Flavour Physics in the Era of the LHC

Flavour Physics in the Era of the LHC Franz Muheim University of Edinburgh ATLAS Cosenors Forum Heavy Flavour Physics 21/22 June 2007 Thanks to collaborators in “Flavour in the LHC era” workshop

Outline l Introduction and Motivation – Standard Model: CKM mechanism – Direct and Indirect New Physics Probes l New Physics searches in flavour sector – Bd mixing, hadronic b s transitions, b s , – D 0 mixing, Bs mixing l Flavour Physics at the LHC – LHC, LHCb, ATLAS and CMS – Bs system, CKM angles, rare decays l Super. LHCb and Super Flavour Factories – Plans l Conclusions Cosenors, 21 June 2007 F. Muheim 2

Five Meetings at CERN: - 3 days each Nov 05, Feb 06, May 06, Oct 06, Mar 07 - O(250) participants, ~400 talks 3 Working Groups: - Flavour in High Pt interactions - B/D/K Decays - Flavour in Leptons sector (incl. edm, g-2) Goals: - Establish flavour physics programme for next decade - Complementarity between high Pt and B/D/K decays for discovery and exploration of BSM Physics 1 st Draft of report ~500 pages -> Yellow Report http: //flavlhc. web. cern. ch/flavlhc Cosenors, 21 June 2007 F. Muheim 3

Motivation for Flavour Physics l Big Bang produced equal amounts of matter and antimatter – Protons & antiprotons annihilated within 1 ms after Big Bang l Why is our Universe matter dominated? Cosenors, 21 June 2007 F. Muheim 4

CKM Unitarity Triangle l Status of FPCP 2007 l UT Sides – |Vub|, |Vtd| |Vcb| – Experimentally very well measured – Accuracy limited by theory l UT Angles – , , and – CP violating asymmetries – Accuracy limited by experiment l Measurements consistent with SM predictions ≠ 0 => CPV established in B and K mesons CKM mechanism is dominant source of CPV in quark sector New Physics (NP) would appear as “corrections” Nir Cosenors, 21 June 2007 F. Muheim 5

Standard Model l SM is low-energy limit l SM fails CPV is required for Universe to look like this – does not explain baryogenesis – does not explain neutrino mass – has no dark matter candidate 23% of universe is dark matter – No unification of strong and electroweak interaction possible – Does not include gravity not – Hierarchy problem Higgs mass unstable wrt to large quantum corrections l that What is the energy scale of New Physics? Cosenors, 21 June 2007 F. Muheim 6

New Dawn of Particle Physics l Direct Searches at ATLAS, CMS, Tevatron – Supersymmetry, Extra Dimensions, Black Holes, Little Higgs, New Gauge Bosons, … l Indirect Searches – CPV and rare decays of Heavy Flavour – Lepton Flavour Violation e , y – g-2 (muon), EDM (neutron & electron) – Neutrinos: flavour mixing, mass hierarchy, CP violation l Race for discovering New Physics has started l ATLAS and CMS need a friend Cosenors, 21 June 2007 F. Muheim 7

Flavour Structure Cosenors, 21 June 2007 F. Muheim Gino Isidori March 2007 8

Probing New Physics in Bd Mesons l Tree diagrams l – Not sensitive to New Physics Loop Diagrams – Sensitive to New Physics (tree) l Probe New Physics – Example: Vub and sin 2 – Use data from tree mediated diagrams to make SM prediction for UT apex ( , ) – Compare above with measurements of apex ( , ) or , and in loop diagrams Cosenors, 21 June 2007 l Indirect measurements – sin 2 = 0. 764 0. 039 – All results l Direct measurement – sin 2 = 0. 675 0. 026 – Probes NP in Bd mixing l Is Discrepancy (>2 ) – Statistics? – Inclusive Vub extraction? – NP in Bd mixing? eff 2 + 2 NP F. Muheim 2 9

