Supersymmetric Higgs
Marcela Carena Theoretical Physics Department, Fermilab Enrico Fermi Institute, University of Chicago
Searching for New Physics at the LHC The Galileo Galilei Institute for Theoretical Physics October 30, 2009, Florence Outline
• The SM-like Higgs Boson: state of the art
• The MSSM Higgs Bosons -- Basics -- The impact of radiative corrections on masses & couplings -- Collider searches
• MSSM Higgs Extensions: A model-independent approach -- The EFT at NLO -- Masses and Couplings -- Comments on collider phenomenology The Standard Model Higgs Mechanism
• One physical state -- the Higgs Boson -- left in the spectrum
First evidence of EWSB ==> masses of gauge bosons Measuring the WWH and ZZH couplings is essential to identify the Higgs as the agent of EWSB: without a v.e.v, no such trilinear coupling at tree level
==> we need to detect the Higgs in association with gauge bosons ==> if the theory remains perturbative, the top mass will mainly come from a Higgs with SM-like couplings to W and Z
The search for the SM Higgs: state of the art
+ ! Z * + # e e "" # HSM Z with H SM ! bb," "
Gluon-gluon fusionwith H WW ! Constraints on m H from 2 isolated leptons + missing Energy precision tests of the SM SM Higgs production processes at hadron colliders Much progress recently in computing NLO and NNLO QCD and EW corrections
with H WW(*).
with H bb, WW*
The Tevatron Projections
based on improvements already achieved for some analysis, extending them to the rest-
95 95 SM R i= S i/Si The SM Higgs LHC potential Talk by A. Nisati
Tevatron excl. LEP excl. !
L E P
-1 With 10 fb , discovery for mh [~125,~500] GeV range; -1 -1 With 1-2 fb , some reach in the H to WW channel (2 fb :exclusion for all mh) What can the LHC do with 10 TeV and 1fb-1?
Looking at the golden channel H WW/ZZ
Main Backgrounds increase relative to the signal
Comparable to Tevatron reach with 10 fb-1 and 1.5 efficiency factor improvement Supersymmetric Higgs ? The Higgs Sector in the Minimal Supersymmetric SM
2 Higgs SU(2) doublets ! 1 and ! 2 : after Higgs Mechanism
2 CP-even h, H with mixing angle ! tan! = v2 v1 ± 1 CP-odd A and a charged pair H 2 2 ! v= v1 +v2 = 246 GeV At tree level, one Higgs doublet couples only to down quarks, the other couples only to up quarks + + !L =" i hˆ ij # d j + hˆ ij # u j + h.c. L ( d 1 R u 2 R ) Since the up and down sectors are diagonalized independently, the Higgs interactions remain flavor diagonal at tree level.
Couplings to gauge bosons & fermions (SM normalized)
Decoupling limit mA >> mZ Lightest (SM-like) Higgs , others heavy and roughly degenerate mh ! mZ
Radiative Corrections to Higgs Boson Masses
Important quantum corrections due to incomplete cancellation of particles and superparticles in the loops Main effects: stops; and sbottoms at large tan beta
4 • m t enhancement
• log sensitivity to stop masses M S
• depend. on stop mass mixing X t
2 -loop corrections: mh !135GeV Brignole, M.C., Degrassi, Ellis, Haber, Hempfling, Heinemeyer, Hollik, Espinosa, Martin, Quiros, Ridolfi, Slavich, Wagner, Weiglein, Zhang, Zwirner, …
• If 3rd gen. scalar masses > tens of TeV
need to resum large logs for reliable mh calc. Radiative Corrections to the Higgs Couplings
2 1) Important effects through radiative corrections to the CP-even mass matrix ! M ij , which defines the mixing angle !
