1. The data status on p+p-p photo/electro- production with the CLAS
V.I. Mokeev
Jefferson Lab
The data are available in the CLAS Physics Data Base:
JPAC Meeting June

2. The CLAS Data on p+p-p Differential Cross Sections at 1. 30<W<1
The CLAS Data on p+p-p Differential Cross Sections at 1.30<W<1.57 GeV; 0.2<Q2<0.6 GeV2 and at 1.40<W<2.30 GeV; 0.5<Q2<1.5 GeV2
full JM calc.
p+D0
p-D++
2p direct
Published data: G.V.Fedotov et al. (CLAS Collaboration), Phys. Rev. C 79, (2009).
M.Ripani et al. (CLAS Collaboration), Phys. Rev. Lett. 91, (2003).
N(1440)1/2+ and N(1520)3/2- electrocouplings from Npp: V.I. Mokeev et al. (CLAS Col-
laboration), Phys. Rev. C 86, (2012).

3. Future studies of p+p-p photoproduction
p+p-p Photoproduction, CLAS Preliminary
Search for the 3/2+(1720) in photoproduction
data:
JM14’ model (fit of differential cross
section)
Bonn-Gatchina approach (event based
likelihood analysis), U.Thoma, A.Sarantsev,
et al.
Exploratory fit
within the
framework of
the JM14’ model
E.N.Golovach,
MSU
blue: inside the CLAS acceptance
black: 100% acceptance, naïve model
red: 100% acceptance, JM model fit to
the data inside the CLAS acceptance
green light: ABBHHM data
green dark: ELSA data

4. Future studies of p+p-p electroproduction
New p+p-p Electroproduction, CLAS Preliminary
Relative contributions from resonance structures
increase with Q2 and W. Structure at W~1.7 GeV
is pronounced in all Q2-bins.
Extraction of gvNN* electrocouplings of most N*‘s
in mass range up to 2.0 GeV from p+p-p electropro-
duction data within the framework of JM-model at
0.4< Q2< 5.0 GeV2.
s, mbn
R.W.Gothe,
G.V.Fedotov,
USC
In each bin of W and Q2 nine independent
one-fold differential cross sections similar
to those shown in previous slides will
be available
W, GeV
E.L. Isupov,
MSU/Univ. of Ohio

5. Back up

6. Published CLAS Data on p+p-p Photoproduction
M.Battaglieri et al, (CLAS Collaboration) Phys. Rev. D80, (2009).
M.Battaglieri et al, (CLAS Collaboration) Phys. Rev. Lett. 102, (2009).
Cross section decomposition over spherical harmonics Ylm at <W<2.83 GeV.
First signal from f0(980) in photoproduction.
S.Strauch et al, (CLAS Collaboration) Phys. Rev. Lett. 95, (2005).
Beam-helicity asymmetries fully integrated and one-fold differential at
1.35 < W < 2.3 GeV
M.Battaglieri et al, (CLAS Collaboration) Phys. Rev. Lett. 87, (2001).
Three one-fold differential cross sections for the final hadron invariant mass
distributions sliced over t-values defined as the difference four-momenta squared
of the initial and final protons at 2.6 < W <2.9 GeV.

7. M.Ripani et al (CLAS Collaboration)., PRL 91 (2003), 022002
The CLAS Data on p+p-p Differential Cross Sections at 1.40<W<2.30 GeV; 0.5<Q2<1.5 GeV2 and their Fit within the Framework of Meson-Baryon Model JM
M.Ripani et al (CLAS Collaboration)., PRL 91 (2003),
no new 3/2+ (1720) state , N(1720)3/2+ conventional
state decays preferentialy to rp
employing 3/2+(1720) candidate or no 3/2+(1720),
while N(1720)3/2+ decays preferentialy to pD.
full JM calc.
p+D0 rp
p-D++
p+N0 (1520) D13
W, GeV

8. Summary of the CLAS Data on Exclusive Meson Electroproduction off Protons in N* Excitation Region
Hadronic final state
Covered
W-range, GeV
Covered Q2-range, GeV2 C
Measured observables
p+n
ds/dW
ds/dW, Ab
p0p
ds/dW, Ab,At,Abt hp
K+L
thresh-2.6
K+S0 P’
p+p-p
Nine 1-fold differential cross sections
ds/dW-CM angular
distributions
Ab,At,Abt-longitudinal
beam, target, and
beam-target asym-
metries
P’ –recoil polarization
of strange baryon
Almost full coverage
of the final hadron
phase space in
pN, p+p-p, hp, and KY electroproduction
The data are available in the CLAS Physics
Data Base: