E93-006 CLAS experiment
- Spokespersons
- V. D. Burkert, M. Ripani
- Year
- 2003
- Abstract
- The cross section for the reaction ep -> e' p pi+ pi- was measured in the resonance region for 1.4 < W < 2.1 GeV and 0.5 < Q2 < 1.5 GeV2/c2 using the CLAS detector at Jefferson Laboratory. The data show resonant structures not visible in previous experiments. The comparison of our data to a phenomenological prediction using available information on N* and Delta states shows an evident discrepancy. A better description of the data is obtained either by a sizable change of the properties of the P13(1720) resonance or by introducing a new baryon state, not reported in published analyses.
- Publication
-
- M. Ripani, V. D. Burkert, V. I. Mokeev, M. Battaglieri, R. De Vita, E. Golovach, V. Tauti, and CLAS Collaboration Measurement of ep->e'p pi+pi- and Baryon Resonance Analysis // Phys. Rev. Let. 91, 022002 (2003)
- Quantities
- σ dσ/dM(π−,p) dσ/dM(π+,p) dσ/dM(π+,π−) dσ/d(−cos(θ(π−))) dσ/d(−cos(θ(π+))) dσ/d(−cos(θ(p))) dσ/dφ(π−) dσ/dφ(π+) dσ/dφ(p) dσ/dψ(π−) dσ/dψ(π+) dσ/dψ(p)
Measurements
| ID | Quantity | Beam | Target | Final state |
Q2min, GeV2 |
Q2max, GeV2 |
Wmin, GeV |
Wmax, GeV |
|---|---|---|---|---|---|---|---|---|
| E1M801 | dσ/d(−cos(θ(π−))) | e | p | π+π−p | 0.8 | 1.1 | 1.85 | 1.875 |
| E1M802 | dσ/d(−cos(θ(π+))) | e | p | π+π−p | 0.8 | 1.1 | 1.85 | 1.875 |
| E1M803 | dσ/d(−cos(θ(p))) | e | p | π+π−p | 0.8 | 1.1 | 1.85 | 1.875 |
| E1M804 | dσ/dM(π−,p) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M805 | dσ/dM(π+,π−) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M806 | dσ/dM(π+,p) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M807 | dσ/dφ(π−) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M808 | dσ/dφ(π+) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M809 | dσ/dφ(p) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M810 | dσ/dψ(π−) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M811 | dσ/dψ(π+) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M812 | dσ/dψ(p) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M813 | dσ/d(−cos(θ(π−))) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M814 | dσ/d(−cos(θ(π+))) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M815 | dσ/d(−cos(θ(p))) | e | p | π+π−p | 0.8 | 1.1 | 1.875 | 1.9 |
| E1M816 | σ | e | p | π+π−p | 0.65 | 1.3 | 1.4125 | 2.0875 |