CP Violation Studies in the Bs System at DØ

Transcription

1 CP Violation Studie in the B Sytem at DØ B B? Rick Van Kooten Indiana Univerity Repreenting the DØ Collaboration 35th International Conference on High Energy Phyic Pari, France 4 July 1

2 CP Violation in B Three kind: Outline In interference of decay and mixing amplitude CP-violating phae DØ publihed in.8 fb PRL 1, 4181 (8) Prelim. update to 6.1 fb DØ Note 698-CONF 1 1 In mixing: B B? Dimuon Charge Aymmetry (ee B. Hoeneien talk) B Semileptonic Aymmetry arxiv: (acc. PRD) arxiv: (acc. PRL) arxiv:94.397, accepted by PRD Implication for B, comparion & combination DØ Note 693-CONF In decay: Aume no CP violation in decay 1

3 Neutral Meon Mixing Particularly for B i Weak Eigentate propagate according to Schrodinger: d dt B B Diagonalize = Ma Eigentate: If CP conerved in mixing, p=q ig M M 1 * ig* 1 M 1 B H M Heavy = B H = ig ig 1 p B B B q B B L = p B + q B B B odd B L = Light b W u,c,t u,c,t B even + V* t V t W b B G Dm = CP DG = MH G L - - ML GH ~ DG = G - G ~ = GL even odd ~ M 1 G 1 G 1 co f + GH 1 ; t = f G SM [ 1 [ M = arg ~.4 in SM G 1 CP-violating! a

4 Neutral Meon Mixing Particularly for B Weak Eigentate propagate according to Schrodinger: i d dt B B = ig M M 1 * ig* 1 M 1 M ig ig 1 B B Diagonalize Ma Eigentate: If CP conerved in mixing, p=q B H Heavy = B H = p B q B B L = p B + q B B odd B L = Light B even G Dm = M - M ~ = ±.1 p 1 CP DG = G L H DG = G - G ~ = GL even - GH L odd ~ M 1 G 1 G 1 co f + GH 1 ; t = f G Tiny for B d meon, but not for B! [ SM M1 G 1 [ Preciion! (better than theory) eigentate propagate with different lifetime! = arg ~.4 in SM b

5 Neutral Meon Mixing Particularly for B Weak Eigentate propagate according to Schrodinger: i d dt B B = ig M M 1 * ig* 1 M 1 M ig ig 1 B B Diagonalize Ma Eigentate: If CP conerved in mixing, p=q B H Heavy = B H = p B q B B L = p B + q B B odd B L = Light B even G Dm = CP DG = MH G L - - ML GH ~ DG = G - G ~ = GL even odd ~ M 1 G 1 G 1 co f + GH 1 ; t = f G Senitive to new phyic Not enitive to new phyic Very enitive to new phyic [ SM M1 G 1 [ = arg ~.4 in SM c

6 CP Violation in B Sytem CP violation in SM occur in complex phae in unitary CKM matrix; new phyic: plenty of new phae!! B unitarity condition Golden mode, Tevatron "Squahed" Triangle V tb ( r, h ) V c V cb * tv * b mix mix CP violation through interference of diagram with and w/o mixing 3a

7 CP Violation in B Sytem CP violation in SM occur in complex phae in unitary CKM matrix; new phyic: plenty of new phae!! B unitarity condition Golden mode, Tevatron (.38 ±.) "Squahed" Triangle V tb ( r, h ) V c V cb * tv * b mix mix CP violation through interference of diagram with and w/o mixing 3c

8 CP Violation in z J/y Ret Frame ( ) B pin- b pin pin c c f J/y m + y J/y K f + m - x K - Decay into two vector meon that are either CP-odd (L=1) or CP-even (L=,) m + J/y m - Time-dependent angular ditribution allow eparation of component Simultaneou fit to two lifetime (, ) and three angle "tranverity bai" K - K + tranvere perp. CP-odd tranvere para. longitudinal CP-even f Ret Frame 4

