Pentaquark Challenges

Transcription

1 Michał Praszałowicz - Jagellonian University Kraków, Poland Pentaquark Challenges Kielce Workshop on Future of Nuclear Collisions at High Energies

2 January 2003 November 15, 2004 M. Praszałowicz (Kraków) 2

3 January 2003 photon neutron neutron November 15, 2004 M. Praszałowicz (Kraków) 3 Θ + MM = γ+n-k - γk - K - K +

4 January 2003, June Preliminary Θ MM γκ (GeV) November 15, 2004 M. Praszałowicz (Kraków) 4

5 Antidecuplet November 15, 2004 M. Praszałowicz (Kraków) 5

6 # of papers Exotic activity I 2003 I 2004 months since January 2003 November 15, 2004 M. Praszałowicz (Kraków) 6

7 Do we see Theta + at all? Experiments that do not see Θ + : HERA-B STAR & PHENIX (RHIC) -? Opal, Aleph, Delphi (LEP) BES (Beijing) CDF, Hyper-CP (Fermilab), E690 BaBar Phase shifts from old K-scattering exps. mostly high energy inclusive November 15, 2004 M. Praszałowicz (Kraków) 7

8 How many Theta's? Final state: K + + n K 0 + p K 0 + p? Kielce Workshop: Future of Nuclear Collisions November 15, 2004 M. Praszałowicz (Kraków) 8

9 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism November 15, 2004 M. Praszałowicz (Kraków) 9

10 Unknown, in most models S = Spin and parity parity: + - ChSM, correlated QM, QM with flavor dep.forces, 1 lattice parity: - - uncorrelated QM (but wider), lattice (if at all), SumRules November 15, 2004 M. Praszałowicz (Kraków)

11 Spin and parity S. Sasaki, talk at Spring-8 Kielce Workshop: Future of Nuclear Collisions November 15, 2004 M. Praszałowicz (Kraków) 11

12 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory November 15, 2004 M. Praszałowicz (Kraków) 12

13 Unknown, in most models S = Spin and parity parity: + - ChSM, correlated QM, QM with flavor dep.forces parity: - - uncorrelated QM (but wider), lattice (if at all), SR However, most models predict S = 2 partners only a few 10's MeV higher: - ChSM: 27-plet, wider (30-70 MeV?), I=1 Θ ++ - corr.qm: L-S partner, still narrow, I=0 November 15, 2004 M. Praszałowicz (Kraków)

14 Further exotics from STAR and CLAS S. Kabana, AGS&RHIC Users Meeting M. Bttaglieri, JLAB Users Meeting June 16, 2004 Invariant Mass (GeV/c 2 ) November 15, 2004 M. Praszałowicz (Kraków) 14 Θ Θ Θ Invariant Mass (GeV/c 2 ) Θ pk p K + Invariant Mass (GeV/c 2 )

15 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ November 15, 2004 M. Praszałowicz (Kraków) 15

16 Width Most experiments give only upper limits: CLAS (γ p) < 23 MeV DIANA (K + Xe) < 9 MeV However, some other experiments quote errors: ZEUS (DIS) 6.1 ± 1.6 ± COSY (p p) 18 ± 4 MeV HERMES (e p) 17 ± 9 ± 3 MeV DUBNA (bubbl.ch.) 16 ± 4 MeV Phase shifts: < 2 MeV MeV November 15, 2004 M. Praszałowicz (Kraków)

17 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured November 15, 2004 M. Praszałowicz (Kraków) 17

18 Θ Width in the soliton model Decuplet decay: Antidecuplet decay: In NRQM limit: November 15, 2004 M. Praszałowicz (Kraków) 18 SU(3) relations

19 Θ Width in the soliton model Decuplet decay: Antidecuplet decay: In reality: However, G 10 is still small < 15 MeV November 15, 2004 M. Praszałowicz (Kraków) 19 SU(3) relations

20 Width in the soliton model - mixing effects Once G 10 is small, even moderate admixtures of other representations with nonsuppressed transitions modify the width For Θ only the admixture in the final state matters November 15, 2004 M. Praszałowicz (Kraków) 20

