HEPData Search

We have measured the inclusive production of J ψ in 16 and 22 GeV π − copper collisions in a wide aperture magnetic spectrometer. The cross section per Cu nucleus for x > 0 corrected for branching ratio is 64 ± 38 nb at 16 GeV and 196 ± 38 nb at 22 GeV. As threshold is approached, the mean values of the Feynman x distribution increase and the cross section for J ψ production drops steeply. This can be understood in terms of the quark-fusion model where the antiquark content of the pion makes an increasingly significant contribution as M 2 s increases.

2 data tables

Table 1

Table 2

Measurement of inclusive electron cross-section in gamma gamma collisions at TRISTAN

The TOPAZ collaboration Iwasaki, M. ; Enomoto, R. ; Hayashii, H. ; et al.

Phys.Lett.B 341 (1994) 99-108, 1994.

Inspire Record 378075 DOI 10.17182/hepdata.43778

We have studied open charm production in $\gamma \gamma$ collisions with the TOPAZ detector at the TRISTAN $e~{+}e~{-}$ collider. In this study, charm quarks were identified by electrons (and positrons) from semi-leptonic decays of charmed hadrons. The data corresponded to an integrated luminosity of 95.3 pb$~{-1}$ at a center-of-mass energy of 58 GeV. The results are presented as the cross sections of inclusive electron production in $\gamma \gamma$ collisions with an anti-tag condition, as well as the subprocess cross sections, which correspond to resolved-photon processes. The latter were measured by using a sub-sample with remnant jets. A comparison with various theoretical predictions based on direct and resolved-photon processes showed that our data prefer that with relatively large gluon contents in a photon at small $x (x \le 0.1)$, with the next-to-leading order correction, and with a charm-quark mass of 1.3 GeV.

2 data tables

Table 1

The description of events with anti-tag, remnant-jet-tag, and no-tag are presnted in text.

Table 2

A Study of D*+- production in Z0 decays

The OPAL collaboration Alexander, G. ; Allison, J. ; Allport, P.P. ; et al.

Phys.Lett.B 262 (1991) 341-350, 1991.

Inspire Record 315060 DOI 10.17182/hepdata.9272

In this paper an investigation of the production of D ∗ ± mesons produced in e + e − collisions at energies around the Z 0 pole is presented. Based on 115 D ∗ ± mesons with x D∗  2E D ∗ /E cm > 0.2 the properties of D ∗ mesons produced in the reaction Z 0 → c c are studied. Fixing the yield and the fragmentation function of bottom quarks to the values obtained at LEP using lepton tags, and average energy fraction of the D ∗ ± mesons from primary charmed quarks of 〈x c → D ∗ 〉 = 0.52 ± 0.03 +- 0.01 is found and Γ z 0 →c c = (323 ± 61 ± 35) MeV is determined. The first error is the combined statistical and systematic error from this experiment, and the second the total error from other sources.

2 data tables

Table 1

FD denotes the fraction of D* mesons from primary charmed quarks, derived from the fit (see text).

Table 2

No description provided.

EXPERIMENTAL DATA ON ELASTIC p p, n p, p d AND p gamma FORWARD SCATTERING AT INTERMEDIATE-ENERGIES

Dobrovolsky, A.V. ; Khanzadeev, A.V. ; Korolev, G.A. ; et al.

LENINGRAD-88-1454, 1988.

Inspire Record 270168 DOI 10.17182/hepdata.38078

None

26 data tables

Table 1

Table 2

Table 3

More…

Charge Asymmetry Measurement in $e^+ e^- \to \mu^+ \mu^-$ and $\tau^+ \tau^-$ Reactions at $\sqrt{s}=52$-{GeV}

The TOPAZ collaboration Adachi, I. ; Aihara, H. ; Dijkstra, H.B. ; et al.

Phys.Lett.B 208 (1988) 319-323, 1988.

Inspire Record 251920 DOI 10.17182/hepdata.29948

The reactions e + e − → μ + μ − and τ + τ − were measured at s =52 GeV and 55 GeV by using the TOPAZ detector at TRISTAN. For the combined data, the observed charge asymmetry is −0.29±0.13 and the total cross section is 27.9±3.0 (stat.)±0.8 (syst.) pb for μ + μ − production, and those for τ + τ − production are −0.20±0.14 and 35.7±4.3 (stat.)±2.4 (syst.)pb, respectively. These values are consistent with predictions by the standard model of electroweak interactions.

