Skip to main content
SpringerLink
Log in

Lepton flavour violation in the presence of a fourth generation of quarks and leptons

  • Published:
Journal of High Energy Physics Aims and scope Submit manuscript

Abstract

We calculate the rates for the charged lepton flavour violating (LFV) decays ℓ i → ℓ j γ, τ → ℓ π, τ → ℓ η (′), μ − → e − e + e −, the six three-body leptonic decays τ − → ℓ i − ℓ j + ℓ k − and the rate for μ − e conversion in nuclei in the Standard Model (SM3) extended by a fourth generation of quarks and leptons (SM4), assuming that neutrinos are Dirac particles. We also calculate branching ratios for K L → μe, K L → π 0 μe, B d,s → μe, B d,s → μe and B d,s → τμ. We find that the pattern of the LFV branching ratios in the SM4 differs significantly from the one encountered in the MSSM, allowing to distinguish these two models with the help of LFV processes in a transparent manner. Also differences with respect to the Littlest Higgs model with T-parity are found. Most importantly the branching ratios for ℓ i → ℓ j γ, τ → ℓ π, τ → ℓ η (′), μ − → e − e + e −, τ − → e − e + e −, τ − → μ − μ + μ −, τ − → e − μ + μ − and τ − → μ − e + e − can all still be as large as the present experimental upper bounds but not necessarily simultaneously. Also the rate for μ − e conversion in nuclei can reach the corresponding upper bound.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. MEGA collaboration, M.L. Brooks et al., New Limit for the Family-Number Non-conserving Decay μ + → e + γ, Phys. Rev. Lett. 83 (1999) 1521 [hep-ex/9905013] [SPIRES].

    Article  ADS  Google Scholar 

  2. S. Yamada, Search for the lepton flavor violating decay μ → eγ in the MEG experiment, Nucl. Phys. Proc. Suppl. 144 (2005) 185 [SPIRES].

    Article  ADS  Google Scholar 

  3. MEG home page, http://meg.web.psi.ch/.

  4. M. Blanke, A.J. Buras, B. Duling, A. Poschenrieder and C. Tarantino, Charged Lepton Flavour Violation and (g − 2) μ in the Littlest Higgs Model with T-Parity: a clear Distinction from Supersymmetry, JHEP 05 (2007) 013 [hep-ph/0702136] [SPIRES].

    Article  ADS  Google Scholar 

  5. A.J. Buras et al., Patterns of Flavour Violation in the Presence of a Fourth Generation of Quarks and Leptons, arXiv:1002.2126 [SPIRES].

  6. A.J. Buras et al., The Impact of a 4th Generation on Mixing and CP-violation in the Charm System, JHEP 07 (2010) 094 [arXiv:1004.4565] [SPIRES].

    Article  ADS  Google Scholar 

  7. G.D. Kribs, T. Plehn, M. Spannowsky and T.M.P. Tait, Four generations and Higgs physics, Phys. Rev. D 76 (2007) 075016 [arXiv:0706.3718] [SPIRES].

    ADS  Google Scholar 

  8. A. Soni, A.K. Alok, A. Giri, R. Mohanta and S. Nandi, The Fourth family: A Natural explanation for the observed pattern of anomalies in B − CP asymmetries, Phys. Lett. B 683 (2010) 302 [arXiv:0807.1971] [SPIRES].

    ADS  Google Scholar 

  9. B. Holdom et al., Four Statements about the Fourth Generation, PMC Phys. A 3 (2009) 4 [arXiv:0904.4698] [SPIRES].

    Article  ADS  Google Scholar 

  10. G. Eilam, B. Melic and J. Trampetic, CP violation and the 4th generation, Phys. Rev. D 80 (2009) 116003 [arXiv:0909.3227] [SPIRES].

    ADS  Google Scholar 

  11. S. Bar-Shalom, G. Eilam and A. Soni, Collider signals of a composite Higgs in the Standard Model with four generations, Phys. Lett. B 688 (2010) 195 [arXiv:1001.0569] [SPIRES].

    ADS  Google Scholar 

  12. A. Soni, A.K. Alok, A. Giri, R. Mohanta and S. Nandi, SM with four generations: Selected implications for rare B and K decays, Phys. Rev. D 82 (2010) 033009 [arXiv:1002.0595] [SPIRES].

    ADS  Google Scholar 

  13. W.-S. Hou and C.-Y. Ma, Flavor and CP-violation with Fourth Generations Revisited, Phys. Rev. D 82 (2010) 036002 [arXiv:1004.2186] [SPIRES].