2 2 2 2 sin! cos! = M12 / (Tr M ) " 4 det M
The off diagonal elements are prop. to
4 2 m µX % X ( M 2 ! " m2 + m2 cos # sin # + t t t " 6 M.C. Mrenna, Wagner 12 ( A Z ) 2 2 2 ' 2 * 16$ v M S & M S )
Important effects of rad. correc. on sin ! or cos ! depending on the sign of µXt µ / M and the magnitude of X t / M S and S ===> govern couplings of Higgs to fermions and vector bosons
When off-diagonal elements vanish, either sin ! or cos ! vanish ===> strong suppression of the SM-like Higgs boson coupling to b-quarks and taus
!! Enhancement of BR (h/H --> WW/ ) for mh/H < 135 GeV 2) Important Vertex corrections to Higgs-fermion couplings from SUSY loops - relevant for sizeable tan ! - Can induce Flavor changing neutral and charged current effects
* * !L = d 0hˆ " 0 + " 0 #ˆ + #ˆ hˆ +hˆ d o + " 0u 0hˆ u0 + h.c. eff . R d [ 1 2 ( 0 Y u u)] L 2 R u L
+ ! loop factors intimately hd h u connected to the structure of the squark mass matrices. hu hd
• In terms of the quark mass eigenstates
L 1 tan 0* 0* d M $V+ R-1V &d h.c. ... Dedes, Pilaftsis ! = ( " #1 ! #2 ) R d % CKM CKM ' L + + eff v2
2 and R = 1 + !0 tan" + !Y tan" hu R diagonal * * * * µ At 2# µ Mg˜ Dependence i s !Y " ! " 2 2 2 2 0 2 2 2 16 max m ,m , on SUSY param. 3$ # t˜ t˜ µ max md˜ i ,md˜ i ,Mg˜ [ 1 2 ] [ 1 2 ]
Higgs Physics strongly connected to flavor physics and to the SUSY mechanism
Looking at VCKM ! I " Flavor Conserving Higgs-fermion couplings
1 $ 0* 0* ' 1 1 0* !L = & tan " #1 ! #2 ) b RM b 33 bL + #2 b RM d bL + h.c. eff v2 % ( R v2 33 3 2 R =1+ (!0 + !Y ht )tan" #1+ $ b In terms of h,H and A: 0 !1 = "sin# h +cos# H +i sin$ A 0 !2 = cos# h +sin# H - i cos$ A Hence:
"mb sin# ghbb ! (1" $b /tan# tan %) destroy basic relation (1+ $b ) v cos% gh,H,Abb gh,H,A !! " mb m! mb cos" g Hbb ! (1% #b tan" /tan $) (1+ #b ) v cos$
mb tan " At large tan ! " g Hbb # gAbb gAbb ! (1+ #b )v M.C. Mrenna, Wagner; Haber,Herrero, Logan, Penaranda, Rigolin, Temes Noth, Spira: Muhlleitner, Rzehak, Spira Strong suppression of h(H) -bottom coupling
tan! ! "b / tan# $ g ! 0; gh ! "bm / v (Similar for H) hbb %% % Radiative corrections main decay modes of the SM-like MSSM Higgs into b- and tau-pairs can be drastically changed What can the Tevatron say about an SM-like MSSM Higgs? Different SUSY benchmark scenarios will yield very different results M.C.,Heinemeyer, Wagner,Weiglein max • The mh scenario: [Maximizes mh]
M S = 1 TeV ; Xt = 2.4 MS ; mg˜ = 0.8 MS ; M 2 = !µ = 200GeV; At = Ab g hbb , g h !! due to factor for low m and intermediate enhanced sin!eff , /cos " A max to large tan beta (analogous for H if mA> mh )
hence, strong suppression of BR( h ! " " ) and BR(h WW) with respect to SM
min • The mh scenario: [zero mixing in the stop sector] max Similar coupling’s behaviour as mh , but minimizes mh.
• The small sin ! eff . scenario:
M S = 800 GeV ; Xt = - 1.2 TeV ; µ = 2.5 M s ; mg˜ = M 2 = 500GeV; At = Ab
g hbb , g h !! importantly suppressed for large tan beta and small mA, and in different ways due to ! b corrections
hence, BR( h ! " " ) and BR(h WW) enhanced with respect to SM
Tevatron reach for the MSSM SM-like Higgs All channels included in CDF/DO combination. 95% C.L. Exclusion- 10 fb-1.
