Shedding light on Hexaquarks Mikhail Bashkanov Total cross

Shedding light on Hexaquarks Mikhail Bashkanov

Total cross section pn d 0 0 “d* resonance” 70 Me. V NN*(1440) P. Adlarson et. al Phys. Rev. Lett. 106: 242302, 2011 2

u u u d d d Threshold I(Jp) = 0(3+) 80 Me. V d* Δ Δ 3

Dibaryon hadronic decays PLB 721 (2013) 229 PRL 106 (2011) 242302 WASA data pn d*(2380) PRL 112 (2014) 202301 PRC 90, (2014) 035204 d* d* d* PRC 88 (2013) 055208 PLB 743 (2015) 325 4

Branching ratio, % 12(3) 14(1) 23(2) 30(5) 12(2) 6(1) 0(<9) Eur. Phys. J. A 51 (2015) 7, 87 5

d* Internal Structure 6

d* internal structure Hexaquark Molecule Meson assisted Diquark dominated -dressed 7

Molecular Picture, A. Gal, P-wave p Phys. Lett. B 769 (2017) d* D-wave p Hidden color picture/hexaquark Yubing Dong, Fei Huang, Pengnian Shen, Zongye Zhang Phys. Lett. B 769 (2017) 223 see T. Skorodko talk for details (next talk this session) T. Skorodko et al. ar. Xiv: 1702. 07212 8

d*(2380) internal structure and the ABC effect L=0 Δ Δ L=2 M. Bashkanov et al, Nucl. Phys. A 958 (2017) 129 10

Deltaron vs Hexaquark 0. 7 fm Narrow width Branching ratios Dalitz plots L=0 Δ Δ L=2 F. Huang et al, Chin. Phys. C 39 (2015) 7, 071001 11

ee- * d*(2380) d Transition form factor Charge distribution Internal structure 12

d*(2380) in photoproduction? d d* p n d d* d Conventional Background M. Egorov, A. Fix, Nucl. Phys. A 933 (2015) 104 -113 M. Guenther Master Thesis, Basel 2015, see Friday 12: 40 talk (meson spectroscopy) T. Ishikawa et al. Phys. Lett. B 772 (2017) 398, see Thu. 15: 35 talk (baryon spectroscopy) 13

Deuteron photodisintegration experiment at MAMI d p n 14

d p n H. Arenhoevel, M. Sanzone “Photodisintegration of the deuteron” 15

p N T. Watabe et al. hep-ph 9502244 R. Beck et al. (MAMI-A 2) Phys. Rev. C 61 (2000) 035204 Analysis of beam asymmetry 16

d p n 17

d p n 18

d*(2380) in photoproduction? R. Gilman and F. Gross nucl-th/0111015 (2001) d* d p n T. Kamae, T. Fujita Phys. Rev. Lett. 38, Feb 1977, 471 H. Ikeda et al. , Phys. Rev. Lett. 42, May 1979, 1321 I(Jp) = 0(3+) 19

The benchmark measurement Edinburgh polarimeter d* d p n Measure polarization of both proton and neutron ! Mikhail Bashkanov "Dibaryons" 20

Experiment p p Target Polarimeter 21

Recoil polarization at 90 degree proton Conventional background, Kang et al background+ d* H. Ikeda et al. , Phys. Rev. Lett. 42, May 1979, 1321 22

Recoil polarization at 90 degree neutron ry a in m ry e V i l e pr background+ d* proton Conventional background, Kang et al background+ d* H. Ikeda et al. , Phys. Rev. Lett. 42, May 1979, 1321 23

Recoil polarization at 90 degree neutron y r a in proton y r e V m i l e r p 24

Nuclear matter at high density Mikhail Bashkanov "Dibaryons" 25

The d ∗ (2380) in neutron stars a new degree of freedom? I. Vidaña, M. Bashkanov, D. P. Watts, A. Pastore ar. Xiv: 1706. 09701 v 1 26

Conclusion �The very first dibaryon d*(2380) is established �Mass, Width, Quantum numbers �Main decay branches �Structure: Hexaquark vs Molecule? �d*(2380) electro-magnetic coupling �Size, Magnetic moment… �Neutron Stars? 27

d*(2380) SU(3) multiplet Jp = 3+ * * 29

Deltaron: the width quest 30

Deltaron: the with quest 31

Deltaron: the with quest see A. Gal, Phys. Lett. B 769 (2017) 436 for details 32

Molecular Picture, A. Gal, Phys. Lett. B 769 (2017) Hidden color picture/hexaquark Yubing Dong, Fei Huang, Pengnian Shen, Zongye Zhang Phys. Lett. B 769 (2017) 223 33

Pure isovector (I=1) Mixed (I=1& I=0) Predominantly isovector Interested in isoscalar part only Proton beam Deuteron target 34

Systematical errors!!!! • Same beam • Same detector • Same deuteron target • Two protons in final state measured in the same kinematics 35

Phys. Rev. D 89 (2014) no. 4, 043014 Phys. Rev. C 90 (2014) no. 6, 065809 Alessandro Drago et al. 36

d Δ 37

eee- * * d*(2380) e * d*(2380) 38