v.k.lukyanov, e.v.zemlyanaya, k.v.lukyanov
DESCRIPTION
THE K + -NUCLEUS MICROSCOPIC OPTICAL POTENTIAL AND CALCULATIONS OF THE CORRESPONDING DIFFERENTIAL ELASTIC AND TOTAL REACTION CROSS SECTIONS. V.K.LUKYANOV, E.V.ZEMLYANAYA, K.V.LUKYANOV Joint Institute for Nuclear Research, Dubna 141980, Russia; K.M.HANNA - PowerPoint PPT PresentationTRANSCRIPT
THE K+-NUCLEUS MICROSCOPIC OPTICAL POTENTIAL AND CALCULATIONS OF THE CORRESPONDING DIFFERENTIAL ELASTIC AND TOTAL REACTION CROSS SECTIONS
V.K.LUKYANOV, E.V.ZEMLYANAYA, K.V.LUKYANOVJoint Institute for Nuclear Research, Dubna 141980, Russia;
K.M.HANNAMath. and Theor. Phys. Dep., NRC, Atomic Energy Authority, Cairo, Egypt
On the Kaon interaction with nuclei
suK
suK
p=uud n=udd- weaken K+N interaction
- strong K-N interaction
• Comparison of total cross sections at T ~ 0.2-1.0 GeV
K+N ~ 10 mb NN ~ 50 mb ~ 100 mb
• The mean free path in nuclear matter
lK+N ~ 5-6 fm lNN ~ 1-1.5 fm ~ 0.8 fm
• Thus a folding potential is available for K+A interaction
1
~l
• klab > mK+= 0.494 GeV
• The semi-relativistic wave equation with U=Uopt+Uc
• k – relativistic momentum in c.m. system
• – relativistic correction factor
• - (non)relativistic reduced mass, M1= 1*m1
Relativization approach for K+ + A scattering
Microscopic optical potential (OP)
• Microscopic OP obtained in *) from the optical limit of the Glauber
theory
=k/E - relative velocity in the system
• – the KN total cross section
• =Re FK(0)/Im FK(0) – with FK , the KN amplitude
(q) – unfolded nuclear form factor
*) Phys.At.Nucl. 69 (2006) 240
The K+N scattering amplitude
The K+N scattering amplitude is parameterized as
follows
For example, in the case of klab=0.8 GeV/c one has
K
Input values for K+ + 12C,40Ca
Relativistic momentum in c.m. system
Correlation factors
Ingemarsson, 1974
Faldt, Ingemarsson, Mahalanabis, 1992
Goldberger, Watson, 1964
(r1)
(r2)
(r3)
(r4)
Calculated microscopic OP (at r=1)
Differential elastic cross sections K++40Ca (0.8 GeV/c)
r = 367 mb
r(r=1) = 245 mb
Differential elastic cross sections K+ + 12C
r(r=1) = 93 mb
r = 125 – 129 - 129 mb
rexp = 140 – 155 mb
Role of the U2/2E corrections in the full OP
r(635) = 125 128 mb
r(715) = 129 132 mb
r(800) = 129 131 mb
Effect of density distributions on cross sections
Phys.At.Nucl, 67 (2004)
Nucl.Phys. A 717 (2003)
Nucl.Phys. A 438 (1985)
r(635) = 125 + 1% mb
r(715) = 129 + 1% mb
r(800) = 129 + 1% mb
The surface term (-gr dU/dr) of OP
g = 0 r = 130 mb
g = 0.06 r = 140 mb
g = 0.13 r = 153 mb rexp
= 155 mb
Effect of (-gr d(Im U)/dr) on cross sections
g = 0 r = 125 mb
g = 0.07 r = 140 mb
rexp
~ 140 mb
g = 0 r = 129 mb
g = 0.1 r = 149 mb
rexp
~ 150 mb
Summary
Microscopic model of OP doesn’t use free parameters
Relativistic effects are very important to get the agreement with the existing experimental data
Problem is still open on the “in-medium” effects on K+N amplitude
Model can be improved by addition the surface terms to optical potential
Model is proved to be a workable one for predictions of the K++A scattering cross sections.
Thank you!