max The m min scenario: m < 120 GeV The mh scenario: mh ~ 125 GeV h h
No reach at present BUT with the expected improvement factor of 1.5 assumed good/full coverage Draper, Liu, Wagner An interesting case: The small sin ! eff .scenario CDF/DO combination: 95% C.L. Exclusion- 10 fb-1. Draper, Liu, Wagner H/h bb final channel only H/h bb + WW channels
• Useful h WW Tevatron search for a low mass MSSM SM-like Higgs • Full coverage of the MSSM plane once the tan beta enhanced channels !! inclusive, b!!, and bbb, with present efficiency and 10fb-1, are included Non-Standard Higgs Production at the Tevatron and LHC
• Enhanced couplings to b quarks and tau-leptons • Considering value of running bottom mass and 3 quark colors 9 2 + # (1+ % b ) BR(A ! bb ) " 2 BR(A ! " " ) $ 2 9 + (1+ # b ) 9 + (1+ % b )
tan% 2 9 Strong dependence on the ! bb A " BR A # bb $ ! bb A " " ( ) ( ) ( )SM 2 2 SUSY parameters (1+ & b ) (1+ & b ) + 9 in the bb channel. tan& 2 ! bb ,gg " A # BR A " $$ % ! bb ,gg " A # Robust predictions ( ) ( ) ( )SM 2 (1+ ' b ) + 9 in the tau-tau channel
Excellent coverage at both colliders in the di-tau inclusive channel
M.C, Heinemeyer, Weiglein, Wagner MSSM Higgs at the Tevatron . H/A tau pairs, with both exp. and for 10 fb-1 Draper, Liu, Wagner
max Small scenario Mh . Scenario sin!eff . Limits are robust under variation of SUSY parameters
MSSM Higgs at the Tevatron . All channels combined both exp. and for 10 fb-1 Draper, Liu, Wagner
max M min scenario Mh scenario h Extensions of the MSSM Higgs Sector
• MSSM with Explicit CP violation
• Additional SM singlets
• Additional gauged U(1)’s
• Models with enhanced weak gauge symmetries
• Effective field theory with higher dimensional operators: A more model-independent approach More general MSSM Higgs extensions: EFT approach
• The non-minimal part of Higgs sector is parametrically heavier than the weak scale (understood as v = 174 GeV)
• SUSY breaking is of order v, hence heavy masses nearly supersymmetric : overall ``heavy” scale SUSY breaking mass splittings
In practice: formalism applies for e.g.
Low energy superpotential: at leading order in 1/M
2 ! • can include SUSY breaking via a spurion X= mS ! 1
M.C, Kong, Ponton, Zurita and Only two new parameters: see also Dine, Seiberg, Thomas; Antoniadis, Dudas, Ghilencea, Tziveloglou • At NLO, Kähler potential only:
Custodially violating (treel level) :
Custodially preserving (tree level) :
Plus SUSY breaking terms obtained by multiplication by spurion, with new coefficients
• EFT coefficients can be essentially arbitrary, if UV theory complicated enough Examples Example 1: singlets
Integrating out the singlet: Example 2: triplets with
Integrating out the triplets:
Induce custodially violating ops.
For triplets with
Induce custodially violating ops. Why to go beyond LO in the EFT approach
Quartic interactions of 2HDM can be written as
At O(1/M), only modified
2 At O(1/M ) all ! i ' s receive contributions
But at tree-level in MSSM: (small)
NLO effects can be relevant without indicating breakdown of EFT (however, higher order effects should be small...) Higgs Spectra in EFT extensions of the MSSM
The lightest tree level Higgs mass can be well above the LEP bound!!.
Expansion parameters: µ M a nd m S M (mS is the spurion F term)
Second order terms can have a relevant impact.
Large deviations from the MSSM mass values, specially for low tanb Higgs Spectra in EFT extensions of the MSSM M.C., Kong, Ponton, Zurita
The lightest tree level Higgs mass is well above MZ.
Expansion parameters: µ M and mS M
Second order terms can have a relevant impact.
Large deviations from the MSSM mass values, specially for low tanb
Scanning over model parameters
Scan: and Higgs Spectra in EFT extensions of the MSSM M.C., Kong, Ponton, Zurita
The lightest tree level Higgs mass is well above MZ.
Expansion parameters: µ M and mS M
Second order terms can have a relevant impact.
Smaller effects for large tanb main contributions proportional to 1/M2.
