1 / 23

ISOSPIN-MIXED X HYPERNUCLEAR STATES AND (K,K) REACTIONS

ISOSPIN-MIXED X HYPERNUCLEAR STATES AND (K,K) REACTIONS. Dmitry Lanskoy Institute of Nuclear Physics Moscow State University. INPC2007, Tokyo, June 6.

arva
Download Presentation

ISOSPIN-MIXED X HYPERNUCLEAR STATES AND (K,K) REACTIONS

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. ISOSPIN-MIXED X HYPERNUCLEAR STATES AND (K,K) REACTIONS Dmitry Lanskoy Institute of Nuclear Physics Moscow State University INPC2007, Tokyo,June6

  2. *Isospin mixing in X hypernuclei and Lane potentialwith Y.Yamamoto (Tsuru Univ)*The (K-,K0) versus (K-,K+) reaction on nuclei*Phenomenological model for the elementary processes with V.Korotkikh, D.Sharov (Moscow Univ)

  3. X HYPERNUCLEI AZ with Z=(A-1)/2 (mirror cores) X Pure X charge states Pure isospin states A(Z+1)+X- V0+V1(tT) AZ, T=1 X D AZ+X0 X0n-X-p coupling M(X-)- M(X0)=6.48±0.24 MeV AZ, T=0 X

  4. X HYPERNUCLEI AZ with Z=(A-1)/2 (mirror cores) X ??? Pure X charge states Pure isospin states A(Z+1)+X- V0+V1(tT) AZ, T=1 ??? X D AZ+X0 M(X-)- M(X0)=6.48±0.24 MeV AZ, T=0 X D, MeV (without Lane potential V1) X X X X X X X X

  5. X HYPERNUCLEI AZ with Z=(A-1)/2 (mirror cores) X Pure X charge states Isospin-mixed states A(Z+1)+X- AZ a|T=1>-b|T=0> V0+V1(tT) X D AZ+X0 AZ a|T=0>+b|T=1> M(X-)- M(X0)=6.48±0.24 MeV X D, MeV X X X X X X X X

  6. Calculational scheme Single-channel X wave functions are calculated by a folding procedure with G-matrix XN interactions obtained from various meson-exchange (mostly Nijmegen) potentials core wave functions from a Skyrme-Hartree-Fock calculation Density dependence of the XN interaction is taken into account within LDA; nonlocality is treated in the effective mass approximation Lane potential arises from the X0n-X-p coupling or, equivalently, from the isospin dependence of the XN interaction

  7. Results for the ESC04d model (strong Lane potential) 12B(1sX) 40K(1sX) X X 11C+X- threshold p(T=0)=8% p(T=0)=21% BX0=-2.1 MeV BX0=6.0MeV 11B+X0 threshold p(T=0)=92% p(T=0)=79% BX0=6.8 MeV BX0=10.8 MeV

  8. Results for the ESC04d model (strong Lane potential) 12B(1sX) 40K(1sX) X X 11C+X- threshold p(T=0)=8% p(T=0)=21% BX0=-2.1 MeV BX0=6.0MeV 11B+X0 threshold p(T=0)=92% p(T=0)=79% BX0=6.8 MeV BX0=10.8 MeV Results for various potential models (the lower state) Ehime 51% ESC04c 72% Ehime 53% NHCD 58% ESC04c 81% ESC04d 92% NHCD 56% ESC04d 79% p(T=0)=50% (pure X charge state) p(T=0)=100% (pure isospin state) p(T=0)=50% p(T=0)=100%

  9. hypernuclei with Z=(A-1)/2 can be produced in the (K-,K0) (not in the (K-,K+)) reaction from Z=N targets The (K-,K0) reaction is more complicated both for experiment (neutral particle detection is needed) and for theory: X hyperon can be produced on protons as well as on neutrons K-p→K0X0 K-p→K+X- K-n→K0X-

  10. |A(Z-2)>=|(A-1)(Z-1)+X-> AZ(K-,K+)A(Z-2) reaction X X ds dW ds dW (K-p→K+X-) ·Zeff = AZ(K-,K0)A(Z-1) reaction |A(Z-1)>=cosq|(A-1)(Z-1)+X0>+sinq|(A-1)Z+X-> X X ds dW ds dW ds dW ds dW (K-p→K0X0)·Zeff·cos2q + (K-n→K0X-)·Neff·sin2q = +(f(K-p→K0X0)f*(K-n→K0X-)+c.c.)(ZeffNeff)½cos q·sin q From isospin algebra ds dW (K-p→K0X0) f(K-p→K0X0)f*(K-n→K0X-)+c.c.= ds dW ds dW + (K-n→K0X-) - (K-p→K+X-)

