Charmed Hadron Spectroscopy At

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Charmed Hadron Spectroscopy At. Introduction D ** D S ** S C , S C * L C *. Robert K. Kutschke Fermilab FCP01 March 7, 2001. At Fermilab g BeO charm. g. FOCUS: The Successor to E687. Segmented BeO Target interleaved with SMDs. Upgraded: EM Calorimetry. Cerenkov system. - PowerPoint PPT Presentation

Text of Charmed Hadron Spectroscopy At

  • Charmed Hadron Spectroscopy AtRobert K. KutschkeFermilab FCP01 March 7, 2001

    Introduction D** DS** SC , SC* LC*

    Frontiers in Contemporary Physics, 2001.

  • At Fermilabg BeO charmg

    Frontiers in Contemporary Physics, 2001.

  • FOCUS: The Successor to E687Segmented BeO Target interleaved with SMDs.Upgraded:EM Calorimetry.Cerenkov system.Muon ID capability.Data taken in 1996-1997.More than 10 times the Luminosity>106 reconstructed Golden Mode Decays: D0K-p+, K-p+p-p+ and D+K-p+p+.

    Frontiers in Contemporary Physics, 2001.

  • Candidate Driven VertexingFind charm candidate: good vertex, good particle ID.Seed primary vertex finder with the charm candidate.Require isolated secondary. One measure: L/sL> cut.Add tracks from primary to form Lc p combinations.

    Frontiers in Contemporary Physics, 2001.

  • P-wave Charmed Mesons c D*, D c qq-p, r, (K, K*) L=1 between c and light quark ( q=u,d,s ). jlight = Slight + L , approximately good Q number if mC >> LQCD Rosner: the hydrogen atom of QCD Idealized picture is a doublet of doublets. Strong decays to D(*)p ( or D(*)K for DS )

    Frontiers in Contemporary Physics, 2001.

  • Idealized Picture of P-wave Charmed MesonsHeavy quark symmetry:jl=3/2 dominant decays are D-wavejl=1/2 dominant decays are S-waveReminder: D : JP = 0- D*: JP = 1-JlightP =1/2-

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  • Angular Momentum and Parity Selection RulesAll 5 decays in the multiplet are described by 2 parameters, the S wave and D wave amplitudes (x Wigner 6-j, x phase space)1+3/2 Decays via D-wave1+1/2 Decays via S-wave

    DecayLDecayL2+ 1- 0-2 0- 0-23/2+ 1/2- 0-21+ 1- 0-0 , 20-0-1/2+ 1/2- 0-00+ 1- 0-0- 0-0

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  • Whats Overly Simplified in the Ideal Picture? Doublets may overlap ( which 1+ is more massive?)

    Is suppression of S wave widths complete? Ds1 right at threshold for D*K: Very narrow, G < 2.3 MeV/c2 @ 90% CL. Data suggests mostly S-wave!

    Frontiers in Contemporary Physics, 2001.

  • S-Wave Charm States at FOCUSD0 K- p+D0 K- p+ p+ p-D+ K- p+ p+For S/B > 7,> 330,000 D candidatesEntries / 5 MeV/c2D*+ D0 p+ K- p+ K- p+ p+ p+Entries / 0.5 MeV/c23000020000100000.140M(D0p+)-M(D0)(GeV/c2)0.1440.148For S/B > 5, 70,000 D*+ candidates(GeV/c2)D+D0M(Kp or K3p) M(Kpp) D*+

    Frontiers in Contemporary Physics, 2001.

  • D0p+ and D+p- Mass DistributionsWrong signWrong signFeed down from D2*, D1 partial reconstructionFeed down from D2*, D1 partial reconstructionM(D0p+)-M(D0)+1.8646 (GeV/c2)M(D+p-)-M(D+)+1.8693 (GeV/c2)[ Shorthand: MF(D0p+)MF(D+p-) ]Entries / 10 MeV/c2Entries / 10 MeV/c2FOCUSFOCUS

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  • Get Feed-down Line Shapes from Monte CarloMCMC

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  • Beyond Signal Region all Shapes are ExponentialSide band: e-2.670.04Wrong sign: e-2.380.01Right sign: e-2.350.01D2*0 D+-Side band: e-2.650.03Wrong sign: e-2.270.01Right sign: e-2.530.01D2*+ Do+MF(D0p+) (GeV/c2)MF(D+p-) (GeV/c2)Entries / 10 MeV/c2Entries / 10 MeV/c2

