HEPData Search

The production of electron-positron pairs of masses below 1200 MeV/ c 2 and of transverse momentum above 1.8 GeV/ c has been studied in pp collisions at √ s = 53 and 63 GeV. The cross section for ϱ, ω, and φ production are presented. The continuum below 600 MeV/ c 2 is consistent with origination from Dalitz decays of η and ω mesons and from semileptonic decay of D and D mesons.

1 data table

Table 1

No description provided.

Hadron Production by Virtual Photons in the Quark Fragmentation Region

Scarr, J.M. ; Chen, C.K. ; Knowles, J. ; et al.

Nucl.Phys.B 135 (1978) 224-236, 1978.

Inspire Record 122308 DOI 10.17182/hepdata.35139

We have measured the inclusive electroproduction of positive and negative hadrons in the quark fragmentation region using the streamer chamber at DESY. Data are presented in terms of the variable z p = p / v in the kinematic region 1.8 < W < 2.8 GeV and 0.3 < Q 2 < 1.4 GeV 2 . The positive hadron distributions contain a strong proton component. After subtraction of the proton component and elastic rho events, the distribution (1/ σ tot ) d σ /d z p for positive and negative hadrons agrees well with the corresponding distribution from e + e − annihilation (DORIS data). This behaviour supports the validity of the quark-parton model at surprisingly low Q 2 and W .

1 data table

Table 1

No description provided.

J/psi Production by 24-GeV/c Protons

The Annecy(LAPP)-Brussels-Freiburg collaboration Bamberger, A. ; Binon, F.G. ; Bricman, C. ; et al.

Nucl.Phys.B 134 (1978) 1-13, 1978.

Inspire Record 122150 DOI 10.17182/hepdata.35143

We report measurements at the CERN PS of the production cross section of J/ψ(3.1) by 24 GeV protons on hydrogen, carbon, and tungsten.

2 data tables

Table 1

No description provided.

Table 2

ASSUME B.R.(E+E-) =0.069.

Charged Hadron Multiplicities and Inclusive pi- Distributions in Inelastic e p Scattering

Chen, C.K. ; Knowles, J. ; Martin, D. ; et al.

Nucl.Phys.B 133 (1978) 13-37, 1978.

Inspire Record 121936 DOI 10.17182/hepdata.35153

Electroproduction of hadrons is studied in the kinematic region W < 2.8 GeV and 0.3 < Q 2 < 1.4 GeV 2 using the DESY streamer chamber. Prong cross sections, charged-particle multiplicities and inclusive π − distributions are presented. The average charged multiplicity is found to be independent of Q 2 in the Q 2 range studied here; however it is lower than in photoproduction. The fraction of forward π − is found to be significantly less in electroproduction than in photoproduction. The 〈 p ⊥ 2 〉 for inclusive π − is, for all x values, similar to that found in photoproduction.

15 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Measurement of the Production of Massive $e^+ e^-$ Pairs in Proton Proton Collisions at $\sqrt{s}$=62.4 GeV

The CERN-Columbia-Oxford-Rockefeller & CCOR collaborations Angelis, A.L.S. ; Besch, H.J. ; Blumenfeld, Barry J. ; et al.

Phys.Lett.B 87 (1979) 398-402, 1979.

Inspire Record 142896 DOI 10.17182/hepdata.27278

An apparatus consisting of a superconducting solenoid magnet, cylindrical drift-chambers, and two arrays of lead-glass Čerenkov counters has been used at the CERN ISR to study the production of e + e − pairs of invariant mass above 6.5 GeV/ c 2 . Cross sections for the continuum and the ϒ family of resonances are presented, as well as the mean transverse momentum 〈 p T 〉 of the electron-positron pairs in the continuum and resonance region.

1 data table

Table 1

No description provided.

Inclusive High {P(T)} $\omega^0$ and $\eta{'}$ Production at the {ISR}

Diakonou, M. ; Kourkoumelis, C. ; Resvanis, L.K. ; et al.

Phys.Lett.B 89 (1980) 432-436, 1980.

Inspire Record 143931 DOI 10.17182/hepdata.27254

The inclusive production cross section of ω 0 and η′ were measured at transverse momenta of 3 to 7GeV/ c at 90° in the centre of mass. The ω 0 /π 0 and η′/π 0 production ratios were found to be 0.87 ± 0.17 and 0.9 ± 0.25, respectively, at 3.5 GeV and constant up to 7 GeV/ c . The large meson/ π 0 production ratio supports the hypothesis that high- p T mesons are the leading fragments of the basic constituent jet. The η ′/ η ratio exemplifies the SU(3) singlet nature of the η ′.

2 data tables

Table 1

OMEGA DECAY TO PI0 GAMMA IS DETECTED.

Table 2

ETAPRIME DECAY TO GAMMA GAMMA IS DETECTED.

Observation of High Mass electron-Positron Pairs Produced in Proton Proton Collisions at the CERN ISR

Busser, F.W. ; Camilleri, L. ; Di Lella, L. ; et al.

Phys.Lett.B 56 (1975) 482, 1975.

Inspire Record 99170 DOI 10.17182/hepdata.27858

In an experiment performed at the CERN Intersecting Storage Rings (ISR), 11 e + e − pairs of high invariant mass value (> 2.5 GeV/c 2 ) have been observed. Of these events, 9 can be interpreted as arising from the reaction p + p → J (3.1) + anything. the cross-section for this reaction is estimated and compared with the result obtained at lower centre-of-mass energies.

1 data table

Table 1

No description provided.

Elastic Electron-Proton Scattering at Momentum Transfers up to 110 Fermi$^−^2$

Behrend, H.J. ; Brasse, F.W. ; Engler, J. ; et al.

Nuovo Cim.A 48 (1967) 140-164, 1967.

Inspire Record 1185336 DOI 10.17182/hepdata.1060

Using the internal beam of DESY elastic electron-proton cross-sections were measured at various angles between 32° and 130°, and with momentum transfers ofq 2=39, 60, 80 and 110 fm−2. Two single-quadrupole spectrometers, movable around a common liquid-hydrogen target, were used for analysing the momentum of the scattered electrons. Čerenkov and shower counters discriminated against pion and low-energy background. As a cross-section reference, recoil protons from elastic scattering atq 2=10 fm−2 were used, with a quantameter serving as an intermediate monitor. The data are consistent with the Rosenbluth formula, giving real form factorsG E andG M . Both continue to decrease with increasing momentum transfer, but somewhat faster than indicated by measurements performed so far.

9 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Some Recent Measurements of Proton Form Factors

Small-Angle Electron-Proton Elastic Scattering Cross Sections for Momentum Transfers between 10 and 105 f $^{-2}$

Production of High Transverse Momentum Low Mass Electron - Positron Pairs in High-energy $p p$ Collisions

Hadron Production by Virtual Photons in the Quark Fragmentation Region

J/psi Production by 24-GeV/c Protons

Charged Hadron Multiplicities and Inclusive pi- Distributions in Inelastic e p Scattering

A Measurement of the Production of Massive $e^+ e^-$ Pairs in Proton Proton Collisions at $\sqrt{s}$=62.4 GeV

Inclusive High {P(T)} $\omega^0$ and $\eta{'}$ Production at the {ISR}

Observation of High Mass electron-Positron Pairs Produced in Proton Proton Collisions at the CERN ISR

Elastic Electron-Proton Scattering at Momentum Transfers up to 110 Fermi$^−^2$