Date

Version 4
Measurement of the $\mathrm e^+\mathrm e^-\rightarrow\mathrm\pi^+\mathrm\pi^-$ Cross Section between 600 and 900 MeV Using Initial State Radiation

The BESIII collaboration Ablikim, M. ; Achasov, M.N. ; Adlarson, P. ; et al.
Phys.Lett.B 753 (2016) 629-638, 2016.
Inspire Record 1385603 DOI 10.17182/hepdata.73898

In Phys. Lett. B 753, 629-638 (2016) [arXiv:1507.08188] the BESIII collaboration published a cross section measurement of the process $e^+e^-\to \pi^+ \pi^-$ in the energy range between 600 and 900 MeV. In this erratum we report a corrected evaluation of the statistical errors in terms of a fully propagated covariance matrix. The correction also yields a reduced statistical uncertainty for the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, which now reads as $a_\mu^{\pi\pi\mathrm{, LO}}(600 - 900\,\mathrm{MeV}) = (368.2 \pm 1.5_{\rm stat} \pm 3.3_{\rm syst})\times 10^{-10}$. The central values of the cross section measurement and of $a_\mu^{\pi\pi\mathrm{, LO}}$, as well as the systematic uncertainties remain unchanged.

10 data tables

Bare cross section $\sigma^\mathrm{bare}(e^+e^-\to\pi^+\pi^-(\gamma_\mathrm{FSR}))$ of the process $e^+e^-\to\pi^+\pi^-$ measured using the initial state radiation method. The data is corrected concerning final state radiation and vacuum polarization effects. The final state radiation is added using the Schwinger term at born level.

Results of the BESIII measurement of the cross section $\sigma^{\rm bare}_{\pi^+\pi^-(\gamma_{\rm FSR})} \equiv \sigma^{\rm bare}(e^+e^-\rightarrow\pi^+\pi^-(\gamma_{\rm FSR}))$ and the squared pion form factor $|F_\pi|^2$. The errors are statistical only. The value of $\sqrt{s'}$ represents the bin center. The 0.9$\%$ systematic uncertainty is fully correlated between any two bins.

Results for the bare cross section $\sigma^\text{bare}_{\pi^+\pi^-}$ and the pion form factor together with their statistical uncertainties. The systematical uncertainties are given by 0.9% (see <a href="https://inspirehep.net/literature/1385603">arXiv:1507.08188</a>).

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Medium effects in proton-induced $K^{0}$ production at 3.5 GeV

The HADES collaboration Agakishiev, G. ; Arnold, O. ; Belver, D. ; et al.
Phys.Rev.C 90 (2014) 054906, 2014.
Inspire Record 1292844 DOI 10.17182/hepdata.64407

We present the analysis of the inclusive $K^{0}$ production in p+p and p+Nb collisions measured with the HADES detector at a beam kinetic energy of 3.5 GeV. Data are compared to the GiBUU transport model. The data suggest the presence of a repulsive momentum-dependent kaon potential as predicted by the Chiral Perturbation Theory (ChPT). For the kaon at rest and at normal nuclear density, the ChPT potential amounts to $\approx 35$ MeV. A detailed tuning of the kaon production cross sections implemented in the model has been carried out to reproduce the experimental data measured in p+p collisions. The uncertainties in the parameters of the model were examined with respect to the sensitivity of the experimental results from p+Nb collisions to the in-medium kaon potential.

2 data tables

The K0 production cross section in P P collisions.

The K0 production cross section in P + NB collisions. The uncertainty given on SIG(P NB --> K0 X) is the dominating absolute normalization uncertainty.


Version 2
Precise Measurement of the $e^+ e^- \to \pi^+\pi^- (\gamma)$ Cross Section with the Initial-State Radiation Method at BABAR

The BaBar collaboration Lees, J.P. ; Poireau, V. ; Tisserand, V. ; et al.
Phys.Rev.D 86 (2012) 032013, 2012.
Inspire Record 1114155 DOI 10.17182/hepdata.115140

A precise measurement of the cross section of the process $e^+e^-\to\pi^+\pi^-(\gamma)$ from threshold to an energy of 3GeV is obtained with the initial-state radiation (ISR) method using 232fb$^{-1}$ of data collected with the BaBar detector at $e^+e^-$ center-of-mass energies near 10.6GeV. The ISR luminosity is determined from a study of the leptonic process $e^+e^-\to\mu^+\mu^-(\gamma)\gamma_{\rm ISR}$, which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process $e^+e^-\to\pi^+\pi^-(\gamma)$ is obtained with a systematic uncertainty of 0.5% in the dominant $\rho$ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $\pi\pi$ cross section from threshold to 1.8GeV is $(514.1 \pm 2.2({\rm stat}) \pm 3.1({\rm syst}))\times 10^{-10}$.