6 data tables

Table 1

Table 2

Table 3

More…

Inclusive $\pi^0$ Production in $\pi^+ p$, $K^+ p$ and $p p$ Interactions at 250-{GeV}/$c$

The NA22 collaboration Aiinenko, I.V. ; Atayan, M.R. ; Belokopytov, Yu. A. ; et al.

Z.Phys.C 35 (1987) 7, 1987.

Inspire Record 240345 DOI 10.17182/hepdata.40897

Data are presented on inclusive π0 production in the forward c.m. hemisphere (xF>0.025) in π+p,K+p andpp interactions at 250 GeV/c. These data are compared to results at other energies and interpreted in terms of quark-parton models.

4 data tables

Table 1

Table 2

Table 3

More…

A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.

Z.Phys.C 36 (1987) 27, 1987.

Inspire Record 237043 DOI 10.17182/hepdata.39599

TheA-dependence of the polarization ofΛ0,s produced inclusively in neutron-nucleus interactions at a mean neutron momentum of about 40 GeV/c has been measured in an experiment performed using the BIS-2 spectrometer at the Serpukhov accelerator. Carbon, Aluminium and Copper targets were used. TheΛ0,s were produced in the kinematical region of 0.6<pT<1.3 GeV/c and 0.2<xF<0.9. Describing the polarization of theΛ0,s by ℘=a·A a value of (−0.15+0.07/−0.60) was obtained by a fit to our data.

2 data tables

Table 1

POLARIZATION IS DESCRIBED BY A POWER LOW: POL = C*A**B, WHERE C = -1.1, +0.4, -0.3 , A- ATOMIC NUMBER AND B = -0.15, +0.07, -0.6.

Table 2

COMPARISON BETWEEN HADRONIC FINAL STATES PRODUCED IN mu p AND e+ e- INTERACTIONS

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.

Z.Phys.C 35 (1987) 417, 1987.

Inspire Record 233424 DOI 10.17182/hepdata.16655

A comparison is made between the properties of the final state hadrons produced in 280 GeV μp interactions and ine+e− annihilation. The Lund model of hadroproduction is used as an aid in understanding the differences observed. The hadron distributions from μp ande+e− interactions are consistent with the quark parton model assumption of environmental independence, provided that the differences in heavy quark production and hard QCD effects in the two processes are taken into account. A comparison with aK+p experiment is also made. Values are also determined for the Lund model parameters σq = 0.410 ± 0.002 ± 0.020 GeV and σ′ = 0.29−0.15 −0.13+0.09+0.10 GeV, controlling the transverse momenta in fragmentation and intrinsic transverse momenta of the struck quark respectively.

23 data tables

Table 1

With respect to the virtual photon axis.

Table 2

With respect to the sphericity axis.

Table 3

With respect to the thrust axis.

More…

STUDY OF anti-p p ELASTIC SCATTERING AT 22.4-GeV/c

The Dubna-Alma Ata-Kosice-Moscow-Prague-Sofiya-Helsinki collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.

Sov.J.Nucl.Phys. 44 (1986) 969, 1986.

Inspire Record 222984 DOI 10.17182/hepdata.39005

None

3 data tables

Table 1

Table 2

INTEGRATED D(SIG)/D(T).

Table 3

OBTAINED FROM FIT D(SIG)/D(T)=A*EXP(B*T+C*T**2) IN 0.05 < -T < 0.3.

Date

Collaboration

Subject_areas

Phrases

Reactions

Observables

CM Energies (GeV)

Authors Reset

Precision measurement of R = sigma-L / sigma-T on hydrogen, deuterium and beryllium targets in deep inelastic electron scattering

Production of $J/\psi$ in 16-{GeV} and 22-{GeV} $\pi^-$ Cu Collisions

Measurement of inclusive electron cross-section in gamma gamma collisions at TRISTAN

A Study of D*+- production in Z0 decays

EXPERIMENTAL DATA ON ELASTIC p p, n p, p d AND p gamma FORWARD SCATTERING AT INTERMEDIATE-ENERGIES

Charge Asymmetry Measurement in $e^+ e^- \to \mu^+ \mu^-$ and $\tau^+ \tau^-$ Reactions at $\sqrt{s}=52$-{GeV}

Inclusive $\pi^0$ Production in $\pi^+ p$, $K^+ p$ and $p p$ Interactions at 250-{GeV}/$c$

A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

COMPARISON BETWEEN HADRONIC FINAL STATES PRODUCED IN mu p AND e+ e- INTERACTIONS

STUDY OF anti-p p ELASTIC SCATTERING AT 22.4-GeV/c