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  • Fitting the D0p+ Mass Distribution (1)Entries / 10 MeV/c2G=724 MeV/c2c2 / dof= 3.1MF(D0p+) (GeV/c2)Fit Results:Terms in the Fit:Signal: D-wave Rel. BW, convoluted with a gaussian, s = 7 MeV/c2.Exponential extrapolated from 2.4 4.5 GeV/c2.MC D1 Feed-down.MC D2 Feed-downGet horrible fit!FOCUS ( GPDG (D2*+) = 25 8 MeV/c2 )

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  • Fitting the D0p+ Mass Distribution (2)MF(D0p+) (GeV/c2)G=724 MeV/c2c2 / dof= 3.1Fit Results:Entries / 10 MeV/c2MF(D0p+) (GeV/c2)M=2468.21.5 MeV/c2c2 / dof= 1.8G= 28.61.3 MeV/c2Add 5th term to the fit: S-wave Rel. BWFOCUSFOCUS

    Frontiers in Contemporary Physics, 2001.

  • Reducing BG from Soft p+ From D*+ DecaysM = 2468.5 2.1 MeV/c2G = 30.3 3.6 MeV/c2D2*+ pp > 10 GeV/cMF(D0p+) (GeV/c2)Entries / 10 MeV/c2FOCUSMCMC

    Frontiers in Contemporary Physics, 2001.

  • Fitting the D+p- Mass Distributionc2 / dof = 0.9MF(D+p-) (GeV/c2)G = 55 3 MeV/c2c2 / dof= 2 GPDG ( D2*0 ) = 23 5 MeV/c2 MF(D+p-) (GeV/c2)Signal + Exp + D1 + D2+ S-Wave Rel. BWEntries / 10 MeV/c2Entries / 10 MeV/c2G = 30.5 1.9 MeV/c2M = 2463.5 1.5 MeV/c2FOCUSFOCUS

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  • D2*+ Width D2* Mass and Width Systematics D2*+ Mass FOCUS D2* Results Mass (MeV/c2) G (MeV/c2)D2*+ 2468.2 1.5 1.4 28.6 1.3 3.8 D2*0 2463.5 1.5 1.5 30.5 1.9 3.8PreliminaryD2*+ Mass MeV/c2D2*+ Width MeV/c2PDG 2000: M+=24594, M0=2458.92.0, G+=258, G0=235 MeV/c2.

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  • D*+p- Mass DistributionWrong signD10 Yield = 889 92D2*0 Yield = 977 101M((D0p+)p-)-M(D0p+)+2.01002.72.42.1[ Shorthand: MF(D*+p-)]800600Entries / 10 MeV/c2(GeV/c2)200400Preliminary12002.7

    Frontiers in Contemporary Physics, 2001.

  • Observation of the DS2* and DS1 DS2* D0 K+ D+ KS0D0 K-+, K- ++-D+ K-++DS1 D*+ KS0D*+ D0 +

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  • Observation of the Ds2* at FocusPreliminaryFOCUSFirst observation of the D+KS0 mode!D0K+D+KS0There are some real KS0 in the sideband sample.

    Frontiers in Contemporary Physics, 2001.

  • Simultaneous Fits to D0K+ and D+KS0 SpectraDS2 Signal: D-wave Rel. BWSmooth background shapeMC DS1 feeddown shapeMC DS2 feeddown shape. Significance is not stable with cut variations!Terms in the fit: Simultaneous: M and G same. Errors are statistical only PDG:M = 2573.5 1.7 MeV/c2G = 15 5 MeV/c2

    PreliminaryFirst observation of D+KS0 mode

    Frontiers in Contemporary Physics, 2001.

  • Observation of the DS1 at FOCUSPreliminaryDS1 Signal: Non Rel BW, convoluted with a gaussian.Smooth background shape.DS2* Signal: D-wave Rel BW.Terms in the fit: Errors are statistical only PDG:D = 525.35 0.34 MeV/c2G < 2.3 MeV/c2 @ 90 % CL. M(D*+Ks0)-M(D*+)

    Frontiers in Contemporary Physics, 2001.

  • Some Charmed Baryons:cddcudcuuSc*+Sc0Sc*++JP 3/2-Lc(2625)Sc+Sc*01/2+Sc++Lc+Lc(2593)Lc*Lc p pSc(*) Lc p cudJP 3/2+ 1/2-P-Wave BaryonLc*Lc p

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  • Selection of Lc for Sc++ and Sc0 Studies40002000300010005000Entries / 5 MeV/c22.12.22.32.4M(p+K-p+)(GeV/c2)Yield=12410 180S/B = 1.7=7.890.11 MeV/c2Cut 2sSidebandsFOCUS

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  • Sc++ and Sc0 MassesM(Sc0) M(Lc+) =167.38 0.21 MeV/c2M(Sc++) M(Lc+) =167.35 0.19 MeV/c2SC++ LC+ p+SC0 LC+ p-Entries / 500 KeV/c2Yield = 362 36Yield = 461 390.150.170.19(GeV/c2)0.150.170.19(GeV/c2)M(LC+p) M(LC+)FOCUS604020604020( CLEO 2.5 ICHEP 2000167.20.10.2 MeV/c2 )( CLEO 2.5 ICHEP 2000167.40.10.2 MeV/c2 )

    Frontiers in Contemporary Physics, 2001.

