Tau-Charm Workshop, IHEP, Beijing, China, Jun 5-7, 2006 Brian Meadows, U. Cincinnati. Charm Decays at B Factories Brian Meadows University of Cincinnati

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Outline  Charm Decays at B Factories:  (Semi-) Leptonic and rare decays – P. Jackson  D Mixing – A. Rahimi  Dalitz Plots – M. Papagallo  Charm Baryons – R. Chistov  Charmonium and other spectroscopy – S. Olsen, A. Palano, B. Yabsley, P. Pakhlov  Tau Physics – G. Lafferty  Here - Choice of some results (probably) not covered in above:  Charm Baryons (mostly from BaBar)  Charm Mesons – a few items  Summary

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Main purpose: Study CP violation in asymmetric e + e -  (4S)  BB Both experiments have far exceeded their design goals Approx. 1 ab -1 integrated flux combined BaBar and Belle e - (8 GeV/c) e + (3.5 GeV/c) Peak luminosity 1.08  cm –2 s –1 Integrated luminosity 363 fb –1 Peak luminosity 1.62  cm –2 s –1 Integrated luminosity 602 fb –1

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati  Cross sections are largeCan use “off peak” data  Very high statistics (~1.4 x 10 6 D’s / fb -1 ). Also:  Continuum production above and below 4S.  B decays – allow measurement of absolute BF’s, and maybe spins ?  D tagging - ~10 7 reconstructed D’s.  Can study charm baryons  ISR events - allow scan be used for continuum scans  ,  -  events Charm Hadrons at “B”B” Factories? On Off E CM (GeV)

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charm Baryons

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charm Baryon States  |C| = 1:  L=0 Ground State – almost full: J P =1/2 +: {6} qq  c (2455),  c (2470),  c (2698)All seen J P =1/2 +: {3} qq  c (2285),  0 c (2575)All seen J P =3/2 +: {6} qq  c (2520),  c (2645), ??All but  c *  L>1 – filling up ? J P =1/2 -: –  c (2593),  c (2790), … J P =3/2 -: –  c (2625),  c (2815), …  Several more new states from BaBar and Belle … and more BUT - No J P are yet measured ! J P =3/2 + (L=0) J P =1/2 + (L=0) Strangeness Charm Isospin … from CLEO 2  (or  ) c (2880),  (or  ) c (2765) ??

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Λ c (2940) + : M = (2939.8±1.3±1.0) MeV/c 2 Γ = (17.5±5.2±5.9) MeV First Charm Baryon  Charm Meson  c (2940) Λ c (2880) + Λ c (2940) + D 0 mass sidebands Wrong sign D 0 p 287 fb -1 hep-ex/ Observed in cc continuum production in D 0 p decay mode (D 0  K -  +, K -  +  -  + ) New data on Λ c (2880) + : New Decay Mode  D 0 p BaBar: M = (2881.9±0.1±0.5) MeV/c 2 Γ = (5.8±1.5±1.1) MeV PDG: (“Could be  c ”) M = (2880.9±2.3) MeV/c 2 ; Γ < 8 MeV

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati New Baryon  c (2940)  Neither  c (2940) nor  c (2880) seen in D + p system  Neither are  c ’s Other observations: Why not seen in  c  +  - or  c  ? Three states predicted near this mass 3 / 2 -, ½ +, ½ -  c (2940) is 6 MeV/c 2 below D*p threshold  c (2940) is  mass above  c (2880) 287 fb -1 hep-ex/  c ++ ’s ??

