1 / 25

ハドロン原子のカスケード過程

2006 年 3 月 1 日　「 QCD とハドロン物理の新展開」研究会 , KEK. ハドロン原子のカスケード過程. 理研　岩崎先端中間子研究室　　 小池　貴久. Today’s topics ★ X-ray spectrum of X - - 12 C atoms for J-PARC ★ K - mass mesurement using K - - 14 N atom x-rays at DA F NE. ◆ Exotic Atom / Hadronic Atom / Mesic Atom.

denise
Download Presentation

ハドロン原子のカスケード過程

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. 2006年3月1日　「QCDとハドロン物理の新展開」研究会, KEK ハドロン原子のカスケード過程 理研　岩崎先端中間子研究室　　 小池　貴久

  2. Today’s topics ★ X-ray spectrum of X --12C atoms for J-PARC ★K- mass mesurement using K--14N atom x-rays at DAFNE ◆Exotic Atom / Hadronic Atom / Mesic Atom X- = m -, p -, K-, p, S-, X-, W-, … ・ Hypernucleus formation --- stoppedK-, X- reactions ・ Some exotic structures --- long-lived p-4He --- deeply bound nuclear state ・ X-ray spectroscory --- deducing X--nucleus strong interaction, X- mass, nuclear radius, … etc. ・ Collison problem of unusual atoms/molecules

  3. Part. I Cascade Calculation ofK--14N Atom --- for the precise K- mass mesurement planned at DAFNE.

  4. Cited from Particle Data Group Review; S. Eidelman et. al, Phys. Lett. B592, 1 (2004) ←C ←Pb, W ←K (potassium) ←Pb ←Au, Ba Most two recent data differ 60 KeV, although their uncertainties are about 10 KeV ! New mass mesurement using kaonic nitrogen atom x-rays is planned at DAFNE.

  5. ~ 0.1 eV diff. in 6-5 x-ray energy ~10 keV diff. in kaon mass Electron screening effect becomes crucial for determing kaon mass within 10 keV errors!

  6. ◆ Problem on the precise mass determination ・ The electron screening effect of the x-ray energy can not be acculately evaluated without the knowledge of; How many electron remain at the moment of x-ray emmision? The DAFNE measurement uses the gaseouse nitrogen target at the density r = 3.4 rNTP. Complete ionization ??? --- not sure… ・ The atomic cascade calculation including electron refilling prosess enables us to determin the electron configration.

  7. ~48 for X --12C X --12C

  8. Pick-up from outside K- Na(t) G 1s-Augf1s(t) + G 2s-Augf2s(t) + G 2p-Augf2p(t) radiative Na’(t) ◆Our electron refilling model e e f2p(t) e e f2s(t) KLL-Auger f1s(t)

  9. ◆ Auger transition b d a c ・Multipole expansion

  10. ・LS coupling scheme ・using analytic hydrogen-like atom wave functions with the effective charge Z*. ・ Z*is estimatedusing semi-emprical rule.

  11. ◆ Kaon-electronAuger transition rate formulas ・ Auger transition rate for ejecting one1s-electron ・ Auger transition rate for ejecting one2s-electron ・ Auger transition rate for ejecting one2p-electron

  12. kaon population n l

  13. One electron remains with the prob. of ~4% at n = 6.

  14. K-shell filled cases

  15. K-shell half-filled cases

  16. K-shell empty cases

  17. Part.II Cascade Calculation ofX--12C Atom --- for the S=-2 strangeness nuclear physics sector at J-PARC.

  18. ◆ Twin L-hypernucleus fomation events in KEK-PS E176 ・Yokohama event ・Korea event interpreted as the nuclear absorption from X--12C atom 2p-state, assuming Woods-Saxon typeof X- - nucleus potential with V0 ~ -16 MeV.

  19. “attractive shift” “repulsive shift” V0 = -16 MeV case V0 = -24 MeV case ・ X--nucleus strong interaction → Woods-saxon potential V0 : parameter, W0 = -1 MeV, Rreal = 1.1×A1/3 fm, Rimag = 0.9×A1/3 fm, a = 0.65 fm

  20. (V0 = -16 MeV case)

  21. ◆ Calculated decay profile of 12C-X- atom

  22. Same as 16 MeV case Same as 16 MeV case ◆ Calculated x-ray yields for 12C-X- atom

  23. ・Natural line width is taken into account. ・No detector resolution. ・No buckground. Preliminary calculation Detectable ???

  24. ◆ Summary ・ The atomic cascade code of exotic atoms with many electrons has been developed . Topic 1: K- mass mesurement using K--14N atom 6 → 5 x-ray at DAFNE ・ The electron configration at the moment of the x-ray emmision is important to achive the desired accuracy (~10 keV). ・ Only 1 electron remains in 1s-orbit with the probabilie of 4% under the DAFNE condition (gas, r = 3.4 rNTP). ・The complicated electron configrations at high density target. Topic 2: X-ray spectroscopy of X--12C atom at J-PARC. ・ 2p-state; V0= -16 MeV → attractive shift, -24 MeV → repulsive shift. ・ 3d→2p x-ray yields = 1~2 % per stopped X-. ・ The expected x-ray spectrum can be calculated. ・ Is there any other suitable atoms? --- more studies are now in progress.

More Related