Probing New Physics in Bs Mesons Flavour Changing Neutral Currents l – Suppressed in Standard Model – New Physics appears as virtual particles in loop processes – leading to observable deviations from SM expectations in flavour physics and CP violation ( ) Bs penguin decay Supersymmetry New Physics Standard Model ? – Bs-Bs oscillations ? s s l Role of Flavour Physics in LHC era – If New Physics is found establish NP flavour structure – If no New Physics is found probe NP at higher energies scales Cosenors, 21 June 2007 F. Muheim 10

Probing New Physics in b s l Experiment – BR(b s )=(3. 55± 0. 26)x 10 -4 l + Theory – BR(b s )=(3. 15± 0. 23)x 10 -4 – Misiak et. al, hep-ph/0609232 l Limit on H+ mass – >295 Ge. V at 95% CL for tan > 2 – plot shows central Values & ± 1 bands l Excluded B(b s ) in 2 Higgs Doublet Model with tan =2 experiment Flavour Physics SM theory – Severely constrains NP models Cosenors, 21 June 2007 F. Muheim 11

NP Limits from B+ → t+n l Evidence Use known f. B and |Vub | Ratio to the SM BF. r. H=1. 13 0. 51 l Belle result excludes – M(H+) < 100, 130 < M(H+) < 190 Ge. V (at tan = 30) Cosenors, 21 June 2007 F. Muheim 12

b s Transitions in Bd Mesons l CPV asymmetry sin 2 – Expected to be same in l sin 2 eff Measurements – Results for all modes in agreement with SM – But all measurements lower than sin 2 from Bd→ J/ KS – Average – sin 2 eff = 0. 52 0. 05 – 2. 6 discrepancy to SM – More data required Cosenors, 21 June 2007 F. Muheim 13

Squark Mass Matrix (d sector)Flavour structure: Super. B, LHCb Mass spectrum: LHC, ILC Flavour mixing parametrization b g s (23), b g d (13) Off diagonal terms can provide unique information on CP phases Cosenors, 21 June 2007 F. Muheim 14

Evidence for D 0 Mixing hep-ex/0703020 K. Flood at Moriond EW 2007 3. 9 Cosenors, 21 June 2007 F. Muheim 15

D 0 Mixing l Expected Sensitivities – From draft of Yellow Report l CP violation in charm – Holy grail – Establishes Non-MFV new physics Cosenors, 21 June 2007 F. Muheim 16

Bs Meson Mixing l CDF at Tevatron Bs Mass difference ms Phys. Rev. Lett. 97, 242003 (2006) – SM Prediction ms = 20 7 ps-1 – Measure fast Bs anti-Bs oscillations l First ms measurement – 2006 at Tevatron CDF (5. 4 ) – D 0 – Double-sided 90% CL 17 ps-1 < ms < 21 ps-1 Phys. Rev. Lett. 97, 061802 (2006) – Need theory (Lattice QCD) to reduce error on SM prediction – Smaller errors on ratio Cosenors, 21 June 2007 F. Muheim 17

Large Hadron Collider LHC Flavour physics programme l ATLAS LHCb dedicated for precision measurements of CP violation and rare decays in B hadrons l ATLAS/CMS optimized for high-p. T discovery physics Cosenors, 21 June 2007 F. Muheim 18

B Physics at Hadron Colliders l Large b quark production cross section – – l All b-hadron species – l – <L> ~ 7 mm at LHC ~ 3 mm at Fermilab secondary vertices well separated Low b Purity – – l Bu+, Bd 0, Bs 0, b-Baryons Large b-hadron boost – l For Tevatron > 1000 times e+e- B-factories For LHC ≈ 500 b 5 about 10 to 106 bb pairs/s bb/ inel = 0. 6% at LHC Trigger is a challenge Event topology – – Additional particles not associated Multiple interactions at high luminosities Cosenors, 21 June 2007 F. Muheim 19