    ADS  Google Scholar 

  14. D. Choudhury and D.K. Ghosh, A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC, arXiv:1006.2171 [SPIRES].

  15. M.S. Chanowitz, Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing, Phys. Rev. D (2010) 035018 [arXiv:1007.0043] [SPIRES].

  16. H. Lacker and A. Menzel, Simultaneous Extraction of the Fermi constant and PMNS matrix elements in the presence of a fourth generation, JHEP 07 (2010) 006 [arXiv:1003.4532] [SPIRES].

    Article  ADS  Google Scholar 

  17. W.-j. Huo and T.-F. Feng, The anomalous lepton magnetic moment, LFV decays and the fourth generation, hep-ph/0301153 [SPIRES].

  18. W.-S. Hou, F.-F. Lee and C.-Y. Ma, Fourth Generation Leptons and Muon g - 2, Phys. Rev. D 79 (2009) 073002 [arXiv:0812.0064] [SPIRES].

    ADS  Google Scholar 

  19. M. Bobrowski, A. Lenz, J. Riedl and J. Rohrwild, How much space is left for a new family of fermions?, Phys. Rev. D 79 (2009) 113006 [arXiv:0902.4883] [SPIRES].

    ADS  Google Scholar 

  20. H. Fritzsch and J. Plankl, The Mixing of Quark Flavors, Phys. Rev. D 35 (1987) 1732 [SPIRES].

    ADS  Google Scholar 

  21. H. Harari and M. Leurer, Recommending a Standard Choice of Cabibbo Angles and KM Phases for Any Number of Generations, Phys. Lett. B 181 (1986) 123 [SPIRES].

    MathSciNet  ADS  Google Scholar 

  22. A.A. Anselm, J.L. Chkareuli, N.G. Uraltsev and T.A. Zhukovskaya, On the Kobayashi-Maskawa model with four generations, Phys. Lett. B 156 (1985) 102 [SPIRES].

    ADS  Google Scholar 

  23. P.F. Harrison, D.H. Perkins and W.G. Scott, Tri-bimaximal mixing and the neutrino oscillation data, Phys. Lett. B 530 (2002) 167 [hep-ph/0202074] [SPIRES].

    ADS  Google Scholar 

  24. G. Burdman, L. Da Rold and R.D. Matheus, The Lepton Sector of a Fourth Generation, arXiv:0912.5219 [SPIRES].

  25. T. Feldmann and T. Mannel, Minimal Flavour Violation and Beyond, JHEP 02 (2007) 067 [hep-ph/0611095] [SPIRES].

    Article  ADS  Google Scholar 

  26. Particle Data Group collaboration, C. Amsler et al., Review of particle physics, Phys. Lett. B 667 (2008) 1 [SPIRES].

    ADS  Google Scholar 

  27. G. Altarelli, L. Baulieu, N. Cabibbo, L. Maiani and R. Petronzio, Muon Number Nonconserving Processes in Gauge Theories of Weak Interactions, Nucl. Phys. B 125 (1977) 285 [SPIRES].

    Article  ADS  Google Scholar 

  28. B.M. Dassinger, T. Feldmann, T. Mannel and S. Turczyk, Model-independent Analysis of Lepton Flavour Violating Tau Decays, JHEP 10 (2007) 039 [arXiv:0707.0988] [SPIRES].

    Article  ADS  Google Scholar 

  29. R. Kaiser and H. Leutwyler, Pseudoscalar decay constants at large-N c , hep-ph/9806336 [SPIRES].

  30. R. Kaiser and H. Leutwyler, Large-N c in chiral perturbation theory, Eur. Phys. J. C 17 (2000) 623 [hep-ph/0007101] [SPIRES].

    Article  ADS  Google Scholar 

  31. T. Feldmann, P. Kroll and B. Stech, Mixing and decay constants of pseudoscalar mesons, Phys. Rev. D 58 (1998) 114006 [hep-ph/9802409] [SPIRES].

    ADS  Google Scholar 

  32. T. Feldmann, Quark structure of pseudoscalar mesons, Int. J. Mod. Phys. A 15 (2000) 159 [hep-ph/9907491] [SPIRES].

    ADS  Google Scholar 

  33. J. Hisano, T. Moroi, K. Tobe and M. Yamaguchi, Lepton-Flavor Violation via Right-Handed Neutrino Yukawa Couplings in Supersymmetric Standard Model, Phys. Rev. D 53 (1996) 2442 [hep-ph/9510309] [SPIRES].

