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Heavy flavours and QCD Selected LHCb results. Sergey Barsuk, LAL Orsay. on behalf of the LHCb collaboration. Outline. : La nascita, la vita e la morte degli aromi pesanti a LHCb. Heavy flavour production Onia production / Open charm and beauty production / Exotics
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Heavy flavours and QCD Selected LHCb results Sergey Barsuk, LAL Orsay on behalf of the LHCb collaboration Outline : La nascita, la vita e la morte degli aromi pesanti a LHCb • Heavy flavour production • Onia production / Open charm and beauty production / Exotics • Lifetime-based studies • Heavy flavour hadron decays & CPV • Angle / BsBs mixing phase φs/ New results on b-baryons / / Radiative penguines bs / Search for Bsμμ
Introduction • Heavy flavours – excellent place to hunt for effects beyond Standard Model • Strategic attack on SM by LHCb : examples of where LHCb can contribute • Hot channels for the near future: • Bs μ μ : Is there SUSY? BR ~ tan6β / m4A . • Bs J/ψφet al. : Beyond-SM CPV? • Bd μ μ K* : Right-handed currents? • (φ3) : Is the CKM matrix sufficient? • yCP: Beyond-SM CPV in charm? • My goal is to show results / potential • of LHCb in these areas … talks by Antonio Masiero and Marco Ciuchini
LHCb design overview JINST 3:S08005,2008 • Correlated bb production, second b in acceptance once the first b is in (flavour tagging) • LHCb covers forward region: 1.9 < η < 4.9 • optimized for forward peaked HQ production at the LHC • only ~4% of solid angle, but ~40% of HQ production cross section • Unique acceptance amongst LHC experiments: can explore QCD in the forward region • LHCb covers forward region: 1.9 < η < 4.9 • Large cc and bb production cross section at LHC : • with ALL c- and b-species produced, • e.g. 50k bb events/s • Busy events, O(200) particles/event • Bunch crossings at 40 MHz, can store < 3 kHz • Aim at reducing rate, while storing as many HQ as possible, two-stage trigger: • Hardware-based L0 trigger employs moderate pT cuts, reduces rate to 800 kHz • Then full event information can be used by the trigger farm (HLT)
LHCb detector – single-arm forward spectrometer 10-250 mrad (V), 10-300 mrad (H) 250 mrad Calorimeters RICH counters p/K/π Identification 10 mrad p p VErtex LOcator Muon System Tracking Kinematics: Magnet Tracker Calorimeters Vertex reconstruction: VELO PID: RICHs Calorimeters Muon Chambers Trigger: Muon Chambers Calorimeters Tracker
VErtex LOcator: precision tracking and vertexing 1.638 ± 0.011 1.525 ± 0.009 1.525 ± 0.009 1.477 ± 0.046 1.391 ± 0.038 LHCb-CONF-2011-001 Vertex Locator (VELO) provides excellent proper time resolution of ~50 fs LHCblifetime measurements using 36 pb-1of 2010 data VELO sensitive area gets 8 mm to the beam axis LHCb [ps] PDG [ps]
Particle identification photon/electron/hadron PID: calorimeter Muon detector X 0 Charged hadron identification: Cherenkov detectors
LHCb operation LHCb collected ~37 pb-1 in 2010 and already >700 pb-1 in 2011. Goal for 2011: 1 fb-1 • LHC reached nominal peak luminosity of 2x1033 cm-2s-1with number of bunches ~1300 from ~2600 • LHCb recording >1pb-1/hour running at • L~3.3x1032cm-2s-1(higher, than nominal, 2x1032 cm-2s-1 ) in auto-leveling mode • LHCb tested operation up to 4x1032 cm-2s-1 ATLAS CMS dL/dt ~ 100 pb-1/week possible ! ~30 pb-1 in 29 h in a single fill. LHCb luminosity levelling LHCb (design) • Visual average number of vertices now is higher µ ~1.4, compared to nominal µ =0.4 • Higher µ higher track multiplicity, 1 PV gives 30 tracks/rapidity range, dangerous for reconstruction • dangerous background for D and B decay vertex reconstruction • average minimum distance between 4 PVs ~12 mm, comparable to average B travel distance ~10 mm
