Abstract
We consider a tree-level enhancement to the violation of lepton flavour universality in light meson decays arising from modified Wℓν couplings in the standard model minimally extended by sterile neutrinos. Due to the presence of additional mixings between the active (left-handed) neutrinos and the new sterile states, the deviation from unitarity of the leptonic mixing matrix intervening in charged currents might lead to a tree-level enhancement of R P = Γ(P → eν)/Γ(P → μν), with P = K, π. We illustrate these enhancements in the case of the inverse seesaw model, showing that one can saturate the current experimental bounds on Δr K (and Δr π ), while in agreement with the different experimental and observational constraints.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
V. Cirigliano and I. Rosell, Two-loop effective theory analysis of π(K) → e \(\overline{\nu}\) e [γ] branching ratios, Phys. Rev. Lett. 99 (2007) 231801 [arXiv:0707.3439] [INSPIRE].
M. Finkemeier, Radiative corrections to π l2 and K l2 decays, Phys. Lett. B 387 (1996) 391 [hep-ph/9505434] [INSPIRE].
NA48/2 and NA62 collaborations, E. Goudzovski, Kaon programme at CERN: recent results, PoS(EPS-HEP2011)181 [arXiv:1111.2818] [INSPIRE].
G. Czapek et al., Branching ratio for the rare pion decay into positron and neutrino, Phys. Rev. Lett. 70 (1993) 17 [INSPIRE].
NA48/2 and NA62 collaborations, E. Goudzovski, Kaon experiments at CERN: recent results and prospects, arXiv:1208.2885 [INSPIRE].
D. Pocanic et al., New studies of allowed pion and muon decays, arXiv:1210.5025 [INSPIRE].
C. Malbrunot et al., Measurement of the pion branching ratio at TRIUMF, AIP Conf. Proc. 1441 (2012) 564 [INSPIRE].
A. Celis, M. Jung, X.-Q. Li and A. Pich, Sensitivity to charged scalars in B → D (∗) τν τ and B→τν τ decays, JHEP 01 (2013) 054 [arXiv:1210.8443] [INSPIRE].
W.-S. Hou, Enhanced charged Higgs boson effects in B − → τ \(\overline{\nu}\) , μ \(\overline{\nu}\) and b → τ n¯u + X, Phys. Rev. D 48 (1993) 2342 [INSPIRE].
A. Masiero, P. Paradisi and R. Petronzio, Probing new physics through μ-e universality in K →lν, Phys. Rev. D 74 (2006) 011701 [hep-ph/0511289] [INSPIRE].
A. Masiero, P. Paradisi and R. Petronzio, Anatomy and phenomenology of the lepton flavor universality in SUSY theories, JHEP 11 (2008) 042 [arXiv:0807.4721] [INSPIRE].
J. Ellis, S. Lola and M. Raidal, Supersymmetric grand unification and lepton universality in K →lν decays, Nucl. Phys. B 812 (2009) 128 [arXiv:0809.5211][INSPIRE].
J. Girrbach and U. Nierste, Γ(K → eν)/Γ(K → μν) in the minimal supersymmetric standard model, arXiv:1202.4906 [INSPIRE].
R. Fonseca, J. Romao and A. Teixeira, Revisiting the Γ(K → eν)/Γ(K → μν) ratio in supersymmetric unified models, Eur. Phys. J. C 72 (2012) 2228 [arXiv:1205.1411] [INSPIRE].
A. Kusenko, Sterile neutrinos: the dark side of the light fermions, Phys. Rept. 481 (2009) 1 [arXiv:0906.2968] [INSPIRE].
J. Schechter and J. Valle, Neutrino masses in SU(2) × U(1) theories, Phys. Rev. D 22 (1980) 2227 [INSPIRE].
M. Gronau, C.N. Leung and J.L. Rosner, Extending limits on neutral heavy leptons, Phys. Rev. D 29 (1984) 2539 [INSPIRE].
R. Shrock, New tests for and bounds on, neutrino masses and lepton mixing, Phys. Lett. B 96 (1980) 159 [INSPIRE].
R.E. Shrock, General theory of weak leptonic and semileptonic decays. 1. Leptonic pseudoscalar meson decays, with associated tests for and bounds on, neutrino masses and lepton mixing, Phys. Rev. D 24 (1981) 1232 [INSPIRE].
T. Asaka, S. Blanchet and M. Shaposhnikov, The νMSM, dark matter and neutrino masses, Phys. Lett. B 631 (2005) 151 [hep-ph/0503065] [INSPIRE].
