assoiated production. hyperon photoproduction lambda polarization normal to production plane...
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Assoiated production
Hyperon photoproduction
Lambda polarization
●normal to production plane (parity!!)●weak decay:
Sigma polarization
Hyperon polarization in photoproduction
Hyperon polarization in photoproduction
Hyperon polarization in photoproduction
Michael Ostrick, Universität Bonn
pseudoscalar mesons γ p → p π0 , γ p→ p η
strangeness γ p→ K Λ, γ p→ K Σ
Selected results:
Photoexcitation of N*/∆*-resonances
Extraction of resonance parameters
Michael Ostrick, Universität Bonn
amplitude analyses → resonance parameters
● single-channel isobar models (e.g. MAID)
● multi-channel approaches SAID, Giessen-coupled-channel-model
dynamical models → relation of N* parameters to quark-models, lattice QCD
Bonn-Gatchina (A. Sarantsev et al. hep-ph/0407211)•isobar analysis (Breit-Wigner/K-matrix)•u- and t-channel•relativistically invariant•analyticity/(unitarity)
Michael Ostrick, Universität Bonn
N*/∆* resonances in PWA
N* ∆*
selected results: π0 and η photoproduction
Michael Ostrick, Universität Bonn
ELSA
Michael Ostrick, Universität Bonn
PRL 94(2005)012004
γ p → p π0
Δ(1232)
Michael Ostrick, Universität Bonn
PRL 94(2005)012004
γ p → p π0
Data in PWA:
Crystal-Barrel π0 & η
TAPS/MAMI π0 & η (low energy)
GRAAL π0 & η lin. polarization
Bonn γp → nπ+
(isospin !)
Δ(1232)
Michael Ostrick, Universität Bonn
PRL 94(2005)012004
S11(1535)D13(1520)2-3% P11(1440)
D33(1700)F15(1680)S11(1650) F37(1950)
P33(1920)
γ p → p π0
Δ(1232)
Michael Ostrick, Universität Bonn
PRL 94(2005)012004
Δ(1232)
S11(1535)D13(1520)2-3% P11(1440)
D33(1700)F15(1680)S11(1650) F37(1950)
P33(1920)
γ p → p π0
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η
MAMI
GRAAL
CLAS
CB-ELSA
PWA
S11
(1535)
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η
MAMI
GRAAL
CLAS
CB-ELSA
PWA
S11
(1535)
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η: PWA
P13
(1720)
S11
(1535)
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η: PWA
P13
(1720)
S11
(1535)
No 3rd S11
needed
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η: PWA
P13
(1720)
proposed "new"
D15
(2070)
m = 2068 ± 22 MeVΓ = 295 ± 40 MeV
S11
(1535)
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η: PWA
P13
(1720)
proposed "new"
D15
(2070)
m = 2068 ± 22 MeVΓ = 295 ± 40 MeV
5/2-
1/2-
1/2+
S11
(1535)
Michael Ostrick, Universität Bonn
PRL 94(2005)012003
γ p → p η: PWA
P13
(1720)
proposed "new"
D15
(2070)
m = 2068 ± 22 MeVΓ = 295 ± 40 MeV
5/2-
1/2-
1/2+
S11
(1535)
(double) polarization
observables !
Michael Ostrick, Universität Bonn
γ p → p η: double polarization
long. pol. target, circ. pol γ : helicity 1/2 - 3/2
long. pol. target, lin. pol γ :
5/2-
1/2-
1/2+
Michael Ostrick, Universität Bonn
strangeness production
p p
p p X
SAPHIR: EPJ A 19, 251 (2004) EPJ A 24, 275 (2005)
γ p → K+ Λγ p → K+ Σ0
γ p → K0 Σ+
Michael Ostrick, Universität Bonn
strangeness production
γ p → K+ Λ
energy dependent discrepancy up to 20% between SAPHIR and CLAS
Michael Ostrick, Universität Bonn
strangeness production
γ p → K+ Λ
energy dependent discrepancy up to 20% between SAPHIR and CLAS
PWA fit with the same N*/∆* states as in π0 and η production is possible (hep-ex/0506011)
Michael Ostrick, Universität Bonn
strangeness production: γ p → K+ Λ
Linear rise -> s,p wave interference!
Michael Ostrick, Universität Bonn
strangeness production: γ p → K+ Λ
S11
(1650)
P13
(1720)
P11
(1710)?
new P11
(1840)?
Linear rise -> s,p wave interference!
Michael Ostrick, Universität Bonn
strangeness production: γ p → K+ Λ
D13
(1895) ?
(P11
(1900) ?3rd S
11 (1900) ?)
S11
(1650)
P13
(1720)
P11
(1710)?
new P11
(1840)?
Michael Ostrick, Universität Bonn
strangeness production: γ p → K+ Λ
D13
(1895) ?
(P11
(1900) ?3rd S
11 (1900) ?)
S11
(1650)
P13
(1720)
P11
(1710)?
new P11
(1840)?
Michael Ostrick, Universität Bonn
strangeness production: γ p → K Σ
∆(1700)D33
∆(1940)D33
N(1840)P11
γ p → K+ Σ0 γ p → K0 Σ+
Main resonance contributions:
Michael Ostrick, Universität Bonn
strangeness production: γ p → K Σ
∆(1700)D33
∆(1940)D33
N(1840)P11
γ p → K+ Σ0 γ p → K0 Σ+
Main resonance contributions:
(double) polarization
and
electroproduction!
Michael Ostrick, Universität Bonn
photoexcitation of N*/∆* resonances
N* ∆*
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