Separation of σS and σT in the region of the Δ (1236) resonance and determination of the magnetic dipole transition form factor

The unitary and analytic model for nucleons works very well. The model for spin [Formula: see text] baryons can predict static parameters for [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]. We prepared the scheme how to construct the model also for [Formula: see text] nucleon resonance. It was used to describe transition form factor [Formula: see text] and the experimentally measured ratio [Formula: see text] with the help of relations for magnetic dipole transition and charge quadrupole form factors.

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$$\omega \rightarrow 3\pi $$ and $$\omega \pi ^{0}$$ transition form factor revisited

The European Physical Journal C ◽

10.1140/epjc/s10052-020-08576-6 ◽

2020 ◽

Vol 80 (12) ◽

Author(s):

M. Albaladejo ◽

◽

I. Danilkin ◽

S. Gonzàlez-Solís ◽

D. Winney ◽

...

Keyword(s):

Form Factor ◽

Experimental Determination ◽

Dalitz Plot ◽

Transition Form Factor ◽

Decay Amplitude ◽

Experimental Results ◽

Transition Form ◽

Dispersive Analysis ◽

Low Energies

AbstractIn light of recent experimental results, we revisit the dispersive analysis of the $$\omega \rightarrow 3\pi $$ ω → 3 π decay amplitude and of the $$\omega \pi ^0$$ ω π 0 transition form factor. Within the framework of the Khuri–Treiman equations, we show that the $$\omega \rightarrow 3\pi $$ ω → 3 π Dalitz-plot parameters obtained with a once-subtracted amplitude are in agreement with the latest experimental determination by BESIII. Furthermore, we show that at low energies the $$\omega \pi ^0$$ ω π 0 transition form factor obtained from our determination of the $$\omega \rightarrow 3\pi $$ ω → 3 π amplitude is consistent with the data from MAMI and NA60 experiments.

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Determination of the η-transition form factor in the γp→pη→pγe+e− reaction

Physics Letters B ◽

10.1016/j.physletb.2011.06.069 ◽

2011 ◽

Vol 701 (5) ◽

pp. 562-567 ◽

Cited By ~ 40

Author(s):

H. Berghäuser ◽

V. Metag ◽

A. Starostin ◽

P. Aguar Bartolomé ◽

L.K. Akasoy ◽

...

Keyword(s):

Form Factor ◽

Transition Form Factor ◽

Transition Form

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STUDY OF THE η → γe+e- DECAY WITH THE WASA-at-COSY

International Journal of Modern Physics A ◽

10.1142/s0217751x11052359 ◽

2011 ◽

Vol 26 (03n04) ◽

pp. 650-651

Author(s):

◽

MAŁGORZATA HODANA

Keyword(s):

Form Factor ◽

Mass Spectrum ◽

Invariant Mass ◽

Virtual Photon ◽

Transition Form Factor ◽

Invariant Mass Spectrum ◽

Transition Form ◽

Lepton Pairs ◽

Dalitz Decay

In October 2008, the WASA-at-COSY collected more than 107 events for the pd → 3 He η reaction. The aim is the determination of the invariant mass of the lepton pairs created in the Dalitz decay η → γe+e-. The e+e- invariant mass spectrum is directly related to the distribution of the four-momentum squared of the virtual photon from the η → γγ* process and hence it allows for the study of the transition form factor which in turn reflects the structure of the decaying meson.

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Towards a dispersive determination of the pion transition form factor

EPJ Web of Conferences ◽

10.1051/epjconf/201816600013 ◽

2018 ◽

Vol 166 ◽

pp. 00013 ◽

Cited By ~ 1

Author(s):

Stefan Leupold ◽

Martin Hoferichter ◽

Bastian Kubis ◽

Franz Niecknig ◽

Sebastian P. Schneider

Keyword(s):

Experimental Data ◽

Form Factor ◽

Standard Model ◽

Model Calculation ◽

Transition Form Factor ◽

Current Status ◽

Transition Form ◽

Dispersion Theory ◽

Ongoing Project

We start with a brief motivation why the pion transition form factor is interesting and, in particular, how it is related to the high-precision standard-model calculation of the gyromagnetic ratio of the muon. Then we report on the current status of our ongoing project to calculate the pion transition form factor using dispersion theory. Finally we present and discuss a wish list of experimental data that would help to improve the input for our calculations and/or to cross-check our results.

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