1 / 19

Miguel-Angel Sanchis-Lozano

A light non-standard Higgs: to be or not to be @ a (Super) B factory*. email: mas@ific.uv.es. Department of Theoretical Physics & IFIC University of Valencia – CSIC Spain. Miguel-Angel Sanchis-Lozano. * Based on arXiv:0709.3747 hep-ph/0702190, hep-ph/0610046

timothy-bradshaw
Télécharger la présentation

Miguel-Angel Sanchis-Lozano

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A light non-standard Higgs: to be or not to be @ a (Super) B factory* email: mas@ific.uv.es Department of Theoretical Physics & IFIC University of Valencia – CSIC Spain Miguel-Angel Sanchis-Lozano *Based on arXiv:0709.3747 hep-ph/0702190, hep-ph/0610046 hep-ph/020156, hep-ph/0307313 Special thanks to J.Duboscq (CLEO) for many iIluminating discussions Miguel A. Sanchis-Lozano IFIC-Valencia

  2. Light neutral Higgs scenarios Higgs sector in the NMSSM: (seven) 2 neutral CP-odd Higgs bosons (A1,2) 3 neutral CP-even Higgs bosons (H1,2,3 ) 2 charged Higgs bosons (H±) L & H Light and heavy Higgs bosons can live together PQ symmetry or U(1)R slightly broken → a light pseudoscalar Higgs A1  A0 tan β = v2 / v1 Coupling of A1 to down type fermions Light dark matter? NMSSM candidate compatible with present bounds: Light neutralino with a singlet component McElrath [hep-ph/0506151] The A1 would be the lightest Higgs: Miguel A. Sanchis-Lozano IFIC-Valencia

  3. Light Higgs windows at LEP (CPV MSSM) hep-ex/0406057 hep-ex/0406057 Diagram illustrating the effective coupling of a Higgs mass eigenstate H1 to the Z. Only the CP-even admixture h and H couple to Z while the CP-odd A does not: hence the coupling of the H1 is reduced wrt a CPC scenario. hep-ex/0406057 CPX MSSM 95% exclusion areas using scans with different values of arg (At,b).The region excluded by Yukawa searches, Z-width constraints or decay independent searches is shown in red CPX MSSM 95% exclusion areas using scans with different values of the top mass Miguel A. Sanchis-Lozano IFIC-Valencia

  4. Next-to-Minimal Supersymmetric Model (NMSSM) Much less constrained by LEP data and B-physics observables than the MSSM Higgs mass values allowed down to several GeV Hiller, hep-ph/0404220 Similarly for Little Higgs models with an extended structure of global U(1) symmetries broken both spontaneously and explicitly, possibly leading to light pseudoscalar particles in the Higgs spectrum Kraml et al. hep-ph/0608079 Upsilon decays should be useful in the search for a light Higgs Miguel A. Sanchis-Lozano IFIC-Valencia

  5. Formalism  Leptonic decays Miguel A. Sanchis-Lozano IFIC-Valencia

  6. Mixing of a pseudoscalar Higgs A0 and a b resonance e+ e-     τ+ τ- A00 , b0 unmixed states A0 , b mixed (physical) states 0 0 Smaller coupling strength than in the MSSM Xd = cosA tanβ Miguel A. Sanchis-Lozano IFIC-Valencia

  7. b / A0 mixing Xd = cosA tanβ Xd =10,20,40 Xd = 10 Possible spectroscopic consequences broader b ? bmass shift ? due to the new physics contribution Hyperfine splitting m-mb unexpectedly large/or small b > [b2g] Miguel A. Sanchis-Lozano IFIC-Valencia

  8. Our proposal:Test of lepton universality in  leptonic decays QCD+binding energy effects small for the pseudoscalar A0 Wilczek formula Mixing effect • Non-resonant decay • Resonant decay Mixing effect M1 transition probability Miguel A. Sanchis-Lozano IFIC-Valencia

  9. Lepton universality in the SM Neglecting phase space and helicity flip effects. Higher-order SM effects are negligible • Γll is an inclusive quantity:   l+ l- is accompanied byaninfinite number of soft photons • The test of lepton universality can be seen as complementary to searches for monochromatic photons in the  γττ channel (see B. Heltsley talk) • To order α3:Γll = Γll0 [1+δvac+δvertex ]  Γll0 [1+δvac] • Divergencies/singularities free at any order: Bloch and Nordsieck theorem & Kinoshita-Sirlin-Lee-Nauenberg theorem Warning! 3α /4π~ 0.17% 7.6% Contribution potentially dangerous for testing lepton universality if final-state radiation is not properly taken into account in the MC to obtain the detection efficiency in the analysis of experimental data Albert et al. Nucl. Phys. B 166 (1980) 460 δvac=δee+δ+δ+ δquarks Miguel A. Sanchis-Lozano IFIC-Valencia