Heavy flavour production: LHCb as a flavour factory Onia production: J/ψ, χc, ϒ(1S), χb Exotics: X(3872), X(4140) b-hadron production: inclusive production, B, Bs, Bc Exclusive charmonium production
Onia production: J/ψ and ϒ(1S) LHCb-CONF-2011-016 Eur.Phys.J. C71 (2011) 1645 Mechanism of onia production: colour single model, octet model, evaporation model...? Measurements getting more precise than theory, given polarisation will be measured. P.Artoisenet, M.Butenschon, B.A.Kniehl J/ψ from b J/ψ prompt 5.2 pb-1 5.2 pb-1 P.Artoisenet, J.M.Campbell, J.P.Lansberg, F.Maltoni, F.Tramonato 32 pb-1 ϒ(1S) 32 pb-1 Adequate description of J/ψ production, while still big uncertainty for ϒ(1S)
χc and χb production using radiative decays χcJ/ψ γ and χbϒ(1S)γ LHCb-CONF-2011-020 Challenge to resolve χc1 vs. χc2 35 pb-1 NLO NRQCD σ(χc2)/σ(χc1) 35 pb-1 LO colour singlet First results for relative production of χc1 vs. χc2 are not well described by NLO NRQCD. • χb0,1,2 can not be resolved • No sign of χb(2P) reported by CDF (PRL 84 (2000) 2094), • though ϒ(1S) statistics ~30 times larger. 37 pb-1 350±59 events
Exotics: X(3872), observation, mass, x-section LHCb-CONF-2011-021 LHCb-CONF-2011-043 Exotic, internal structure uncertain, possibly a DoD*o molecule. Precise mass crucial Inclusive measurement, LHCb 2010 data, 35 pb-1 Mass calibrated by scaling track momenta and constraining ϒ(1S),ψ(2S)μμ, DoKπ and KoS ππ masses. Control channel: ψ(2S)J/ψππ. for 5 GeV/c < pT < 20 GeV/c, 2.5 < η < 4.5. 35 pb-1 LHCb preliminary 376 pb-1 • With 2011 data perform: • precise mass measurements • angular studies [LHCb-PUB-2010-003] in BX(3872)K to access JPC of X(3872) B+X(3872)K+ M(J/Ψππ)-M(J/Ψ)
Exotics: search for the X(4140) LHCb-CONF-2011-045 CDF ~6 fb-1 CDF observed a 5σ structure, X(4140), X(4140)J/Ψ φ in B+J/ΨφK+ events [arXiv:1101.6058]. LHCb now has a large sample of these decays. LHCb preliminary 376 pb-1 LHCb preliminary 376 pb-1 expected signal scaled from CDF: 39±9±6 B+J/ΨφK+ ~360 decays (c.f. 115 for CDF in 6 fb-1) fit: 7±5 Background model is 3-body phase space convoluted with resolution LHCb does not confirm presence of X(4140). 2.4σ tension with CDF (using this background model)
b-hadron production Eur. Phys. J. C 71 (2011) 1645 b-hadron production studies: Phys. Lett. B 698 (2011) 14 • Detached J/Ψ: σ4πbb = (288 ± 4 ± 48) μb • Dμ tags: σ2 < η < 4bb = (75 ± 5 ± 13) μb LHCb-CONF-2011-033 σ4πbb = (284 ± 20 ± 49) μb • Fully reconstructed J/Ψ X states: 35 pb-1 b-production with B+J/ΨK+ Measurements reasonably well described by theory (FONLL, MC@NLO)
b-hadron production LHCb measured fragmentation fractions: relative rates of B+, Bo, Bs, Λb ... Two complementary approaches: 1. Ratio of related hadronic decays, e.g. BoD-K+ and BsDs-π+ 2. Semi-leptonic analysis with DoμX, D+μX, DsμX & ΛcμX events and accounting for cross-feeds [LHCb-CONF-2011-028] [arXiv:1106.4436, sub. to PRL] LHCb, 35 pb-1 LHCb, 35 pb-1 BsDs-π+ BoD-K+ Consistent results for Bs/Bo fragmentation ratio, fs/fd, which thus can be combined: +0.021 fs/fd not a priori a ‘universal’ number, but similar to LEP and Tevatron result. <fs/ fd> LHCb = 0.267 -0.020 LHCb-CONF-2011-034 Necessary input for e.g. BR(Bsμμ)
Relative Bc+ to B+ meson production LHCb-CONF-2011-017 Production of Bc+ is added by measuring it relative to B+, in the fiducial region pT > 4 GeV/c, 2.5 < η < 4.5. LHCb 2010 data: 32.5 pb-1 32.5 pb-1 32.5 pb-1 3476 ± 62 events 43 ± 13 events Uncertainty is mainly statistical, systematics dominated by the Bc+ lifetime measurement.
