Measurement of time-like baryon electromagnetic form factors in processes with initial state radiation

The process [Formula: see text] has been studied in the [Formula: see text] mass range from threshold to 6.5 GeV/c2 using the initial-state-radiation technique with both detected and undetected photon. The analysis is based on 469 fb-1 of integrated luminosity collected with the BABAR detector at the PEP-II collider at e+e- center-of-mass energies near 10.6 GeV.

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Measurement of proton electromagnetic form factors in the time-like region using initial state radiation at BESIII

Physics Letters B ◽

10.1016/j.physletb.2021.136328 ◽

2021 ◽

pp. 136328

Author(s):

M. Ablikim ◽

M.N. Achasov ◽

P. Adlarson ◽

S. Ahmed ◽

M. Albrecht ◽

...

Keyword(s):

Form Factors ◽

Initial State Radiation ◽

Electromagnetic Form Factors ◽

Initial State ◽

State Radiation

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BESIII results on time-like baryon form factors

EPJ Web of Conferences ◽

10.1051/epjconf/201921804002 ◽

2019 ◽

Vol 218 ◽

pp. 04002

Author(s):

Alaa Dbeyssi

Keyword(s):

Form Factor ◽

Center Of Mass ◽

Form Factors ◽

Initial State Radiation ◽

Proton Form Factor ◽

Electromagnetic Form Factors ◽

Initial State ◽

Data Set ◽

Preliminary Results ◽

State Radiation

This contribution reports on the recent measurements of baryon electromagnetic form factors at the BESIII experiment in Beijing. The Beijing e+e − collider BEPCII is a double-ring symmetric collider running at $ \sqrt s $ between 2.0 and 4.6 GeV. Baryon electromagnetic form factors can be measured at BESIII in direct e+e−-annihilation and in initial state radiation processes. Based on the data collected by the BESIII detector at 12 center of mass energies between 2.23 and 3.67 GeV, the measured $ \mathop e\nolimits^ + \mathop e\nolimits^ - \to \mathop p\limits^ - p $ cross section and the time-like proton form factor are presented. Preliminary results from the analysis of the initial state radiation process $ \mathop e\nolimits^ + \mathop e\nolimits^ - \to \mathop p\limits^ - p\gamma $ using a data set of 7.408 fb−1 collected at center of mass energies between 3.773 and 4.6 GeV, are also shown. The cross sections for $ \mathop e\nolimits^ + \mathop e\nolimits^ - \to \mathop {\mathop \Lambda \nolimits_c^ - }\limits^ - \mathop \Lambda \nolimits_c^ + $ and $ \mathop e\nolimits^ + \mathop e\nolimits^ - \to \mathop \Lambda \limits^ - \Lambda $ are measured near threshold with unprecedented precision. Preliminary results on the first measurement of the ^c form factor ratio |GE|/|GM| are also given. Ongoing analysis based on the high luminosity energy scan from 2015 and from radiative return at different $ \sqrt s $ are also described.

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BABAR measurement of baryon time-like form factors via initial state radiation

Chinese Physics C ◽

10.1088/1674-1137/34/6/040 ◽

2010 ◽

Vol 34 (6) ◽

pp. 860-862

Author(s):

R. Baldini Ferroli

Keyword(s):

Form Factors ◽

Initial State Radiation ◽

Initial State ◽

State Radiation

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Time-Like Proton Form Factors in Initial State Radiation Process

10.20944/preprints202112.0030.v1 ◽

2021 ◽

Author(s):

Dexu Lin ◽

Alaa Dbeyssi ◽

Frank Maas

Keyword(s):

Cross Section ◽

Experimental Studies ◽

Form Factors ◽

Initial State Radiation ◽

Initial State ◽

Radiation Process ◽

Proton Form ◽

Born Cross Section ◽

State Radiation ◽

Proton Form Factors

The measurements of the proton electromagnetic form factors in the time-like region using the initial state radiation technique are reviewed. Recent experimental studies have shown that initial state radiation processes at high luminosity electron-positron colliders can be effectively used to probe the electromagnetic structure of hadrons. The BABAR experiment at the B-factory PEP-II in Stanford and the BESIII experiment at the $\tau$-charm factory BEPC-II in Beijing have measured the time-like form factors of the proton using the initial state radiation process $e^{+}e^{-}\to pbar{p}\gamma$. The two kinematical regions where the photon is emitted from the initial state at small and large polar angles have been investigated. In the first case the photon is in the region not covered by the detector acceptance and is not detected. The Born cross section and the proton effective form factor have been measured over a wide and continuous range of the the momentum transfer squared $q^2$ from threshold up to ~42 (GeV/c)$^2$. The ratio of electric and magnetic form factors of the proton has been also determined. In this report, the theoretical aspect and the experimental studies of the initial state radiation process $e^{+}e^{-}\to p\bar{p}\gamma$ are described. The measurements of the Born cross section and the proton form factors obtained in these analyses near the threshold region and in the relatively large $q^2$ region are examined. The experimental results are compared to the predictions from theory and models. Their impact on our understanding of the nucleon structure is discussed.

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Time-like Proton Form Factors with Initial State Radiation Technique

Symmetry ◽

10.3390/sym14010091 ◽

2022 ◽

Vol 14 (1) ◽

pp. 91

Author(s):

Dexu Lin ◽

Alaa Dbeyssi ◽

Frank Maas

Keyword(s):

Experimental Studies ◽

Form Factors ◽

Initial State Radiation ◽

Initial State ◽

Radiation Process ◽

Electron Positron ◽

Born Cross Section ◽

State Radiation ◽

Radiation Technique ◽

Proton Form Factors

Electromagnetic form factors are fundamental quantities describing the internal structure of hadrons. They can be measured with scattering processes in the space-like region and annihilation processes in the time-like region. The two regions are connected by crossing symmetry. The measurements of the proton electromagnetic form factors in the time-like region using the initial state radiation technique are reviewed. Recent experimental studies have shown that initial state radiation processes at high luminosity electron-positron colliders can be effectively used to probe the electromagnetic structure of hadrons. The BABAR experiment at the B-factory PEP-II in Stanford and the BESIII experiment at BEPCII (an electron positron collider in the τ-charm mass region) in Beijing have measured the time-like form factors of the proton using the initial state radiation process e+e−→pp¯γ. The two kinematical regions where the photon is emitted from the initial state at small and large polar angles have been investigated. In the first case, the photon is in the region not covered by the detector acceptance and is not detected. The Born cross section and the proton effective form factor have been measured over a wide and continuous range of the the momentum transfer squared q2 from the threshold up to 42 (GeV/c)2. The ratio of electric and magnetic form factors of the proton has been also determined. In this report, the theoretical aspect and the experimental studies of the initial state radiation process e+e−→pp¯γ are described. The measurements of the Born cross section and the proton form factors obtained in these analyses near the threshold region and in the relatively large q2 region are examined. The experimental results are compared to the predictions from theory and models. Their impact on our understanding of the nucleon structure is discussed.

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