21 modification factor Width in the soliton model - mixing effects November 15, 2004 M. Praszałowicz (Kraków) 21

22 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured 7. Warning: SU(3) relations for Γ's will not hold November 15, 2004 M. Praszałowicz (Kraków) 22

23 Exotic Cascades Kielce Workshop: Future of Nuclear Collisions November 15, 2004 M. Praszałowicz (Kraków) 23

24 Exotic Cascades in ChQSM M.Diakonov, V.Petrov, M.Polyakov, Z.Phys. A359 (1997) 305 ChQSM NA plet M.M.Pavan, I.I.Strakovsky, R.L.Workman, R.A.Arndt, PiN Newslett. 16 (2002) 110 T.Inoue, V.E. Lyubovitskij, T.Gutsche, A.Faessler, arxiv:hep-ph/ November 15, 2004 M. Praszałowicz (Kraków) 24

25 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured 7. Warning: SU(3) relations for Γ's will not hold 8. Confirmation of Ξ(1860) is badly needed November 15, 2004 M. Praszałowicz (Kraków) 25

26 Y 2 Exotic Cascades in ideal mixing scenario (diquarks) flavor SU(3): 4 quarks antiquark I 3 November 15, 2004 M. Praszałowicz (Kraków) 26

27 Exotic N states in ideal mixing scenario (diquarks) Symmetry states have mixed quark content: Diagonalize strange quark content: November 15, 2004 M. Praszałowicz (Kraków) 27

28 Decay widths for N* πn : Exotic N states in ideal mixing scenario (diquarks) Θ is very narrow, neglect 10 piece Roper? N * (1710)? experimentally: November 15, 2004 M. Praszałowicz (Kraków) T.D. Cohen, hep-ph/

29 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured 7. Warning: SU(3) relations for Γ's will not hold 8. Confirmation of Ξ(1860) is badly needed 9. N * masses and widths suffer from mixing new nucleon-like resonances? November 15, 2004 M. Praszałowicz (Kraków) 29

30 Exotic N states in ChQSM Where is the "missing" octet? vibrations Neglecting vibrations: N * = 1648 MeV H. Weigel, hep-ph/ Indications for narrow nucleon-like states at 1680 and 1730 MeV R.A. Arndt, Y.I. Azimov, M.V. Polyakov, I.I. Strakovsky and R.L. Workman, Phys.Rev. C69:035208,2004 S. Kouznetsov (Graal, Grenoble) NSTAR2004 ~ 1671 S. Kabana (STAR), hep-ex/ ~ 1734 Crystal Barrel/TAPS (Mainz) ~ November 15, 2004 M. Praszałowicz (Kraków) 30

31 Mixing in ChQSM Kielce Workshop: Future of Nuclear Collisions November 15, 2004 M. Praszałowicz (Kraków) 31

32 Mixing in QM November 15, 2004 M. Praszałowicz (Kraków) 32

33 Full Mixing November 15, 2004 M. Praszałowicz (Kraków) 33

34 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured 7. Warning: SU(3) relations for Γ's will not hold 8. Confirmation of Ξ(1860) is badly needed 9. N * masses and widths suffer from mixing new nucleon-like resonances? 10. New N * resonances are difficult to predict because of the complicated mixing patterns 11. The same ( ) applies to Σ November 15, 2004 M. Praszałowicz (Kraków) 34

35 What will happen to this entry in PDG? Kielce Workshop: Future of Nuclear Collisions November 15, 2004 M. Praszałowicz (Kraków) 35

36 Conclusions 1. Still a convincing experiment is needed. Perhaps KN More experiments production mechanism 3. Spin will be shortly measured 4. Measure parity important impact on theory 5. Spin 3/2 partner of Θ + is almost sure. Perhaps Θ Width should be measured 7. Warning: SU(3) relations for Γ's will not hold 8. Confirmation of Ξ(1860) is badly needed 9. N * masses and widths suffer from mixing new nucleon-like resonances? 10. New N * resonances are difficult to predict because of the complicated mixing patterns 11. The same ( ) applies to Σ November 15, 2004 M. Praszałowicz (Kraków) 36