Slide 1

Exotic states with cc Riccardo Faccini University La Sapienza and INFN Rome FPCP 2009 31 May 2009 Lake Placid, NY, USA Slide 2 Quarkonium for Pedestrians Quarkonium is a bound state of a quark and an antiquark Quarkonium is a bound state of a quark and an antiquark Relevant quantum numbers: n,L,S,J Relevant quantum numbers: n,L,S,J Relationship with Parity and Charge Conj: Relationship with Parity and Charge Conj: P=(-1) L+1, C=(-1) L+S P=(-1) L+1, C=(-1) L+S Not all J PC allowed (e.g. 0 +-,0 --,1 -+,2 +- forbidden) Not all J PC allowed (e.g. 0 +-,0 --,1 -+,2 +- forbidden) : Decay Properties: Below open quark threshold (e.g. (cc) DD) only electromagnetic or s suppressed decays allowed mostly narrow states Below open quark threshold (e.g. (cc) DD) only electromagnetic or s suppressed decays allowed mostly narrow states Above open quark threshold (if DD decays allowed) mostly broad states Above open quark threshold (if DD decays allowed) mostly broad states 2 Slide 3 Charmonium: state of the art M(MeV) J PC (2S+1) L J Increasing L Increasing n cc cc J/ c2 c1 c0 hchc Open charm thr. Basically all states below the open charm threshold are observed and explained same J PC as J/ but mostly D wave ! (3770) (4040) (4160) (pot. Models) QWG: hep-ph/0412158 3 Slide 4 Beyond the quarkonium Search for states with 2 quarks+something else Search for states with 2 quarks+something else New forms of aggregation New forms of aggregation Expected but never identified!!! Expected but never identified!!! Hybrids: qq+n gluons Hybrids: qq+n gluons Lowest state 1 -+ (forbidden for quarkonium) Lowest state 1 -+ (forbidden for quarkonium) Dominant decay H DD ** Dominant decay H DD ** Tetraquarks: [qq][qq] Tetraquarks: [qq][qq] Large amount of states Large amount of states small widths also above threshold small widths also above threshold Molecules: M[qq]M[qq] Molecules: M[qq]M[qq] Smaller number of states but still small widths also above threshold Smaller number of states but still small widths also above threshold Search for resonances: with non-quarkonium J PC unnaturally small widths not null charge: would be clear indication of something new going on 4 Slide 5 Measuring the quantum numbers Production: Production: ISR only produces with same quantum numbers as the photon (J PC =1 -- ) ISR only produces with same quantum numbers as the photon (J PC =1 -- ) only produces with C=+ only produces with C=+ Double charmonium production Double charmonium production e + e - * X cc 1 X cc 2 Possible only if quantum numbers of the two charmonia can be combined to give a 1 --. Decay: Decay: Angular distributions of decay products depend on J P. Angular distributions of decay products depend on J P. Selection rules Selection rules Conservation of J Conservation of J Conservation of P,C in strong and electromagnetic decays Conservation of P,C in strong and electromagnetic decays ISR e+e+ e-e- e-e- e+e+ X e-e- e+e+ X 5 Slide 6 The new zoology X(3872) X(3872) The 1-- family The 1-- family The charged states The charged states hot off the press hot off the press Slide 7 X(3872): known facts Decays Decays X J/ (original observation) X J/ (original observation) Maybe J/ Maybe J/ BF(X J/ BF(X J/ BF(X J/ BF(X J/ Full angular analysis from CDF Full angular analysis from CDF X J/ X J/ Implications: C(X)=+1 C(X)=+1 C( in J/ decay)=-1 C( in J/ decay)=-1 I( )=L( )=1 consistent with J/ decay hypothesis I( )=L( )=1 consistent with J/ decay hypothesis J PC =1 ++ or 2 -+ from angular analysis J PC =1 ++ or 2 -+ from angular analysis Production Production only B decays so far only B decays so far No prompt e + e - production observed (BaBar No prompt e + e - production observed (BaBar arXiv:0707.1633 ) 7 Slide 8 The X(3872) puzzle Open options DD* molecule DD* molecule Right above the threshold Right above the threshold favors DD* decay over J/ over J/ (as observed) favors DD* decay over J/ over J/ (as observed) Tetraquark Tetraquark Explains small width Explains small width Predicts a set of 4 states (2 charged and 2 neutral). Predicts a set of 4 states (2 charged and 2 neutral). Finding these states is critical Finding these states is critical M(MeV) J PC (2S+1) L J Increasing L Increasing n cc cc J/ c2 c1 c0 hchc Open charm thr. (3770) (4040) (4160) (pot. Models) X(3872)? Not matching any