Exclusive quarkonia production LHCb-CONF-2011-022 Talk by Alain Martin Usually proton collisions produce very many final state particles because the gluon is a coloured object. But if a colourless object is exchanged….. • J/ψ and ψ’ exclusive production are interpreted as photon-pomeron fusion or odderon-pomeron fusion; • χc exclusive production is interpreted as double pomeron exchange; • exclusive di-muons come from photon-photon fusion. • Clean signature: • No backward tracks (gap of 2 units of rapidity) • Precisely two forward muons • No photons (for J/ψand diphoton process) • One photon (for c analysis)
Use of backwardstracks, non-exclusive production Muon Primary vertex Backward tracks Requiring a gap, there is evidence for central exclusive production decaying to two muons. Backward Forward tracks
Exclusive production: signatures fromJ/ψ, ψ’ and χc LHCb 2010 data 3.1 ± 0.6 pb-1 J/ψ and ψ’: number of forward tracks J/ψ subtracted ψ’ J/ψ ψ’ feeddown Purity from forward track counting: fitting the background under the peak by using a straight line or exponential fit, yields purity estimate ~85%. J/ψ and ψ’: number of photons LHCb 2010 data 3.1 ± 0.6 pb-1 Estimated feeddown from χc J/ψ ψ’ χc
Exclusive production: purityfromdimuonpTspectrum Fit elastic and inelastic components LHCb 2010 data 3.1 ± 0.6 pb-1 Estimate purity below 900 MeV : 80±3% J/ψ and ψ’ signals Clean mass peaks of J/ψ and ψ’ resonances despite looking at prompt production in pp-collisions at 7 TeV. Contribution from non-resonant background & misidentification is small J/ψ Ψ’ LHCb 2010 data 3.1 ± 0.6 pb-1 Events with no backward tracks, two forward tracks and no photon.
Exclusive production: χcstates Require two forward tracks and one identified photon > 200 MeV. Even cleaner! Fit M(μμγ) to MC templates for ψ’, χc0, χc1, χc2 LHCb 2010 data 3.1 ± 0.6 pb-1 LHCb 2010 data 3.1 ± 0.6 pb-1 M(μμ) GeV/c2 M(μμγ) GeV/c2 All the three χc states needed to describe the observed spectrum !
Exclusive production: results • Contributions from all the 5 charmonium states (J/ψ, ψ’, χc0, χc1, χc2) is seen. • Comparison theory-experiment requires major efforts from both parts. • Reasonable precision for J/ψ and ψ’, systematics will be improved in 2011. • Consistent* with Starlight, SuperChiC, Motyka & Watt [Phys. Rev. D 78, (2008) 014023] and Schaffer & Szcsurek [Phys.Rev. D76 (2007) 094014] • Still no precise determination of individual χc0, χc1, χc2 production. • Consistent* with SuperChiC, Harland-Lang et al. [arXiv:hep-ph/0909.4748]. • Does not agree to CDF 2009 [Phys. Rev. Lett. 102, (2009) 242001]. • Most clean ratio of ψ’ to J/ψ production, corrected for BR(ψμμ), 0.20 ± 0.03. • Consistent with HERA and Tevatron results. • Consistent* with Starlight and Schaffer & Szcsurek [Phys.Rev. D76 (2007) 094014. arXiv:hep-ph/0811.2488] • New dedicated trigger line implemented now & statistics x 30 improvement in 2011 ! * Large theoretical uncertainties. Rescattering corrections (alters cross-section by ~20%).
