Abstract
Flavor symmetries successfully explain lepton and quark masses and mixings yet it is usually hard to distinguish different models that predict the same mixing angles. Further experimental input could be available, if the agents of flavor breaking are sufficiently low in mass and detectable or if new physics with non-trivial flavor charges is sufficiently low in mass and detectable. The recent hint for lepton-nonuniversality in the ratio of branching fractions B → Kμμ over B → Kee, R K , suggests the latter, at least for indirect detection via rare decays. We demonstrate the discriminating power of the rare decay data on flavor model building taking into account viable leptonic mixings and show how correlations with other observables exist in leptoquark models. We give expectations for branching ratios B → Kℓℓ′, B (s) → ℓℓ′ and ℓ → ℓ′γ, and Higgs decays h → ℓℓ′.
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References
LHCb collaboration, Test of lepton universality using B + → K +ℓ+ℓ− decays, Phys. Rev. Lett. 113 (2014) 151601 [arXiv:1406.6482] [INSPIRE].
G. Hiller and F. Krüger, More model independent analysis of b → s processes, Phys. Rev. D 69 (2004) 074020 [hep-ph/0310219] [INSPIRE].
G. Hiller and M. Schmaltz, R K and future b → sℓℓ physics beyond the standard model opportunities, Phys. Rev. D 90 (2014) 054014 [arXiv:1408.1627] [INSPIRE].
S.L. Glashow, D. Guadagnoli and K. Lane, Lepton flavor violation in B decays?, Phys. Rev. Lett. 114 (2015) 091801 [arXiv:1411.0565] [INSPIRE].
B. Gripaios, M. Nardecchia and S.A. Renner, Composite leptoquarks and anomalies in B-meson decays, JHEP 05 (2015) 006 [arXiv:1412.1791] [INSPIRE].
S. Sahoo and R. Mohanta, Scalar leptoquarks and the rare B meson decays, Phys. Rev. D 91 (2015) 094019 [arXiv:1501.05193] [INSPIRE].
CMS collaboration, Search for lepton-flavour-violating decays of the Higgs boson, arXiv:1502.07400 [hrefhttps://cds.cern.ch/record/1994783CMS-PAS-HIG-14-005] [INSPIRE].
I. de Medeiros Varzielas and G.G. Ross, SU(3) family symmetry and neutrino bi-tri-maximal mixing, Nucl. Phys. B 733 (2006) 31 [hep-ph/0507176] [INSPIRE].
G. Altarelli and F. Feruglio, Tri-bimaximal neutrino mixing, A 4 and the modular symmetry, Nucl. Phys. B 741 (2006) 215 [hep-ph/0512103] [INSPIRE].
G. Altarelli and D. Meloni, A simplest A 4 model for tri-bimaximal neutrino mixing, J. Phys. G 36 (2009) 085005 [arXiv:0905.0620] [INSPIRE].
I. de Medeiros Varzielas and L. Merlo, Ultraviolet completion of flavour models, JHEP 02 (2011) 062 [arXiv:1011.6662] [INSPIRE].
I. de Medeiros Varzielas and D. Pidt, UV completions of flavour models and large θ 13, JHEP 03 (2013) 065 [arXiv:1211.5370] [INSPIRE].
I. Dorsner, S. Fajfer and N. Kosnik, Heavy and light scalar leptoquarks in proton decay, Phys. Rev. D 86 (2012) 015013 [arXiv:1204.0674] [INSPIRE].
Particle Data Group collaboration, K.A. Olive et al., Review of particle physics, Chin. Phys. C 38 (2014) 090001 [INSPIRE].
CMS Collaboration, Search for pair-production of first generation scalar leptoquarks in pp collisions at \( \sqrt{s}=8 \) TeV, CMS-PAS-EXO-12-041 (2012).
ATLAS collaboration, Search for third generation scalar leptoquarks in pp collisions at \( \sqrt{s}=7 \) TeV with the ATLAS detector, JHEP 06 (2013) 033 [arXiv:1303.0526] [INSPIRE].
ZEUS collaboration, Search for first-generation leptoquarks at HERA, PoS(ICHEP2012)145.
Heavy Flavor Averaging Group (HFAG) collaboration, Y. Amhis et al., Averages of b-hadron, c-hadron and τ -lepton properties as of summer 2014, arXiv:1412.7515 [INSPIRE].
T. Blake, T. Gershon and G. Hiller, Rare b hadron decays at the LHC, arXiv:1501.03309 [INSPIRE].
C.D. Froggatt and H.B. Nielsen, Hierarchy of quark masses, Cabibbo angles and CP-violation, Nucl. Phys. B 147 (1979) 277 [INSPIRE].
P.H. Chankowski, K. Kowalska, S. Lavignac and S. Pokorski, Update on fermion mass models with an anomalous horizontal U(1) symmetry, Phys. Rev. D 71 (2005) 055004 [hep-ph/0501071] [INSPIRE].
MEG collaboration, J. Adam et al., New constraint on the existence of the μ + → e +γ decay, Phys. Rev. Lett. 110 (2013) 201801 [arXiv:1303.0754] [INSPIRE].
A.M. Baldini et al., MEG upgrade proposal, arXiv:1301.7225 [INSPIRE].
Belle collaboration, K. Hayasaka et al., New search for τ → μγ and τ → eγ decays at Belle, Phys. Lett. B 666 (2008) 16 [arXiv:0705.0650] [INSPIRE].
