scholarly journals BESIII results on time-like baryon form factors

2019 ◽  
Vol 218 ◽  
pp. 04002
Author(s):  
Alaa Dbeyssi

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.

2014 ◽  
Vol 35 ◽  
pp. 1460425
Author(s):  
V. P. DRUZHININ ◽  

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.


2018 ◽  
Vol 172 ◽  
pp. 03002
Author(s):  
Haiming HU

The measurements of hadronic form factors of three modes using the data samples collected with the BESIII detector at BEPCII collider are presented. The cross section of e+e- → p p̅ at 12 energies from 2232.4 to 3671.0 MeV are measured, the electromagnetic form factor is deduced, and the ratio |GE/GM| is extracted by fitting the polar angle distribution. The preliminary results about the form factors of e+e- → ∧c+ ⊼c- will also be described. The cross section of e+e- → π+ π-between effective center-of-mass energy 600 and 900 MeV is measured by the ISR return method using the data set with the integrated luminosity of 2.93 fb-1 taken at ψ(3773) peak, the pion form factor is extracted.


2018 ◽  
Vol 46 ◽  
pp. 1860027
Author(s):  
Zhaoxia Meng

Form factors of hadron provide fundamental information about its structure and dynamics. They constitute a rigorous test of non-perturbative QCD as well as of phenomenological models. Based on data samples collected with BESIII detector at BEPCII collider, born cross section of [Formula: see text] and proton effective form factors are measured at 12 center-of-mass energies between 2.2324 and 3.671 GeV. The ratio [Formula: see text]s are extracted by fitting polar angle distribution of proton for data samples with large statistics. For data between 3.773 and 4.6 GeV, we use initial state radiation (ISR) method to study [Formula: see text] by tagged or un-tagged ISR photon, where the pair cross section, effective form factors and [Formula: see text]s are obtained from proton pair threshold to about 3 GeV. For [Formula: see text] and [Formula: see text], the pair cross section and [Formula: see text] form factors are measured near threshold. With data scanned in 2015 from 2-3.08 GeV, charged Kaon pair cross section and form factors are measured at 21 center-of-mass energies.


2004 ◽  
Vol 69 (1) ◽  
Author(s):  
B. Aubert ◽  
R. Barate ◽  
D. Boutigny ◽  
J.-M. Gaillard ◽  
A. Hicheur ◽  
...  

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