LHC Status l LHC tunnel Magnets – 1250 Dipole Magnets – 4500 total – Commissioning progressing well – Repair of triplet progressing l Cool down of Sector 7 - 8 – At 1. 8 K since 4 weeks l Engineering Run 2007 – Cancelled – Sector test planned in Dec 2007 l Three sectors completed Physics Run in 2008 – Collisions at 7+7 Te. V – Machine closure end of March 2008 Cosenors, 21 June 2007 F. Muheim 20

LHC Schedule Draft Courtesy Sylvain Weisz Cosenors, 21 June 2007 F. Muheim 21

Luminosities at LHC l Design Parameters – 40 MHz pp interaction rate – Starting luminosity L = 1032 to 1033 cm-2 s-1 – Design luminosity L = 103 cm-2 s-1 in 2010 l ATLAS/CMS – run at highest available luminosity – expect L ~1033 cm– 2 s– 1 for first 3 years – Flavour physics in first 3 years l 2008 ~2. 5 fb– 1 2009 -2011 10 fb– 1 /year 30 fb– 1 total @ low L LHCb – Luminosity tuneable by adjusting beam focus – Design is to run at L ~ 2 1032 cm– 2 s– 1 2008 ~ 0. 5 fb– 1 – detectors up to 2009 -2013 5 1032 cm– 2 s– 1 2 fb– 1 / year – little pile-up (n = 0. 5) 10 fb– 1 in 5 years – Luminosity will be available for 1 st physics run Cosenors, 21 June 2007 F. Muheim 22

LHCb Experiment Cosenors, 21 June 2007 F. Muheim 23

LHC(b) B-Physics Programme a ~Vub* ~Vtd ~Vts ~Vcb -2 Vtd. Vud + Vts. Vus + Vtb. Vub = 0 Vtd. Vtb + Vcd. Vcb + Vud. Vub = and 0 B production, Bc , b-baryon physics Charm decays Tau Lepton flavour violation Cosenors, 21 June 2007 Rare decays - very sensitive to NP – Radiative penguin e. g. Bd K* , Bs – Electroweak penguin e. g. Bd K*0 + - – Gluonic penguin – Rare box diagram F. Muheim e. g. Bs , Bd Ks e. g. Bs + 24

Bs Mixing Phase s from Bs J/ l CP Violation in Bs mesons – Interference in Bs mixing and decay – equivalent of “sin 2 “ for Bs mesons – SM prediction for CPV asymmetry is very small – Bs weak mixing phase s s = 2 arg(Vts*Vtb) = -2 ≈ – 0. 035 l Bs mixing phase s Illustration of CPV: – Almost unconstrained from data toy-modeling LHCb data with s = -0. 2 (i. e. 5 SM) events tagged as Bs – Very sensitive probe for New Physics – If large value observed clear signal for Non-Minimal Flavour Violation Cosenors, 21 June 2007 events tagged as Bs F. Muheim 25

s from Bs J/ l Analysis Method CDF 2006 ms – B VV mode Angular analysis to separate 2 CP-even and 1 CP-odd amplitudes of final state – Fit for sin s, s and CP-odd fraction (use external ms ) l s Sensitivity hep-ph/0604112 hep-ph/0509242 – studied at ms = 20 ps– 1 – Expect 131 k Bs J/ signal events per 2 fb– 1 (1 year) – Expected precision (sin s) ~ 0. 023 (sin s) ~ 0. 042 Cosenors, 21 June 2007 LHCb 2 fb-1 Bs J/ 2 fb– 1 0. 5 fb– 1 F. Muheim 26

