1. Mikhail Bashkanov Dibaryons at COSY Wasa-at-COSY

2. Types of particles/resonances color anticolor white Meson Baryon Mikhail Bashkanov "Dibaryons"2

3. Possible particles Pentaquark Meson-Baryon molecule Hexaquark Baryon-Baryon molecule Mikhail Bashkanov "Dibaryons"3 Tetraquark Meson-Meson molecule

4. Deuteron to Deltaron 4 Threshold pn 2.2 MeV deuteron ΔΔ 80 MeV d* I(J p ) = 0(1 + ) I(J p ) = 0(3 + ) u u u d d d u u u d d d

5. WASA 4  Detector π π p d   n  

6. 6 “d* resonance”  70 MeV Total cross section pn  d  0  0 P. Adlarson et. al Phys. Rev. Lett. 106:242302, 2011  NN*(1440)

7. 7 Angular distribution in the peak J=1 J=3 P. Adlarson et. al Phys. Rev. Lett. 106:242302, 2011

8. 8 The extracted properties of the new particle pn  dibaryon    d     Δ Δ d π π p n I(J p ) = 0(3 + ) Mikhail Bashkanov "Dibaryons"

9. 9 Total cross section pN  d  P. Adlarson et. al Phys. Lett. B721 (2013) 229

10. 10

11. 11 From fusion to free case pn  d*    d  Δ Δ d π π p n pn  d*    NN  Δ Δ π π p n N N Fäldt & Wilkin, PLB 701 (2011) 619 Fäldt & Wilkin, PLB 701 (2011) 619 Albaladejo & Oset, Phys.Rev. C88 (2013) 014006 Albaladejo & Oset, Phys.Rev. C88 (2013) 014006

12. 12 pn  pn  0  0 d* Conventional process Conventional process +d* d* P. Adlarson et al., Phys.Lett. B743 (2015) 325-332

13. Dibaryon non-fusion decays 13 PLB 743 (2015) 325 d* PRC 88 (2013) 055208HADES arXiv:1503.04013arXiv:1503.04013

14. Dibaryon hadronic decays 14 pn  d*(2380) PRL 112 (2014) 202301 PRC 90, (2014) 035204 PLB 721 (2013) 229 PRL 106 (2011) 242302 PRC 88 (2013) 055208 PLB 743 (2015) 325 WASA data d*

15. 15 The decay modes of the dibaryon ChannelPublications d     M. Bashkanov et. al Phys.Rev.Lett. 102 (2009) 052301 P. Adlarson et. al Phys. Rev. Lett. 106:242302, 2011 P. Adlarson et. al Phys.Lett. B721 (2013) 229-236 d     P. Adlarson et. al Phys.Lett. B721 (2013) 229-236 pp     P. Adlarson et. al Phys. Rev. C 88, 055208 np     P. Adlarson et. al Phys.Lett. B743 (2015) 325 npA. Pricking, M. Bashkanov, H. Clement. arXiv:1310.5532 P. Adlarson et al. Phys. Rev. Lett. 112, 202301, (2014) P. Adlarson et al. Phys. Rev. C 90, 035204, (2014) pn e + e - M. Bashkanov, H. Clement, Eur.Phys.J. A50 (2014) 107 3 He  M. Bashkanov et. al Phys.Lett. B637 (2006) 223-228 P. Adlarson et. al Phys. Rev. C 91 (2015) 1, 015201 4 He  P. Adlarson et. al Phys.Rev. C86 (2012) 032201 + activities from other groups Mikhail Bashkanov "Dibaryons" M. Bashkanov, Stanley J. Brodsky, H. Clement Phys.Lett. B727 (2013) 438-442

16. 16

17. 17 pn  d*    d  Δ Δ d π π p n pn  d*    NN  Δ Δ π π p n N N pn  d*  pn p n n p

18. 18 Expectations p n n p SAID SAID with resonance A. Pricking, M. Bashkanov, H. Clement: arXiv:1310.5532

19. 19 p n n p SAID A. Pricking, M. Bashkanov, H. Clement: arXiv:1310.5532

20. 20 p n n p SAIDNew SAID solutions P. Adlarson et al. Phys. Rev. Lett. 112, 202301, (2014)

