HEPData Search

Showing 10 of 197 results

The Reaction $e^+ e^- \to \Omega \pi^0$ in the Center-of-mass Energy Range From 1.0-{GeV} to 1.4-{GeV}

Dolinsky, S.I. ; Druzhinin, V.P. ; Dubrovin, M.S. ; et al.

Phys.Lett.B 174 (1986) 453-457, 1986.

Inspire Record 233797 DOI 10.17182/hepdata.69630

The reaction e + e - → ωπ 0 → π 0 π 0 γ has been studied with the Neutral Detector at the VEPP-2M collider. The cross section values differ from the predictions of the vector dominance model with one ϱ(770) meson, and are consistent with the contributions of ϱ(770) and ϱ(1600). ϱ(1250) has not been observed.

1 data table match query

Table 1

No description provided.

Measurement of the $K_L$ nuclear interaction length in the NaI(Tl) calorimeter

Achasov, M.N. ; Beloborodov, K.I. ; Berdyugin, A.V. ; et al.

JINST 10 (2015) P09006, 2015.

Inspire Record 1392011 DOI 10.17182/hepdata.69471

In the study of the reaction $e^+e^-\to K_{S}K_{L}$ at the VEPP-2M $e^+e^-$ collider with the SND detector the nuclear interaction length of $K_{L}$ meson in NaI(Tl) has been measured. Its value is found to be 30--50 cm in the $K_{L}$ momentum range 0.11--0.48 GeV/$c$. The results are compared with the values used in the simulation programs GEANT4 and UNIMOD.

1 data table match query

Table 1

The energy interval ($\sqrt{s}$), integrated luminosity ($IL$), number of selected events ($N$), number of background events ($N_{\rm bkg}$), number of events with five or more photons ($N_{5\gamma}$, $N_{5\gamma,{\rm bkg}}$), and the measured $K_L$ nuclear interaction length in NaI(Tl) ($\lambda_{\rm int}$).

A Search For the $\rho^0$ Meson and a Check of the Dispersion Relations in π-N Scattering

Zinov, V.G. ; Konin, A.D. ; Korenchenko, S.M. ; et al.

Sov.Phys.JETP 11 (1960) 1233-1238, 1960.

Inspire Record 1407582 DOI 10.17182/hepdata.70224

The total 1r- -p interaction cross sections (of) were measured with an accuracy of 1.5-2% for about 50 pion energies between 140 and 360 Mev. The pion energy was known to within ± 1%. No anomalies in the energy dependence of Of were found which could indicate the existence of a p0meson with a mass in the range of 270 to 410 Mev/c2• The data are inconsistent with the energy value E2 = 650 Mev for the second maximum of Of found by Frisch et al. 7 but agree with the conclusion drawn by Brisson et al. 8 that it should be located at a lower energy ( E2 :::::: 610 Mev). The data are in agreement with the dispersion relations for 1r- -p scattering. It is thus demonstrated that the PuppiStanghellini problem as such no longer exists and that it arose only as a result of an inaccurate knowledge of the total 1r--p interaction cross section.

1 data table match query

Table 1

No description provided.

Measurement of the polarization of the backscattered neutron from the reaction gamma p -> pi n in the region of the second resonance

Wallraff, Wolfgang ;

BONN-PI-1-162, 1972.

Inspire Record 1498200 DOI 10.17182/hepdata.75411

None

1 data table match query

Table 1

No description provided.

Polarisation of recoil neutrons from single-pion photoproduction off protons in the resonance region

Hahn, U. ; Wallraff, W. ; Weingarten, W. ;

BONN-PI-1-143, 1971.

Inspire Record 1498199 DOI 10.17182/hepdata.75407

None

1 data table match query

Table 1

No description provided.

rivet Analysis
Measurement of the $e^+e^- \to \eta\pi^+\pi^-$ cross section in the center-of-mass energy range 1.22--2.00 GeV with the SND detector at the VEPP-2000 collider

The SND collaboration Aulchenko, V.M. ; Achasov, M.N. ; Barnyakov, A.Yu. ; et al.

Phys.Rev.D 91 (2015) 052013, 2015.

Inspire Record 1332929 DOI 10.17182/hepdata.73176

In the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider the cross section for the process $e^+e^-\to\eta\pi^+\pi^-$ has been measured in the center-of-mass energy range from 1.22 to 2.00 GeV. Obtained results are in agreement with previous measurements and have better accuracy. The energy dependence of the $e^+e^-\to\eta\pi^+\pi^-$ cross section has been fitted with the vector-meson dominance model. From this fit the product of the branching fractions $B(\rho(1450)\to\eta\pi^+\pi^-)B(\rho(1450)\to e^+e^-)$ has been extracted and compared with the same products for $\rho(1450)\to\omega\pi^0$ and $\rho(1450)\to\pi^+\pi^-$ decays. The obtained cross section data have been also used to test the conservation of vector current hypothesis.

1 data table match query

Table 1

The c.m. energy ($\sqrt{s}$), integrated luminosity ($L$), detection efficiency ($\varepsilon$), number of selected signal events ($N$), radiative-correction factor ($1 + \delta$), measured $e^+e^- \to \eta \pi^+\pi^-$ Born cross section ($\sigma_B$). For the number of events and cross section the statistical error is quoted. The systematic uncertainty on the cross section is 8.3% at $\sqrt{s}<1.45$ GeV, 5.0% at $1.45<\sqrt{s}<1.60$ GeV, and 7.8% at $\sqrt{s}>1.60$ GeV.