Study of the process $e^+e^-\to p\bar{p}$ in the c.m. energy range from threshold to 2 GeV with the CMD-3 detector

The CMD-3 collaboration Akhmetshin, R.R. ; Amirkhanov, A.N. ; Anisenkov, A.V. ; et al.
Phys.Lett. B759 (2016) 634-640, 2016.
Inspire Record 1385598 DOI 10.17182/hepdata.73805

Using a data sample of 7.7 pb−1 collected with the CMD-3 detector at the VEPP-2000 e+e− collider we select about 2900 events of the process e+e−→pp¯ and measure its cross section at 12 energy points with about 6% systematic uncertainty. From the angular distribution of produced nucleons we obtain the ratio GE/GM .

2 data tables

The c.m. energy, beam energy shift, luminosity, number of selected $e^+e^- \to p\bar{p}$ events, detection efficiency, radiative correction, and cross section with statistical and systematic errors. The data for collinear type events.

The c.m. energy, luminosity, number of signal events, fraction of antiprotons stopped in beam pipe and DC inner shell, efficiency, cross section with statistical and systematic errors, for annihilation events.


Measurement of the proton form factor by studying $e^{+} e^{-}\rightarrow p\bar{p}$

The BESIII collaboration Ablikim, M. ; Achasov, M.N. ; Ai, X.C. ; et al.
Phys.Rev. D91 (2015) 112004, 2015.
Inspire Record 1358937 DOI 10.17182/hepdata.73442

Using data samples collected with the BESIII detector at the BEPCII collider, we measure the Born cross section of e+e-→pp¯ at 12 center-of-mass energies from 2232.4 to 3671.0 MeV. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal (|GE|=|GM|). In addition, the ratio of electric to magnetic form factors, |GE/GM|, and |GM| are extracted by fitting the polar angle distribution of the proton for the data samples with larger statistics, namely at s=2232.4 and 2400.0 MeV and a combined sample at s=3050.0, 3060.0 and 3080.0 MeV, respectively. The measured cross sections are in agreement with recent results from BABAR, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BABAR results in the same q2 region, which indicates the data are consistent with the assumption that |GE|=|GM| within uncertainties.

1 data table

Summary of the Born cross section $\sigma_\text{Born}$, the effective FF $|G|$, and the related variables used to calculate the Born cross sections at the different c.m.energies $\sqrt{s}$, where $N_\text{obs}$ is the number of candidate events, $N_\text{bkg}$ is the estimated background yield, $\varepsilon^\prime=\varepsilon\times(1+\delta)$ is the product of detection efficiency $\varepsilon$ and the radiative correction factor $(1+\delta)$, and $L$ is the integrated luminosity. The first errors are statistical, and the second systematic.


Study of $e^+e^−$ → $p\bar{p}$ in the vicinity of ψ(3770)

The BESIII collaboration Ablikim, M. ; Achasov, M.N. ; Ai, X.C. ; et al.
Phys.Lett. B735 (2014) 101-107, 2014.
Inspire Record 1286898 DOI 10.17182/hepdata.64597
2 data tables

Summary of results at center-of-mass energies from 3.65 to 3.90 GeV. N(SIG) is the number of E+ E- --> P P events; EPSILON is the detection efficiency; L is the integrated luminosity; (1 + DELTA)(DRESSED) is the initial state radiation correction factor without the vacuum polarization correction; and SIG(OBS), SIG(DRESSED) and SIG(BORN) are the observed cross section, the dressed cross section and the Born cross section, respectively.

The two solutions of the dressed cross section and the corresponding phase angles, PHI.


The first measurement of the neutron electromagnetic form-factors in the timelike region

Antonelli, A. ; Baldini, R. ; Benasi, P. ; et al.
Nucl.Phys. B517 (1998) 3-35, 1998.
Inspire Record 471263 DOI 10.17182/hepdata.32681
3 data tables

The uncertainty on the evaluated cross section is given by the quadratic combination of the following terms: the statistical uncertainty on the number of events, the statistical and systematic uncertainty on the luminosity (about 6PCT), the systematic uncertainty on the efficiency evaluation, dominated by the scanning efficiency contribution (about 15PCT). The SQRT(S) values with (C=NOMIN) and (C=SHIFT) correspond to the nominal energy and shifted energy analysis (see text of paper for details).

The uncertainty on the evaluated cross section is given by the quadratic combination of the following terms: the statistical uncertainty on the number of events, the statistical and systematic uncertainty on the luminosity (about 6PCT), the systematic uncertainty on the efficiency evaluation, dominated by the scanning efficiency contribution (about 15PCT). The NEUTRON formfactor value are calculated in two hypotheses: GE = GM and GE = 0.

The uncertainty on the evaluated cross section is given by the quadratic combination of the statistical and systematic uncertainties.


Measurement of the electromagnetic form-factor of the proton in the timelike region

Antonelli, A. ; Baldini, R. ; Bertani, M. ; et al.
Phys.Lett. B334 (1994) 431-434, 1994.
Inspire Record 377833 DOI 10.17182/hepdata.28572
2 data tables

Cross section measurement.

Proton form-factor measurement.


First measurement of the neutron electromagnetic form-factor in the timelike region

Antonelli, A. ; Baldini, R. ; Bertani, M. ; et al.
Phys.Lett. B313 (1993) 283-287, 1993.
Inspire Record 359376 DOI 10.17182/hepdata.28867
2 data tables

Neutron form factor and cross section.

Preliminary analysis of proton form factor and cross section.


Baryon pair production in e+ e- annihilation at S**(1/2) = 2.4-GeV

The DM2 collaboration Bisello, D. ; Busetto, G. ; Castro, A. ; et al.
Z.Phys. C48 (1990) 23-28, 1990.
Inspire Record 297706 DOI 10.17182/hepdata.15128
5 data tables

No description provided.

No description provided.

No description provided.

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Preliminary results concerning the reaction e+ e- ---> p anti-p at a total energy of 2.1 gev

Di Giugno, G. ; Humphrey, J.W. ; Sassi, E. ; et al.
Lett.Nuovo Cim. 2S2 (1971) 873-877, 1971.
Inspire Record 70981 DOI 10.17182/hepdata.37402
1 data table

No description provided.


The reaction e+ e- ---> p anti-p at a total energy of 2.1 gev

Castellano, M. ; Di Giugno, G. ; Humphrey, J.W. ; et al.
Nuovo Cim. A14 (1973) 1-20, 1973.
Inspire Record 87244 DOI 10.17182/hepdata.37782
1 data table

ISOTROPIC ANGULAR DISTRIBUTION ASSUMED.


Study of the Reaction $e^+ e^- \to p \bar{p}$ in the Total Energy Range 1925-{MeV} - 2180-{MeV}

Delcourt, B. ; Derado, I. ; Bertrand, J.L. ; et al.
Phys.Lett. B86 (1979) 395-398, 1979.
Inspire Record 141565 DOI 10.17182/hepdata.27308
1 data table

TOTAL CROSS SECTION ASSUMING ISOTROPIC PRODUCTION. RADIATIVE CORRECTIONS CALCULATED USING PEAKING APPROXIMATION (ABOUT 20 PCT). AUTHORS ALSO QUOTE RESULTS FOR LIMITED (COSMIC RAY FREE) ACCEPTANCE AS A CHECK. FORM FACTOR DERIVED ASSUMING ELECTRIC AND MAGNETIC FORM FACTORS EQUAL IN MAGNITUDE.