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4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 1 Miguel A. Sanchis-Lozano* Department of Theoretical Physics.

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Presentation on theme: "4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 1 Miguel A. Sanchis-Lozano* Department of Theoretical Physics."— Presentation transcript:

1 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 1 Miguel A. Sanchis-Lozano* Department of Theoretical Physics & IFIC University of Valencia – CSIC Spain Limits/Signals of a light non-standard Higgs boson in Upsilon leptonic decays † *email: mas@ific.uv.es † † Special thanks to the CLEO Collaboration particularly to Jean Duboscq for many discussions

2 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 2 Testing Lepton Universality Channel: * BF[e + e - ]BF[μ + μ - ] BF[  +  - ] R/lR/l  (1S) 2.52 ± 0.08 %2.54 ± 0.13 %0.01 ± 0.06  (1S) 2.49 ± 0.07 %2.54 ± 0.13 %0.02 ± 0.05  (2S) 2.01 ± 0.16 %2.11 ± 0.15 %0.05 ± 0.11  (2S) 2.03 ± 0.09 %2.11 ± 0.15 %0.04 ± 0.06  (3S) 1.92 ± 0.24 %2.55 ± 0.24 %0.33 ± 0.18  (3S) 2.39 ± 0.12 %2.55 ± 0.24 %0.07 ± 0.09 *Obtained from recent but in some cases preliminary CLEO data Statistical and systematic errors are summed in quadrature Lepton Universality in Upsilon decays implies =0 BF(  e + e - ) =BF(   +  - ) = BF(   +  -)

3 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 3 Testing Lepton Universality Channel: * BF[e + e - ]BF[μ + μ - ] BF[  +  - ] R/lR/l  (1S) 2.38 ± 0.11 %2.61 ± 0.13 %0.10 ± 0.07  (1S) 2.48 ± 0.06 %2.61 ± 0.13 %0.05 ± 0.06  (2S) 1.97 ± 0.11 %2.11 ± 0.15 %0.07 ± 0.09  (2S) 1.93 ± 0.17 %2.11 ± 0.15 %0.09 ± 0.12  (3S) 1.92 ± 0.24 %2.55 ± 0.24 %0.33 ± 0.18  (3S) 2.18 ± 0.21 %2.55 ± 0.24 %0.17 ± 0.15 *Obtained from recent but preliminary CLEO data and already existing PDG values Statistical and systematic errors are summed in quadrature Lepton Universality in Upsilon decays implies =0 BF(  e + e - ) =BF(   +  - ) = BF(   +  -)

4 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 4 Lepton Universality Breaking? LU R  /l 0.00.10.2 R  / e (1S) R  /  (1S) R  /e (2S) R  /  (2S) R  / e (3S) R  /  (3S) 0.3 Hypothesis test Null hypothesis: lepton universality predicting = 0 Alternative hypothesis: > 0 From this set of data Lepton Universality can be rejected at a level of significance of 0.5 % (corresponding to a 2.8 sigma effect ) 0.4 preliminary

5 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 5 (Hidden) systematic errors? There could be hidden systematic errors in the extraction of the muonic and tauonic branching fractions from experimental data, e.g. use is made of lepton universality as an intermediate step The muonic branching fraction would be overestimated if The tauonic branching fraction would be underestimated if Defining: hep-ex/0409027 hep-ex/9409004 Besides phase space disfavors the tauonic decay mode by  1% (Van-Royen Weisskopf formula) B ee = B  = B  In the opposite direction !

6 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 6 Searching for a light non-standard Higgs  nS    s A 0 (  ) Such NP contribution would be unwittingly ascribed to the leptonic branching fraction (photon undetected!* ) actually only for the tauonic decay mode A leptonic mass dependence of the decay width would break lepton universality. Contribution from the SM should be negligible Van Royen-Weisskopf formula Notice that a light non-standard Higgs boson has not been excluded by LEP direct searches for a broad range of model parameters in different scenarios n=1,2,3 and A 0 stands for a light (possibly CP-odd) Higgs particle  -- ++ A0A0 ss Prior M1 transition Prejudice against a light Higgs?  b intermediate state or bb continuum Tree-level NP process theoretically very simple! Our conjecture to interpret a possible Lepton Universality breakdown photon unseen! * Key ideas: *Missing energy in events (neutrinos from tauonic decays) but photons can be searched for in data recorded on tape However, they likely would not be monochromatic!  nS    s  b ( * ) (  A 0 *  )

7 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 7 A large value of tanβ would imply a large A 0 coupling to the bottom quark but a small coupling (i.e. small cot β) to the charm quark. Therefore, in the quest for NP effects we will focus on bottomonium decays and spectroscopy but not on charmonium as this is the case (see PDG) tanβ stands for the 2 Higgs VEVs ratio / and v=246 GeV *The MSSM is a particular 2HDM(II) realization CPC: 1 CP-odd Higgs (A 0 ) 2 CP-even Higgses h 0 =-  1 sin  +  2 cos  H 0 =  1 sin  -  2 cos  2 charged H  At tree level: In a general 2HDM: Coupling of fermions and the CP-odd Higgs A 0 In a 2HDM of type II CPV MSSM Two-Higgs Doublet Model (II)* Higgs sector At one-loop level, MSSM with complex parameters is not CP conserving The three Higgs neutral bosons mix together and the resulting three physical mass eigenstates H 1, H 2 and H 3 (M H1 < M H2 < M H3 ) have mixed parities Higgs couplings to the Z boson would vary: the H 1 ZZ coupling can be significantly suppressed raising the possibility of a relatively light H 1 boson having evaded detection at LEP [hep-ph/0211467]

