Virtual Compton scattering measurements in the nucleon resonance region
- Temple Univ., Philadelphia, PA (United States)
- Johannes Gutenberg Univ., Mainz (Germany)
- Clermont Univ., Clermont-Ferrand (France)
- Jozef Stefan Inst. (IJS), Ljubljana (Slovenia)
- Univ. of Pavia (Italy)
- Jozef Stefan Inst. (IJS), Ljubljana (Slovenia); Univ. of Ljubljana (Slovenia)
We report on new measurements of the electric Generalized Polarizability (GP) of the proton \( \alpha_{E}\) in a kinematic region where a puzzling dependence on momentum transfer has been observed, and we have found that \( \alpha_E = (5.3 \pm 0.6_{stat} \pm 1.3_{sys}) 10^{-4}\) fm3 at \( Q^{2}=0.20\) (GeV/c)2. The new measurements, when considered along with the rest of the world data, suggest that \( \alpha_E\) can be described by either a local plateau or by an enhancement in the region \( Q^2=0.20\) (GeV/c)2 to 0.33 (GeV/c)2. The experiment also provides the first measurement of the Coulomb quadrupole amplitude in the \( N \rightarrow \Delta\) transition through the exploration of the \( p(e,e'p)\gamma\) reaction. The new measurement gives \( CMR = (-4.4 \pm 0.8_{stat} \pm 0.6_{sys})\%\) at \( Q^2=0.20\) (GeV/c)2 and is consistent with the results from the pion electroproduction world data. It has been obtained using a completely different extraction method, and therefore represents a strong validation test of the world data model uncertainties.
- Research Organization:
- Temple Univ., Philadelphia, PA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP); German Research Foundation (DFG)
- Grant/Contract Number:
- SC0016577
- OSTI ID:
- 1596686
- Journal Information:
- European Physical Journal. A, Vol. 55, Issue 10; Related Information: Adam Blomberg, PhD Thesis, Temple University, Dept. of Physics (2016); ISSN 1434-6001
- Publisher:
- SpringerCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
New Insight in the Q 2 Dependence of Proton Generalized Polarizabilities
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journal | November 2019 |
New Insight in the Q2 Dependence of Proton Generalized Polarizabilities
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text | January 2019 |
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