Evaluation of the E2/M1 ratio in the N → ∆(1232) transition from the ⃗γ⃗p → pπ0 reaction
| Parent link: | Physical Review C: covering nuclear physics.— .— New York: American Physical Society Vol. 109, iss. 5.— 2024.— Article number 055201, 15 p. |
|---|---|
| Corporate Author: | |
| Other Authors: | , , , , , |
| Summary: | Title screen A new data set for the helicity-dependent differential cross section of the single-meson photoproduction reaction 𝛾𝑝→𝑝𝜋0 was obtained for the photon energy interval 150–400 MeV. The experiment was performed at the A2 tagged photon facility of the Mainz Microtron MAMI using a circularly polarized photon beam and a longitudinally polarized proton target. The reaction products were detected with the large-acceptance Crystal Ball and TAPS calorimeters covering 97% of the full solid angle. These new results, obtained with a fine energy and polar angle binning, greatly increase both the existing quantity and quality of the data available for this observable. A moment analysis, based on a finite expansion in Legendre polynomials, was applied to these data by using a bootstrap-based fitting method to correctly account for their systematic uncertainties. From the resulting decomposition of the differential cross sections, the 𝐸2/𝑀1 ratio for the 𝑁→Δ(1232) transition was determined to be [−2.38±0.16(stat.+sys.)±0.10(model)]%. Combining this value with previous results also allowed us to evaluate the most precise available estimate of the 𝐸2/𝑀1 ratio to be used for all further reference and model comparisons. Текстовый файл AM_Agreement |
| Language: | English |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://doi.org/10.1103/PhysRevC.109.055201 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=675793 |
| Summary: | Title screen A new data set for the helicity-dependent differential cross section of the single-meson photoproduction reaction 𝛾𝑝→𝑝𝜋0 was obtained for the photon energy interval 150–400 MeV. The experiment was performed at the A2 tagged photon facility of the Mainz Microtron MAMI using a circularly polarized photon beam and a longitudinally polarized proton target. The reaction products were detected with the large-acceptance Crystal Ball and TAPS calorimeters covering 97% of the full solid angle. These new results, obtained with a fine energy and polar angle binning, greatly increase both the existing quantity and quality of the data available for this observable. A moment analysis, based on a finite expansion in Legendre polynomials, was applied to these data by using a bootstrap-based fitting method to correctly account for their systematic uncertainties. From the resulting decomposition of the differential cross sections, the 𝐸2/𝑀1 ratio for the 𝑁→Δ(1232) transition was determined to be [−2.38±0.16(stat.+sys.)±0.10(model)]%. Combining this value with previous results also allowed us to evaluate the most precise available estimate of the 𝐸2/𝑀1 ratio to be used for all further reference and model comparisons. Текстовый файл AM_Agreement |
|---|---|
| DOI: | 10.1103/PhysRevC.109.055201 |