B. Golob, D Mixing & CPV 1/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Boštjan Golob University of Ljubljana/Jožef Stefan Institute & Belle/Belle II Collaboration D Mixing and CP Violation University of Ljubljana “Jožef Stefan” Institute Topical Seminars on Frontier of Particle Physics, Hu Yu Village, Aug 27 – Aug 31, 2010 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 2/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV phenomenology CP violation in charm Magnitude of CPV...is small. Why? CPV: complex CKM matrix phase; D 0 (and other processes involving charm hadrons): first two quark generations; CKM elements ≈ real; V cs V us * D0D0 K-K- K+K+ CPV of O (10 -3 ) is (just) bellow current exp. sensitivity; larger CPV signals New Physics CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 3/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV phenomenology CP violation in charm Parametrization...is sometimes messy R D ≠1: Cabbibo suppression 3 types of CPV: A D ≠0: CPV in decay A M ≠0: CPV in mixing  ≠0 : CPV in interference quantity appearing in decay rates (“ f ”): n.b.: (R D ), A D, A M,  << 1 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 4/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV phenomenology CP violation in charm Parametrization direct CPV for direct CPV two amplitudes with different strong and weak (CKM) phases are necessary; in D meson decays this is only possible in CS decays with contribution of penguin decays (beside tree contrib.) V cd V* ud d W c u V cs V* us s W c u CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 5/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV phenomenology CP violation in charm Observables master formulas p. I/18, 19 still valid, need to keep q/p and write amplitudes A f etc. in accordance with parametrization on previous slide uncorrelated production coherent production with C=-1 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 6/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Decays to CP eigenstates Principle t-dependent method measuring lifetime in K + K - /  +  - state separately for D 0 and D 0  KK =  /(1+y CP ); y CP =(  /  KK )-1=y cos  -(A m /2)x sin  no CPV: y CP =y following derivation on p. I/26 and keeping CPV parameters following same derivation separately for D and D CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 7/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Decays to CP eigenstates Results t-dependent method dominant syst.: same as for y CP A  = (A M /2)y cos  -x sin  CPV in mixing and interference Belle, PRL 98, (2007), 540fb -1 BaBar, PRD78, (2008), 384fb -1 HFAG, no CPV at  3 ·10 -3 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 8/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Decays to CP eigenstates Principle t-integrated method asymmetry of t-integrated rates; CPV in decay, mixing and interference; However..... measuring absolute rates instead of decay-t distrib. involves sensitivity to acceptance n.b.: A M and  universal among various decay modes; A D is decay mode specific CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 9/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Decays to CP eigenstates Principle t-integrated method A   :  + /  - detection eff. asymmetry D* +/- →D 0  +/- ; e.g. due to different  +/- interactions on detect. material A FB : forward-backward asymmetry  */Z 0 → c c; A FB is an odd function of  D (in CMS); vanishes if integrated over  D ; since working in bins of   (correlated with  D ) need to correct for it A CP f : physical CPV asymmetry comparison of tagged/untagged (D* + →D 0  + ),D 0 →K -  + assuming A FB D* =A FB D  A tag -A untag = A   ; need to perform meas. in bins of p ,   CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 10/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Decays to CP eigenstates Results t-integrated method stat. precission of  somewhat worse; dominant syst.: stat. uncertainty of A   world average: A   in bins of p ,   (n.b.: O (10 -2 )) cos   Belle, PLB670, 190 (2008), 540fb -1 BaBar, PRL 100, (2007), 386fb -1 Belle, PLB670, 190 (2008), 540fb -1 HFAG, xorg/hfag/ no CPV at  2 ·10 -3 A CP f A FB K+K-K+K-  +  - CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 11/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements WS 2-body decays Principle D* + → D 0  slow + RS: D 0 → K -  + WS: D 0 → D 0 → K +  - equivalent measurement separately for D 0, D 0 (x’ 2,y’,R D ) → (x’ ± 2, y’ ±,R D ± ); CPV in decay and mixing CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 12/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements WS 2-body decays Results D 0 → K +  - A D = (23 ± 47) ·10 -3 A M = (670 ± 1200) ·10 -3 does not fit for CPV param ·10 -3 x’ + 2 D0D0 D0D0 D 0 +D 0 (no CPV) y’ BaBar, PRL 98, (2007), 384fb -1 values from BaBar, PRL 98, (2007), 384fb -1 Belle, PRL 96, (2006), 400fb -1 CDF, PRL 100, (2008), 1.5fb -1 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 13/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Multi-body self conjugated states Principle D 0 → K S  +  - t-depedent matrix elements M, M are in case of CPV not trivially related; no CPV: CPV: a r,  r ≠ a r,  r : direct CPV (in decay) |q/p| ≠ 1,  ≠ 0: indirect CPV (in mixing and interference) same as eqs. on p. I/42 but including q/p CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 14/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Multi-body self conjugated states Results D 0 → K S  +  - no evidence of direct CPV; x, y almost unchanged w.r.t. no CPV fit K S  +  - / K S  K +  K - does not fit for CPV param. Belle, PRL 99, (2007), 540fb -1 BaBar, arXiv: , 470 fb -1 95% C.L. contour CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 15/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Other states Principle various decay modes of D (s) 0(+) t-integrated asymmetry; example: D (s) + → K S h + h=K,  charged mesons: CPV in decay only; corrections for detector induced asymmetries and A FB (n.b.: p. II/9); example: A rec (D → K S  + ) - A rec (D s →  + )  A CP (D → K S  + ) (technically much more involved due to p ,  ,  D dependence, see p. II/9) D + → K S  + CF D + → K S K + CS D s + → K S K + CF D s + → K S  + CS CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 16/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Other states Principle K S in final state not a CP eigenstate itself; in weak D decays K 0, K 0 produced; CPV in K 0 system  even in absence of CPV in D system some asymmetry expected Results Results A K 2.6  from 0, consistent with A K Belle, PRL 104, (2010), 673fb -1 no CPV at  3 ·10 -3 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 17/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 CPV measurements Averages Results same fit as for the mixing parameters, + CPV parameters CPV x (0.59 ± 0.20)%  ( −12.2 )° y (0.80 ± 0.13)%  Kππ ( −23.3 )° R D (0.332 ± 0.008)% A D (−2.0 ± 2.4)% |q/p| −0.16  (− −8.7 )° HFAG, xorg/hfag/  2 /n.d.f.= 31.9/(30-8)= 31.9/22 (largest cont. from K +  -  0 and Cleo-c) CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 18/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Constraints on NP Constraints from mixing (examples from ) 4th generation of fermions b’ beside d,s,b exchanged in loop; |V ub’ V cb’ |<1.4 ∙10 -3 for m b’ > 400 GeV more severe constraints than from CKM unitarity c u u c b’b’ b’ W+W+ W-W- D0D0 D0D0 V cb’ V ub’ * E. Golowich et al., PRD76, (2007) |V ub’ V cb’ | m b’ [GeV] allowed area lines of constant |x| complementarity of such constraints w.r.t. down-like FCNC obvious CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 19/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Constraints on NP Constraints from mixing R-parity violating SUSY squark-lepton (or vice versa) exchange in loop; E. Golowich et al., PRD76, (2007) R couplings [GeV] D0D0 D0D0 allowed area lines of constant |x| CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 20/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Constraints on NP Constraints from CPV SCS decays (probing penguins); small in SM, small DCPV; SUSY: squark-gluino loops; could lead to CPV c u W±W± s V cs V us g q q approximate current sens. |M 12 | m(g˜ ) |M 12 | vs. m(g˜ ) for r f =1% Y. Grossman et al., PRD75, (2007) see eqs. on p. II/6, 8 contrib. to r f of O (1%) allowed using current constraints from mixing; if  f,  f  O (1) (i.e. if no similar CPV suppression in NP like in SM) A D constraint excludes all shown values CPV phenomenologyOutlook CPV measurements Constraints on NP for M 12 relation to observables see p. II/27, 28

