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Wasa- at - COSY. Investigations of the Basic double- pionic fusion in the region of the ABC effect. Mikhail Bashkanov. Content. Double- pionic fusion The ABC-effect ABC Resonance in Quantum numbers Isospin decomposition , Resonance structure in the open channel
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Wasa-at-COSY Investigations of the Basic double-pionic fusion in the region of the ABC effect Mikhail Bashkanov
Content • Double-pionic fusion • The ABC-effect • ABC Resonance in • Quantum numbers • Isospin decomposition • , • Resonance structure in the open channel • Resonance in elastic scattering
Fusion n n p p g
Double-pionic fusion g g n n p p p p g g
Double-pionic fusion n n p p p p
The ABC-effect n n p p p p
History of the ABC effect Low mass enhancement in M P. Adlarsonet. al, Phys. Rev. Lett. 106 (2011) 242302 M.Bashkanovet. al, Phys. Lett. B637 (2006) 223-228 P. Adlarsonet. al, Phys. Rev. C86(2012) 032201 • Alexander Abashian, Norman E. Booth Kenneth M. Crowe, Phys. Rev. Lett. 5, 258 (1960)
Total cross section pn d00 “ABC resonance” 70 MeV NN*(1440) P. Adlarson et. al Phys. Rev. Lett. 106:242302, 2011
M for different energies t-channel “ABC effect”
Angular distribution in the peak J=3 J=1
1+ 3+ Quantum numbers of the structure pn R d 00 Antisymmetrization: Jp=1+or 3+ : if LΔΔ=0 1+ excluded by ().3+ assigned pn d 00 I=0 I=0,1 I=0 I=0,2
Δ π p d π n Δ Status ofTheoretical Description • pn R DD dp0p0 I(Jp) = 0(3+)
Isospinrelations I=1 I=0
Total cross section pN d P. Adlarson et. al Phys. Lett. B721 (2013) 229
pn pp-0 Conventional process +ABC Conventional process Preliminary ABC “expected”
3+Resonance in pn p n L=2 p n L=4
dpnp + psp Kinematics neutron Proton spectator proton
Total pncross-section Devlin et al, PRD8, 136 (73) LisowskI et al, PRL49, 255(82) SAID SAID + resonance
p p n n Expectations SAID with resonance SAID
p p n n Expectation SAID with resonance SAID SAID with resonance
p p n n Reality SAID with resonance SAID SAID with resonance
pn Vector Analysing power Very Preliminary SAID with resonance SAID with resonance SAID
Conclusion • ABC-resonance is seen in • pn-elastic scattering exhibits fast phase motion • Good hints for a resonance in elastic channel • A discovery of a new resonance? • Dibaryon: , ,
1010=35282710 Multiplet Y()=2 I()=0 * * Kim Maltman, Nucl. Phys. A501 (1989) 843
Mirror dibaryon d* I(Jp) = 0(3+) I(Jp) = 3(0+) D D D D d d u u d u u u u u u u
1010=35282710 Mirror Multiplet -- ++++ * **+* **+ **+* *