    ADS  Google Scholar 

  34. J.C. Sens, Capture of Negative Muons by Nuclei, Phys. Rev. 113 (1959) 679 [SPIRES].

    Article  ADS  Google Scholar 

  35. K.W. Ford and J.G. Wills, Calculated properties of μ-mesonic atoms, Nucl. Phys. 35 (1962) 295.

    Article  Google Scholar 

  36. R. Pla and J. Bernabeu, Nuclear Size Effect in Muon Capture, An. Fis. 67 (1971) 455.

    Google Scholar 

  37. H.C. Chiang, E. Oset, T.S. Kosmas, A. Faessler and J.D. Vergados, Coherent and incoherent (μ −, e −) conversion in nuclei, Nucl. Phys. A 559 (1993) 526 [SPIRES].

    ADS  Google Scholar 

  38. J. Bernabeu, E. Nardi and D. Tommasini, μ − e conversion in nuclei and Z′ physics, Nucl. Phys. B 409 (1993) 69 [hep-ph/9306251] [SPIRES].

    Article  ADS  Google Scholar 

  39. T. Suzuki, D.F. Measday and J.P. Roalsvig, Total Nuclear Capture Rates for Negative Muons, Phys. Rev. C 35 (1987) 2212 [SPIRES].

    ADS  Google Scholar 

  40. R. Kitano, M. Koike and Y. Okada, Detailed calculation of lepton flavor violating muon electron conversion rate for various nuclei, Phys. Rev. D 66 (2002) 096002 [hep-ph/0203110] [SPIRES].

    ADS  Google Scholar 

  41. M. Antonelli et al., An evaluation of |V us | and precise tests of the Standard Model from world data on leptonic and semileptonic kaon decays, arXiv:1005.2323 [SPIRES].

  42. M. Antonelli et al., Flavor Physics in the Quark Sector, Phys. Rept. 494 (2010) 197 [arXiv:0907.5386] [SPIRES].

    Article  ADS  Google Scholar 

  43. BNL collaboration, D. Ambrose et al., New Limit on Muon and Electron Lepton Number Violation from K L 0 → μ ± e ∓ Decay, Phys. Rev. Lett. 81 (1998) 5734 [hep-ex/9811038] [SPIRES].

    Article  ADS  Google Scholar 

  44. KTeV collaboration, E. Abouzaid et al., Search for Lepton Flavor Violating Decays of the Neutral Kaon, Phys. Rev. Lett. 100 (2008) 131803 [arXiv:0711.3472] [SPIRES].

    Article  ADS  Google Scholar 

  45. UTfit collaboration, M. Bona et al., An Improved Standard Model Prediction Of B r (B → τν) And Its Implications For New Physics, Phys. Lett. B 687 (2010) 61 [arXiv:0908.3470] [SPIRES].

    ADS  Google Scholar 

  46. W. Altmannshofer, A.J. Buras, S. Gori, P. Paradisi and D.M. Straub, Anatomy and Phenomenology of FCNC and CPV Effects in SUSY Theories, Nucl. Phys. B 830 (2010) 17 [arXiv:0909.1333] [SPIRES].

    Article  ADS  Google Scholar 

  47. Belle collaboration, I. Adachi et al., Measurement of \( B \to {\tau^{-} }{\bar{\nu }_\tau } \) Decay With a Semileptonic Tagging Method, arXiv:0809.3834 [SPIRES].

  48. BABAR collaboration, B. Aubert et al., A Search for B + → ℓ + ν ℓ Recoiling Against \( {B^{-} } \to {D^0}{\ell^{-} }\bar{\nu }X \), Phys. Rev. D 81 (2010) 051101 [arXiv:0809.4027] [SPIRES].

    ADS  Google Scholar 

  49. Heavy Flavor Averaging Group collaboration, E. Barberio et al., Averages of b–hadron and c–hadron Properties at the End of 2007, arXiv:0808.1297 [SPIRES].

  50. J. Laiho, E. Lunghi and R.S. Van de Water, Lattice QCD inputs to the CKM unitarity triangle analysis, Phys. Rev. D 81 (2010) 034503 [arXiv:0910.2928] [SPIRES].

    ADS  Google Scholar 

  51. R. Escribano and J.-M. Frere, Study of the η − η′ system in the two mixing angle scheme, JHEP 06 (2005) 029 [hep-ph/0501072] [SPIRES].

    Article  ADS  Google Scholar 

  52. J. Erler and P. Langacker, Precision Constraints on Extra Fermion Generations, Phys. Rev. Lett. 105 (2010) 031801 [arXiv:1003.3211] [SPIRES].