3 data tables

Bare cross-section $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ The cross section values (nb) for 337 CM energy intervals (GeV) from 0.3 to 3 GeV. The cross section is bare (excluding vacuum polarization) and includes the emission of final state photons. ***WARNING*** The quoted errors are from the diagonal elements of the statistical covariance matrix (reported on the Table titled "Bare cross-section statistical covariance") and added quadratically with the systematic uncertainties (reported in the Table titled "Bare cross-section systematic uncertainties"). These errors can be used when plotting the results as they are representative of the precision achieved. However, any calculation involving the cross section over some energy range MUST use, to be meaningful, the full statistical covariance matrix and the proper correlations of the systematic uncertainties. ***WARNING*** The Bare cross-section statistical covariance is reported as additional resource in YAML, since its size exceeds the maximum size of 10 MB for the library hepdata_lib. It is a statistical covariance matrix, for 337x337 CM energy intervals (GeV), from 0.3 to 3 GeV, matching the ones of this table.

Bare cross-section $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ systematic uncertainties contributions and total systematic uncertainties, for 337 CM energy intervals (GeV), from 0.3 to 3 GeV. All systematics contributions are each 100% correlated in all energy bins.

Bare cross-section $e^+e^-\rightarrow\pi^+\pi^-(\gamma)$ statistical covariance matrix, for 337x337 CM energy intervals (GeV), from 0.3 to 3 GeV.


Measurement of $\sigma(e^+ e^- \to \pi^+ \pi^-)$ from threshold to 0.85 GeV$^2$ using Initial State Radiation with the KLOE detector

The KLOE collaboration Ambrosino, F. ; Antonelli, A. ; Antonelli, M. ; et al.
Phys.Lett.B 700 (2011) 102-110, 2011.
Inspire Record 859660 DOI 10.17182/hepdata.96268

We have measured the cross section of the radiative process e+e- -> pi+pi-gamma with the KLOE detector at the Frascati phi-factory DAPHNE, from events taken at a CM energy W=1 GeV. Initial state radiation allows us to obtain the cross section for e+e- -> pi+pi-, the pion form factor |F_pi|^2 and the dipion contribution to the muon magnetic moment anomaly, Delta a_mu^{pipi} = (478.5+-2.0_{stat}+-5.0_{syst}+-4.5_{th}) x 10^{-10} in the range 0.1 < M_{pipi}^2 < 0.85 GeV^2, where the theoretical error includes a SU(3) ChPT estimate of the uncertainty on photon radiation from the final pions. The discrepancy between the Standard Model evaluation of a_mu and the value measured by the Muon g-2 collaboration at BNL is confirmed.

15 data tables

Differential cross section for $e^+e^-\rightarrow\pi^+\pi^-\gamma$, with $50^o<\theta_\gamma<130^o$

Statistical covariance matrix for differential cross section for $e^+e^-\rightarrow\pi^+\pi^-\gamma$, with $50^o<\theta_\gamma<130^o$

Inverse statistical covariance matrix for differential cross section for $e^+e^-\rightarrow\pi^+\pi^-\gamma$, with $50^o<\theta_\gamma<130^o$

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Angular correlations in three-jet events in ep collisions at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Phys.Rev.D 85 (2012) 052008, 2012.
Inspire Record 793931 DOI 10.17182/hepdata.45283

Three-jet production in deep inelastic ep scattering and photoproduction was investigated with the ZEUS detector at HERA using an integrated luminosity of 127 pb-1. Measurements of differential cross sections are presented as functions of angular correlations between the three jets in the final state and the proton-beam direction. These correlations provide a stringent test of perturbative QCD and show sensitivity to the contributions from different colour configurations. Fixed-order perturbative QCD calculations assuming the values of the colour factors C_F, C_A and T_F as derived from a variety of gauge groups were compared to the measurements to study the underlying gauge group symmetry. The measured angular correlations in the deep inelastic ep scattering and photoproduction regimes are consistent with the admixture of colour configurations as predicted by SU(3) and disfavour other symmetry groups, such as SU(N) in the limit of large N.

9 data tables

Integrated 3-jet photoproduction cross section.

Integrated 3-jet cross sections in NC DIS.

Normalized differential 3-jet photoproduction cross section as a function of THETA(H).

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Di-jet production in gamma-gamma collisions at LEP2

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 58 (2008) 531-541, 2008.
Inspire Record 806241 DOI 10.17182/hepdata.51688

The production of two high-p_T jets in the interactions of quasi-real photons in e+e- collisions at sqrt{s_ee} from 189 GeV to 209 GeV is studied with data corresponding to an integrated e+e- luminosity of 550 pb^{-1}. The jets reconstructed by the k_T cluster algorithm are defined within the pseudo-rapidity range -1 < eta < 1 and with jet transverse momentum, p_T, above 3 GeV/c. The differential di-jet cross-section is measured as a function of the mean transverse momentum ptmean of the jets and is compared to perturbative QCD calculations.