Charm studies: LHCb as LHCc C Mixing parameter yCP via lifetime comparison Search for CP violation via AΓ (Search for direct CP violation) Moved to backup
Mixing and CP violation in charm sector D1,2 = p |Do> ± q |Do> x=m/, y=/2 Charm is abundant at LHC: 6.5 mb cross-section. However need to reconstruct low pT decays. • Mixing in charm sector is non-zero at >5σ by HFAG, however no single measurement excludes 0. • CPV in mixing (SM or NP) driven by mixing parameters x,y (~1%). CPV in D mixing in SM is negligible, but can be enhanced in many models. Existing constraints are weak. • Direct CPV best looked for in CSD, where gluonic penguins are significant. Φ SM |q/p| Large samples of charm mesons are being reconstructed. Presently ~700 pb-1 collected. 220 pb-1 195 pb-1 D*+Do(K+K-)π+ Ds+K+K-π+ D+K+K-π+
Measurement of the charmmixingparameteryCP LHCb-CONF-2011-054 Charm mixing parameter yCP : 2010 data, 28 pb-1, flavour tagging using Do sample from D*Doπ decays. Challenges in time-dependent charm studies at LHC: • Contribution from BDX • to prompt charm sample • Correct lifetime bias • on the event-by-event basis DoK-π+ DoK-K+ LHCb preliminary 28 pb-1 LHCb preliminary 28 pb-1 • Future improvement in sensitivity : • Statistics x30 in 2011 • Improved treatment of background events τDo=410.2±0.9 fs DoK-K+ DoK-π+ HFAG 2011 average (without LHCb): (11.1 ± 2.2) x 10-3 yCP= (5.5 ± 6.3 ± 4.1) x 10-3
Measurement of AΓ LHCb-CONF-2011-046 One of most important ways to search CPV in charm mixing: 2010 data, 28 pb-1, flavour tagging using Do sample from D*Doπ decays. • Challenges in time-dependent charm studies at LHC: • Contribution from BDX • to prompt charm sample • Correct lifetime bias • on the event-by-event basis Obtained event-by-event on data AΓ= (-0.59 ±0.59 ±0.21) x 10-2 HFAG 2011 average (without LHCb): ( 0.12 ± 0.25 ) x 10-2 • Future improvement in sensitivity : • Statistics x30 in 2011 • Improved treatment of background events
Beauty studies: LHCb as LHCb Touch rare effects and mostly bs transitions: penguine or box diagram, NP diagrams can compete. Angle : Evidence of suppressed ‘ADS’ mode BDK Charged hadron ID and Direct CP violation in charmless B-decays with eyes New results on b-baryons: ΛbDopK- Bs mixing phase φs from BsJ/Ψφ and BsJ/Ψ fo(980) Rare decays: Radiative penguines bs (Forward-backward asymmetry in BK*ℓℓ) Moved to backup Search for Bsμμ
Precision CKM studies: angle γ • The Rt side precision limited by theory (lattice calculations), while precision of γlimited by experiment. Improve precision of angle γ to improve CKM triangle closure check • Search for NP by comparing tree-mediated processes (γ, Rb) to those involving loop diagrams (γ, β, Rt) 2010 Rb Rt 1 B± DK± decays using common mode for Do & Do • γ sensitive interference • different rates for B+ & B- (CPV) Maximize interference by using mode suppressed for Do & favoured for Do e.g. DoK+π- (DCS) , DoK+π- (CF) the ‘ADS’ method [Atwood, Dunietz, Soni] Total visible BR very small (~10-7). ± The suppressed ‘ADS’ mode is needed to access γ. B± (K π±) K±
Evidence for suppressed ADS mode LHCb-CONF-2011-044 Signal seen with 4.0σ significance & hint of asymmetry, consistent with previous results Ratio to favoured mode: 343 pb-1 ± B± (K π±) K± HFAG average (without LHCb): (1.6 ± 0.3) x 10-2 B-(K+π-)K- B+(K-π+)K+ 343 pb-1 343 pb-1 Asymmetry: HFAG average (without LHCb): -0.58 ± 0.21
‘Bhh’ (h=π,K,p) at LHCb Two-body charmless B decays: significant contribution of penguin diagrams, important for NP searches BoKπ Rely on good performance of trigger and RICH LHCb preliminary Inclusive spectrum, ππ hypothesis Deploy RICH to decript ‘hh’ ! Boππ BsKK ΛbpK Λbpπ