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Search for  cc States  Predicted in mass range 3.5 – 3.8 GeV/c 2  Predicted cross-sections from e + e 10 GeV/c 2 ~ fb Double-charm cross-sections under-estimated by NRQCD  expect to produce 10 2 – 10 4 from 232 fb -1 SELEX Phys.Lett.B628:18-24,2005 SELEX reports state at 3.52 GeV/c 2  - beam ~ 1,630   c Not confirmed by FOCUS  beam ~ 19,500  + c Nor BaBar, nor Belle e + e - ~ 10 6  c +

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Search for  cc States  cc +(+)   c + K -  + (  + ) Search made throughout ranges indicated  for both charge states,  with and without p*cuts 21 two-d fits: Gaussian signal on background in overlapping 10 MeV/c 2 ranges. Results normalized to cross- section for producing  c + 95% C.L. limits: Λ c + K – π + p*> 0 GeV/c Λ c + K – π + p*>2.3 GeV/c Λ c + K – π + π + p*>2.3 GeV/c Λ c + K – π + π + p*> 0 GeV/c 232 fb -1 hep-ex/

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Search for  cc States  c c +(+)   c 0  + (  + ) Search made throughout ranges indicated 50 fits: Double Gaussian signal on linear background in 10 MeV/c 2 ranges. Results compare with 95% C.L. limits: Ξ c 0 π + p*> 0 GeV/c Ξ c 0 π + p*> 2 GeV/c Ξ c 0 π + π + p*> 0 GeV/c Ξ c 0 π + π + p*> 2 GeV/c 232 fb -1 hep-ex/

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Search for  cc States  Belle also found no evidence for the state seen by SELEX using an even larger sample. 462 fb -1 PRELIMINARY M(  c + K -  + ) (GeV/c 2 )

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Observation of Two New  c (csu) States in cc Continuum Production 462 fb -1 PRELIMINARY While searching for weak decay of  cc   c + K -  +  p K -  + Found strong decays of new  c * ‘s instead:  cx   c + K -  + No structure in  c + sidebands Nor in  c + K +  - or  c + K -  - wrong sign combinations. 462 fb -1

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati The Spin of The  -  The existence of large samples of charm baryons makes possible what was once incredibly difficult ! c0-K+c0-K+ c0-+c0-+ 116 fb -1 Preliminary 230 fb -1 Preliminary Assume the spin of charmed parent is ½: In the charm hyperon rest frame, the  - is produced with helicity § ½ independent of the  - spin J. Earlier results from bubble chambers using small, unaligned samples of  - could only conclude that J>1/2.

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati The Spin of The  -  The  -   K - decay distribution in its “helicity frame” is then  Conclude J = 3/2 (if charmed parents are J=1/2). 230 fb -1 Preliminary 116 fb -1 Preliminary c0-K+c0-K+ c0-+c0-+ J = 5/2 J = 1/2 J = 3/2

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati How About Charm Baryons?  Information on charm baryon spins could come from decays like B +,0   c 0,-  c +   -  +  So far (Belle 357 fb -1 ) only ~12 events where  c 0   -  +  Not promising for determination of J 357 fb -1 hep-ex/ (2005)

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Maybe Three- (or more-) Body Decays ?  3-body BF’s about 10 x 2-body B -   c + p  - (product of BF’s ~ 2 x 10  5 ) have. significant # events: B -   c 0 p (  c 0   c +  - )  Lots of other things going on  Good techniques for dealing with coherent backgrounds may be required. 140 fb -1 hep-ex/ (2005)  c 0 (2455)   c +  -

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charm Mesons

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Heavy-Light Systems  Narrow states are easy to find.  Two wide states are harder.  Since charm quark is not infinitely heavy, some j q =1/2, 3/2 mixing can occur between the two J P =1 + states. j q = 3/2 L = 1 L = 0 spin-orbit tensor j q = 1/ JPJP 2j q +1 L J 3P23P2 1P11P1 3P13P1 1P01P0 1S11S1 1S01S0  small large small Expected by quark models To be below D ( * ) K threshold  S-wave  D-wave

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Mixing in J P = 1 + D sJ (2460)/D s1 (2536) ?  Belle has analyzed D s1 (2536) decays to D * K to look for an S-wave component.  (In the limit the c quark has infinite mass, the narrow states would decay in pure D-wave)  Angular distribution of  + in D *+ system leads to the limits: <  S /(  S +  D ) < Indicative of some S-wave hep-ex/ fb -1 K0K0 D sJ   D*D* D 1 + A cos 2  : S-wave: A=0 D-wave: A=3 A = § 0.03 D + s1  D *+ K 0

