1 / 27

Presented by L. Tauscher Basel University, Switzerland

Using  -  and  -K atoms for the experimental check of low-energy QCD L. Nemenov (CERN, Switzerland). Presented by L. Tauscher Basel University, Switzerland. Why atoms ?. Particles scatter off each other in well defined atomic quantum states

nakia
Download Presentation

Presented by L. Tauscher Basel University, Switzerland

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. Using - and -K atoms for the experimental check of low-energy QCD L. Nemenov (CERN, Switzerland) Presented by L. Tauscher Basel University, Switzerland L. Nemenov, EXA05

  2. Why atoms ? • Particles scatter off each other in well defined atomic quantum states • Very low Q’s  atomic level scheme sensitive to scattering length Strong interaction leads to complex energy eigenvalues Enl - iGnl/2 = EnlQED + enl - iGnl/2 Example: pp e1S 2a0 + a2G1S |a0 - a2|2 “Model-independent” determination of scattering lengths L. Nemenov, EXA05

  3. Experimental status on pp K++-e+ve (Ke4)  phase difference d00(s)-d11(s) for 4mp2<s<mK2 a0 = 0.26 ± 0.05[mp-1] Roy eq. Rosselet et al. CERN 1977 a0 = 0.203 ± 0.033[mp-1] Roy eq. Pislak et al. BNL / E865 a2 = -0.055 ± 0.023[mp-1] 2001/2003 a0 = 0.216 ± 0.013stat ± 0.004syst ± 0.002th [mp-1] Roy eq a2 = from ChPT DIRAC (A2p) after analysis of ALL collected data so far s|a0-a2| ± 5%stat(± 3%syst ± 2%th)estimated  ± 0.013stat(± 0.008syst ± 0.005th)estimated L. Nemenov, EXA05

  4. Theory pp a0 = 0.220 ± 0.005 [mp-1] (2.3%) a2 = -0.0444 ± 0.0010[mp-1] (2.3%) a0- a2 = 0.265 ± 0.004 [mp-1] (1.5%) L. Nemenov, EXA05

  5. Theory pK L. Nemenov, EXA05

  6. Experimental status on pK In the 60’s and 70’s set of experiments were performed to measure πK scattering amplitudes.Most of them were done studying the scattering of kaons on protons or neutrons, and later also on deuterons. The kaon beams used in theseexperiments had energies ranging from2 to 13 GeV. The main idea of those experiments was to determine the contribution of the One PionExchange (OPE) mechanism. This allows to obtain the πK scattering amplitude. Analysis of experiments gave the phases of πK-scatteringin the region of 0.7≤m(πK) ≤ 2.5 GeV. The most reliable data on thephases belong to the region 1 ≤m(πK) ≤ 2.5 GeV. L. Nemenov, EXA05

  7. Theoretical accuracy on atomic quantities L. Nemenov, EXA05

  8. Theoretical accuracy on atomic quantities L. Nemenov, EXA05

  9. Principle of lifetime measurement L. Nemenov, EXA05

  10. Pbr to lifetime conversion L. Nemenov, EXA05

  11. DIRAC II (Addendum) L. Nemenov, EXA05

  12. DIRAC II Set-up L. Nemenov, EXA05

  13. DIRAC II Set-up • Decrease the systematic errors. • Single–multilayer targets • Identification of e±,  ±, K ± and p • Increasing of statistics and efficiency of the setup • Shielding K ≈ 1.9 • Formation of time structure of the spillwith the trigger of setup • Microdriftchambers • New electronics for SFD • Increase in the aperture on VH hodoscopeand PSH • Total K ≈ 4 L. Nemenov, EXA05

  14. Metastables L. Nemenov, EXA05

  15. Metastables L. Nemenov, EXA05

  16. Metastables L. Nemenov, EXA05

  17. Metastables L. Nemenov, EXA05

  18. Metastables L. Nemenov, EXA05

  19. Metastables L. Nemenov, EXA05

  20. Metastables L. Nemenov, EXA05

  21. Metastables L. Nemenov, EXA05

  22. Metastables L. Nemenov, EXA05

  23. Prospects beyond DIRAC II • Measure at machines with • higher proton current • Higher duty factor • Higher energy L. Nemenov, EXA05

  24. Yields of atoms as a function of the proton beam momentum L. Nemenov, EXA05

  25. *) Precision of Pbr=f(t) can be increased to better then 0.6% private communication by D.Trautmann L. Nemenov, EXA05

  26. *) Precision of Pbr=f(t) can be increased to better then 0.6% private communication by D.Trautmann L. Nemenov, EXA05

  27. Conclusions L. Nemenov, EXA05

More Related