Little Higgs Model with T Parity l Weak mixing phase S – Very sensitive to New Physics models l Little Higgs Model – consistent with measurement in parameter space where large S is predicted & MS is found smaller than in the SM. l Predicts significant enhancements – for S and – semileptonic asymmetry ASL(S) relative to the SM values LHT SM Blanke & Buras [hep-ph/0703117] S Cosenors, 21 June 2007 F. Muheim 27

b s Transitions in Bs l CPV asymmetry s Tree – SM prediction expected to be close to zero in Bs and Bs J/ l Bs hadronic penguin decay – Expect different NP contributions in Bs hadronic penguin decay compared to tree decay Bs J/ l Penguin New Physics? 3 Excellent probe for New Physics – Measurement of s ( ) ≠ 0 would be clear signal for NP beyond SM (NMFV) l s ( ) Sensitivity for LHCb – Best b s penguin mode for LHCb – Expect 4 k Bs events per 2 fb– 1 (1 year) – Estimated precision ( s ( )) ~ 0. 10 Cosenors, 21 June 2007 F. Muheim (0. 04 in 10 fb– 1) 28

from B+ D 0 K+ Colour allowed l “ADS+GLW” strategy: – Measure the relative rates of B– DK– and B+ DK+ decays with neutral D’s observed in final states such as: K– + and K+ –, K– + and K+ – + –, K+K– – Dependencies • • – l Colour suppressed Relative magnitude, weak phase and strong phase in B– D 0 K– and B– anti. D 0 K– Relative magnitudes and strong phases between D 0 K– + and anti-D 0 K– +, and D 0 K– + and anti-D 0 K– + Can solve for all unknowns, including the weak phase : Sensitivity – ( ) ~ 5 -15º with 2 fb– 1 – Combine with many other similar methods, e. g. Dalitz • • ( ) ~ 5º with 2 fb– 1 today = 61+38 -25° ( ) ~ 3º with 10 fb– 1 Cosenors, 21 June 2007 F. Muheim 29

B 0 K *0 + l Flavour Changing Neutral Current Decay – BR ~1. 2 10– 6 AFB(s), theory – Forward-backward asymmetry AFB(s) in the rest-frame is sensitive NP probe – Predicted zero of AFB(s) depends on Wilson coefficients C 7 eff/C 9 eff AFB(s), fast MC, 2 fb– 1 l Sensitivity s = (m )2 [Ge. V 2] – 7. 7 k signal events/2 fb– 1, Bbb/S = 0. 4 ± 0. 1 – After 10 fb– 1: zero of AFB(s) located to ± 0. 28 Ge. V 2 s = (m )2 [Ge. V 2] Cosenors, 21 June 2007 – determine C 7 eff/C 9 eff with 7% stat error F. Muheim 30

B 0 K*0 + - Angular Distributions l Matias hep-ph/0612166 Transversity amplitudes – Longitudinal polarisation FL Asymmetry AT(2) SUSY 1 Study for 2 fb-1 SM NLO SUSY II Cosenors, 21 June 2007 F. Muheim 31

Probing NP with Bs→ + l Very rare FCNC decay – in SM low uncertainty – BR(Bs→μ+μ-) = (3. 5 ± 0. 9) 10– 9 l Very sensitive NP probe – NP models, e. g. multiple Higgs doublets and large tan enhance rate l Type II 2 HDM – rate ~ tan 4 l MSSM – Minimal Flavor Violation (MFV) – squark loops increase enhancement to tan 6 l Constrained SUSY models (m. SUGRA, CMSSM) – correlations between Bs → + -, b → s , ms, g -2 and SUSY Higgs sector l SO(10) SUSY GUTS – Branching Ratio and ms, B→ tn disentangle top-bottom Yukawa unification Cosenors, 21 June 2007 F. Muheim 32

Complementary: High PT & Heavy Flavour l High PT – Discover SUSY with masses at electroweak scale – SUSY has 100+ free parameters l SPA SUSY benchmark point – MSSM with MFV – masses and precision defined for all sparticles for 300 fb-1 l Tools – Use SUSY benchmark points poncalculate flavour observables – Micr. OMEGAs, ISARED – Example: BR(Bs→μ+μ-) and BR(b→s ) Polesello Cosenors, 21 June 2007 F. Muheim 33

