706] [INSPIRE].
M. Le Dall and A. Ritz, Leptogenesis and the Higgs Portal, Phys. Rev. D 90 (2014) 096002 [arXiv:1408.2498] [INSPIRE].
T. Alanne, A. Meroni and K. Tuominen, Neutrino mass generation and leptogenesis via pseudo-Nambu-Goldstone Higgs portal, Phys. Rev. D 96 (2017) 095015 [arXiv:1706.10128] [INSPIRE].
T. Alanne, T. Hugle, M. Platscher and K. Schmitz, Low-scale leptogenesis assisted by a real scalar singlet, JCAP 03 (2019) 037 [arXiv:1812.04421] [INSPIRE].
Y. Abe, T. Ito and K. Yoshioka, Leptonic CP asymmetry and Light flavored scalar, arXiv:2110.11096 [INSPIRE].
G.C. Branco, P.A. Parada and M.N. Rebelo, A Common origin for all CP violations, hep-ph/0307119 [INSPIRE].
S.Y. Khlebnikov and M.E. Shaposhnikov, The Statistical Theory of Anomalous Fermion Number Nonconservation, Nucl. Phys. B 308 (1988) 885 [INSPIRE].
J.A. Harvey and M.S. Turner, Cosmological baryon and lepton number in the presence of electroweak fermion number violation, Phys. Rev. D 42 (1990) 3344 [INSPIRE].
J. Gluza and M. Zralek, Feynman rules for Majorana neutrino interactions, Phys. Rev. D 45 (1992) 1693 [INSPIRE].
A. Denner, H. Eck, O. Hahn and J. Kublbeck, Feynman rules for fermion number violating interactions, Nucl. Phys. B 387 (1992) 467 [INSPIRE].
A. Denner, H. Eck, O. Hahn and J. Kublbeck, Compact Feynman rules for Majorana fermions, Phys. Lett. B 291 (1992) 278 [INSPIRE].
A. Abada, S. Davidson, F.-X. Josse-Michaux, M. Losada and A. Riotto, Flavor issues in leptogenesis, JCAP 04 (2006) 004 [hep-ph/0601083] [INSPIRE].
E. Nardi, Y. Nir, E. Roulet and J. Racker, The Importance of flavor in leptogenesis, JHEP 01 (2006) 164 [hep-ph/0601084] [INSPIRE].
S. Blanchet and P. Di Bari, Flavor effects on leptogenesis predictions, JCAP 03 (2007) 018 [hep-ph/0607330] [INSPIRE].
P.S.B. Dev, P. Di Bari, B. Garbrecht, S. Lavignac, P. Millington and D. Teresi, Flavor effects in leptogenesis, Int. J. Mod. Phys. A 33 (2018) 1842001 [arXiv:1711.02861] [INSPIRE].
G.F. Giudice, A. Notari, M. Raidal, A. Riotto and A. Strumia, Towards a complete theory of thermal leptogenesis in the SM and MSSM, Nucl. Phys. B 685 (2004) 89 [hep-ph/0310123] [INSPIRE].
E.W. Kolb and S. Wolfram, Baryon Number Generation in the Early Universe, Nucl. Phys. B 172 (1980) 224 [INSPIRE].
W. Buchmuller and M. Plümacher, CP asymmetry in Majorana neutrino decays, Phys. Lett. B 431 (1998) 354 [hep-ph/9710460] [INSPIRE].
W. Buchmuller, Some aspects of baryogenesis and lepton number violation, in NATO ASI 2000: Recent Developments in Particle Physics and Cosmology, Cascais Portugal, June 26 – July 7 2000, pp. 281–3142000 [hep-ph/0101102] [INSPIRE].
S. Dimopoulos and L. Susskind, On the Baryon Number of the Universe, Phys. Rev. D 18 (1978) 4500 [INSPIRE].
A.D. Dolgov and Y.B. Zeldovich, Cosmology and Elementary Particles, Rev. Mod. Phys. 53 (1981) 1 [INSPIRE].