  11. Effective numbers of protons and neutrons pK=1.8 GeV/c, forward angle DWIA + eikonal approximation ESC04d model 12C(K-,K0)12B 40Ca(K-,K0)40K X X Zeff 1.7·10-3 1.9·10-4 Neff 2.0·10-3 2.8·10-4

  12. Effective numbers of protons and neutrons pK=1.8 GeV/c, forward angle DWIA + eikonal approximation ESC04d model 12C(K-,K0)12B 40Ca(K-,K0)40K X X Zeff 1.7·10-3 1.9·10-4 Neff 2.0·10-3 2.8·10-4 But empirical data on the elementary reactions are too poor, especially on the K-n→K0X- reaction Therefore, we need a theoretical model

  13. X0 X- K‾ K‾ S L,S p p K0 K+ X- K‾ L,S n K0 Phenomenological u channel exchange model Exchanged hyperons: Y=Λ, Λ(1520), Σ, Σ(1385) 8 fitted parameters: 4 products of the coupling constants fKNYfKXY and 4 cut-off parameters Fit was performed to available data on differential and integral cross sections at Ecm<3.2 GeV c2=871 for 374 points

  14. Results for the K-p→K+X-reaction Integral cross section versus cm energy Differential cross sections at various cm energies

  15. Results for the K-p→K0X0reaction Integral cross section versus cm energy Differential cross sections at various cm energies

  16. Forward differential cross section for hypernuclear production pK=1.8 GeV/c 12C(K-,K+)12Be 12C(K-,K0)12B 40Ca(K-,K0)40K X X X ESC04d model (strong mixing) Lower (ground) state 70 nb/sr 37 nb/sr 4 nb/sr Upper state 5 nb/sr 1 nb/sr Ehime model (almost pure X charge states) Lower (ground) state 67 nb/sr 23 nb/sr 6 nb/sr Upper state 20 nb/sr 5 nb/sr

  17. Summary In X hypernuclei with Z=(A-1)/2, mixed states appear, which possess neither pure isospin, nor pure X charge. Such hypernuclei can be produced in the (K-,K0) reaction from Z=N targets. Cross sections of the (K-,K0) reaction are of the same order of magnitude as those of the (K-,K+) reaction (though somewhat smaller) and are strongly dependent on the isospin mixing. A simple phenomenological u channel exchange model of the elementary processes gives fairly good description of available data and provides information necessary for hypernuclear calculations.

  18. Summary In X hypernuclei with Z=(A-1)/2, mixed states appear, which possess neither pure isospin, nor pure X charge. Such hypernuclei can be produced in the (K-,K0) reaction from Z=N targets. Cross sections of the (K-,K0) reaction are of the same order of magnitude as those of the (K-,K+) reaction (though somewhat smaller) and strongly dependent on the isospin mixing. A simple phenomenological u channel exchange model of the elementary processes gives fairly good description of available data and provides information necessary for hypernuclear calculations. Thank you!

  19. Backup slides

  20. Kinematics of hypernuclear production Q=00

  21. Results for the K-n→K0X-reaction Integral cross section versus cm energy Differential cross sections at various cm energies

  22. Effective Lagrangians Formfactors F(q)=e-(q/L)2 Fitted parameters L(1116): fKNLfKXL= 0.151; L= 809 MeV L(1520): fKNLfKXL=-0.346; L=1141 MeV S(1190): fKNSfKXS=-0.405; L= 692 MeV S(1385): fKNSfKXS= 0.196; L=1261 MeV

  23. Forward differential cross section for hypernuclear production pK=1.8 GeV/c 40Ca(K-,K0)40K 12C(K-,K+)12Be 12C(K-,K0)12B X X X ESC04d* model Lower state 31 nb/sr 16 nb/sr 1 nb/sr Upper state 3 nb/sr 0.2 nb/sr ESC04c model Lower state 7 nb/sr 4 nb/sr 0.06 nb/sr Upper state 1 nb/sr 0.01 nb/sr NHCD1 model Lower state 123 nb/sr 45 nb/sr 13 nb/sr Upper state 35 nb/sr 10 nb/sr NHCD2 model Lower state 70 nb/sr 26 nb/sr 10 nb/sr Upper state 20 nb/sr 8 nb/sr

More Related