Bd,sKπ: direct CPV LHCb-CONF-2011-042 320 pb-1 320 pb-1 BoK-π+ BoK+π- Most precise single measurement and first 5σ observation of CPV at hadron machine: HFAG average (without LHCb): 320 pb-1 320 pb-1 BsK-π+ BsK+π- First evidence of CPV in Bs decays: CDF result: 0.17 In future perform time dependent study, particularly of BsKK: New Physics sensitive measurement of γ [e.g. Fleischer, PLB 459 (1999) 306]
New measurementswithb-baryons LHCb-CONF-2011-036 Cabibbo-suppressed decay ΛbDopK-, potentially powerful mode for measuring CKM angle γ. Normalization channel: ΛbDopπ-. ΞobDopK- ΛbDopπ- ΛbDopK- M(Dopπ-) M(DopK-) MeV/c2 MeV/c2 ΛbDopK- • First observation of with significance of 6.3σ: ΞobDopK- • A signal with (stat+syst) significance of 2.6σ, consistent with decay. Relative production rate x BR: Mass relative to Λb: Ξob [Ξ+cπ-, Ξ+cΞ-π+π-,Ξ-Λπ-,Λpπ-] recently observed by CDF [arXiv:1107.4015]. Consistent masses from two experiments: MLHCb(Ξob) - MCDF(Ξob) = -14.2 ± 7.7 MeV/c2
Precision CKM studies: Bs mixing phase φs from BsJ/Ψφ • Phase is small in SM (box diagram) : 0.0363 ± 0.0017 rad [CKMFitter] • Deviations due to NP could be large • LHCb measurement with 2010 data: 37 pb-1, 757 ± 28 signal candidates • [LHCb-CONF-2011-006] • Time dependent analysis • Time resolution measured using prompt J/Ψ background: στ = 50 fs • Tagging • Need to tag initial flavour of the Bs • Per event mistag calibrated on B+ J/Ψ K and Bd D* μνμ • Dilution Dtag = 0.277 ± 0.011 ± 0.025 • Tagging power εD2 = (2.08 ± 0.41)% • Angular analysis • PVV decay: needs an angular analysis to resolve CP-even and CP-odd components • Angular acceptance determined from MC • Maximum deviation from uniform: 5%
φs from BsJ/Ψφ ~770 decays ΔΓs [rad] SM 36 pb-1 337 pb-1 Φs [rad] Φs [rad] First evidence (4σ) of ΔΓs > 0 ! φsJ/Ψφ= 0.13 ± 0.18 (stat) ± 0.07 (sys) rad Γs = 0.656 ± 0.009 (stat) ± 0.008 (sys) ps-1 ΔΓs = 0.123 ± 0.029 (stat) ± 0.008 (sys) ps-1
φs from BsJ/Ψ fo(980) • First observation of BsJ/Ψ fo(980) (fo(980)ππ) by LHCb with 30 pb-1 [Phys. Letters B 698 (2011) 115] • confirmed by • Belle [Phys.Rev.Lett.106:121802,2011] and • CDF [arXiv:http://arxiv.org/abs/1106.3682] LHCb preliminary 330 pb-1 • With 330 pb-1 LHCb extractsφs. • The fo(980) looks pure scalar no angular analysis needed. 330 pb-1 Bs J/ψfo(980) BoJ/ψπ+π- LHCb preliminary 330 pb-1 BoJ/ψK*
φs from BsJ/Ψ fo(980) and BsJ/Ψφ φsJ/Ψfo(980)= -0.44 ± 0.44 ± 0.02 rad 330 pb-1 Or, combining, BsJ/Ψφ and BsJ/Ψ fo(980) : φsJ/Ψφ+J/Ψfo= 0.03 ± 0.16 ± 0.07 rad BsJ/Ψ fo(980) SM fit: 0.0363 ± 0.0017 rad LHCb with 0.3 fb-1 already more sensitive, than CDF and D0 BsJ/Ψφ
Radiativepenguines: bs LHCb-CONF-2011-055 Measure ratio of the branching fractions for BK* and Bsφ Test for NNLO QCD predictions Ali, Pecjak, Greub [Eur.Phys.J.C 55 (2008) 577] 340 pb-1 BK* • Photons Broader signal peak than typical B decay • More work on backgrounds (B Kππo etc) • However, largest Bsφ sample 340 pb-1 Bsφ Expect: 1.0 ± 0.2 from SM. • Next: study time evolution and CP asymmetries
Search for Bsμμ In SM, Bsμμ occurs only via loop diagrams, and is helicity suppressed: BR(Bsμμ)SM = (3.2 ± 0.2) x 10-9 [A.J.Buras, arXiv:1012.1447] Can be strongly enhanced in NP models, especially those with extended Higgs sector. E.g. MSSM: NUHM (= generalised version of CMSSM) [O. Buchmuller et al, arXiv:0907.5568] Talk by M.Kraemer BR(Bsμμ) - highly discriminatory Many previous measurements Recent CDF result with 7 fb-1: +1.1 BR(Bsμμ) = (1.8 ) x 10-8 or < 4.0 x 10-8 @ 95% CL -0.9 [arXiv:1107.2304] LHCb 2010 data, 0.037 fb-1: BR(Bsμμ) < 5.6 x 10-8 @ 95% CL [PLB 699 (2011) 330]
