New states, rare decays and branching ratios

Transcription

1 New states, rare decays and branching ratios Ulrich Kerzel University of Karlsruhe, Germany for the CDF Collaboration - Förderschwerpunkt Elementarteilchenphysik Großgeräte der physikalischen Grundlagenforschung mailto:kerzel@fnal.gov 16th June 24 U.Kerzel, University of Karlsruhe HCP24, Michigan State University 1

2 Overview 1. Detectors 2. Rare decays and branching ratios 3. New states: PentaQuarks X J/Ψπ + π 4. Conclusion U.Kerzel, University of Karlsruhe HCP24, Michigan State University 2

3 Detectors I CDF Central Calor Muon System Time of Flight Drift Chamber Forward Mini drift chamber Shielding Central Scintillator Forward Scintillator DØ Solenoid New Muon Old Partially New Plug Calor Silicon Microstrip Tracker New Solenoid, Tracking System Si, SciFi, Preshowers + New Electronics, Trig, DAQ BELLE 9. GeV 3.1 GeV SVD CDC PID (Aerogel) TOF CsI KL/µ Superconducting Solenoid Belle Detector For the KEK B factory U.Kerzel, University of Karlsruhe HCP24, Michigan State University 3

4 Detectors II H1 Zeus Saphir U.Kerzel, University of Karlsruhe HCP24, Michigan State University 4

5 BR and rare decays Branching ratios and rare decays selected results from 24 U.Kerzel, University of Karlsruhe HCP24, Michigan State University 5

6 Branching Ratios I BaBar B X c lν V cb = (41.4 ±.4 exp ±.4 HQE ±.6 th ) 1 3 BR(b clν) = (1.61 ±.16 exp ±.6 HQE )% Results are in agreement with recent calculations BaBar B ± [K π ± ] D K ± no signal seen r B = A(B D K ) A(B D K ) <.22 (9%CL) amplitude b u small? γ = arg( V ub V ud/v cb V cd) difficult from this mode U.Kerzel, University of Karlsruhe HCP24, Michigan State University 6

7 Branching Ratios II Belle B p p New BR < factor 1 lower constrain theory: rule out QCD sum-rule based prediction, consistent with pole model Belle B ωk ; B ωπ Originate from interference of b s penguin loop and b u spectator tree BR(B + ωk + ) = ( ±.6) 1 6 large BR problematic in factorisation approach BR(B + ωπ + ) = ( ±.6) 1 6 A 2.4σ sign. CP (B + ωk + ) = ±.1 A CP (B + ωπ + ) = ±.2 U.Kerzel, University of Karlsruhe HCP24, Michigan State University 7

8 Branching Ratios III BaBar B η ( ) K, η ( ) ρ, η ( ) π, ωπ, φπ interf. penguin tree, constrain CKM parameters BR(B + ηk + ) = (25.6 ± 4. ± 2.4) 1 6 BR(B ηk ) = (18.6 ± 2.3 ± 1.2) 1 6 BR(B + ηρ + ) = (9.2 ± 3.4 ± 1.2) σ sig. for new mode B + ηρ + Belle B K γ Isospin, CP asymmetries BR(B + K + γ) = (4.1 ±.21 ±.15) 1 5 BR(B K γ) = (4.25 ±.31 ±.24) 1 5 Isospin asymm.: =.12 ±.44 ±.26 CP asymm.: A CP =.15 ±.44 ±.12 U.Kerzel, University of Karlsruhe HCP24, Michigan State University 8

9 CDF B µ + µ forbidden in SM at tree level (FCNC), higher order process BR new physics: enhancements in some SuSy, SO(1) models BR(B s µ + µ ) < %CL BR(B d µ + µ ) < %CL Belle BR(B d µ + µ ) < %CL D < BR(B s µ + µ ) > %CL (expected value, not yet unblinded) U.Kerzel, University of Karlsruhe HCP24, Michigan State University 9

10 New states PentaQuarks X New states U.Kerzel, University of Karlsruhe HCP24, Michigan State University 1

11 PentaQuarks introduction PentaQuarks: bound 5 quark state (qqqq q) Baryon + Meson not prohibited by QCD but not seen so far either Since summer 23: much activity regarding 5-quark state also from smaller experiments U.Kerzel, University of Karlsruhe HCP24, Michigan State University 11

12 PentaQuarks - overview I Ξ : Ξ + 3 2, Ξ 3, Ξ 3 2 2, Ξ 3 2 NA49 (CERN): evidence (4.σ sign.) for narrow resonance in Ξ π channel M = ±.2 GeV/c 2 not seen by CDF, DELPHI, Hera-B Entries / 7.5 MeV/c a) Ξ - π - b) Ξ - π + 15 c) Ξ + π - d) Ξ + π M(Ξπ) [GeV/c 2 ] Θ c D px H1 (Desy): evidence in M(D + p), M(D p) M = 399 ± 3 ± 5 MeV/c 2 not seen by Zeus, CDF all widths reported compatible with resolution U.Kerzel, University of Karlsruhe HCP24, Michigan State University 12