9 CP Violation in Select event in 6.1 fb Multidimenional unbinned likelihood fit to: 1. B ma, 3435 ± 84 ignal event Candidate per 5. mm m. Lifetime: of data Vertex contraint Kinematic contraint to J/y ma DØ Preliminary, 6.1 fb Data Background M(B ) <5. or >5.5 GeV Background Region Candidate per 5. mm m Candidate per 8. MeV/c DØ Preliminary 6.1 fb Data Total Fit Prompt Bkg non-prompt Bkg Ma (GeV) DØ Note 698-CONF DØ Preliminary, 6.1 fb Data Total Fit Total Signal CP-even CP-odd Background 5.31< M(B ) <5.43 GeV Signal Region ct (cm) ct (cm) 5

10 CP Violation in Event per.1 3. Decay product angle Detector acceptance ditort the angular ditribution Ue MC imulation to determine efficiency and include in fit Reweight MC to match data kinematic DØ Preliminary, 6.1 fb 5.31< M(B ct >. cm Event per.1 4 Aume that in the decay i in a P-wave Any S-wave? Data DØ Preliminary, 6.1 fb Total Fit 35 ) < 5.43 GeV CP-even CP-odd < M(B ) < 5.43 GeV Total Signal 5 ct >. cm Background Fit prob. = 13.1% Fit prob. = 5.7% 15 ytem DØ Note 698-CONF Data Total Fit Total Signal Background Tranverity = co( q ) co( y) 6a

11 Event per.1 CP Violation in 3. Decay product angle Detector acceptance ditort the angular ditribution Ue MC imulation to determine efficiency and include in fit Reweight MC to match data kinematic DØ Preliminary, 6.1 fb 5.31< M(B ct >. cm Event per.1 4 Forward-backward aymmetry, conitent with no aymmetry Any S-wave? mall, not included (yet) Data DØ Preliminary, 6.1 fb Total Fit 35 ) < 5.43 GeV CP-even CP-odd < M(B ) < 5.43 GeV Total Signal 5 ct >. cm Background Fit prob. = 13.1% Fit prob. = 5.7% 15 F-B Aymmetry A = -. ± M(KK) GeV Data Total Fit Total Signal Background Tranverity = co( q ) co( y) 6b

12 CP Violation in 4. Tag the flavor: of production or at time Dilution, D Data: B d Æ m D* (IIa) + + Data: B Æ J/y K Data: Weighted Ave Fit to Data...error region p17 MC: B Æ m f p DØ Preliminary Oppoite-ide tagging: electron, muon charge; ec. vertex charge (plu including lepton), event charge (opp. track).4. Calibrated uing and, probability correct d ot 5. Contraint Gauian contraint for ocillation frequency: Strong phae between polarization amplitude Gronau & Roner: (PL B336, 31 (8)) : magnitude of polarization amplitude hould be imilar, trong phae equal to within1 deg. Contrain trong phae to world average value for : 7

13 CP Violation in 6. Check: e.g., Full MC imulation with no ignificant biae oberved Enemble of toy MC ample, each experiment, ame tatitic a data Fit no ignificant biae, check uncertaintie (although ig. biae if allowed to float) determine adjutment for correct tatitical coverage of CL region effect of external ytematic uncertaintie Input Mean: f Mean: (f ) Event per.4 3 Mean: -.1 Sigma: c /ndf: f (Recon - Gen)/ 8

14 CP Violation in Reult, conitent with.4.. Preliminary D, 6.1 fb SM DØ Note 698-CONF 68% CL 95% CL ) max -ln(l/l DØ Preliminary 6.1 fb Adjuted for tat. coverage and ytematic uncertaintie J/yf f [rad]

15 Semileptonic Charge Aymmetry "Right-ign" decay: "Wrong-ign" decay: only poible via flavor ocillation of and Semileptonic charge aymmetry PRL 97, (6) Dimuon charge aymmetry Another way to tet meaure CP violation! 1

16 Dimuon Charge Aymmetry Recall that meaured dimuon aymmetry i a linear combination: a l DØ, 6.1 fb.1 SM b DØ A l Standard Model d a l 11a

17 Conitency with Other Reult Conitent with world average of from B factorie (BaBar, Belle, CLEO; HFAG) a l.1 DØ, 6.1 fb SM Conitent with DØ direct meaurement of b DØ A l Standard Model uing DØ -.3 (arxiv:94.397, accepted by PRD) d a l 11b

