1 / 39

The ABC Effect in Double-Pionic Nuclear Fusion and a pn Resonance as its Possible Origin

This study experimentally explores the ABC effect, a low-mass enhancement in fusion reactions, and suggests a possible origin in the t-channel ΔΔ excitation. The study also investigates the preliminary total cross-section, angular distributions, and invariant mass of the reactions.

hayst
Download Presentation

The ABC Effect in Double-Pionic Nuclear Fusion and a pn Resonance as its Possible Origin

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wasa-at-Cosy The ABC Effect in Double-Pionic Nuclear Fusion and a pn Resonance as its Possible Origin

  2. ABC effect • Experimentally • low-mass enhancement in M • observed in many fusion reactions • accompanied with ΔΔ excitations • Theoretically • originates from t-channel ΔΔ excitation • expected double-hump structure in M (not supported by experimental observations)

  3. n p What we actually did p

  4. p What we actually did   0 d 0  

  5. WASA 4 Detector   d COSY/   

  6. t - channel  Total xsection pp d+0 pn d+- pn d00 (+0)=(I=1) (+-)=0.5(I=1)+2(I=0) (00)=(I=0)=0.2(I=1)

  7. Total x-section preliminary  mass d threshold

  8. 2D x-section preliminary

  9. Δ π d π Δ Δ π p d n π Δ Qualitative description p n +

  10. Total xsection slices: qualitative description preliminary

  11. Total xsection slices: qualitative description preliminary

  12. Total xsection slices: qualitative description preliminary

  13. Total xsection slices: qualitative description preliminary

  14. Total xsection slices: qualitative description preliminary

  15. Total xsection slices: qualitative description preliminary

  16. Total xsection slices: qualitative description preliminary

  17. Total xsection slices: qualitative description preliminary

  18. Total xsection slices: qualitative description preliminary

  19. Total xsection slices: qualitative description preliminary

  20. Total xsection slices: qualitative description preliminary

  21. Total xsection slices: qualitative description preliminary

  22. Total xsection slices: qualitative description preliminary

  23. Total xsection slices: qualitative description preliminary

  24. Total xsection slices: qualitative description preliminary

  25. Total xsection slices: qualitative description preliminary

  26. Total xsection slices: qualitative description preliminary

  27. Total xsection slices: qualitative description preliminary

  28. Total xsection slices: qualitative description preliminary

  29. Total xsection slices: qualitative description preliminary

  30. Angular distributions preliminary

  31. pn  d00 and pp  d+0 (p-spectator) (n-spectator) preliminary

  32. +0 invariant mass Tp  1GeV pp  2He p0p0 preliminary pp  d p+p0

  33. First results on He • December 07 (dd  3He/+X) • Measurements Td=0.8, 0.9, 1.05, 1.117, 1.25, 1.32, 1.4 GeV

  34. dd  4He p0p0 : Invariant Mass p0p0 1.117 GeV 1.05 GeV 0.9 GeV preliminary

  35. Conclusion • ABC effect due to narrow s -channel resonance with • ABC resonance: • eigenstate in isoscalarpn and  systems • can not originate from coherent production on deuteron • robust enough to survive in nuclear medium • More than just a  state ? • Is it a genuine dibaryon? • Is it a member of dibaryonic multiplet?

  36. 1010=35282710 Multiplet Y()=2 I()=0  * *  Kim Maltman, Nucl. Phys. A501 (1989) 843

  37. Outlook • 1.0 GeV ,1.2 GeV ,1.4 GeV – done • Finalization of the data to be done • Perform Partial Wave Analysis (JPC) • Do we need polarization? • Analysis of is on the way • Analysis of to be started • Measure • Measure pn elastic scattering

  38.  * *  Thank you

  39. Total x-section  mass preliminary d threshold

More Related