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati D sJ ’s - Overtly Exotic ?  No indication of overtly exotic charge states Circles are D s side-bands  For D sJ (2460) need to look in D s ( * )+  0  +,- if J P =1 + (See Antimo Palano’s talk for full details) Ds+-Ds+- Ds++Ds++ D sJ (2460) ? D sJ (2317) ? 232 fb -1 hep-ex/

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Decays of B 0  D s (D sJ ) + + h -  Exotic nature of D sJ states could show up in  B 0  D s(J) K - is especially interesting none of the final state quarks (cus s ) are in the initial B ( b d) meson.  Expect R h ~ 1 for c s and R h ~ 0.1 for c s u u hep-ex/ fb -1 C.-H. Chen, H.-n Li, Phys. Rev. D 69, (2004) PRL 93, fb -1  R K ~ R D ~ 1 (no clear evidence for c s d d)

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Doubly Cabbibo Suppressed Decays First measurement of (CLEO 1990 < 0.04%) Measured rate relative to D +  K -  +  + then used average of PDG and recent CLEO measurement for this rate. Uncertainty in D +  K -  +  + Decays normalized to K -  +  + D++0D++0 D++0D++0 124 fb -1 hep-ex/

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Doubly Cabbibo Suppressed Decays SU(3) predictions are over- simplified:  First ratio affected by K s -K L interference  D +  K +  0 can also proceed by W-exchange or annihilation diagrams.  Measurements are challenging Results still not well understood. d c d s d u c d d u c u s d u c d d u s Naïve, exact SU(3): BaBar: 2/(1.49 § 0.29)  Also: BaBar: 0.70 § 0.17

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Before After Wrong Sign D 0 Decays  Time-integrated rates can be compared with tan 4  c = (0.281 § 0.006) x  Belle/BaBar agreement excellent  big improvement over PDG values  D * tagging allows measurement of CP asymmetries Belle: K + 2  ( § 0.053); K + 3  ( § 0.044) consistent with zero.  any new physics at level much smaller than DCS for “wrong sign” decays. Despite high backgrounds, measurements at few % level (BaBar tags other side) 229 fb -1 PRELIMINARY hep-ex/ PRELIMINARY 281 fb -1  MeV/c   K + 2  K + 3  K + 2   MeV/c  

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati  (D (s) *  D (s)  0 )/  (D (s) *  D (s)   BaBar has improved measurements of the  0 /  ratios: Agree with current results Fresh input to  PT 90.4 fb -1 hep-ex/ Ds*DsDs*Ds Ds*DsDs*Ds M(K + K -  +  M(K + K -  + ) M(K + K -  +  0  M(K + K -  + ) D0*D0D0*D0 D0*D0D0*D0 M(K + K -  +  M(K + K -  + ) M(K + K -  +  0  M(K + K -  + ) GeV/c 2 Lost 

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Summary  B Factories provide a very clean environment for the production of all charm hadrons  new particle paradise !  BUT no doubly charmed baryons  Large (and growing) samples of charm mesons and baryons are likely to complement results from  -charm facilities for some time to come  In several ways, we are learning how information on systems to which charm hadrons, or B mesons, decay can be extracted  There is a large and enthusiastic community anxious to work on all aspects of the physics available.

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Back up Slides

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Precision Measurement of  c Mass  Important measurement  most charm baryon masses measured relative to this  Method:  Choose decay modes with small Q- value/large BR:  c   K + K s 0 and  0 K + K s 0  Estimate / adjust major systematic uncertainties in:  Material audit – determine  and K 0 mass vs. decay path length  Magnetic field – determine  and K 0 mass vs. momentum in lab.  Much larger control samples:   c +  pK -  x 10 6 evs.   c +  pK x 10 5 evs. Q = MeV/c 2 Q = MeV/c 2 hep-ex/ fb § 84 events 264§ 20 events

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Results c  K+Ks0c  K+Ks § (stat.) § (syst.) c  0K+Ks0c  0K+Ks § (stat.) § (syst.) c  pK-+c  pK- § (stat.) § (syst.) c  pKs0c  pKs § (stat.) § (syst.)  Most precise measurement of charm mass to date  Approximately 4 x more precise than Current PDG value: § 0.6 MeV/c 2 and about 2.5  higher m(  c ) =  0.14 MeV/c 2 Combined measurement : hep-ex/ fb -1 Large Q