    Article  ADS  Google Scholar 

  53. M.S. Chanowitz, Bounding CKM Mixing with a Fourth Family, Phys. Rev. D 79 (2009) 113008 [arXiv:0904.3570] [SPIRES].

    ADS  Google Scholar 

  54. O. Eberhardt, A. Lenz and J. Rohrwild, Less space for a new family of fermions, arXiv:1005.3505 [SPIRES].

  55. M. Blanke, A.J. Buras, B. Duling, S. Recksiegel and C. Tarantino, FCNC Processes in the Littlest Higgs Model with T-Parity: a 2009 Look, Acta Phys. Polon. B 41 (2010) 657 [arXiv:0906.5454] [SPIRES].

    Google Scholar 

  56. SINDRUM collaboration, U. Bellgardt et al., Search for the Decay μ + → e + e + e −, Nucl. Phys. B 299 (1988) 1 [SPIRES].

    Article  ADS  Google Scholar 

  57. SINDRUM II. collaboration, C. Dohmen et al., Test of lepton flavor conservation in μ → e conversion on titanium, Phys. Lett. B 317 (1993) 631 [SPIRES].

    ADS  Google Scholar 

  58. BABAR collaboration, B. Aubert et al., Searches for Lepton Flavor Violation in the Decays μ → eγ and τ → μγ, Phys. Rev. Lett. 104 (2010) 021802 [arXiv:0908.2381] [SPIRES].

    Article  ADS  Google Scholar 

  59. K. Hayasaka et al., Search for Lepton Flavor Violating τ Decays into Three Leptons with 719 Million Produced τ + tau − Pairs, Phys. Lett. B 687 (2010) 139 [arXiv:1001.3221] [SPIRES].

    ADS  Google Scholar 

  60. S. Banerjee, Searches for lepton flavor violating decays τ ± → ℓ ± γ, τ ± → ℓ ± P0 (where ℓ − = e −, μ − and P 0 = π 0, η, η′) at B − factories: Status and combinations, Nucl. Phys. Proc. Suppl. 169 (2007) 199 [hep-ex/0702017] [SPIRES].

    Article  ADS  Google Scholar 

  61. K. Arisaka et al., Search for the lepton-family number violating decays K L → π 0 μ ± e ∓, Phys. Lett. B 432 (1998) 230 [SPIRES].

    ADS  Google Scholar 

  62. CDF collaboration, F. Abe et al., Search for the decays B s 0, B d 0 → e ± μ ∓ and Pati-Salam leptoquarks, Phys. Rev. Lett. 81 (1998) 5742 [SPIRES].

    Article  ADS  Google Scholar 

  63. J.R. Ellis, J. Hisano, M. Raidal and Y. Shimizu, A new parametrization of the seesaw mechanism and applications in supersymmetric models, Phys. Rev. D 66 (2002) 115013 [hep-ph/0206110] [SPIRES].

    ADS  Google Scholar 

  64. A. Brignole and A. Rossi, Anatomy and phenomenology of μ τ lepton flavour violation in the MSSM, Nucl. Phys. B 701 (2004) 3 [hep-ph/0404211] [SPIRES].

    Article  ADS  Google Scholar 

  65. P. Paradisi, Higgs-mediated τ → μ and τ → e transitions in II Higgs doublet model and supersymmetry, JHEP 02 (2006) 050 [hep-ph/0508054] [SPIRES].

    Article  ADS  Google Scholar 

  66. P. Paradisi, Higgs-mediated e → μ transitions in II Higgs doublet model and supersymmetry, JHEP 08 (2006) 047 [hep-ph/0601100] [SPIRES].

    Article  ADS  Google Scholar 

  67. A.J. Buras, W. Slominski and H. Steger, B Meson Decay, CP-violation, Mixing Angles and the Top Quark Mass, Nucl. Phys. B 238 (1984) 529 [SPIRES].

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Physik Department, Technische Universität München, James-Franck-Straße, D-85748, Garching, Germany

    Andrzej J. Buras, Björn Duling, Thorsten Feldmann, Tillmann Heidsieck & Christoph Promberger

  2. TUM Institute for Advanced Study, Technische Universität München, Arcisstr. 21, D-80333, München, Germany

    Andrzej J. Buras

Authors
  1. Andrzej J. Buras
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Björn Duling
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Thorsten Feldmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Tillmann Heidsieck
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Christoph Promberger
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Tillmann Heidsieck.

Additional information

ArXiv ePrint: 1006.5356

Rights and permissions

Reprints and permissions

About this article

Cite this article

Buras, A.J., Duling, B., Feldmann, T. et al. Lepton flavour violation in the presence of a fourth generation of quarks and leptons. J. High Energ. Phys. 2010, 104 (2010). https://doi.org/10.1007/JHEP09(2010)104

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/JHEP09(2010)104

Keywords

Search

Navigation