18 Extracting Input world average of N.B.: allow ome level of CP violation in a well in ret of what follow from B factorie into: From dimuon aymmetry: c.f. Combine with DØ independent meaurement of Combined: from DØ Note 693-CONF Allow for intereting comparion/combination: (.4 ±.14) Same new phyic phae a in if new phyic only in M 1 of B ytem 1

19 Comparion D, fb a l 68% CL DØ average [ ] DØ Note 693-CONF 95%CL Preliminary Auming one new phyic phae affecting in the ytem 13

20 Combination DØ Note 693-CONF p-value at SM value i 7.5% region of new phyic model where affected 14

21 Combination, Br i CP-even to ~5%, ~aturate DØ Note 693-CONF p-value at SM value i 6% DØ,.8 fb 1 PRL 1, 9181 (9) % theory unc.

22 Summary 1 Uing 6.1 fb of data, DØ ha made a preliminary update of their 1 previouly publihed (with.8 fb ) analyi to find: CP-violating phae Conitent with the CP-violating emileptonic charge aymmetry for extracted from the DØ dimuon emileptonic charge aymmetry ( > 3 from SM) and from DØ aymmetry analyi Combination of DØ reult indicate conitency with SM in the ytem at the level of 6 7.5% Future: add data, add mode (e.g., combine with CDF ), ame-ide tagging, 16

23 Backup

24 Full Sample Firt.8 fb 1 Lat 3.3 fb 1 All Candidate Signal B Ma (MeV) B Ma Width (MeV) Proper length error cale (p) (p 1 ) A () A () A () A () A () ) max -ln(l/l DØ Preliminary 6.1 fb d 1 Ú -.4 ±.18 d Ú 3.1 ±.14 DM Ú ±.1 p ) max -ln(l/l DØ Preliminary 6.1 fb d 1 Ú -.4 ±.18 d Ú 3.1 ±.14 DM Ú ±.1 p ) max -ln(l/l fb d 1 Ú -.4 ±.18 d Ú 3.1 ±.14 DM Ú ±.1 p 3 DG Ú.4 p 3 DG Ú. p 3 DG Ú.1 p J/yf 3 f [rad] -3-1 J/yf 3 f [rad] -3-1 J/yf 3 f [rad]

25 Weighting & Acceptance Correction p (GeV) 6 of J/y ct/(ct) >.1 h leading m <1 T ) /dn mc WGT( dn data parb(p T para 1 - e para = 1. ±.6 parb =.5 ±.9 parc = 4.4 ±.13 c /ndf =.95 - parc) p (GeV) 6 of J/y ct/(ct) >.1 h leading m >1 T ) /dn mc WGT( dn data parb(p T para 1 - e para = 1.68 ±.13 parb =.7 ±.5 parc = 3.3 ±.7 c /ndf = parc) p (GeV) T p (GeV) T B1 f di, after weighting B tranverity di, after weighting B y 7 B di, after weighting *cof -.59*co f *T r -.8*T r f (deg) coq T ( T ) r coy

26 Sytematic Source A () p p 1 Matching the MC kinematic to data Acceptance function Flavor tagging parameter Total Event per DØ Preliminary, 6.1 fb 5.31< M(B ct >. cm ) <5.43 GeV Data Total Fit Total Signal Background f

27 No Flavor Tag Comparion to Previou Reult ) (p DG.4.3. PRL 1, 4181 (8) DØ,.8 fb B DM Ú Æ J/y f p Contrain trong phae to value of but more weakly, Gauian contraint of.1 - SM DG = DG SM co(f ) (radian) f Not adjuted for coverage or ytematic

28 Comparion to Previou Reult Improvement in the track recontruction efficiency Refinement in the vertex fitting and in the proper time uncertainty calculation Detector acceptance correction derived for the preent data et Gauian contraint for ocillation frequency (intead of fixed) Contrain trong phae to world average value for DØ Note 598-CONF: D.8 fb, with prel. yt % CL 95% CL 99% CL from SM Publihed reult, no trong phae d contraint i

29 CDF mm (Run I) CDF mm (1.6 fb ) prel. D mm (6.1 fb ) D D mx(tagged) (5 fb ).967 ± ± ±.51 ± ± Average -.85 ±.58 Heavy Flavour Averaging Group a l (B )