BaBar collaboration, B. Aubert et al., Searches for lepton flavor violation in the decays τ ± →e ±γ and τ ± → μ ±γ, Phys. Rev. Lett. 104 (2010) 021802 [arXiv:0908.2381] [INSPIRE].
T. Aushev et al., Physics at super B factory, arXiv:1002.5012 [INSPIRE].
Belle collaboration, Y. Miyazaki et al., Search for lepton flavor violating τ − decays into l − η, l − η′ and l − π 0, Phys. Lett. B 648 (2007) 341 [hep-ex/0703009] [INSPIRE].
BaBar collaboration, B. Aubert et al., Measurements of branching fractions, rate asymmetries and angular distributions in the rare decays B → Kℓ+ℓ− and B → K ∗ℓ+ℓ−, Phys. Rev. D 73 (2006) 092001 [hep-ex/0604007] [INSPIRE].
BaBar collaboration, B. Aubert et al., Search for the rare decay B → πℓ+ℓ−, Phys. Rev. Lett. 99 (2007) 051801 [hep-ex/0703018] [INSPIRE].
I. Dorsner, J. Drobnak, S. Fajfer, J.F. Kamenik and N. Kosnik, Limits on scalar leptoquark interactions and consequences for GUTs, JHEP 11 (2011) 002 [arXiv:1107.5393] [INSPIRE].
S. Davidson, D.C. Bailey and B.A. Campbell, Model independent constraints on leptoquarks from rare processes, Z. Phys. C 61 (1994) 613 [hep-ph/9309310] [INSPIRE].
SINDRUM II collaboration, W.H. Bertl et al., A search for muon to electron conversion in muonic gold, Eur. Phys. J. C 47 (2006) 337 [INSPIRE].
COMET collaboration, Y.G. Cui et al., Conceptual design report for experimental search for lepton flavor violating μ − -e − conversion at sensitivity of 10−16 with a slow-extracted bunched proton beam (COMET), KEK-2009-10 (2009) [INSPIRE].
Mu2e collaboration, L. Bartoszek et al., Mu2e technical design report, arXiv:1501.05241 [INSPIRE].
C. Bobeth et al., B s,d → ℓ+ℓ− in the standard model with reduced theoretical uncertainty, Phys. Rev. Lett. 112 (2014) 101801 [arXiv:1311.0903] [INSPIRE].
LHCb collaboration, Search for the lepton-flavor violating decays B 0 s → e ± μ ∓ and B 0 → e ± μ ∓, Phys. Rev. Lett. 111 (2013) 141801 [arXiv:1307.4889] [INSPIRE].
I. de Medeiros Varzielas, Non-Abelian family symmetries in Pati-Salam unification, JHEP 01 (2012) 097 [arXiv:1111.3952] [INSPIRE].
I. de Medeiros Varzielas and G.G. Ross, Discrete family symmetry, Higgs mediators and θ 13, JHEP 12 (2012) 041 [arXiv:1203.6636] [INSPIRE].
I. de Medeiros Varzielas, S.F. King and G.G. Ross, Neutrino tri-bi-maximal mixing from a non-Abelian discrete family symmetry, Phys. Lett. B 648 (2007) 201 [hep-ph/0607045] [INSPIRE].
G. Altarelli, F. Feruglio and C. Hagedorn, A SUSY SU(5) grand unified model of tri-bimaximal mixing from A 4, JHEP 03 (2008) 052 [arXiv:0802.0090] [INSPIRE].
A.J. Buras, J. Girrbach-Noe, C. Niehoff and D.M. Straub, \( B\to {K}^{\left(\ast \right)}\nu \overline{\nu} \) decays in the standard model and beyond, JHEP 02 (2015) 184 [arXiv:1409.4557] [INSPIRE].
R. Harnik, J. Kopp and J. Zupan, Flavor violating Higgs decays, JHEP 03 (2013) 026 [arXiv:1209.1397] [INSPIRE].
A. Dery, A. Efrati, Y. Nir, Y. Soreq and V. Susič, Model building for flavor changing Higgs couplings, Phys. Rev. D 90 (2014) 115022 [arXiv:1408.1371] [INSPIRE].
A. Crivellin, G. D’Ambrosio and J. Heeck, Explaining h → μ ± τ ∓ , B → K ∗ μ + μ − and B → Kμ + μ − /B → Ke + e − in a two-Higgs-doublet model with gauged L μ −L τ , Phys. Rev. Lett. 114 (2015) 151801 [arXiv:1501.00993] [INSPIRE].
A. Crivellin, G. D’Ambrosio and J. Heeck, Addressing the LHC flavor anomalies with horizontal gauge symmetries, Phys. Rev. D 91 (2015) 075006 [arXiv:1503.03477] [INSPIRE].
Y. Nir, Probing new physics with flavor physics (and probing flavor physics with new physics), arXiv:0708.1872 [INSPIRE].
G. Hiller and M. Schmaltz, Diagnosing lepton-nonuniversality in b → sℓℓ, JHEP 02 (2015) 055 [arXiv:1411.4773] [INSPIRE].
I. Dorsner et al., New physics models facing lepton flavor violating Higgs decays at the percent level, arXiv:1502.07784 [INSPIRE].
LHCb collaboration, Angular analysis of the B 0 → K ∗0 μ + μ − decay, LHCb-CONF-2015-002 (2015).
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de Medeiros Varzielas, I., Hiller, G. Clues for flavor from rare lepton and quark decays. J. High Energ. Phys. 2015, 72 (2015). https://doi.org/10.1007/JHEP06(2015)072
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DOI: https://doi.org/10.1007/JHEP06(2015)072