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Electroexcitation of the Roper resonance for 1.7 < Q**2 < 4.5 -GeV2 in vec-ep ---> en pi+

Journal Article · · Physical Review C
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DOI: http://dx.doi.org/10.1103/PhysRevC.78.045209
The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q2 < 4.5 GeV2 from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for pi+ electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent results. It is found that the transverse helicity amplitude A_{1/2} for the gamma* p -> N(1440)P11 transition, which is large and negative at Q2=0, becomes large and positive at Q2 ~ 2 GeV2, and then drops slowly with Q2. The longitudinal helicity amplitude S_{1/2}, which was previously found from CLAS ep -> eppi0,enpi+ data to be large and positive at Q2=0.4,0.65 GeV2, drops with Q2. Available model predictions for gamma* p -> N(1440)P11 allow us to conclude that these results provide strong evidence in favor of N(1440)P11 as a first radial excitation of

Research Organization:
Thomas Jefferson Lab National Accelerator Facility
Sponsoring Organization:
USDOE
OSTI ID:
956089
Report Number(s):
JLAB-PHY-08-811; arXiv:0804.0447; DOE/OR/23177-0340
Journal Information:
Physical Review C, Journal Name: Physical Review C Vol. 78; ISSN 0556-2813; ISSN PRVCAN
Country of Publication:
United States
Language:
English

References (37)

Measurement of the N → Δ + ( 1232 ) Transition at High-Momentum Transfer by π 0 Electroproduction journal September 2006
A consistent explanation of the Roper phenomenology journal July 1998
Q 2 Dependence of Quadrupole Strength in the γ * p → Δ + ( 1232 ) → p π 0 Transition journal March 2002
Measurement of the polarized structure function σ L T ′ for p ( e ⃗ , e ′ π + ) n in the Δ ( 1232 ) resonance region journal October 2004
Electroproduction of the Δ ( 1232 ) Resonance at High Momentum Transfer journal January 1999
Review of Particle Physics journal July 2006
Measurement of the polarized structure function σ LT ′ for p ( e → , e ′ p ) π 0 in the Δ ( 1232 ) resonance region journal September 2003
Baryon current matrix elements in a light-front framework journal April 1995
Unitary isobar model --MAID2007 journal October 2007
Electroexcitation of the P 33 ( 1232 ) , P 11 ( 1440 ) , D 13 ( 1520 ) , and S 11 ( 1535 ) at Q 2 = 0.4 and 0.65 ( GeV / c ) 2 journal January 2005
Electroexcitation of the N * (1440) in the relativistic constituent quark model journal June 1990
Mesonic content of the nucleon and the Roper resonance journal June 2007
Single quark transition model analysis of electromagnetic nucleon resonance excitations in the [ 7 0 ,   1 − ] supermultiplet journal March 2003
Baryons in a relativized quark model with chromodynamics journal November 1986
Photoproduction signatures of hybrid baryons: An application of the quark model with gluonic degrees of freedom journal November 1991
Determination of the pion form factor up to Q 2 = 4 GeV 2 from single-charged-pion electroproduction journal January 1976
The nonrelativistic three-body problem for baryons journal March 1992
Single π + electroproduction on the proton in the first and second resonance regions at 0.25 GeV 2 < Q 2 < 0.65 GeV 2 journal February 2006
Determination of the Pion Charge Form Factor at Q 2 = 1.60 and 2.45     ( GeV / c ) 2 journal November 2006
Multipole amplitudes of pion photoproduction on nucleons up to 2 GeV using dispersion relations and the unitary isobar model journal January 2003
Pion photoproduction resonance couplings in the second resonance region journal November 1990
Relativistic quark model predictions for meson radiative transition form factors journal October 1990
Electroproduction of the Roper resonance and the constituent quark model journal March 1997
Strong pionic decays of baryons from a spectroscopic quark model journal June 1996
A unitary isobar model for pion photo- and electroproduction on the proton up to 1 GeV journal January 1999
Electroproduction of single pions at low ε and a measurement of the pion form factor up to Q 2 = 10 GeV 2 journal April 1978
Precise Determination of the Neutron Magnetic Form Factor to Higher journal June 2005
Global analysis of proton elastic form factor data with two-photon exchange corrections journal September 2007
Electroproduction of the Roper resonance as a hybrid state journal July 1992
Electroexcitation of the Roper resonance in relativistic quark models journal August 2007
Cross sections and beam asymmetries for e → p → e n π + in the nucleon resonance region for 1 . 7 ⩽ Q 2 ⩽ 4 . 5 GeV 2 journal January 2008
The spectrum of the nucleons and the strange hyperons and chiral dynamics journal April 1996
Determination of the pion charge form factor for Q 2 = 0.60–1.60 GeV 2 journal May 2007
Measurements of G E n / G M n from the H 2 ( e → , e ′ n → ) H 1 Reaction to Q 2 = 1.45 ( G e V / c ) 2 journal September 2003
What is the structure of the Roper resonance? journal July 2000
Baryon form factors of relativistic constituent-quark models journal March 2004
Electroexcitation of nucleon resonances at Q 2 = 0 . 65 ( GeV / c ) 2 from a combined analysis of single- and double-pion electroproduction data journal October 2005

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Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ASYMMETRY
CROSS SECTIONS
DISPERSION RELATIONS
ELECTROPRODUCTION
EXCITATION
HELICITY
ISOBAR MODEL
N-1440 BARYONS
POLARIZED BEAMS
PROTONS