Charged Meson Pair Production in $\gamma \gamma$ Interactions

Boyer, J. ; Burke, D.L. ; Butler, F. ; et al.
Phys.Rev.Lett. 56 (1986) 207, 1986.
Inspire Record 220003 DOI 10.17182/hepdata.20236

The cross section for the production of π+π− or K+K− pairs in γγ interactions is measured for mππ between 1.7 and 3.5 GeV/c2 and for two intervals of γγ center-of-mass scattering angle. Results are compared with predictions of a QCD model.

2 data tables match query

Data read off graph.

Data read off graph.


Inclusive Charged Particle Distribution in Nearly Threefold Symmetric Three Jet Events at $e$({CM}) = 29-{GeV}

Petersen, A. ; Abrams, G.S. ; Amidei, D. ; et al.
Phys.Rev.Lett. 55 (1985) 1954, 1985.
Inspire Record 216850 DOI 10.17182/hepdata.20285

We report a measurement of the inclusive charged-particle distribution for gluon jets derived from nearly threefold-symmetric three-jet events taken at center-of-mass energy of 29 GeV in e+e− annihilation. The charged-particle spectrum for these jets is observed to fall off more rapidly than those of quark jets of the same energy.

1 data table match query

Errors include both statistics and the uncertainty in correction factors. X is defined at the energy of the individual particle divided by the total energy of the jet to which it is assigned.


Measurement of the Total Hadronic Cross-section in $e^+ e^-$ Annihilation at $\sqrt{s}=29$-{GeV}

The MARK-II collaboration Von Zanthier, Christoph ; de Boer, W. ; Grindhammer, Guenter ; et al.
Phys.Rev.D 43 (1991) 34-45, 1991.
Inspire Record 295286 DOI 10.17182/hepdata.22852

A precise measurement of the ratio R of the total cross section e+e−→hadrons to the pointlike cross section e+e−→μ+μ− at a center-of-mass energy of 29.0 GeV is presented. The data were taken with the upgraded Mark II detector at the SLAC storage ring PEP. The result is R=3.92±0.05±0.09. The luminosity has been determined with three independent luminosity monitors measuring Bhabha scattering at different angular intervals. Recent calculations of higher-order QED radiative corrections are used to estimate the systematic error due to missing higher-order radiative corrections in the Monte Carlo event generators.

1 data table match query

No description provided.


Two photon production of pion pairs

Boyer, J. ; Butler, F. ; Gidal, G. ; et al.
Phys.Rev.D 42 (1990) 1350-1367, 1990.
Inspire Record 304882 DOI 10.17182/hepdata.22881

We present a new high-statistics measurement of the cross section for the process e+e−→e+e−π+π− at a center-of-mass energy of 29 GeV for invariant pion-pair masses M(π+π−) between 350 MeV/c2 and 1.6 GeV/c2. We observe the f2(1270) and measure its radiative width to be 3.15±0.04±0.39 keV. We also observe an enhancement in the π+π− spectrum near 1 GeV. General agreement is found with unitarized models of the γγ→π+π− reaction that include final-state interactions.

2 data tables match query

No description provided.

Statistical errors only.


Determination of $\alpha^- s$ From Energy-energy Correlations in $e^+ e^-$ Annihilation at 29-{GeV}

Wood, D.R. ; Petersen, A. ; Abrams, G.S. ; et al.
Phys.Rev.D 37 (1988) 3091, 1988.
Inspire Record 250899 DOI 10.17182/hepdata.23323

We have studied the energy-energy correlation in e+e− annihilation into hadrons at √s =29 GeV using the Mark II detector at the SLAC storage ring PEP. We find to O(αs2) that αs=0.158±0.003±0.008 if hadronization is described by string fragmentation. Independent fragmentation schemes give αs=0.10–0.14, and give poor agreement with the data. A leading-log shower fragmentation model is found to describe the data well.

6 data tables match query

Correlation data from the original PEP-5 detector.

Correlation Asymmetry data from the original PEP-5 detector.

Correlation data from the upgraded detector.

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Pion Pair Production From $\gamma \gamma$ Collisions at {PEP}

Smith, J.R. ; Burke, D.L. ; Abrams, G.S. ; et al.
Phys.Rev.D 30 (1984) 851, 1984.
Inspire Record 195739 DOI 10.17182/hepdata.23582

We have studied several features of the production of charged-hardon pairs by γγ collisions. We have measured the f0 partial width Γf0→γγ(Q2) for Q2 in the range 0<Q2<1.4 GeV2/c2, and obtained Γf0→γγ=2.52±0.13±0.38 keV at Q2≈0. The measured Q2 dependence is in agreement with the generalized vector-dominance model. The cross section for γγ→(π+π−+K+K−) in the mass region 1.6≤Mππ≤2.5 GeV/c2 has also been measured and the result compared with that expected from the QCD continuum.

1 data table match query

Data read from graph.. Both statistical and systematic errors included.


Measurements of Z Boson Resonance Parameters in e+ e- Annihilation

Abrams, G.S. ; Adolphsen, Chris ; Averill, D. ; et al.
Phys.Rev.Lett. 63 (1989) 2173, 1989.
Inspire Record 281818 DOI 10.17182/hepdata.20033

We have measured the mass of the Z boson to be 91.14±0.12 GeV/c2, and its width to be 2.42−0.35+0.45 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.46±0.10 GeV, corresponding to 2.8±0.6 neutrino species, with a 95%-confidence-level upper limit of 3.9.

1 data table match query

No description provided.


New Results From Asp on Single Photon Production at $\sqrt{s}$ 29-{GeV}

Hearty, C. ; Rothberg, J.E. ; Young, K.K. ; et al.
Phys.Rev.Lett. 58 (1987) 1711, 1987.
Inspire Record 244697 DOI 10.17182/hepdata.20171

This Letter reports results of a search for radiative production, by e+e− annihilation of particles that interact only weakly in matter. The search has been made in the total data set of 115 pb−1 acquired with the ASP detector at the SLAC storage ring PEP (s=29 GeV). No anomalous signal was observed. The number of generations of light neutrinos has been limited to Nν<7.5 (90% confidence level). Limits are also placed on the masses of particles predicted to exist by models of supersymmetry.

1 data table match query

No description provided.


First Measurements of Hadronic Decays of the $Z$ Boson

The MARK-II collaboration Abrams, G.S. ; Adolphsen, Chris ; Aleksan, R. ; et al.
Phys.Rev.Lett. 63 (1989) 1558, 1989.
Inspire Record 282670 DOI 10.17182/hepdata.20044

We have observed hadronic final states produced in the decays of Z bosons. In order to study the parton structure of these events, we compare the distributions in sphericity, thurst, aplanarity, and number of jets to the predictions of several QCD-based models and to data from lower energies. The data and models agree within the present statistical precision.

5 data tables match query

Corrected event shape distributions.

Corrected event shape distributions.

Corrected event shape distributions.

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A Search for Supersymmetric Electrons

Gladney, Larry D. ; Hollebeek, R.J. ; LeClaire, B. ; et al.
Phys.Rev.Lett. 51 (1983) 2253, 1983.
Inspire Record 192285 DOI 10.17182/hepdata.20505

A search for single electrons from the decay of singly produced scalar electrons has been made at the PEP storage ring at SLAC. No events of this type have been found in 123 pb−1 of data, resulting in a cross-section limit of less than 2.4×10−2 pb within the detector acceptance, and a 95%-confidence-level lower limit on the scalar-electron mass of 22.2 GeV/c2.

1 data table match query

No description provided.