11 data tables

Total cross section for dijet production. Errors are combined statistics and systematics.

Measured dijet production cross section as a function of the mean jet transverse momentum. Errors include both statistics and systematics.

Measured dijet production cross section as a function of jet pseudorapiditydifference. Errors include both statistics and systematics.

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Measurement of Charm Production Cross Sections in $e^+e^-$ Annihilation at Energies between 3.97 and 4.26 GeV

The CLEO collaboration Cronin-Hennessy, D. ; Gao, K.Y. ; Hietala, J. ; et al.
Phys.Rev.D 80 (2009) 072001, 2009.
Inspire Record 777917 DOI 10.17182/hepdata.47185

Using the CLEO-c detector at the Cornell Electron Storage Ring, we have measured inclusive and exclusive cross sections for the production of D+, D0 and Ds+ mesons in e+e- annihilations at thirteen center-of-mass energies between 3.97 and 4.26 GeV. Exclusive cross sections are presented for final states consisting of two charm mesons (DD, D*D, D*D*, Ds+Ds-, Ds*+Ds-, and Ds*+Ds*-) and for processes in which the charm-meson pair is accompanied by a pion. No enhancement in any final state is observed at the energy of the Y(4260).

6 data tables

Exclusive cross section for two body neutral non-strange charm mesons.

Exclusive cross section for two body charged non-strange charm mesons.

Exclusive cross section for two body strange charm mesons.

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Measurement of D mesons production in deep inelastic scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 07 (2007) 074, 2007.
Inspire Record 749371 DOI 10.17182/hepdata.45530

Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb^{-1}. Charm has been tagged by reconstructing D^{*+}, D^0, D^{+} and D_s^+ (+ c.c.) charm mesons. The charm hadrons were measured in the kinematic range p_T(D^{*+},D^0,D^{+}) > 3 GeV, p_T(D_s^+)>2 GeV and |\eta(D)| < 1.6 for 1.5 < Q^2 < 1000 GeV^2 and 0.02 < y < 0.7. The production cross sections were used to extract charm fragmentation ratios and the fraction of c quarks hadronising into a particular charm meson in the kinematic range considered. The cross sections were compared to the predictions of next-to-leading-order QCD, and extrapolated to the full kinematic region in p_T(D) and \eta(D) in order to determine the open-charm contribution, F_2^{c\bar{c}}(x,Q^2), to the proton structure function F_2.

24 data tables

Production cross section for all D0 mesons, those not originating fom D* decays and those originating from D* decays.

Production cross section for additional D* mesons (not decaying to D0) and all D* mesons.

Production cross section for D+ mesons.

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Leading neutron energy and p(T) distributions in deep inelastic scattering and photoproduction at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 776 (2007) 1-37, 2007.
Inspire Record 744787 DOI 10.17182/hepdata.45630

The production of energetic neutrons in $ep$ collisions has been studied with the ZEUS detector at HERA. The neutron energy and $p_T^2$ distributions were measured with a forward neutron calorimeter and tracker in a $40 \pb^{-1}$ sample of inclusive deep inelastic scattering (DIS) data and a $6 \pb^{-1}$ sample of photoproduction data. The neutron yield in photoproduction is suppressed relative to DIS for the lower neutron energies and the neutrons have a steeper $p_T^2$ distribution, consistent with the expectation from absorption models. The distributions are compared to HERA measurements of leading protons. The neutron energy and transverse-momentum distributions in DIS are compared to Monte Carlo simulations and to the predictions of particle exchange models. Models of pion exchange incorporating absorption and additional secondary meson exchanges give a good description of the data.

35 data tables

Ratio of leading neutron to inclusive cross sections integrated to the full PT range.

Normalized double differential cross sections for leading neutron production for the full DIS sample. Statistical errors only are given.

Normalized double differential cross sections for leading neutron production for the full DIS sample. Statistical errors only are given.

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Experimental study of exclusive H-2(e,e' p)n reaction mechanisms at high Q**2.

The CLAS collaboration Egiyan, K.S. ; Asryan, G. ; Gevorgyan, N. ; et al.
Phys.Rev.Lett. 98 (2007) 262502, 2007.
Inspire Record 741920 DOI 10.17182/hepdata.41751

The reaction $^2$H$(e,e^\prime p)n$ has been studied with full kinematic coverage for photon virtuality $1.75<Q^2<5.5$ GeV$^2$. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum ($p_n<100$ MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For $100<p_n<750$ MeV/c proton-neutron rescattering dominates the cross section, while $\Delta$ production followed by the $N\Delta \to NN$ transition is the primary contribution at higher momenta.

4 data tables

Recoil neutron momentum distributions.

Recoil neutron angular distributions for neutron momenta in the range 400 to 600 MeV.

Recoil neutron angular distributions for neutron momenta in the range 200 to 300 MeV.

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