  10. Testing Lepton Universality * From PDG ‘07 Lepton Universality in Upsilon decays implies <R/l > = 0 Miguel A. Sanchis-Lozano IFIC-Valencia

  11. LU A0 Lepton Universality Breaking? R/e(1S) R/(1S) R/e(2S) R/(2S) R/e(3S) R/(3S) 0.0 0.1 0.2 0.3 0.4 -0.1 0.0 R/l Miguel A. Sanchis-Lozano IFIC-Valencia

  12. Expected LUbreaking Green line: non-resonant decay Black line: resonant decay Red line: sum Xd=10, b0 = 5 MeV Miguel A. Sanchis-Lozano IFIC-Valencia

  13. A closer look at the NMSSM parameter space Miguel A. Sanchis-Lozano IFIC-Valencia

  14. Xd > 5`` Xd =10 Xd κ λ λ Aλ= -200 GeV μ = 150 GeV Aκ = -15 GeV tanβ= 50 Aλ~ - Κμ / λ Κ - (4/3) λ=0 0.1 ≤| cos A |≤0.5 tanβ~ 1/ [Aλ+Κ (μ / λ) ] Ananthanarayan & Pandita, hep-ph/9601372 Miguel A. Sanchis-Lozano IFIC-Valencia

  15. In several NMSSM parameter regions, it may happen at the same time: • Large tanβ(for Aλ+ κs ≈ 0) • 0.1 ≤ | cos A | ≤ 0.5 (A0 mainly singlet but not completely) • |Xd| = 5 – 25 for tanβ = 50 • Low mass (e.g. 10 GeV) of the lightest CP-odd Higgs boson A0 • Low fine-tunning in order to get a Higgs-like boson explaining the Z+b-jets event excess at LEP (Dermisek & Gunion, hep-ph/0510322) Suggestive coincidence ! “There should be one thousand reasons for not running a B factory at (3S) but right now I cannot think of one” Miguel A. Sanchis-Lozano IFIC-Valencia

  16. Summary What if... there exists a light Higgs-like particle about 10 GeV? • A high luminosity B factory would be the ideal place to discover/study it, e.g. looking at - decay into τ+τ- ():Lepton universality test (M.A.S.L.,arXiv:0709.3747) -direct searches for monochromatic photons (seeB. Heltsley talk) Dermisek, Gunion and McElrath, hep-ph/0612031 ( alsoMangano and Nason in  γμμ decays, arXiv:0704:1719 ) • Complementary/Implications to LHC/ILC searches! + related topics: muon g-2 anomaly, light dark matter Miguel A. Sanchis-Lozano IFIC-Valencia

  17. Back up Miguel A. Sanchis-Lozano IFIC-Valencia

  18. Proposal of testing lepton universality (to the percent level) @ a (Super) B factory hep-ph/0610046 With the machine sitting on the (3S)Final state & BF (3S)  π+π- (1S,2S) →+- π+π- +- BF  2-4 x 10-2 BF  2 x 10-2 BF  4 - 8 x 10-4 (3S)  π+π- (1S,2S) →  +- π+π-l +l- BF  10-1  +- → l+l- X, l = e, BF  5 - 10 x 10-5 (3S)  +-+- BF  2 x 10-2 BF  2 x 10-2 (3S)   +- l +l- X → l+l - X, l = e, BF  2 x 10-3 With the machine sitting on the (4S) (4S)  π+π- (1S,2S) →+- π+π- +- BF  10-4 BF  2 x 10-2 BF  2 x 10-6 (4S)  π+π- (1S,2S)→  +- π+π-l +l- X BF  10-1  +- → l+l - X, l = e, BF  2 x 10-7 Compare rates Compare rates Statistical error ≈ 0.07 / √ # fb-1 Systematic error ≤ 0.037 Compare rates Miguel A. Sanchis-Lozano IFIC-Valencia

  19. Searches for b states over more than 20 years No signal found so far! Entangled both theoretically and experimentally? Mixing b resonance A0 Higgs boson / Enfant terrible Petit bourgeois Spectroscopic consequences: quite larger or smaller hyperfine splitting An unlikely but not impossible situation: (ns) and b(nS) mass levels might be reversed! Miguel A. Sanchis-Lozano IFIC-Valencia

More Related