M. Plümacher, Baryogenesis and lepton number violation, Z. Phys. C 74 (1997) 549 [hep-ph/9604229] [INSPIRE].
M. Plümacher, Baryon asymmetry, neutrino mixing and supersymmetric SO(10) unification, Nucl. Phys. B 530 (1998) 207 [hep-ph/9704231] [INSPIRE].
M. Plümacher, Baryon asymmetry, neutrino mixing and supersymmetric SO(10) unification, Ph.D. Thesis, Fakultät für Physik, Institut für Experimentalphysik (IExpPh), Universität Hamburg (1998) [DOI] [hep-ph/9807557] [INSPIRE].
G.C. Branco, L. Lavoura and J.P. Silva, CP Violation, International Series of Monographs on Physics 103, Clarendon Press (1999) [ISBN: 9780198503996].
KamLAND-Zen collaboration, First Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen, arXiv:2203.02139 [INSPIRE].
KATRIN collaboration, Direct neutrino-mass measurement with sub-electronvolt sensitivity, Nature Phys. 18 (2022) 160 [arXiv:2105.08533] [INSPIRE].
F. Hahn-Woernle, M. Plümacher and Y.Y.Y. Wong, Full Boltzmann equations for leptogenesis including scattering, JCAP 08 (2009) 028 [arXiv:0907.0205] [INSPIRE].
G.C. Branco, P.M. Ferreira, L. Lavoura, M.N. Rebelo, M. Sher and J.P. Silva, Theory and phenomenology of two-Higgs-doublet models, Phys. Rept. 516 (2012) 1 [arXiv:1106.0034] [INSPIRE].
W. Buchmuller and M. Plümacher, Neutrino masses and the baryon asymmetry, Int. J. Mod. Phys. A 15 (2000) 5047 [hep-ph/0007176] [INSPIRE].
W. Buchmuller, P. Di Bari and M. Plümacher, Cosmic microwave background, matter-antimatter asymmetry and neutrino masses, Nucl. Phys. B 643 (2002) 367 [hep-ph/0205349] [INSPIRE].
W. Buchmuller, P. Di Bari and M. Plümacher, Some aspects of thermal leptogenesis, New J. Phys. 6 (2004) 105 [hep-ph/0406014] [INSPIRE].
S. Biondini et al., Status of rates and rate equations for thermal leptogenesis, Int. J. Mod. Phys. A 33 (2018) 1842004 [arXiv:1711.02864] [INSPIRE].
B. Garbrecht, Why is there more matter than antimatter? Calculational methods for leptogenesis and electroweak baryogenesis, Prog. Part. Nucl. Phys. 110 (2020) 103727 [arXiv:1812.02651] [INSPIRE].
J. Klarić, M. Shaposhnikov and I. Timiryasov, Reconciling resonant leptogenesis and baryogenesis via neutrino oscillations, Phys. Rev. D 104 (2021) 055010 [arXiv:2103.16545] [INSPIRE].
E.W. Kolb and M.S. Turner, The Early Universe, vol. 69 (1990), [DOI] [INSPIRE].
M.A. Luty, Baryogenesis via leptogenesis, Phys. Rev. D 45 (1992) 455 [INSPIRE].
I.F. Ginzburg, Effect of initial particle instability in muon collisions, hep-ph/9509314 [INSPIRE].
K. Melnikov and V.G. Serbo, Processes with the T channel singularity in the physical region: Finite beam sizes make cross-sections finite, Nucl. Phys. B 483 (1997) 67 [hep-ph/9601290] [INSPIRE].
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Barreiros, D.M., Câmara, H.B., Felipe, R.G. et al. Scalar-singlet assisted leptogenesis with CP violation from the vacuum. J. High Energ. Phys. 2023, 10 (2023). https://doi.org/10.1007/JHEP01(2023)010
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DOI: https://doi.org/10.1007/JHEP01(2023)010