Scanning over model parameters MSSM-like vacua Scan: and Heavy CP Even and Charged Higgs Masses
• •
LEP bounds not imposed LEP bounds not imposed MSSM-like MSSM-like
sEWSB
sEWSB
Charged Higgs Heavy CP-even Higgs Precision Electroweak Constraints 1. Tree-level effects due to new physics:
2. Effects from MSSM Higgs sector:
• Heavier SM-like Higgs Loop-level contr. to S and T • Mass splittings among non-standard Higgses
3. Custodially violating mass splittings in SUSY sector Medina, Shah, Wagner
Here: require that
Consistent with for CP-even Higgs Couplings to gauge bosons and fermions
Variations of couplings with respect to SM and MSSM can lead to important variations in the production processes and BR’s relevant for Higgs searches Gluon Fusion Production
A generic enhancement of the production for the Higgs that is SM-like (the one with largest coupling to WW/ZZ) • The couplings of the CP-odd and charged Higgs bosons differ from the MSSM due to corrections to their kinetic terms only at order 1/M2 much less significant
• The main effects involving A and H+- are those related to new decay modes due to variations in the mass spectrum
• New decay channels such as H AA/AZ, h AA and H+ W+A open with BR’s of order one
• Regular MSSM channels with decays into h are closed at low tanb and open at large tan beta: A ! hZ; H ± ! W ± h; H ! hh
• At sufficiently large mA (> 300 GeV) behavior similar to MSSM
• Many models for which BR’s into bb/tau-pairs are significantly enhanced or suppressed with respect to SM ones, leading to important variations of BR’s into golden modes WW/ZZ
• Models with enhancement in BR’s to cc/gg/di-photons -sometimes challenging dominant decay into jets-
In the following: Full study with LEP and Tevatron bounds using Higgsbounds
Bechtle, Brein, Heinemeyer, Weiglein, Williams plus Tevatron projections based on SM Higgs present reach and projections [Tevatron projections based on heavy MSSM Higgs searches underway]
All the above for our specific multi parameter SUSY scenarios CP-even Higgs Bosons: low tanb
Tevatron searches in the h/H WW channel effective, (h/H bb remains borderline) CP-even Higgs Bosons: large tanb
• Excellent reach in the h WW channel at the Tevatron
H always MSSM-like behavior in dominant bb, tau pair channels at the Tevatron reach for sufficiently large tanb. A challenge for the LHC: lightest CP-even Higgs, large tanb
• BR(hcc,gg,diphotons) can be significantly enhanced with respect to SM ones => challenging dominant decay into jets Enhanced reach in hdiphoton at LHC (only possible channel in many scenarios) Lightest Higgs Mass in the light of collider searches Heavy CP-even Higgs mass as a function of MA. Outlook
Some type of SM-like Higgs is probably around the corner
The Higgs sector can shed light to many SM puzzles the origin of mass, flavor, dark matter …
Many types of experiments are exploring the Higgs sector -impressive results from the Tevatron-
The SM and many new physics models, in particular SUSY M0dels, are being constrained
Let’s make a wish for Multi -HIGGS discoveries ! CP-odd and Charged Higgs behave MSSM like, but
• For low tanb: enhanced BR’s: A ! b b , " + " # , due to closed channel A ! hZ • For large tanb the above h channel contribute moderately
CP-odd and Charged Higgs behave MSSM like, but • For low tanb: enhanced BR’s: H ± ! bt , " ± # due to closed channel ± ± ± ± H ! W h (MSSM for low mh specific). Recall, new channel H ! W A
• For large tanb the above h channel contributes moderately
• New decay channels such as H AA/AZ, H+ W+A • New decay channels such as H AA/AZ, H+ W+A CP-even lightest Higgs: low tanb