Bs→ + - in Constrained MSSM Anomalous magnetic moment of muon Measured at BNL, disagrees with SM at 2. 7. am = (25. 2 ± 9. 2) 10 -10 To explain it with CMSSM: for different A 0 and tan : 250 < m 1/2 (gaugino mass) < 650 Ge. V 10 -7 CMSSM with this same range of gaugino mass predicts BR (Bs → m+m-) ~ a few 10 -9 to 10 -7 much higher than SM Cosenors, 21 June 2007 F. Muheim 10 -8 34 10 -9

Bs→μ+μ- at LHC l Current Status – Upper limits dominated by Tevatron – D 0 at Moriond 2007 BR(Bs→μ+μ-) < 7. 5 10 -8 @ 90% CL l LHC expectations – Will observe decay down to SM level – LHCb at SM level with < 2 fb-1 – ATLAS/CMS also have good sensitivity l ATLAS New Physics Sensitivity – Competitive with direct searches 35

LHCb Sensitivities with 2 fb-1 Cosenors, 21 June 2007 F. Muheim 36

Summary of LHC(b) prospects l LHC is a super b-factory 10 fb– 1 ~2013 – 1 st physics run at 2008 l 2008 Data – Will allow to exclude/discover New Physics in Bs sector down to SM level – e. g. weak mixing phase s in Bs J/ and BR(Bs→μ+μ-) l LHCb (2 fb– 1, 10 fb– 1) – – (sin(2 )) = 0. 02, 0. 01 ( ) = 4. 2º, 2. 4º ( ) = 10º, 4. 5º CKM metrology at precision to probe NP at 10% level – Requires theoretical progress |Vub| and Lattice QCD (mixing) – Rare decays Cosenors, 21 June 2007 F. Muheim 37

Flavour Physics after 5 LHC years l Possible Scenarios – ATLAS/CMS discover Higgs & NP Flavour physics observes NP effects that constrain NP models More flavour physics sensitivity required to further elucidate NP – ATLAS/CMS discover Higgs & NP Flavour physics observes nothing beyond SM More flavour physics sensitivity required to further elucidate NP – ATLAS/CMS discover Higgs but no NP Flavour physics observes NP effects that constrain NP models More flavour physics sensitivity required to further elucidate NP – ATLAS/CMS discover Higgs but no NP Flavour Physics sees nothing beyond SM More flavour physics sensitivity required to further probe NP l Flavour Physics – More sensitivity will be required to further probe or establish NP beyond SM Cosenors, 21 June 2007 F. Muheim 38

Future Flavour Facilities l Super. KEKB Flavour Factory – Upgrade KEKB Increase currents 1. 75 A 9. 6 A (LER) 2. 36 A 4. 1 A (HER) – reduce beam divergence *: 6 mm 3 mm – Increase beam-beam parameter : 0. 053 > 0. 24 – Luminosity goal ℒ ~ 8 x 1035 cm-2 s-1 – Collect ~50 ab-1 – http//belle. kek. jp/superb l Super. B Flavour Factory – Low emittance – ILC like final focus – RF Power ~17 MW – Luminosity goal ℒ >1 x 1036 cm-2 s-1 – Collect ~50 ab-1 – http//www. pi. infn. it/Super. B Cosenors, 21 June 2007 F. Muheim 39

Future Flavour Facilities l LHCb Upgrade – Upgrade LHCb experiment such that it can operate at ℒ ~ 2 x 1033 cm-2 s-1 10 times design luminosity – Collect ~100 fb-1 data sample in ~5 yrs – Is compatible with LHC luminosity upgrade (Super-LHC) does not require SLHC – LHCb is only B-physics experiment approved for running after 2010 – Can LHCb exploit the full potential of B physics at hadron colliders? l LHCb Upgrade - Detectors, Trigger and DAQ – Vertex detector sensors require replacing with radiation-hard sensors after ~6 fb-1 – Add Vertex Detector and Tracker to L 0 Trigger, possible factor 3 improvement of hadron trigger – Readout full detector at 40 MHz – All Front-end electronics must be F. redesigned Muheim Cosenors, 21 June 2007 – Need to replace all silicon sensors 40