Search for Bsμμ, LHCb 2011 data, 300 pb-1 LHCb-CONF-2011-037 • Similar to 2010 analysis [PLB 699 (2011) 330] • Select Bsμμ, using Boosted Decision Tree out of 9 kinematical and topological variables • BDT tuned on MC, but calibrated on data: • Bhh, triggered on ‘other B’, and sidebands • Calibrate invariant mass resolution (~25 MeV) on data (dimuon resonances & Bhh) • Look on 6 x 4 grid of μ+μ- invariant mass vs. BDT output 300 pb-1 300 pb-1 300 pb-1 300 pb-1 • Normalize to: B+J/ΨK+, BsJ/Ψφ and BoKπ– all give consistent results
Search for Bsμμ, LHCb 2011 data, 300 pb-1 LHCb preliminary 300 pb-1 LHCb preliminary 300 pb-1 Data Combinatorial background LHCb preliminary 300 pb-1 LHCb preliminary 300 pb-1 Bhh misid background 0.1±0.1 events in each of 4 BDT bins Signal with SM BR
Search for Bsμμ, LHCb limits Compute limits using frequentist CLs method and LHCb combined result for fs/fd LHCb preliminary 300 pb-1 LHCb preliminary 300 pb-1 expected: background and signal SM BR expected: background only ±1σ ±1σ observed observed BR(Bsμ+μ-) BR(Bdμ+μ-) Expected limit assuming bkg only (95% CL) 1.0x10-8 3.1x10-9 Expected limit assuming bkg + SM signal (95% CL) 1.5x10-8 Observed limit (95% CL) 1.6x10-8 5.1x10-9 p-value of background only hypothesis 14% 79% Observed limit, 2010+2011 (95% CL) 1.5x10-8
Search for Bsμμ, combining LHCb and CMS results A preliminary CMS (1.14 fb-1)-LHCb (0.34 fb-1) combination on BR(Bsμ+μ-) has been performed, again using the CLs approach, & taking LHCb value of fs/fd as common input LHCb-CONF-2011-047 CMS PAS BPH 11-019 CMS + LHCb preliminary LHCb (0.34 fb-1) + CMS (1.14 fb-1) preliminary expected: background only ±1σ observed Observed candidates in both experiments are consistent with the sum of backgrounds and SM signal BR < 1.1 x 10-8 @ 95% CL. This limit is 3.4 times the expected SM value. A BR of 1.8 x 10-8 has a CLs value of ~0.3%
Hunting for physics Beyond Standard Model (“New Physics”) continues and either we discover it within our lifetime scale or …
... or we have to ask for help this time ... … and New New Physics == Beyond New Physics discover on our own.
Summary • LHCb is proving to be a heavy flavour factory • Production of quarkonia and open heavy flavour hadrons is being systematically studied • Charm cross section is large, huge D-meson samples collected, and first CPV studies with 2010 data look promising • Precision CKM angle studies are launched, hint on the ‘ADS’ asymmetry in BDK is observed • Most precise measurement of the direct CPV in BKπ • First evidence of the direct CPV in BsKπ • New data on the b-baryons • LHCb and CMS do not confirm the hint seen by TEVATRON for Bsμμ, and set the limit, which is x 3.4 SM value • 2011 data being analysed, many analyses still on 2010 data • Expect 1 fb-1 in 2011, more in 2012, setting the scene for precision rare effects studies
Direct CPV search Paper in preparation Cabibbo favoured control modes (no CPV expected) Perform model independent binned CPV search in singly Cabibbo suppressed D+K-K+π- events Same topology Ds+K+K-π+ 2010 370k decays 37 pb-1 10x more abundant D+K-π+π+ • Compare with 43k events in BABAR, 80 fb-1 • [PRD 71 (2005) 091101 (R)] • Normalize D+ vs. D- to remove production asymmetries • Use resonance motivated binning & uniform binning • Look for statistically significant difference in D+ vs. D- bin contents (based on PRD 80 (2009) 096006) • Look for fake CPV in sidebands and control modes No fake CPV seen: data & method robust against biases No evidence of CPV for signal in any binning
b l l s • b l l s, very rare in the SM • BR (B l l K*) = (3.3 ± 1.0) x 10-6 • Sensitive to Supersymmetry, any • 2HDM, Fourth generation, Extra • dimensions, Axions . . . • Ideal place to look for new physics
Angular Distributions & AFB Many observables depending on q2 = m2μμc4
Models probed by AFB(q2) dependence [Krüger & Matias] [Egede et al.] [Ali et al.]