13 PentaQuarks - overview II Most evidence: Θ + (uudd s) predicted 1997 by Diakonov, Petrov, Polyakov should decay equally to K + n, K s p Experiment Θ + Mass / GeV/c 2 stat. sign. CLAS K + n ±.5 5.2σ LEPS K + n 1.54 ±.1 4.6σ SAPHIR K + n 1.54 ±.4 ±.2 4.8σ DIANA K p ±.2 4.4σ HERMES K s p ±.26 ±.21 4σ Zeus K s p ± , 4σ all widths reported around detector resolution. U.Kerzel, University of Karlsruhe HCP24, Michigan State University 13

14 Reported Θ + signals Events/.1 (GeV/c 2 ) CLAS M(nK + ) [ GeV/c 2 ] Events/(.2 GeV/c 2 ) a) Events/(.2 GeV/c 2 ) MM c γk + (GeV/c 2 ) MM c γk (GeV/c 2 ) b) 7 6 M=1528 ± 2.6(stat) MeV σ=8 ± 2(stat) MeV b) LEPS LEPS HERMES M(π + π - p) [GeV] ZEUS counts SAPHIR Θ + (154) b Combinations /.5 GeV KS p(p) 2 2 Q >2 GeV ZEUS 96- Fit Gaussian Background ARIADNE MC DIANA mass(nk + )/GeV χ / ndf =35 / 44 peak= ± 1.5 MeV 12 width= 6.1 ± 1.6 MeV 1 events=221 ± M (GeV) K S S p K p U.Kerzel, University of Karlsruhe HCP24, Michigan State University 14

15 PentaQuark situation now Experimental situation rather unclear: All results have low significance Not seen by all experiments Θ + K + n heavier than Θ + K s p? No evidence at Tevatron so far Physics? Prod. mechanism unclear Many different predictions/explanations from theory Systematic searches needed: establish signal rule out evidences Determine properties to constrain models U.Kerzel, University of Karlsruhe HCP24, Michigan State University 15

16 X J/Ψπ + π hint then history: 1994: E75 (fixed-target at FNAL) : in π Li Ψπ + π + anything observed 58 ± 21 excess events at ±.13GeV/c 2 possible interpretations: 1 P 1 (1 + ), 3 D 2 (2 ), 1 F 3 (3 + ) c c or c cq q However: 1998: BES (e GeV centre-of-mass energy): cannot confirm signal, no excess found U.Kerzel, University of Karlsruhe HCP24, Michigan State University 16

17 2 X J/Ψπ + π present situation Belle (Observation): B ± K ± J/Ψπ + π Events / (.5 GeV ) b) 35.7 ± 6.8 events 1.3σ significance M = ±.6 ±.5 MeV/c M(J/ ψ ππ) (GeV) CDF DØ (confirm): X J/Ψπ + π 2 Candidates/ 5 MeV/c CDF II ± 9 events 1.9σ significance M = ±.7 ±.4 MeV/c 2 5 J/ψπ + π - Mass (GeV/c ) X J/Ψπ + π 8 DØ X(3872) (prelim) ψ(2s) ± 1 events 5.2σ significance ~2 pb M = ± 3.1 ± 3. MeV/c 2 2 (GeV/c ) 2 M µ (GeV/c ) + µ - π + π - BaBar B ± J/Ψπ + π K ± (prelim) M = ± 1.4 MeV/c 2 2 Candidates / 1 MeV/c Candidates / 1 MeV/c M µ + µ - 2 J/ψ M µ + - µ U.Kerzel, University of Karlsruhe HCP24, Michigan State University 17

18 X J/Ψπ + π widths Signals Ψ(2s) and X represented by single Gaussians Belle σ = 2.5 ±.5 MeV/c 2 (consistent with MC expectation) Γ = 1.4 ±.7 MeV/c 2 (resolution-broaded Breit-Wigner) width compatible with zero CDF σ = 5.44 ±.722 MeV/c 2 consistent with detector resolution D σ = 17 ± 3 MeV/c 2 consistent with detector resolution U.Kerzel, University of Karlsruhe HCP24, Michigan State University 18

19 X J/Ψπ + π reconstruction similar approach by Belle, CDF, DØ: J/Ψ µ + µ (add. J/Ψ e + e for Belle) add two oppositely charged tracks as Pion (+ loosely identified Kaon for Belle from B decay) cut on M(π + π ) >.4 GeV/c 2 (Belle).5 GeV/c 2 (CDF).52 GeV/c 2 (D) BG-suppression : event-shape for Belle ( cos(θ B ), R 2 ) p, R, fit χ 2, number cands/tracks for CDF/DØ U.Kerzel, University of Karlsruhe HCP24, Michigan State University 19

