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Mikhail Bashkanov Dibaryons at COSY Wasa-at-COSY

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

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

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Deuteron to Deltaron 4 Threshold pn 2.2 MeV deuteron 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

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WASA 4 Detector p d n

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

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

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8 The extracted properties of the new particle pn dibaryon d d p n I(J p ) = 0(3 + ) Mikhail Bashkanov "Dibaryons"

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

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

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

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

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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*

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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

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17 pn d* d d p n pn d* NN p n N N pn d* pn p n n p

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

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

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

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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)

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

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

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

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

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

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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

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* *+ * * *+ * * *+ * ** ++ ---- d* How many ways can you combine 6q? Isospin Strangeness

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

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34 p p p p p p p p p p p p

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35 Double-Roper

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Charge Z=+4 dibaryon upper limit 36

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

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* *+ * * *+ * * *+ * ** ++ ---- d* How many ways can you combine 6q? Isospin Strangeness

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d*(2380) SU(3) multiplet * * 39 J p = 3 +

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Strange Dibaryon Isospin Strangeness * *+ * * *+ * d*

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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 + )

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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*

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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

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

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Z=+4 dibaryon N N p p p p WASA, HADES

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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