  • Systematic ErrorsM(Sc++) M(Sc0) = -0.03 0.28 0.11 MeV/c2Phys. Lett. B488, 218-224, 2000.M(Sc0) M(Lc+ ) = 167.38 0.21 0.13 MeV/c2M(Sc ) M(Lc ) = 167.35 0.19 0.12 MeV/c2

    Source Systematic Error (MeV/c2)Sc++ -Lc+Sc0 - Lc+Sc++ - Sc0Momentum Scale0.050.050.00Fitting0.020.060.04Recon. Bias0.040.040.00Analysis Cuts0.100.100.10Total 0.120.130.11

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  • Observation of Sc+ Lc+ p0(GeV/c2)100200150 500.20.40.160.200.30.180.14M(Lc+ p0) M(Lc+)20806040N / 1 MeV/c2N / 3 MeV/c2M(Sc+) M(Lc+) = 168.0 1.0 0.3 MeV/c2( CLEO hep_ex/0007041: M(Sc+) M(Lc+) = 166.4 0.2 0.3 MeV/c2 )M(Sc+) M(Sc0) = 0.6 1.0 0.3 MeV/c2 Yield =118 40 p0 gg Reconstructed in EMCAL.PreliminaryFOCUS s = 3.040.84 MeV/c2

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  • Isospin Mass DifferencesPreliminaryTheory has canceling contributions: quark masses, strong potential, Coulomb interaction, hyperfine ( EM + QCD ).

    Mass Difference (MeV/c2)ParticlesPDG 1998CLEO 2.5FOCUS N-P1.293318 0.000009D0 - D++2.6 0.4S- - S+8.08 0.08X- - X06.4 0.6Xc0 - Xc+4.7 0.6Sc0 - Sc++-0.57 0.230.030.280.11Sc0 - Sc+-1.4 0.60.7 0.5-0.61.00.3

    Frontiers in Contemporary Physics, 2001.

  • Natural Widths (MeV/c2)G(Sc0) = 2.58 0.79G(Sc++) = 2.53 0.770.200.180.160.140.160.140.18(GeV/c2)0.208060402080604020M(Lc+ p+) M(Lc)M(Lc+ p-) M(Lc)Signal Shape: BW convoluted with a gaussian.Preliminary s0 = 1.48 0.01 MeV/c2Entries / 0.5 MeV/c2FOCUS( CLEO 2.5 ICHEP 2000: G0 = 2.40.2 0.4 G++ = 2.50.20.4 MeV/c2 ) s++ = 1.49 0.02 MeV/c2

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  • G(Sc++) and G(Sc0)+0.51 -0.56+0.51 -0.55

    Theoretical PredictionsAuthor G (MeV/c2)Sc0 Sc++Ivanov2.65 0.192.85 0.19Tawfig1.571.64Huang2.42.5Pirjol1.0 - 3.01.1 - 3.1Rosner1.32 0.041.32 0.04 References at end of talk.Focus Preliminary Results2.58 0.79 2.53 0.77

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  • Observation of Sc*++ and Sc*0 0.300.250.150.200.300.200.250.15(GeV/c2)M(Lc+p-) M(Lc)M(Lc+p+) M(Lc) 300 200 100 300 200 100Entries / 1.0 MeV/c2DM(Sc0) = 232.7 1.2 MeV/c2DM(Sc++) = 234.21.5 MeV/c2PreliminaryG = 9.4 3.7 MeV/c2G = 23.6 4.5 MeV/c2M(Sc*0) - M(Sc*++) = -1.5 1.9 MeV/c2Yield = 1284 225Yield = 593 146FOCUS( CLEO II: DM0=232.61.00.8 G0=13.03.74.0 DM++=234.51.10.8 G++=17.93.84.0 )Stat errs only

    Frontiers in Contemporary Physics, 2001.

  • Observation of Excited Lc States(GeV/c2)0.300.350.400.45250200150100 50M(Lc+p+p-) M(Lc+) Lc(2625): DM = 341.6 0.3 MeV/c2Lc(2593): DM = 308.1 0.7 MeV/c2Entries / 2 MeV/c