21. Dimensionless partial wave amplitudes 21 Re Im SP07 SP14 Dimensionless partial wave amplitudes Resonance in the pn system P. Adlarson et al. Phys. Rev. Lett. 112, 202301, (2014)

22. 22 Argand plot P. Adlarson et al. Phys. Rev. Lett. 112, 202301, (2014) P. Adlarson et al. Phys. Rev. C 90, 035204, (2014)

23. 23 Argand plots P. Adlarson et al. Phys. Rev. Lett. 112, 202301, (2014) P. Adlarson et al. Phys. Rev. C 90, 035204, (2014)

24. 24

25. Deuteron 25 n p np L=2 0.9 fm 4 fm L=0

26. Deltaron vs Hexaquark 26 Δ Δ ΔΔ L=2 0.9 fm L=0 1.2 fm 0.7 fm F. Huang et al, arXiv:1408.0458

27. d*(2380) internal structure and the ABC effect 27 Δ Δ ΔΔ L=2 0.9 fm L=0 1.2 fm M. Bashkanov et al, arXiv:1502.07500

28. 28

29. Mirror dibaryon 29   I(J p ) = 0(3 + ) d* u u u d d d I(J p ) = 3(0 + )   u u u u u u Freeman J. Dyson, Nguyen-Hue Xuong Phys. Rev. Lett. 13(1964) 815 Avraham Gal, Humberto Garcilazo Nucl. Phys. A928, (2014), 73

30.  *  *+  *  *  *+    *  *  *+  *  **   ++ ---- d* How many ways can you combine 6q? Isospin Strangeness

31. Z=+4 dibaryon isospin coefficients p p p p I

32. 32

33. 33

34. 34 p p p p Δ Δ p p p p p p p p

35. 35 Double-Roper

36. Charge Z=+4 dibaryon upper limit 36

37. NN vs ΔΔ 37 Threshold pn pn 2.2 MeV 66 keV deuteron ΔΔ ΔΔ ? 80 MeV d* Z=+4

38.  *  *+  *  *  *+    *  *  *+  *  **   ++ ---- d* How many ways can you combine 6q? Isospin Strangeness

39. d*(2380) SU(3) multiplet   *  *  39 J p = 3 +

40. Strange Dibaryon Isospin Strangeness  *  *+  *  *  *+    * d*

41. d*(2380) in photoproduction? 41 R. Gilman and F. Gross nucl-th/0111015 (2001) T. Kamae, T. Fujita Phys. Rev. Lett. 38, Feb 1977, 471 H. Ikeda et al., Phys. Rev. Lett. 42, May 1979, 1321 d* I(J p ) = 0(3 + )

42. The benchmark measurement 42 Newly installed Edinburgh polarimeter M.H. Sikora, D.P. Watts et al, Phys.Rev.Lett. 112 (2014) 022501 Mikhail Bashkanov "Dibaryons" Measure polarization of both proton and neutron ! d*

43. Conclusion The very first dibaryon d*(2380) is established Mass Width Quantum numbers Main decay branches Structure: Hexaquark vs Molecule? No convincing signs for the mirror dibaryon (charge Z=+4) so far Size and shape of the conventional background? Mirror multiplet (28-plet) is likely to be unbound 43

45. 45 Δ Δ d π π  d Mikhail Bashkanov "Dibaryons" A. Fix, H. Arenhoevel. Eur. Phys. J. A 25, 115, (2005).

46. Z=+4 dibaryon Δ Δ π π N N p p p p WASA, HADES

47. 47

48. 48 M(GeV)12345exp 2.352.3612.452.38 2.352.833unbound2.692.40  1.Dyson-Xuong, PRL 13 (1964) 815 2.Mulders-Aerts-de Swart, PRD 21 (1980) 2653 3.Oka-Yazaki, PLB 90 (1980) 41. 4.Mulders-Thomas, JPG 9 (1983) 1159. 5.A. Gal, H. Garcilazo Nucl.Phys. A928 (2014) 73-88