• BR(hWWZZ) and BR(hbb/tau’s) can be significantly enhanced or suppressed with respect to SM ones • BR(hAA) of order one for a small parameter region with mh < 150 GeV CP-even Heavy Higgs Boson: low tanb • BR(HWW/ZZ/bb/tau’s) enhanced above the MSSM due to Hhh suppression • HAA/AZ open in a moderate region of parameter space. • BR(Htt) fluctuations around MSSM values above tt-threshold) Lightest CP-even Higgs: large tanb
• BR(hWW/ZZ) and BR(hbb/tau’s) can be significantly enhanced or suppressed with respect to SM ones • BR(hcc,gg,diphotons) can be significantly enhanced with respect to SM ones => challenging dominant decay into jets Heavy CP-even Higgs: large tanb
• H always MSSM-like behavior in dominant bb, tau pair channels at the Tevatron reach for sufficiently large tanb. • BR(Hhh) can be sizable The Tevatron Projections - based on improvements already achieved for some analysis, extending them to the rest-
Low mass regime High mass regime
http://www-cdf.fnal.gov/physics/new/hdg/results/combcdf_mar09/#Projections Search Channels for the SM Higgs at the LHC
Nikitenko
5 sigma at 10 fb-1
With K factors
mH[GeV]
• Low mass range mH < 200 GeV
Production Inclusive VBF WH/ZH ttH DECAY • Intermediate mass range 200 GeV < m < 700 GeV H → γγ YES YES YES YES H Inclusive H ZZ 4l H → bb YES YES YES H → ττ • Large mass range: mH> 700 GeV H → WW* YES YES YES VBF with H WW lv jj ZZ ll vv H → ZZ*, Z l+l- YES Tevatron reach for the MSSM SM-like Higgs
max The mh scenario: mh ~ 125 GeV
All channels included in CDF/DO combination. 95% C.L. Exclusion- 10 fb-1. LHC projected reach for the same benchmark point
•First, full simulation analysis of qqH, H->ττ->l+jet • Optimized NN with kinematics &γ isolation Nikitenko
No reach at present BUT with the expected improvement factor of 1.5 assumed good coverage Draper, Liu, Wagner
Indirect searches for MSSM Higgs bosons in B meson observables Important interplay between B physics observables and SUSY Higgs searches at the Tevatron and the LHC
Loop-induced A/H mediated FCNC’s: 2 2 bs m h # tan$ * S bs with XH/A ! " b t Y Vtb Vts !LFCNC = bR (XRL ) sL"S + h. c. ( RL ) 3 CKM CKM v (1+#0 tan$)(1+ %b )
32 23* 32 tan!
32 32 2 2 SUSY X 32 tan 2 µA tan" 6 X RL X LR + " SUSY RL $ t M BR(B ! µ µ ) # ! 4 ! BS " # 2 S 4 ( ) m mA mA A
Negative sign with respect to SM A/H at collider reach: SUSY 2 !M m strong constraints on !MS MFV: correlation between BS $ A DP + # 2 good agreement with data SUSY contributions BR(BS " µ µ ) tan%
Charged Higgs mediated flavor changing effects:
Similar to neutral Higgs case: tanb enhanced charged Higgs - squark loop corrections
• Charged Higgs and chargino-stop contributions to BR(B ! X S")
µ tR tL + P 32 33 h˜ ˜ + RL PLR 2 h1 + 2# S * __ sL H b !h " h µ M ~ ! ~ R t t g! sL t t b 3$ R At L R
(h " #h tan$) m t t b µ At tan# mb 2 A + ! g[mt ,m + ] Vts A + " ht f [m! ,m! ,µ] Vts H H ! t1 t2 (1+ %b ) 1 + $ ( b )
• Bu ! "# transition MSSM charged Higgs & SM contributions interfere destructively
2 BR(B ! "#)MSSM - % m2 ( tan+ 2 0 ± R u /1 B 2 (H ) Bu !"# = SM = $ ' 2 * 3 BR(Bu ! "#) / m (1+ ,0 tan+)2 . & H ± ) 1
In vast regions of SUSY space, indirect searches in B observables may be more powerful than direct Higgs searches FCNC and the scale of SUSY Breaking
• FCNC’s induced by Higgs-squark loops depend on the flavor structure of the squark soft SUSY breaking parameters
• If SUSY is transmitted to the observable sector at high energies M~MGUT even starting with universal masses (MFV) in the supersymmetric theory: Ellis, Heinemeyer, Olive, Weiglein Due to RG effects: M.C, Menon, Wagner
+ " 1) The effective FC strange-bottom-neutral Higgs is modified: Bs ! µ µ
3 1,2 2 2 bs m ( # " # + h # ) tan$ * ! 3 " !1,2 > 0 and proportional to µM XH/A ! " b 0 0 t Y Vtb Vts 0 0 g! ( RL ) 3 CKM CKM If µA < 0 and µM > 0 v (1+#0 tan$)(1+ %b ) t g! possible cancellation of effects
