determining the q + quantum numbers through the k + p -> p + kn reaction
DESCRIPTION
Determining the Q + quantum numbers through the K + p -> p + KN reaction. Tetsuo Hyodo a ,. A. Hosaka a , M. J. Vicente Vacas b and E. Oset b. a RCNP , Osaka b IFIC, Valencia. 2003, October 23rd. Contents. Introduction Status of theoretical studies Photo-production process - PowerPoint PPT PresentationTRANSCRIPT
Determining the Determining the ++ quantum numbers quantum numbers through the Kthrough the Kp -> p ->
KN reaction KN reaction
Determining the Determining the ++ quantum numbers quantum numbers through the Kthrough the Kp -> p ->
KN reaction KN reaction
Tetsuo Hyodoa,
a RCNP, Osaka b IFIC, Valencia
2003, October 23rd
A. Hosakaa, M. J. Vicente Vacasb and E. Osetb
ContentsContents
1. Introduction1. Status of theoretical studies2. Photo-production process
2.The K+p -> +K+n(K0p) reaction1. Motivation & advantage2. Model for the reaction3. Numerical results4. Conclusions
3.Future (current) works1. Full calculation2. K* production
IntroductionIntroduction
+ : 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 ): 1/2+, I=0: 1/2, I=0: 1/2+ -> 1/2
: 1/2
Photo-production processPhoto-production process
W. Liu et al. nucl-th/0308034S. I. Nam et al. hep-ph/0308313W. Liu et al. nucl-th/0309023Y. Oh et al. hep-ph/0310117
p -> K0, n -> K
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, exchange,…
Monopole, dipole… , value of , …
coupling, K*p coupling, …
Assuming the quantum numbers (spin, parity), we can calculate a reaction
Motivation and advantageMotivation and advantage
K+p -> ++ -> +K+n(K0p) Low energy model is sufficient (pcm ~ 350 MeV) take decay into account -> background estimation -> Width independent Hadronic process : clear mechanism
We propose
to extract a qualitative behavior which dependson the quantum numbers of .
Determination of quantum numbers
A model for p -> +K+n A model for p -> +K+n
E. Oset and M. J. Vicente Vacas, PLB386, 39(1996)
Vertices are derived from the chiral Lagrangian
Proportional to vanishes
Assume final + is almost at rest
Dominant
DiagramsDiagrams
Tree level(background)
One loop
Possibilities of spin & parityPossibilities of spin & parity
1/2(KN s-wave resonance)1/2,3/2(KN p-wave resonance)
MR = 1540 MeV = 20 MeV
Resonance termResonance term
Amplitude of resonance term for K+p -> +K+n :
Angular dependenceAngular dependence
total resonance background
10
8
6
4
2
0.00.50.0-0.5-.0
cosθ
0
8
6
4
2
0.00.50.0-0.5-.0
cosθ5
4
3
2
0.00.50.0-0.5-.0
cosθ
,I JP=0,/2- ,I JP=0,/2+
,I JP=0,3/2+
Mass distributionsMass distributions
8
6
4
2
0580560540520500
MI
,I JP=0,/2-
,I JP=0,/2+
,I JP=0,3/2+kin( )=850 /Lab MeV cθ=90deg
.4
.2
.0
0.8
0.6
0.4
0.2
0.0580560540520500
MI
Polarization testPolarization test
# Same result is obtained for final pK0
Angular dependence : polarization testAngular dependence : polarization test
total resonance background
5
4
3
2
1
0.00.50.0-0.5-.0
cosθ
20
5
0
5
0.00.50.0-0.5-.0
cosθ5
4
3
2
0.00.50.0-0.5-.0
cosθ
,I JP=0,/2- ,I JP=0,/2+
,I JP=0,3/2+
Polarization test
Mass distributions : polarization testMass distributions : polarization test
14
12
10
8
6
4
2
0580560540520500
MI
,I JP=0,/2-
,I JP=0,/2+
,I JP=0,3/2+kin( )=850 /Lab MeV cθ=90deg
.4
.2
.0
0.8
0.6
0.4
0.2
0.0580560540520500
MI
Polarization test
Incomplete polarizationIncomplete polarization
14
12
10
8
6
4
2
0580560540520500
MI
,I JP=0,/2-
,I JP=0,/2+ kin( )=850 /Lab MeV cθ=90deg
Polarization
100 %80 % 0 %
ConclusionConclusion
We calculate the Kp -> 0KN reaction usinga chiral model, assuming the possible quantum numbers of + baryon. � If we find the resonance with polarization test, the quantum number of + can be determined as I=0, JP=1/2+
T. Hyodo, A. Hosaka, and E. Oset, nucl-th/0307105
Future workFuture work
� Full calculation of the present reaction without approximation of kinematics -> information from + angular dependence� photo-production of K* and V. Kubarovsky et al., hep-ex/0307088
Photo-production of K* and Photo-production of K* and
Preliminary
60
50
40
30
20
10
03.02.52.01.51.00.50.0
θ[ ]rad
0
8
6
4
2
3.02.52.0.5.00.50.0
θ[ ]rad
0.3
0.2
0.
0.03.02.52.0.5.00.50.0
θ[ ]rad
30
25
20
5
0
5
03.02.52.0.5.00.50.0
θ[ ]rad
( ) Angular dependence upper and( ) integrated lower cross sections
of -> *p K- ,K exchangeGeV
:[units μ ]bJP=/2+ JP=/2-