1 / 18

Determining Quantum Numbers of the Q+ Baryon via K+p → p+K+n Reaction

This study investigates the quantum numbers of the Q+ baryon through the K+p → p+K+n reaction. Utilizing a chiral model, we examine various theoretical approaches, including naive quark models and lattice QCD predictions, to assess the significance of resonance phenomena and their implications for understanding the quantum properties of Q+. By analyzing numerical results and exploring the photo-production process, we aim to clarify the characteristics of Q+, contributing to ongoing research in the field of hadronic physics.

marv
Télécharger la présentation

Determining Quantum Numbers of the Q+ Baryon via K+p → p+K+n Reaction

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. Determining the Q+ quantum numbers through the K+p -> p+KN reaction Tetsuo Hyodoa, A. Hosakaa, M. J. Vicente Vacasb and E. Osetb a RCNP, Osaka b IFIC, Valencia 2003, October 23rd

  2. Contents • Introduction • Status of theoretical studies • Photo-production process • The K+p -> p+K+n(K0p) reaction • Motivation & advantage • Model for the reaction • Numerical results • Conclusions • Future (current) works • Full calculation • K* production

  3. Introduction Q+: 5-quark (4 quark + 1 anti-quark) LEPS, T. Nakano et al., Phys. Rev. Lett. 91 (2003) 012002 Quantum numbers are not yet determined Theory prediction D. Diakonov et al. (chiral quark soliton) Naive quark model S. Capstick et al. (isotensor formulation) A. Hosaka (chiral potential) R. L. Jaffe et al. (qq-qq-q : 10 + 8) J. Sugiyama et al. (QCD sum rule) F. Csikor et al. (Lattice QCD) S. Sasaki (Lattice QCD) : 1/2+, I=0 : 1/2- : 1/2-, 3/2-, 5/2-, I=2 : 1/2+ (strong p) : 1/2+, I=0 : 1/2-, I=0 : 1/2+->1/2- : 1/2-

  4. Photo-production process Assuming the quantum numbers (spin, parity), we can calculate a reaction W. Liu et al. nucl-th/0308034 S. I. Nam et al. hep-ph/0308313 W. Liu et al. nucl-th/0309023 Y. Oh et al. hep-ph/0310117 gp -> K0Q+, gn -> K-Q+ • Model (mechanism) dependence • Form factor dependence • Unknown parameters Initial cm energy ~ 2 GeV (pcm ~ 750 MeV) not low energy -> linear or nonlinear? N* resonances, K* exchange, K1 exchange,… Monopole, dipole… , value of L, … gQQ coupling, K*pQ coupling, …

  5. Motivation and advantage We propose K+p -> p+Q+ -> p+K+n(K0p) • Low energy model is sufficient (pcm ~ 350 MeV) • take decay into account -> background estimation -> Width independent • Hadronic process : clear mechanism to extract a qualitative behavior which depends on the quantum numbers of Q+. Determination of quantum numbers

  6. A model for K+p -> p+K+n E. Oset and M. J. Vicente Vacas, PLB386, 39(1996) Vertices are derived from the chiral Lagrangian Proportional to vanishes Dominant Assume finalp+is almost at rest

  7. Diagrams Tree level (background) One loop

  8. Possibilities of spin & parity 1/2-(KN s-wave resonance) 1/2+,3/2+(KN p-wave resonance) MR = 1540 MeV G = 20 MeV

  9. Resonance term Amplitude of resonance term for K+p -> p+K+n :

  10. Angular dependence

  11. Mass distributions

  12. Polarization test # Same result is obtained for final pK0

  13. Angular dependence : polarization test

  14. Mass distributions : polarization test

  15. Incomplete polarization 100 % 80 % 0 %

  16. Conclusion We calculate theK+p -> p0KN reaction using a chiral model, assuming the possible quantum numbers of Q+ baryon. • If we find the resonance with polarization • test, the quantum number of Q+ can be • determined as I=0, JP=1/2+ T. Hyodo, A. Hosaka, and E. Oset, nucl-th/0307105

  17. Future work • Full calculation of the present reaction • without approximation of kinematics • -> information from p+ angular dependence • photo-production of K* and Q • V. Kubarovsky et al., hep-ex/0307088

  18. Photo-production of K* and Q Preliminary

More Related