1. Introduction to DsJ Analysis at CDF
UCLA group meeting
Dec. 5, 2005
Yangheng Zheng
Introduction & Motivation
Analysis strategy

2. Narrow Multi-quark Mesons?
In 2003
CLEO
M(Ds*p) - M(Ds*)
2457 MeV
M(Dsp)
BaBar
2317 MeV
CS bond states?
UCLA group meeting
12/05/2005

3. Angular analysis Jz=0 J=0 z (p) Belle found B D DsJ(2317)  p0Ds and
 gDs
J=1
J=2
DsJ(2457) Ds 
J=1
J=0
DsJ(2317) Ds0
DsJ(2317) = 0+
DsJ(2457) = 1+
UCLA group meeting
12/05/2005

4. cs spectrum cs spectrum was not expected any surprise, but…
DsJ(2457) = 1+
DsJ(2317) = 0+
Potential Model prediction
Heavy-Light-quark system
Potential models got the masses wrong
Chiral models seem to work OK (See, e.g. Bardeen, Eichten & Hill PRD68, )
Exotic states not totally ruled out
UCLA group meeting
12/05/2005

5. cs in Chiral Model Not observed Observed by SELEX(E781)
but not by Belle and BaBar
Parity doubling
Angular excitation
Jq in heavy quark limit
UCLA group meeting
12/05/2005

6. Motivation Confirm the existence of DsJ(2632) →D0K+
Positive result → measure JP
Search for other heavier cs states in Dsp+p- decay channel (for exmaple: 2- state)
Learn how to determine the quantum numbers (JPC) of a particle
Angular distributions
Partial Wave Analysis (PWA)
UCLA group meeting
12/05/2005

7. Analysis strategy in CDF
Quick look at the D0K+ and Dsp+p- invariant mass spectrum
Feasible reconstruction decay modes
DsJ→D0K reference: Ds2(2573)
→K-p+
DsJ→ Dsp+p reference: DsJ(2457)
→f p+
→K+K-
Data sample: Two-Track-Trigger (TTT)
Dataset: xbhd0d
Data pre-selection: BStntuple
UCLA group meeting
12/05/2005

8. Frameworks--BStntuple
Stntuple for B physics (Spectroscopy, new particle search, mass, lifetime… )
Data skimming: few percent reduction rate (goal: ~100GB ntuple data size)
Track refitting
Reassign the track mass  decay products
Energy loss correction for K/p hypothesis
Vertex and Kinematical fitting (CTVMFT)
Constrain tracks from same vertex
Mass constrain
UCLA group meeting
12/05/2005

9. Dsp+p- combinations
All DsJ candidates in BStntuple (data sample: few pb-1)
UCLA group meeting
12/05/2005

10. f → K+K- f mass f mass All KK combination After track quality cut
f Pt > 2 GeV
UCLA group meeting
12/05/2005

11. Ds → f p+
Ds mass
D mass
UCLA group meeting
12/05/2005