2) Flavor violation in the gluino vertex induces relevant contributions to b ! s"
2 2 Borzumati, Bertolini, Ag! ! " S (m0 # mQ )M g! µ tan$ F(m0 ,mR ,m ! ,m ! , M g! ) Masiero,Ridolfi 3 bi di • If SUSY is transmitted at low energies: M~ MSUSY, Squark mass matrices approx. block diag, only FC effects in the chargino-stop loop & via H+ B physics constraints on the X t ! µ plane Departures from MFV - the Scale of SUSY breaking
Allowed in low M A = 200 GeV tan!=55 energy SUSY:
M = MSUSY Allowed in high energy SUSY:
M = MGUT
CDMS excluded M.C., Menon, Wagner
Independent of the scale at which SUSY breaking is transmitted M M or M M ! SUSY ! SUSY Large stop mixing is disfavored ==> light Higgs mass below/about 120 GeV
Can be excluded by Tevatron; LHC discovery in di-tau and di-photon channels Indirect searches for MSSM Higgs bosons in direct Dark Matter experiments
Direct DM experiments: WIMPs elastically scatter off nuclei in target, producing nuclear recoils
#8 Sensitive mainly to spin-independent elastic scattering cross section ! SI "10 pb
==> dominated by virtual exchange of H and h, coupling to strange quarks and to gluons via bottom loops
tan! enhanced couplings for H
Indirect Higgs probes also in dark matter explanations of leptonic cosmic ray signals . Non-SM-like Higgs and B-meson Constraints The effect of the SUSY breaking scenario in MFV
X = !400 GeV µ=800 GeV M = 1.5TeV M =800 GeV µA < 0 and µM > 0 t SUSY g! t g!
pp ! H / A ! " +" # excluded : 1.8 fb-1 GREEN (hatched) region: Allowed in low energy
SUSY: M = MSUSY
YELLOW region: -1 Tevatron - 4fb Allowed in high energy LHC - 30 fb-1 SUSY: M = MGUT ___CDMS excluded - - - CDMS expected ..…Xenon expected
For M~MGUT, parameter space less constrained for large tanb: The chargino contribution cancels both, the gluino and charged Higgs ones to b ! s" + " Also, cancellation of B S ! µ µ due to mass splitting effect
For M~Msusy, parameter space more constrained for large tanb: + " The chargino contribution cancels charged Higgs ones to b ! s " but B S ! µ µ very contrained due to non-vanishing At Non-SM-like Higgs and B-meson Constraints The effect of the SUSY breaking scenario in MFV: case 2
X = 0 µ=1000 GeV M = 1.5TeV M =800 GeV t SUSY g! pp ! H / A ! " +" # GREEN (hatched) region: -1 excluded : 1.8 fb Allowed in low energy
SUSY: M = MSUSY
YELLOW region: Tevatron - 4fb-1 Allowed in high energy -1 LHC - 30 fb SUSY: M = MGUT ___CDMS excluded - - - CDMS expected ..…Xenon expected M.C., Menon, Wagner
For M~MGUT, parameter space STRONGLY constrained for large tanb: The chargino and the charged Higgs contributions cancel individually, some contribution from + " the gluino to b ! s " . Strong constrain from gluinos (no cancellation for At=0) to BS ! µ µ
For M~Msusy, parameter space less constrained for large tanb: The chargino and charged Higgs contributions to b ! s " (tend to) cancel individually and no + " constraint for At=0 to BS ! µ µ Loop-induced A/H mediated FCNC can affect in a relevant way:
0 0 1) Bs mixing Bs = (b s) Bs = (bs )
Flavor eigenstates mix via weak interactions
0 0 0 0 Mass eigenstates: BH = pBs + qBs BL = pBs ! qBs
2 GF ˆ 2 2 2 !Ms = MB " MB = 2 |M12| = $B mB BB f B MW S0 (mt ) |Vts| H L 6# 2 S !"S # S lattice Box-diagram Short distance QCD corrections
. "1 CDF: !M S = 17.7 ± 0.10 ± 0.07 ps
CKM +12.2 "1 !M S = 18.9"5.5 ps SM fit : UT "1 !M S = 20.9 ± 5.2 ps + " 2) Rare decay rate: BS ! µ µ Initial state BS = (bs) m SM amplitude ! V µ ts M W
+ "9 BR(Bs ! µ µ")SM # (3.8 ±1.0) $ 10 Final state
• Present CDF limit:
+ _ "8 BR(Bs ! µ µ ) < 5.8 10 at 95% C.L.
LHCb will probe SM values with a few fb-1 Using CKM fitter
Using UT fit
CDF + _ "8 BR (Bs ! µ µ ) < 5.8 10