8 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 8 Light Higgs windows at LEP (2HDM(II)) hep-ex/0408097 Excluded (m A,m h ) region independent of the CP even Higgs mixing angle , from flavor-independent and b-tagging searches at LEP interpreted according to a 2HDM(II) Excluded regions in the (m A,tanβ) plane for different choices of . In the MSSM -  /2   0 ; in a general 2HDM(II) -  /2   /2

9 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 9 Light Higgs windows at LEP (MSSM CPV) hep-ex/0406057 CPX MSSM 95% exclusion areas using scans with different values of arg (A t,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 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 H 1 is reduced wrt a CPC scenario.

10 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 10 Next-to-Minimal Supersymmetric Standard Model (NMSSM) Higgs sector in the NMSSM: (seven) 2 neutral CP-odd Higgs bosons (A 1,2 ) 3 neutral CP-even Higgs bosons (H 1,2,3 ) 2 charged Higgs bosons (H ± ) A new singlet superfield is added to the Higgs sector: In general more extra SM singlets can be added: hep-ph/0405244 The μ-problem of the MSSM would be solved by introducing in the superpotential the term Breaks explicitly the PQ symmetry Spontaneous breaking of the PQ symmetry The A 1 would be the lightest Higgs: Favored decay mode: H 1,2  A 1 A 1 hard to detect at the LHC [hep-ph/0406215] Coupling of A 1 to down type fermions: [hep-ph/0404220] If к =0 → U(1) Peccei-Quinn symmetry Spontaneous breaking  NGB (massless), an “axion” (+QCD anomaly) ruled out experimentally If the PQ symmetry is not exact but explicitly broken  provides a mass to the (pseudo) NGB leading to a light CP-odd scalar for small к If λ and  zero → U(1) R symmetry; if U(1) R slightly broken → a light pseudoscalar Higgs boson too

11 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 11 Contribution from the “continuum” Let us perform a perturbative calculation of the contribution from the “continuum”, i.e. without formation of intermediate bound states assuming the Higgs boson off-shell Numerical estimates Rather large values of tanβ (  50) are needed to obtain R  ~ 10% where the square amplitude is and the decay width (leading term):  nS    A 0 (   +  - ) Higgs boson on-shell Wilczek formula R  =0.1 tanβ ~ 15 Somewhat higher values of tanβ in a relativistic treatment One should also consider : Experimentally excluded region    +”nothing”: BF < 1.3 x10 -5 for M A 0 < 5 GeV [CLEO, PRD 51, 2053 (1995)]  B(A 0   +  - )  1 even for moderate tanβ M Y -M Aº =0.25 GeV A0A0  l+l+ l-l-

12 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 12 Intermediate bound states  nS    s  b (  A 0* (H 1 * )  l + l - ) tanβ ≥ 30 ΔM=0.25 GeV We consider that a prior magnetic dipole transition of the Upsilon yields an intermediate bound state, subsequently annihilating into a lepton pair via A 0 (or H 1 )-exchange A cascade decay formula should apply: The NP contribution would almost saturate the  b decay rate even for moderate tanβ if  M is not too large ! M1 transition probability Numerical estimates In a 2HDM(II) Mass difference between the Higgs boson and the  b Intermediate real 0 -+ state Allowed and hindered M1 transitions between  (3S),  (2S) and  (1S) states ________Y(3S) -------------  b (3S) ________Y(2S) -------------  b (2S) ________Y(1S) -------------  b (1S)  600 MeV  1000 MeV  100 MeV CLEO limit

13 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 13  nS     b 0 (  h 0   +  - ) n=2,3 (  H 1   +  - ) CP-even Higgs boson R   0.1 tanβ ~ 15 Using ΔM=0.25 GeV, tanβ  15 → B (  b0  +  - ) ≈ 6% and B(     b0 ) ≈ 3-6% (PDG) as reference values, we get: h 0 -mediated decay width under the assumption that sin(  -β) ≈ 0 i.e. non-decoupling limit: h 0 couplings deviate maximally from SM whereas the H 0 becomes a SM-like Higgs: Cascade decay via  b0 resonances Numerical estimates Normalizing the above partial width to Again only for the tauonic mode would the NP contribution be significant leading to lepton universality breaking! setting  s (M  ) = 0.15 and |R’ n (0)| 2 = 1.5 GeV 5  Decay channel only open for  (2S) and  (3S) resonances Intermediate real 0 ++ state A CP-even Higgs boson can couple to an intermediate  b0 resonance after a E1 transition of the 

