Upload
chelsa
View
59
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Hyun-Chul Kim. meson photoproduction with hadron rescattering. Department of Physics Inha University. In collaboration with H.Y. Ryu, A. Hosaka, A. Titov. EFB 22, Sept. 10, 2013@Kraków. Motivation. OZI rule violation. - Gluonic dynamics ( Pomeron ) - Hidden strangeness. - PowerPoint PPT Presentation
Citation preview
Hyun-Chul KimDepartment of Physics
Inha University
In collaboration with H.Y. Ryu, A. Hosaka, A. Titov
EFB 22, Sept. 10, 2013@Kraków
meson photoproduction with hadron rescattering
Motivation
OZI rule violation- Gluonic dynamics (Pomeron)- Hidden strangeness• Usual vector-meson exchanges are forbidden by the charge conjugation.• Hybrid exotic vector mesons (C=+1) are allowed but not much data.
Motivation
텍스트
This bump structure cannot be explained by the pomeron and one meson-exchange picture!
Motivation
Motivation
• How to explain the bump structure around the K Lambda(1520) threshold.
• How to describe the production mechanism near the threshold in place of the pomeron.
In the present talk, we propose possible coupled-channel effects that may explain the phi photoproduction mechanism near the threshold region.
Summary of previous works Titov et al. PRC 60, 035205 (1999): Structure of the phi photoproduction
• Ordinary vector-meson exchange is forbidden.
• The pomeron governs the energy dependence of the differential cross section, though it is theoretically plausible only at higher energies.
Summary of previous works• Mibe et al. PRL, 95, 182001 (2005): phi diffractive photoproduction near the threshold
• Ozaki et al. PRC 80, 035201 (2009): K-matrix method (Coupled-channel)
• Chang et al. PRC 82, 015205 (2010): Measurement of the spin-density matrices
• Kiswandhi et al. PLB 691, 214 (2010): Possible N*(2080) resonance with large strangeness
Effective Lagrangian methodsDescribe hadron processes in terms of effective degrees of freedom: Quark-gluon dynamics are encoded in the coupling constants and form factors.
S.i. Nam, A. Hosaka, HChK, Phys. Rev. D 71, 114012 (2005) S.i. Nam, K.S. Choi, A. Hosaka, HChK, D 75, 014027 (2005)
Effective Lagrangian methodsInvariant amplitude
Production MechanismA. Titov et al. PRC 60, 035205 (1999)
Conventional approach
Pomeron
t-channel hadron exchange
Present approachRescattering amplitudes
Rescattering equationHadronic part
Blankenbecler-Sugar type scattering equation
Rescattering equationRescattering part in a coupled-channel formalism
Rescattering equationRescattering part in a coupled-channel formalism
In this work, we will consider only the imaginary part for simplicity,
to see the reliability of the present method. The full computation is under way.
Rescattering amplitudes
Most important term
=
+
Numerical results
HadronsHadrons + Pomeron
Differential Cross Sections
No Pomeron contribution (E = 2 GeV). Hadronic process can explain the angular distribution.
Differential cross sections
• Mibe et al. PRL, 95, 182001 (2005)
Spin-density matrices
Spin-density matrices
In general, spin-density matrices near the threshold region are well described.
Decay angular distributions
C.M. system
Gottfried-Jackson system
Definition of angles
Decay angular distributions
Decay angular distributionsT. Mibe et al. [LEPS
Collaboration], PRL 95, 182001 (2005)
23
Summary and Outlook
• We investigated phi photoproduction, emphasizing the significance of the rescattering contributions, in particular, the K Lambda(1520) channel.
• The K Lambda (1520) plays a dominant role. • However, we have considered here only the imaginary
part of the rescattering amplitudes, to see their importance.
• The real part of the rescattering amplitudes are under investigation, and it seems even more important. The corresponding work will soon appear.
Thank you very much!
Though this be madness,yet there is method in it.
Hamlet Act 2, Scene 2