Physics at a Super Flavour Factory ACP(B X ) AFB(B Xll) CPV in CF and DCS D decays Br( ) …… CKM angles , , Br(B n) and B Dln |Vub|, |Vcb| radiative decays : Br(B , K* ) many other measurements… A Stocchi Flavour in the LHC era March 2007 CERN Cosenors, 21 June Adjusting the 2007 central values so that they are all compatible F. Muheim Keeping the central values as measured 41 today with errors at the Super. B

Physics with LHCb Upgrade l s (Bs ) Sensitivity Tree – Estimated precision in 10 fb– 1 ( s ( )) ~ 0. 04 – precision statistically limited – With 100 fb-1 and 1 st level detached vertex trigger ( s (Bs )) ~ 0. 006 -> 0. 014 l Penguin New Physics? 3 If large s discovered – Establish flavour structure of New Physics – Script will write itself, but likely need more precise LHCb data l If New Physics in Bs is small – ~3 evidence for NP in b s transitions – require better precision l LHCb Upgrade will probe NP at O(0. 01) level Cosenors, 21 June 2007 F. Muheim 42

UK Perspective I l Flavour physics is a UK strength since many years – NA 31, NA 48, CPLEAR in 1980 s and 90 s – Ba. Bar and CDF/D 0 since late 1990 s l UK has established strong involvement in Flavour in LHC era – Rise of phenomenology including flavour experts – Strong in Lattice QCD – Largest single country in LHCb 2 Physics WG convenors in LHCb and other major positions – ATLAS B physics convenor – In excellent position to exploit LHC data and probe New Physics or measure flavour couplings of New Physics discovered at ATLAS/CMS Cosenors, 21 June 2007 F. Muheim 43

UK Perspective II l Time is now to establish future flavour physics programme – Leading LHCb Upgrade effort - UK convenor – Super. Flavor. Factory – 1 UK editor for CDR physics case l New Research Council – STFC opens up new opportunities l Challenge for a new UK Flavour Physics Project l Adventurous l not “solid” – Doing new things not doing the same thing with smaller errors – Leading a project not joining a project – Focused on excellence not doing a bit of everything UK particle physics needs to play to its strength – Flavour physics Cosenors, 21 June 2007 F. Muheim 44

B Factories – “Press Releases” Evidence for D 0 mixing Expect. Exciting excitingresults every year ! with surprise in LHC era Observation of direct CP violation in B g p+p. Evidence for B g tn Observation of b g d Evidence for direct CPV in B g K+p - Discovery of X(3872) Hint at new physics: CPV in B g Ks Observation of B g K(*)ll Observation of CPV in B meson system Cosenors, 21 June 2007 F. Muheim M Hazumi Flavour in the LHC era March 2007 CERN 45

Particle Physics in 2007 LHCb, B-factories CP Violation Let’s start digging! ATLAS, CMS Higgs & SUSY Cosenors, 21 June 2007 F. Muheim 46

Backup Slides Cosenors, 21 June 2007 F. Muheim 47

Supersymmetry SU(5) GUT Degenerate SU(5) GUT Non-degenerate U(2) FS S l S can deviate from the SM by 5 -10% for SU(5) GUT with non- degenerate case and the U(2) model. From Okada talk at BNMII, Nara Women’s Univ. Dec. , 2006 Cosenors, 21 June 2007 F. Muheim 49

CP Violation in B Mesons l How does CP Violation arise? – Difference between transitions of particles and antiparticles in B 0 mixing l – in B decay l – l New Physics could arise in the mixing or in the decay amplitude in interference between B 0 mixing and decay – Cosenors, 21 June 2007 F. Muheim 53

The End Cosenors, 21 June 2007 F. Muheim 54