1. Daniel Sherwood 03/2005 Search for Crypto-Exotic States in Babar Daniel Sherwood Dr. Liliana Teodorescu

2. Daniel Sherwood 03/2005 Outline Introduction –Exotic States –Existing Measurements Search in Babar –Analysis Strategy –Status of the Analysis Conclusions

3. Daniel Sherwood 03/2005 Exotic States (Open) Exotic States Hadrons with Exotic Quantum Numbers (Q, S, I) OR Hadrons with Exotic Combinations of Quantum Numbers (J PC ) Unexplained by qq or qqq quark structures Crypto-Exotic States Hadrons With Hidden Exotic Properties –Ordinary Quantum Numbers (Q, S, I, J PC ) –Anomalously Small Widths, Anomalous Decay Channels, Special Production Mechanisms

4. Daniel Sherwood 03/2005 Existing Measurements Θ + (1540) – CLAS Ξ -- (1842) – NA49 Θ C (3100) – H1 Exotic States Mesons Crypto-Exotic States Mesons DESY 04-038 R(3520) – CERN PL B 281 (1991) 148 PRL 91,012002 (2003)PL B572 127 (2003) PL B 89 (1979) 125 R(3170) – CERN Baryons X(3872) – cqcq BELLE X(3940) – cqcq BELLE a + – susd a 0 – 1/√2(susu – sdsd) a - – sdsu f 0 – 1/√2(susu + sdsd) σ 0 – udud … ududcdsdsuududd

5. Daniel Sherwood 03/2005 Crypto-Exotic Baryons PL B 89 (1979) 125 R(3170) – CERN R(3520) – CERN PL B 281 (1991) 148 CERN 2m HBC (8.25 GeV/c) Argonne 12ft HBC (6.5 GeV/c) K - + p + → π - + R Γ R = 20 MeV R(3170) → Σ K K + pions → Λ K K + pions → Ξ K + pions qqsss CERN 2m HBC (16Gev/c) (p + K + Ks π - π - ) System M R = 3520  3 MeV/c 2  R = 7 -7 +20 MeV/c 2 Decays through K* - uudcc

6. Daniel Sherwood 03/2005 Search for R(3520) at Babar Present Analysis Possible Extensions Similar + Baryon in Final State Similar + Baryon and cc in Final State (Assuming Resonance with Hidden Charm)

7. Daniel Sherwood 03/2005 Babar Experiment e+ e- Interaction 10.6GeV SVT – Silicon Vertex Tracker – Vertexing and Tracking DCH – Drift Chamber - Tracking EMC – Electromagnetic Calorimeter -measures particles energy DIRC – Detector of Internally Reflected Cherenkov Light – Particle Identification IFR – Instumented Flux Return – muon and neutral hadron detection Superconducting Solenoid (1.5T Magnetic Field) 244 fb -1 Data Recorded

8. Daniel Sherwood 03/2005 Event Selection (Preliminary) K* - →K S π - Vertexed Using Cascade Geometric Constraints R XY < 0.6 cm |R Z | < 3.2 cm P(Χ 2 ) < 0.001 DOCA < 0.6 cm K S →π + π - Vertexed Using TreeFitter Geometric Constraints Unfitted Mass Window 0.3-0.8 R XY < 0.6 cm |R Z | < 3.2 cm P(Χ 2 ) < 0.001 DOCA < 0.6 cm Signed Flight Length > 0 cm Flight Significance > 3 Final Mass Window PDG ±10MeV Mass Constraint π- Charged Tracks π + Charged Tracks π - piLHLoose R XY < 0.6 cm |R Z | < 3.2 cm p + pLHTight R XY < 0.6cm |R Z | < 3.2cm K + KLHTight R XY < 0.6cm |R Z | < 3.2cm π - piLHLoose R XY < 0.6cm |R Z | < 3.2cm K* + π - p + K + Missing Mass Spectrum K S π - π - p + K + Missing Mass Spectrum π- piLHLoose

9. Daniel Sherwood 03/2005 Selection Criteria Interaction Region –R Z — Half Length of Cylinder (3.2 cm) –R XY — Radius of Cylinder (0.6 cm) Daughters Originate from Same Decay –DOCA between Daughters’ Tracks < 0.6cm Signed Flight Length (> 0) –Removes Candidates With Unphysical Decay Lengths Dunwoodie and Coleman (DOCA) SelectorCriteria p+pLHTightL(p)/L(K) > 5.0 L(p)/L(pi) > 0.75 If p>0.75 reject electrons K+KLHTightL(K)/L(pi) > 0.9 L(K)/L(p) > 0.2 if p>0.4 reject electrons

10. Daniel Sherwood 03/2005 K S Reconstruction CutsPurity (%) Initial75 Final92 Initial Selection Two Charged Tracks with Pion Mass Associated Kalman Filter Based Vertexer Geometric Fit Constraints P(χ 2 ) of the Fit > 0.001 Flight Significance (cτ/σ) > 3 Final Mass Window ±10MeV around the PDG K S Mass Final Selection DOCA ππ < 0.6 cm |cosθ Helicity | < 0.8 (Removes Λs ) |R Z | < 3.2 cm R XY < 0.6 cm Signed Flight Length > 0 cm

11. Daniel Sherwood 03/2005 (K S K + p + π - π - ) Missing Mass Spectrum

12. Daniel Sherwood 03/2005 K* - Reconstruction Initial Selection K S and π- Selected as Described Previously Geometric Fit Constraints Newton-Raphson based Vertexer Mass Window PDG±76 MeV/c 2 Final Selection P(χ 2 ) of the Fit > 0.001 DOCA Ksπ < 0.6 cm |R Z | < 3.2 cm R XY < 0.6 cm CutsPurity (%) Initial6 Final11

13. Daniel Sherwood 03/2005 (K* - K + p + π - ) Missing Mass Spectrum

14. Daniel Sherwood 03/2005 Conclusions Start of This Analysis Key Points –K S Reconstruction – Very Good –K* - Reconstruction – Promising –Additional Studies on Data and Monte-Carlo