scholarly journals Polarization Observables in Double Pion Photo- Production with Circularly Polarized Photons off Transversely Polarized Protons

2017 ◽  
Author(s):  
Leila Net
Keyword(s):  
Circularly Polarized ◽  
Polarized Protons ◽  
Double Pion ◽  
Polarization Observables ◽  
Polarized Photons ◽  
Photo Production

scholarly journals Measurement of the helicity asymmetry E for the reaction $$ \gamma p\rightarrow \pi ^0 p$$

2021 ◽  
Vol 57 (1) ◽  
Author(s):  
M. Gottschall ◽  
F. Afzal ◽  
A. V. Anisovich ◽  
D. Bayadilov ◽  
R. Beck ◽  
...  
Keyword(s):  
Energy Range ◽  
Partial Wave ◽  
Photon Energy ◽  
Photon Energy Range ◽  
Angular Range ◽  
Polarized Electrons ◽  
Circularly Polarized ◽  
Polarized Protons ◽  
Double Polarization ◽  
Polarized Photons

AbstractA measurement of the double-polarization observable E for the reaction $$\gamma p\rightarrow \pi ^0 p$$ γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$$_4$$ 4 H$$_9$$ 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $$E_\gamma =600$$ E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

scholarly journals Measurement of polarization observables in neutral double pion photoproduction off the proton with the CBELSA/TAPS experiment

2020 ◽  
Vol 241 ◽  
pp. 01016
Author(s):  
Tobias Seifen
Keyword(s):  
Internal Structure ◽  
Branching Ratios ◽  
Pion Photoproduction ◽  
Double Polarization ◽  
Double Pion ◽  
Linearly Polarized ◽  
Polarization Observables ◽  
Polarized Photons

Data on the reaction γp → pπ0π0 were taken with the CBELSA/TAPS experiment at ELSA where linearly polarized photons impinged on a transversely polarized butanol target. Target asymmetries and double polarization observables were extracted and entered the BnGa-PWA. Systematic differences in the branching ratios of N* and Δ* resonances hint at the internal structure of these states

scholarly journals POLARIZATION OBSERVABLES FOR K+Λ AND K+Σ0 PHOTOPRODUCTION FROM POLARIZED PROTONS

2014 ◽  
Vol 26 ◽  
pp. 1460098
Author(s):  
◽  
NATALIE K. WALFORD ◽  
FRANZ J. KLEIN
Keyword(s):  
Excited States ◽  
Final States ◽  
Polarization Data ◽  
Polarized Protons ◽  
Model Predictions ◽  
Double Polarization ◽  
Model Independent ◽  
Polarization Observables ◽  
Large Effort ◽  
Polarized Photons

The search for undiscovered excited states of the nucleon continues to be a focus of experiments at Jefferson Lab. Recent LQCD calculations have confirmed long-standing quark-model predictions of many more states than have so far been identified.1 A large effort for the N* program has been launched using the CLAS detector to provide the database that will allow nearly model-independent partial wave analyses to be carried out in the search for such states. Polarization observables play a crucial role in this effort, as they are essential in disentangling overlapping resonant and non-resonant amplitudes. In 2010, double-polarization data were taken at JLab using circularly polarized photons incident on a transversely polarized frozen-spin butanol target.2 Our current analysis yields preliminary data of the T and F asymmetries of the K+Λ and K+Σ0 final states, which are compared to predictions of recent multipole analyses. This work is the first of its kind and will significantly broaden the world database for these reactions.

scholarly journals Facilities for the Performance of Fano Effect Measurements as a Probe of Electron Correlation

2006 ◽  
Vol 986 ◽  
Author(s):  
J. G. Tobin ◽  
S. W. Tobin ◽  
T Komesu ◽  
B W Chung ◽  
S. A. Morton ◽  
...  
Keyword(s):  
Direct Observation ◽  
Electron Correlation ◽  
Selective Excitation ◽  
Photoelectron Emission ◽  
Circularly Polarized ◽  
Fano Effect ◽  
Spin Polarized ◽  
Fano Effects ◽  
Polarized Photons

AbstractFano Effect measurements are the key to direct observation of the Kondo or spin shielding intrinsic to models of electron correlation. The Fano Effect is the observation of spin polarized photoelectron emission from NONMAGNETIC materials, under chirally selective excitation, such as circularly polarized photons. Below are described three spectrometers, with which Fano Effects measurements have been made.

scholarly journals Origin of Terrestrial Bioorganic Homochirality and Symmetry Breaking in the Universe

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 919 ◽  
Author(s):  
Jun-ichi Takahashi ◽  
Kensei Kobayashi
Keyword(s):  
Symmetry Breaking ◽  
Parity Violation ◽  
Circularly Polarized ◽  
Physical Conditions ◽  
Quantum Radiation ◽  
Interstellar Media ◽  
Spin Polarized ◽  
Terrestrial Life ◽  
Polarized Photons ◽  
The Universe

The origin of terrestrial bioorganic homochirality is one of the most important and unresolved problems in the study of chemical evolution prior to the origin of terrestrial life. One hypothesis advocated in the context of astrobiology is that polarized quantum radiation in space, such as circularly polarized photons or spin-polarized leptons, induced asymmetric chemical and physical conditions in the primitive interstellar media (the cosmic scenario). Another advocated hypothesis in the context of symmetry breaking in the universe is that the bioorganic asymmetry is intrinsically derived from the chiral asymmetric properties of elementary particles, that is, parity violation in the weak interaction (the intrinsic scenario). In this paper, the features of these two scenarios are discussed and approaches to validate them are reviewed.

scholarly journals DETERMINATION OF E AND G OBSERVABLES IN η PHOTOPRODUCTION ON THE CLAS FROZEN SPIN TARGET (FROST)

2014 ◽  
Vol 26 ◽  
pp. 1460115
Author(s):  
◽  
IGOR SENDEROVICH ◽  
B. T. MORRISON ◽  
M. DUGGER ◽  
B. RITCHIE ◽  
...  
Keyword(s):  
Baryon Spectrum ◽  
Preliminary Results ◽  
Extensive Data ◽  
Polarized Protons ◽  
The World ◽  
Double Polarization ◽  
Linearly Polarized ◽  
Beam Incident ◽  
Polarization Observables

Polarization observables are vital for disentangling overlapping resonances in the baryon spectrum. Extensive data have been collected at Jefferson Lab in Hall B with circularly and linearly polarized tagged photon beam incident on longitudinally polarized protons provided by the Frozen Spin Target (FROST). The focus of the described work is on η photoproduction, which acts as an "isospin filter", isolating the N*(I = 1/2) resonances. Preliminary results for the double-polarization observables E and G are presented. There are currently no data on these in the world database for η photoproduction.

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