B. Golob, D Mixing & CPV 21/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Outlook Near future facilities Charm-factories main results from BES-III expected in the near future; LHCb great hopes for nice results, although 1 fb -1 (by end of 2011) may not be enough Super B-factories - Super KEKB, 5 ab -1 in 2016; - SuperB, Frascati  L dt [ab -1 ] L [cm -2 s -1 ] CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 22/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Outlook Illustrative expected sensitivities Mixing parameters Mixing parameters Charm-factories 20 fb -1 :  (R M ) ~ 1 ∙10 -4 (from  (3770) →K -  +, K -  + ) (n.b.: R M ~ 1 ∙10 -4 );  (y) ~ 0.3%  (cos  ) ~ 0.04 LHCb  10 fb -1  (x) ~ 0.25%,  (y) ~ 0.05% (estimated from precision on x’ 2, y’ and y CP ) Super B-factories Super-KEKB: 5 ab -1 :  (x),  (y) ~ 0.1% (combined from K , KK, K s  ) BES III, arXiv: G. Wilkinson et al., public note LHCb A.G. Akeroyd et al., arXiv: current W.A. expected Prediction is very difficult, especially of the future. N. Bohr ( ) CPV phenomenologyOutlook CPV measurements Constraints on NP n.b.: p. I/39