14 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 14 Possible spectroscopic consequences in bottomonium Searches for  b states at CLEO: No signal found! A 0 -  b mixing? Mass shift yielding larger hyperfine splitting than expected in the SM (i.e. more than ~100 MeV). Higgs Yukawa couplings to fermions can be affected too, allowing quite large tanβ for special Higgs mass values hep-ex/0207057 Broad  b states? Widths of order 50 MeV could be expected even for moderate values of tanβ hep-ex/0207057 tanβ (LEP) hep-ex/0111010 “Is there any point to which you would wish to draw my attention?” “To the curious incident of the dog in the night-time” “The dog did nothing in the night-time” “That was the curious incident”, remarked Sherlock Holmes from “Silver Blaze” by Sir A.C.D. Most theoretical models are ruled out ! The search for  b states would be a way of hunting a light non-standard Higgs! If  b decay happens to be saturated by the A 0 -mediated channel  b  A 0*  +  - A quite broad  b expected! Drees and Hikasa, PRD 41, 1547 (1990) SM: Also implying lower rates for other decay modes:  b  J/ψ J/ψ  (3S)   ’ bo   b (1S)

15 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 15 Conclusions Keep also an eye on the related issues: ● g-2 muon anomaly (which might require a CP-odd light Higgs contribution in a two-loop calculation) ● Search for B s,d  ,  decays (GIM mechanism can spoil the expected signal hep-ph/0209306) ● Searches for dark matter in the universe (McElrath, this workshop) If lepton universality is found to be (slightly) broken in Upsilon decays, the simplest explanation would require a light non-standard mediated Higgs contribution (subsequent to a M1 transition of the  resonance) unwittingly ascribed to the tauonic decay mode If not, those light Higgs mass windows could be closed! Possibly too hard a job for the LHC ● Reasonable values of tanβ in a 2HDM(II) are needed to yield R  /l of order 10% ● Different scenarios beyond the SM could explain such a LU breaking ● Further exp tests suggested: - search for soft (non-monochromatic) photons in the  +  - sample of Upsilon decays - seek after the  b resonance! - polarization studies of the tau… Based on: hep-ph/0510374 hep-ph/0503266 hep-ph/0407320 hep-ph/0307313 hep-ph/0210364 hep-ph/0206156 Relevance of a Super B Factory running on the  region !!! Complementary to other searches at the LHC Avec de l’audace, on peut tout entreprendre, on ne peut pas tout faire Napoléon Ier

16 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 16 Light Neutralino Dark Matter Neutralino dark matter is generally assumed to be relatively heavy, with a mass near the electroweak scale It has been shown, however, that the claims of dark matter detection made by DAMA can be reconciled with null results of CDMS II if one considers a WIMP lighter than approximately 10 GeV [hep-ph/0504010] A very light CP-odd Higgs can make possible a very light neutralino to annihilate via such a light Higgs boson exchange [hep-ph/0509024] leading to low-enery positrons which would generate the 511 keV gamma-ray emission observed from the galactic bulge by INTEGRAL/SPI experiment

17 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 17 g-2 muon anomaly in a 2HDM(II) hep-ph/0302111 The 2σ allowed regions in the (m A,m h ) plane due to the constraints of a  and R b for tanβ=40. The blue region is where the total  2 is less than 4 while the yellow region is where the total  2 is less than the  2 (SM) One.loop vertex correction Two-loop vertex correction h,A       f

18 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 18 MSSM (CPV) The Higgs potential is explicitly CP-conserving if all Higgs potential parameters are real. Otherwise, CP is explicitly violated CP-violation is generated by loop effects involving top and bottom squarks CP-violation can modify drastically the tree-level couplings of the Higgs particles to fermions and gauge bosons The CP parities of the neutral Higgs bosons may be mixed by radiative effects involving the third generation of squarks Under CP violation, the mass of the CP-odd Higgs scalar is no longer an eigenvalue but rather an entry in a general 3 x 3 neutral Higgs mass matrix M SP 2  m t 4 Im(  A t ) / v 2 M SUSY 2 where  is the mixing parameter of the two Higgs superfields A t denotes the soft SUSY-breaking trilinear coupling of the Higgs bosons to top squarks v=246 GeV VEV of the Higgs M SUSY stands for the common SUSY-breaking scale

19 4th Int Workshop on Heavy Quarkonium June 27-30 BNL Miguel A. Sanchis-Lozano IFIC-Valencia 19 Intermediate bound states  nS    s  b (  A 0* (H 1 * )  l + l - ) We consider that a prior magnetic dipole transition of the Upsilon yields an intermediate bound state, subsequently annihilating into a lepton pair via A 0 (or H 1 )-exchange A cascade decay formula applies: The NP contribution would almost saturate the  b decay rate even for moderate tanβ if  M is not too large ! M1 transition probability Numerical estimates In a 2HDM(II) ΔM (GeV) hep-ph/0407320 Range of tanβ for a given  M value Mass difference between the Higgs boson and the  b Intermediate real 0 -+ state Allowed and hindered M1 transitions between  (3S),  (2S) and  (1S) ________Y(3S) -------------  b (3S) ________Y(2S) -------------  b (2S) ________Y(1S) -------------  b (1S)  600 MeV  1000 MeV


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