A. Ibarra, E. Molinaro and S. Petcov, TeV scale see-saw mechanisms of neutrino mass generation, the Majorana nature of the heavy singlet neutrinos and (ββ)0ν -decay, JHEP 09 (2010) 108 [arXiv:1007.2378] [INSPIRE].
R. Mohapatra and J. Valle, Neutrino mass and baryon number nonconservation in superstring models, Phys. Rev. D 34 (1986) 1642 [INSPIRE].
M. Malinsky, T. Ohlsson and H. Zhang, Non-unitarity effects in a realistic low-scale seesaw model, Phys. Rev. D 79 (2009) 073009 [arXiv:0903.1961] [INSPIRE].
D. Forero, M. Tortola and J. Valle, Global status of neutrino oscillation parameters after Neutrino-2012, Phys. Rev. D 86 (2012) 073012 [arXiv:1205.4018] [INSPIRE].
A. Atre, T. Han, S. Pascoli and B. Zhang, The search for heavy Majorana neutrinos, JHEP 05 (2009) 030 [arXiv:0901.3589] [INSPIRE].
S. Antusch, J.P. Baumann and E. Fernandez-Martinez, Non-standard neutrino interactions with matter from physics beyond the standard model, Nucl. Phys. B 810 (2009) 369 [arXiv:0807.1003] [INSPIRE].
A. Abada, D. Das, A. Vicente and C. Weiland, Enhancing lepton flavour violation in the supersymmetric inverse seesaw beyond the dipole contribution, JHEP 09 (2012) 015 [arXiv:1206.6497] [INSPIRE].
MEG collaboration, J. Adam et al., New limit on the lepton-flavour violating decay μ + → e + γ, Phys. Rev. Lett. 107 (2011) 171801 [arXiv:1107.5547] [INSPIRE].
R. Alonso, M. Dhen, M. Gavela and T. Hambye, Muon conversion to electron in nuclei in type-I seesaw models, JHEP 01 (2013) 118 [arXiv:1209.2679] [INSPIRE].
A. Ilakovac and A. Pilaftsis, Flavor violating charged lepton decays in seesaw-type models, Nucl. Phys. B 437 (1995) 491 [hep-ph/9403398] [INSPIRE].
F. Deppisch and J. Valle, Enhanced lepton flavor violation in the supersymmetric inverse seesaw model, Phys. Rev. D 72 (2005) 036001 [hep-ph/0406040] [INSPIRE].
Particle Data Group collaboration, J. Beringer et al., Review of particle physics (RPP), Phys. Rev. D 86 (2012) 010001 [INSPIRE].
P. Bhupal Dev, R. Franceschini and R. Mohapatra, Bounds on TeV seesaw models from LHC Higgs data, Phys. Rev. D 86 (2012) 093010 [arXiv:1207.2756] [INSPIRE].
F. del Aguila, J. de Blas and M. Pérez-Victoria, Effects of new leptons in electroweak precision data, Phys. Rev. D 78 (2008) 013010 [arXiv:0803.4008] [INSPIRE].
A.Y. Smirnov and R. Zukanovich Funchal, Sterile neutrinos: direct mixing effects versus induced mass matrix of active neutrinos, Phys. Rev. D 74 (2006) 013001 [hep-ph/0603009] [INSPIRE].
G. Gelmini, E. Osoba, S. Palomares-Ruiz and S. Pascoli, MeV sterile neutrinos in low reheating temperature cosmological scenarios, JCAP 10 (2008) 029 [arXiv:0803.2735] [INSPIRE].
M. Gonzalez-Garcia and J. Valle, Fast decaying neutrinos and observable flavor violation in a new class of Majoron models, Phys. Lett. B 216 (1989) 360 [INSPIRE].
J. Casas and A. Ibarra, Oscillating neutrinos and μ → e, γ, Nucl. Phys. B 618 (2001) 171 [hep-ph/0103065] [INSPIRE].
D. Forero, S. Morisi, M. Tortola and J. Valle, Lepton flavor violation and non-unitary lepton mixing in low-scale type-I seesaw, JHEP 09 (2011) 142 [arXiv:1107.6009] [INSPIRE].
L. Lello and D. Boyanovsky, Searching for sterile neutrinos from π and K decays, arXiv:1208.5559 [INSPIRE].
A. Abada, A.M. Teixiera, A. Vicente and C. Weiland, work in preparation.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1211.3052
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License ( https://creativecommons.org/licenses/by/2.0 ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
About this article
Cite this article
Abada, A., Das, D., Teixeira, A.M. et al. Tree-level lepton universality violation in the presence of sterile neutrinos: impact for R K and R π . J. High Energ. Phys. 2013, 48 (2013). https://doi.org/10.1007/JHEP02(2013)048
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP02(2013)048