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charm Baryon States  L>1 – filling up ? J P =1/2 -: –  c (2593),  c (2790), … J P =3/2 -: –  c (2625),  c (2815), …  Most massive in PDG 2005 is  c (2815) CLEO 2 has added  c (2880) and  c (2765) PDG 2005 Dp D*pD*p

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati New  c (2800) Triplet 281 fb -1 PRL94, (2005)  c  pK -  + sidebands Could be J P = 3/2 -  c2 ??

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charmed Meson Spectroscopy pre 2003 D *0 K + threshold D 0 K + threshold BABAR/CLEO may have found these – but below threshold.

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati Charmed Meson Spectroscopy Now John Bartelt, Sept, 2003

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati D sJ * (2317) +  D s +  0   No indication of neutral or doubly-charged partner near 2317 MeV  I=0 Dark shade: D sJ (2460) reflection Circles: D s sidebands D s * (2112) reflection D s * (2112) signal N=3180±80 BABAR: 232 fb -1 Submitted to PRD Preliminary

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati  New, comprehensive study of decays to D s + plus one or two  ±,  0, or  ’s Update on Charmed-Strange Mesons D sJ * (2317) + and D sJ (2460) + D s +  0 only decay mode observed for D sJ * (2317) + NB: all “Seen” modes are also “Allowed” 232 fb -1 hep-ex/ Decay pattern if J P =0 + and J P =1 +, respectively

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati D sJ * Update:  From D sJ * (2317) +  D s +  0 :  From D sJ * (2460) +  D s + , D s +  0  :  New from  D s +  +  - : 232 fb -1 hep-ex/ No indication of D sJ * (2317) +  D s +  +  - New mode: D sJ * (2536) +  D s +  +  -

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati  B B sample with one B fully reconstructed decays of the other B  D ( * )+,0 X  Observe D s + and D sJ (2460) signals in the recoil mass, m X   absolute BF’s for D s + (   + ) and for D sJ * (2460) + B Decays - Absolute Branching Fractions e-e-e-e- D*D*D*D*  e+e+e+e+ B reco B signal D* X 211 fb -1 hep-ex/

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati PDG: (4.3 § 1.2) %  For the D s + signal:  Combine with previous measurements to obtain absolute BFs:  Sum of known BFs:0.76±0.20 D sJ (2460) + Absolute BFs, cont. (D s *+  D s +  ) 211 fb -1 hep-ex/ fb -1 PRL 93, (2004) Is there another mode ?

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati B  D D sJ * (2317) +, D sJ * (2317) +  D s +  0   D sJ * (2317) decay mode  natural spin-parity  D sJ * (2317) decay angular distribution  spin 0 Belle: 274M BB BELLE-CONF (2004) 00 Solid line: J = 0  2 / d.o.f = 3/8 Dotted line: J = 1  2 / d.o.f = 38/8 Natural spin- parity  J P = 0 +

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati D sJ (2460) +  D s +  / D s * (2112) +  0 BABAR: 232 fb -1 Submitted to PRD D s *+  D s +  Open points: D s sidebands Open points: D s sidebands Light shade: D s * (2112) reflection Dark shade: D sJ * (2317) reflection D sJ (2460) +  D s +  N=920±60 N=560±40 Preliminary

IHEP, Beijing, China, June 5-7, 2006Brian Meadows, U. Cincinnati B  D D sJ (2460) + Belle: 274M BB BELLE-CONF-0461 (2004) Solid line: J = 1  2 / d.o.f = 4/8 No D s  decay for J=0 (b): D sJ (2460) +  D s +  (c): D sJ (2460) +  D s * (2112) +  0 D s *+  D s +  Dashed line: J = 2  2 / d.o.f = 89/8 Solid line: J = 1 S-wave Ds*0Ds*0 cos(  D s *  0 ) J P = 1 +