B. Golob, D Mixing & CPV 23/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Outlook Illustrative expected sensitivities CPV parameters CPV parameters Charm-factories several possibilities; decays to same sign CP states; not sensitive due to R M suppression; C=+1 initial state (D 0 D 0  ); 20 fb -1 :  (A  ) ~ 0.6% (stat. only) Super B-factories Super-KEKB: 5 ab -1 :  (  ) ~ 5 o  (A  ) ~ 0.1%-0.2% BES III, arXiv: A.G. Akeroyd et al., arXiv: CPV phenomenologyOutlook CPV measurements Constraints on NP (neglecting direct CPV, i.e. A D =0; see p. II/29 for other asymmetries)

B. Golob, D Mixing & CPV 24/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Outlook Illustrative expected sensitivities CPV parameters CPV parameters Belle II, 50 ab -1 only KK/ , K  and K s  projected sensitivities included 1 50 ab -1 CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 25/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Summary entering precision era in D 0 mixing and CPV (mixing only estab. in 2007) provide unique constraints/searches of NP in u-like FCNC Today: B-factories (and Tevatron) still to say the final word Tomorrow: Charm-factories, LHCb and Super-B factories will be able to search for NP effects (in CPV) in whole range down to SM predictions CPV phenomenologyOutlook CPV measurements Constraints on NP

B. Golob, D Mixing & CPV 26/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Additional material D mixing rate in exclusive approach take as example PP final states: J.F. Donoghue et al., PRD33, 179 (1986) statemeasured Brcontrib. to mixing K-+K-+ 1   r1r1 -√(r 1 r   2 K-K+K-K+   rr rr ++   rr rr K+-K+- 4   r4r4 -√(r 1 r   2 minus sign due to relative sign of V us /V cd (see p. I/32); summing over this states  0 (GIM mechanism); however, in D 0 decays SU(3) is broken; in other words, measured Br’s with r i ≠1 dominant contrib. to mixing; CPV phenomenologyOutlook CPV measurementsAdditional material Constraints on NP

B. Golob, D Mixing & CPV 27/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Additional material Mixing parameters B mesons: calculate M 12,  12 from box diagram; from that calculate  m,  q: d (B d ) or s (B s ) B Bq : bag parameter, f Bq : decay constant  B ( ‘ ) : QCD corr. O (1) S 0 (x t ): known kinematic function CPV phenomenologyOutlook CPV measurementsAdditional material Constraints on NP

B. Golob, D Mixing & CPV 28/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Additional material Mixing parameters B mesons: |  12 | << |M 12 | measured x d =0.776 ± x s =25.5 ± 0.6 from M 12 /  12  y d <1% y s ~10% D mesons: G. Raz, PRD66, (2002) CPV phenomenologyOutlook CPV measurementsAdditional material Constraints on NP

B. Golob, D Mixing & CPV 29/25Frontier of Particle Physics 2010, Hu Yu Village, Aug 2010 Additional material Asymmetries at charm-factories untagged asymmetry semileptonic asymmetry direct CPV (n.b.: A D is decay mode specific, in this case represents direct CPV in S + decay mode) CPV phenomenologyOutlook CPV measurementsAdditional material Constraints on NP