predicted state! Above DD threshold (allowed): should have large width but it is narrow Charmonium highly suppressed decay into J/ (isospin violation) 8 Slide 9 Are there two X J/ CDF with largest sample investigates the mass distribution for two resonances closeby CDF with largest sample investigates the mass distribution for two resonances closeby Fitted mass difference as a function of first gaussian fraction M Y(4140) from CDF M=m( + - K + K - )-m( + - ) M: 4143.0 2.9 1.2 MeV, : 11.7 +8.3 -5 3.7MeV, Signif. > 3.8 arXiv:0903.2229 Search for B YK Y J/ 14 5 events Possible J PC =0 ++,1 -+,2 ++ Another edge state, better candidate molecule 33 Lowest lying hybrid, expected at m~4200MeV Slide 34 Summary M(MeV) J PC (2S+1) L J Open charm thr. (3770) (4040) (4160) (pot. Models) cc cc J/ c2 c1 c0 hchc X ZY X(3872) never ending story (4415) More on the 1 - - family One more member of the 3940 family X(4160) Z(4430) Z(4050) Z(4250) The charged candidates 34 y (4140) New state from CDF Good Hybrid candidate Slide 35 Outlook Plenty of states seen with low stat and in only one channel next generation [SuperB(elle)?] needed J/ D (*) D (*) J/ J/ (2S) J/ K, S J/ J/ X(3872)SeenSeen Not seen No search N/A Not seen Seen Y(3940) No Fit X(3940 )? Seen No search Not seen No search No Fit No fit Y(4260)Seen Not Seen No fit No search Not seen No fit N/A Y(4350) Not seen No fit No search Seen No fit N/A Z(4430) No search No fit No search Seen Not Seen No search No Fit N/A Y(4660) Not seen No fit No search Seen No Fit N/A 35 Slide 36 backup Slide 37 Confirmation of Y(3940) (B K J/ +-0+-0 B YK B 0 YK S B0/BB0/B Isospin cons. New result, based on 350 fb -1 : Belles evidence for B YK, Y J/ confirmed ~30MeV lower mass than Belles Narrower width Clear demonstration of decay into Preliminary BF estimate similar to Belles (~10 -5 ) preliminary G. Cibinetto, talk at this conference M(J/ ) (GeV) Y(3940) closer to X(3940) Can they be the same state? 37 Slide 38 D D*D*D* D D* X(4160) D * D * e + e - J/ D (*) D (*) Obtain J/ D (*) D (*) samples through kinematic separation, look at m(D(*)D(*)) after background subtraction: M = 3942 6 MeV tot =37 12 MeV N ev = 52 11 Inferred (Recoil mass) X(4160) claim: new state M = 4156 15MeV tot = 37 21MeV N ev = 24 +25 - 20 +111 - 61 +12 - 8 5.5 3.8 X(3940)Cross-check X(3940) is still there, 6.0 Somethings here, but its not X(3940) M(DD) M(D*D*) M(DD*) M(D * D) J/ D+ J/ D*+ Number of events One more particle to explain J CP =0 -+ not excluded ( c (3S)) reconstructed BELLE-CONF-0705 38 Slide 39 Just charmonium states? M(MeV) J PC (2S+1) L J Open charm thr. (3770) c1 (pot. Models) c2 c0 cc cc X ZY=X(3915) Poor match with predictions Poor match with predictions Above threshold? Above threshold? If XY, difficult to explain absence of Y open charm If XY, difficult to explain absence of Y open charm Hybrid? Hybrid? 39 Slide 40 Fits to J/ KK invariant mass Standard y(4415) + 1 BW: M = (4875132) MeV = (630126) MeV single BW: M = (443038) MeV = (25449) MeV 40 Slide 41 Thresholds and new states X(3872) Y(4260) X(4160) XYZ(3940) Y(4350) Y(4660) 41 Slide 42 CLEO and Belle on 4260 42 Slide 43 Search for X(3872) J/ in continuum X>2 ch c production is consistent with the expected contributions from prompt (2S) production feed-down to c : no evidence of prompt c1,2 No evidence of X(3872) production in e + e - annihilation. c1,2 or X(3872) c1 c2 X(3872) 386fb -1 J/ production observed in continuum while no evidence of c states. arXiv:0707.1633 43 Slide 44 Experiments e + e - Charmonium (CLEO-c, BES-II) e + e - Charmonium (CLEO-c, BES-II) L~10 33 /cm 2 /s L~10 33 /cm 2 /s E=3.0-4.3 GeV E=3.0-4.3 GeV e + e - Y(4S): (BaBar, Belle, CLEO) e + e - Y(4S): (BaBar, Belle, CLEO) L~10 34 /cm 2 /s L~10 34 /cm 2 /s Charmonium in B decays, ISR and production Charmonium in B decays, ISR and production Capability to measure J PC also in production Capability to measure J PC also in production pp colliders (CDF, D0) pp colliders (CDF, D0) High Xsection copious production High Xsection copious production Extremely high backgrounds Extremely high backgrounds 3M (2S), 1.8 M (3770) 58MJ/ , 14M (2S) 383M Y(4S) 657M Y(4S) 1.5M Y(1S),1.9M Y(2S),1.7M Y(3S),9M Y(4S) Samples used in results 2.4bf-1 1.3 fb -1 Disclamers: time is very short could not cover everything theory statements are indicative 44