HEPData Search

Showing 10 of 31 results

Exclusive leptoproduction of rho0 mesons from hydrogen at intermediate virtual photon energies.

The HERMES collaboration Airapetian, A. ; Akopov, N. ; Akushevich, I. ; et al.

Eur.Phys.J.C 17 (2000) 389-398, 2000.

Inspire Record 526550 DOI 10.17182/hepdata.47010

Measurements of the cross section for exclusive virtual-photoproduction of rho^0 mesons from hydrogen are reported. The data were collected by the HERMES experiment using 27.5 GeV positrons incident on a hydrogen gas target in the HERA storage ring. The invariant mass W of the photon-nucleon system ranges from 4.0 to 6.0 GeV, while the negative squared four-momentum Q^2 of the virtual photon varies from 0.7 to 5.0 GeV^2. The present data together with most of the previous data at W > 4 GeV are well described by a model that infers the W-dependence of the cross section from the dependence on the Bjorken scaling variable x of the unpolarized structure function for deep-inelastic scattering. In addition, a model calculation based on Off-Forward Parton Distributions gives a fairly good account of the longitudinal component of the rho^0 production cross section for Q^2 > 2 GeV^2.

2 data tables

Table 1

Cross sections are corrected for radiative effects (which typically amount s to 18 PCT).

Table 2

Longitudinal cross sections. The listed uncertainties include both the total error on the measured RHO0 photoproduction cross sections and the error on theparametrization of R for W<7 GeV.

Determination of the deep inelastic contribution to the generalised Gerasimov-Drell-Hearn integral for the proton and neutron.

The HERMES collaboration Ackerstaff, K. ; Airapetian, A. ; Akopov, N. ; et al.

Phys.Lett.B 444 (1998) 531-538, 1998.

Inspire Record 476388 DOI 10.17182/hepdata.44128

The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant.

13 data tables

Table 1

Gerasimov-Drell-Hearn sum rule for proton as a function of Q2.

Table 2

Gerasimov-Drell-Hearn sum rule for neutron as a function of Q2 (integral spans from Q2/2M to infinity instead of zero to infinity, see paper).

Table 3

Cross section difference for the proton data. Statistical errors only.

More…

Study of D*+ and search for D**0 production by neutrinos in BEBC

The Big Bubble Chamber Neutrino collaboration Asratvan, A.E. ; Aderholz, M. ; Ammosov, V.V. ; et al.

Z.Phys.C 68 (1995) 43-46, 1995.

Inspire Record 395454 DOI 10.17182/hepdata.47928

Data from BEBC experiments are combined to provide large statistics for neutrino interactions. ChargedD* mesons are produced in (1.22±0.25)% of neutrino and (1.01±0.31)% of antineutrino charged current interactions. The mean fraction of the hadronic laboratory energy taken by theD*+ in these events is 0.59±0.03±0.08. Less than 18% of all chargedD* mesons from (anti)neutrino interactions are found to be daughters ofD**0 (at the 90% confidence level).

4 data tables

Table 1

Mean fractional hadronic energy carried by the D*+- in the laboratory system.

Table 2

Mean value of the Bjorken scaling variable X.

Table 3

Rate of charged D* meson production per charged current neutrino interaction.

More…

Observation of D(s)** (2536) meson production by neutrinos in BEBC

The Big Bubble Chamber Neutrino collaboration Asratyan, A.E. ; Aderholz, M. ; Ammosov, V.V. ; et al.

Z.Phys.C 61 (1994) 563-566, 1994.

Inspire Record 363214 DOI 10.17182/hepdata.14264

Neutrino interactions in BEBC produce theDS** (2536) charmed strange meson. The mass of this state is 2534.2±1.2 MeV. The production rate is 0.011±0.005 per neutrino charged current interaction at a mean neutrino energy of 61 GeV. An earlier claim for another$c\bar s$ bound state near 2565 MeV, produced in neutrino interactions, is not supported.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Study of the system K0(S) K0(L) pi- in the pi- p interactions at 40-GeV.

Barkov, B.P. ; Bolonkin, B.V. ; Vladimirsky, V.V. ; et al.

47-50, 1991.

Inspire Record 329124 DOI 10.17182/hepdata.75419

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

ELASTIC SCATTERING OF pi- AND K- MESONS ON PROTONS AT 43-GeV/c MOMENTUM

The SIGMA-AYaKS & Dubna-Serpukhov-Tbilisi collaborations Antipov, Yu.M. ; Batarin, V.A. ; Bezzubov, V.A. ; et al.

Sov.J.Nucl.Phys. 48 (1988) 85, 1988.

Inspire Record 253399 DOI 10.17182/hepdata.38881

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

FROM EXPONENTIAL FIT OF D(SIG)/D(T) IN RANGE 0. < ABS(T) < 1. GEV.

Strangeness Suppression and Inclusive $\phi$ and $K^*$0 Production in $K^+ P$ Interactions at 250-{GeV}/c

The EHS - NA22 collaboration Adamus, M. ; Agababyan, N.M. ; Ajinenko, I.V. ; et al.

Phys.Lett.B 198 (1987) 427-432, 1987.

Inspire Record 254217 DOI 10.17182/hepdata.30075

We present inclusive ¶ and K *0 (892) cross sections and Feynman x -spectra in K + p collisions at 250 GeV/ c . In the K + fragmentation region, x > 0.2, the ratio of ¶ to K *0 (892) is used to estimate the strangeness suppression factor λ , with the result γ =0.17 ± 0.02 (stat ± 0.01 (syst). We see no evidence for an energy dependence of λ in the CM energy range 7.8 ≤ s ≤21.7 GeV.

4 data tables

Table 1

RESULTS AT 32 AND 70 GEV INCLUDED FOR COMPARISON.

Table 2

RESULTS AT 32 AND 70 GEV INCLUDED FOR COMPARISON.

Table 3

RESULTS AT 32 AND 70 GEV INCLUDED FOR COMPARISON.

More…