20 Further X properties X seems to favour high M(π + π ) Belle events cluster at high end CDF sees signal enhancement if cutting on M(π + π ) intermediate ρ resonance (X J/Ψρ)? Events/.8 GeV Belle BaBar looks for X J/Ψη in B ± XK ± Motivation: if X c c state, decay may be similar to Ψ(2s) expect: BR Limit: BR < CL Events/6.25 MeV/c 2 6 Ψ(2s) X BABAR J/ψη Mass(GeV/c 2 ) U.Kerzel, University of Karlsruhe HCP24, Michigan State University 2

21 X a charmonium? Various possible explanations on the market: X as a charmonium (c c) state? 2 1 P 1, i.e. h c (1+ )? Belle claims disfavoured (looking at cos θ J/Ψ ) 1 3 D 2 (2 ), 1 3 D 3 (3 )? then also: X χ c1 γ(344), X χ c2 γ(33) but: no signal by Belle in χ c1 γ mode seen BES estimates e + e partial width using ISR data: disfavour vector state U.Kerzel, University of Karlsruhe HCP24, Michigan State University 21

22 X a molecule? DeRujula, Georgi, Glashow (1977): Molecular Chamonium X(3872)? 4q molecules poss.: D D, D D, D D D D, D D decay via interm. states J/Ψη, J/Ψρ (molec. trans.) U.Kerzel, University of Karlsruhe HCP24, Michigan State University 22

23 X a Deuson? Törnquist (24): Expect: (D D meson-meson state bound by π exchange deuteron-like meson ) J P C = 1 ++, + (otherwise π exchange too weak/repulsive) very small binding energy: large spatial size, very narrow width decay to J/Ψ ρ allowed, J/Ψ σ ; J/Ψ π π forbidden (C-, spin parity) U.Kerzel, University of Karlsruhe HCP24, Michigan State University 23

24 X todo So far, we know very litte about X Need to determine its properties: Quantum numbers J P C angular distributions, helicity lifetime, fraction prompt/from B other decay modes? is the X a molecular state? if yes, do others exist? Where are the expected c c states? U.Kerzel, University of Karlsruhe HCP24, Michigan State University 24

25 Conclusion Branching ratios: many new results exp. sensitivity theory accuracy constrain param., distinguish between models PentaQuarks: X: many hints reported stat. significance rather low further studies needed to determine existence obs. by Belle, conf. by CDF, seen by D, BaBar nature of X? c c? molecule? U.Kerzel, University of Karlsruhe HCP24, Michigan State University 25

26 BACKUP U.Kerzel, University of Karlsruhe HCP24, Michigan State University 26

27 Experiments I BaBar PEP-II (SLAC, USA) e + (3.1GeV ) e (9GeV ) collider at Υ(4s) resonance ( s = 1.58GeV ) Belle : KEKB (Japan) e + (3.5GeV ) e (8GeV ) collider at Υ(4s) resonance BES Beijing Electron Positron Collider e + e collider at s = 4.3GeV CDF, D FermiLab (USA) p p collider at s = 1.96T ev U.Kerzel, University of Karlsruhe HCP24, Michigan State University 27

28 Experiments II CLAS Jefferson Lab, USA e (2.474, 3.115GeV ) on Bremsstrahlung radiator, resulting γ on 1cm liquid deuterium target DIANA ITEP proton synchrotron (Moskow, Russia) 85MeV K + beam on Xe bubble chamber E75 FermiLab (USA) 3GeV π ±, p, p on Li target H1, Zeus DESY (Hamburg, Germany) e (27.6GeV ) p(82gev, 92GeV ) collider U.Kerzel, University of Karlsruhe HCP24, Michigan State University 28

29 Experiments III Hermes DESY (Hamburg, Germany) using e (27.6GeV ) beam on H, D, He 3 target LEPS SPring-8 (Japan) Use 351nm Ar laser on 8GeV electrons Compton scattered γ on H, C plastic scintillator NA49 SPS (CERN, Switzerland) 158GeV p on liquid hydrogen target Saphir ELSA (Bonn, Germany) e (2.8GeV ) on copper foil, bremsstrahlung γ on liquid H U.Kerzel, University of Karlsruhe HCP24, Michigan State University 29

30 BaBar B X c lν Motivation: weak decay rate b clν proprotional to V cb 2 use OPE to relate to measurement of BR(B X c lν) input: m b (µ), m c (µ), 4 non-pert param. Use measured moments of hadronic mass distribution in semi-leponic B decays: detemine input parameters determine BR(B X c lν), V cb in a simultanious χ 2 fit. Results in agreement with recent they predictions U.Kerzel, University of Karlsruhe HCP24, Michigan State University 3

31 BaBar B η ( ) K, η ( ) ρ, η ( ) π, ωπ, φπ Motivation: measure A ch for B ηk +, B ηk η/η mixing might enhace B η K, suppress B ηk reversed for K modes due to opposite K parity decay with ρ, π in final state from penguin/colour suppressed BR(B η K) 1 6 rather large, BR(B ηk ) also rather large 3.5σ hint for new mode B + ηρ + charge asym. compatible with zero U.Kerzel, University of Karlsruhe HCP24, Michigan State University 31

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