Flechl, Martin
E+ E- Scattering
[5.0, 10.0]
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Measurement of the hadronic cross-section for the scattering of two virtual photons at LEP.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 24 (2002) 17-31, 2002.
Inspire Record 563730 DOI 10.17182/hepdata.48895

The interaction of virtual photons is investigated using the reaction e+e- -> e+e- hadrons based on data taken by the OPAL experiment at e+e- centre-of-mass energies sqrt(s_ee)=189-209 GeV, for W>5 GeV and at an average Q^2 of 17.9 GeV^2. The measured cross-sections are compared to predictions of the Quark Parton Model (QPM), to the Leading Order QCD Monte Carlo model PHOJET to the NLO prediction for the reaction e+e- -> e+e-qqbar, and to BFKL calculations. PHOJET, NLO e+e- -> e+e-qqbar, and QPM describe the data reasonably well, whereas the cross-section predicted by a Leading Order BFKL calculation is too large.

11 data tables
Table 1

Total cross section in the given phase space and assuming ALPHA = 1/137.

Table 2

Differential cross section as a function of X where X is the maximum value of X1 or X2, the upper and lower vertex values.

Table 3

Differential cross section as a function of Q**2 where Q**2 is the maximum value of Q1**2 or Q2**2, the upper and lower vertex values.

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K0 Production in e+ e- Annihilation

Luth, V. ; Pierre, F. ; Abrams, G.S. ; et al.
Phys.Lett.B 70 (1977) 120, 1977.
Inspire Record 119729 DOI 10.17182/hepdata.27537

The production of enutral kaons in e + e − annihilation has been measured for c.m. energies between 3.4 GeV and 7.6 GeV. Near 4 GeV the inclusive K S cross section shows an increase and structure similar to total hadron production. Roughly 40–45% of all hadronic final states contain kaons, except at 4.028 GeV and 4.415 GeV, where a significantly larger kaon fraction is observed.

2 data tables
Table 1

No description provided.

Table 2

THIS IS TWICE THE MEASURED KS CROSS SECTION. THE ERRORS ARE STATISTICAL ONLY. THERE IS 15 PCT ABSOLUTE NORMALIZATION ERROR, PLUS POSSIBLY SOME ENERGY DEPENDENT ERROR. THE DATA ARE NOT EQUALLY SPACED IN THE ENERGY INTERVALS.


THE PRODUCTION OF anti-SIGMA+- 's IN e+ e- ANNIHILATION

Ferguson, T. ; Buchanan, C.D. ; Nodulman, L. ; et al.
Phys.Lett.B 79 (1978) 161-164, 1978.
Inspire Record 140042 DOI 10.17182/hepdata.27422

We find an increase in ∑ ± production between E cm = 4 and 7 GeV which is consistent with charmed baryon production models. A search for the decay ∧ c − → ∑ ± π ± π − yields no significant peaks.

1 data table
Table 1

43 +- 16 ANTI-SIGMAS DETECTED ALTOGETHER.


Inclusive Production of $D$ Mesons in $e^+ e^-$ Annihilation at 7-{GeV}

Rapidis, P.A. ; Feldman, G.J. ; Abrams, G.S. ; et al.
Phys.Lett.B 84 (1979) 507-510, 1979.
Inspire Record 133123 DOI 10.17182/hepdata.27331

Inclusive momentum and energy spectra of neutral and charged D-mesons produced in e + e − annihilation at energies near 7 GeV are presented. The slope of the energy spectrum is similar to the charged pion spectrum at the same energy. The inclusive cross section σ(e + e − → D or D + anything) at 7 GeV is 4.8±1.3 nb.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

SCALING VARIABLE IS X(P=3,DEF=2*E(P=3)/SQRT(S)) > 0.54.

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Inclusive Baryon Production in e+ e- Annihilation

Piccolo, M. ; Peruzzi, I. ; Luke, D. ; et al.
Phys.Rev.Lett. 39 (1977) 1503, 1977.
Inspire Record 121395 DOI 10.17182/hepdata.20965

The inclusive production of antiprotons and Λ's in e+e− annihilation has been measured as a function of the c.m. energy in the range 3.7-7.6 GeV. We find that the baryon cross section has a behavior different from the total hadronic production. Our results show a rapid rise in the ratio σp¯σμμ between 4.4 and 5 GeV, consistent with what would be expected from charmed baryon production. Λ¯ production is 10-15% of p¯ production at all energies.

1 data table
Table 1

NOT INCLUDING SYSTEMATIC ERRORS.


Azimuthal Asymmetry in Inclusive Hadron Production by e+ e- Annihilation

Schwitters, R. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 35 (1975) 1320, 1975.
Inspire Record 100683 DOI 10.17182/hepdata.21192

We have observed an azimuthal asymmetry in inclusive hadron production by e+e− annihilation at the center-of-mass energy s=7.4 GeV. The asymmetry is caused by the polarization of the circulating beams in the storage ring and allows separate determination of the transverse and longitudinal structure functions. We find that transverse production dominates for x>0.2 where x is the scaling variable 2ps.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


rivet Analysis
Total Cross-Section for Hadron Production by electron-Positron Annihilation Between 2.4-GeV and 5.0-GeV Center-Of-Mass Energy

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 34 (1975) 764, 1975.
Inspire Record 100592 DOI 10.17182/hepdata.21227

The total cross section for hadron production by e+e− annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances ψ(3105) and ψ(3695), the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.

2 data tables
Table 1

No description provided.

Table 2

MEAN CHARGED MULTIPLICITY. ERRORS ARE STATISTICAL ONLY.


Production of 4 pi+- and 6 pi+- by e+ e- Annihilation Between 2.4-GeV and 7.4-GeV

Jean-Marie, B. ; Abrams, G.S. ; Boyarski, A. ; et al.
SLAC-PUB-1711, 1976.
Inspire Record 108089 DOI 10.17182/hepdata.18658

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Observation of Semileptonic Decays of Charmed Baryons

Vella, E. ; Trilling, G. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 48 (1982) 1515, 1982.
Inspire Record 176986 DOI 10.17182/hepdata.19674

Direct electrons are observed in baryon events produced in e+e− annihilation at center-of-mass energies above the ΛcΛ¯c threshold. These events are attributed to charmed-baryon pair production and subsequent Λc semileptonic decay. Various semileptonic branching ratios of the Λc are determined, including B(Λc→e+X)=(4.5±1.7)%.

2 data tables
Table 1

ELECTRON-BARYON RATIO ABOVE AND BELOW LAMBDA/C THRESHOLD.

Table 2

No description provided.


Observation of Charmed Baryon Production in e+ e- Annihilation

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.Lett. 44 (1980) 10, 1980.
Inspire Record 142743 DOI 10.17182/hepdata.20754

A peak in the pK−π+ and p¯K+π− invariant-mass spectra at 2.285±0.006 GeV/c2 is observed, which is associated with the lowest-lying charmed baryon (Λc). A cross section times branching ratio of 0.037±0.012 nb at Ec.m.=5.2 GeV is measured with a substantial fraction of the events produced with an equal recoiling mass. New measurements of inclusive p and Λ cross sections are also presented, allowing an estimate of the branching ratio B(Λc→pK−π+)=0.022±0.010.

3 data tables
Table 1

THE TOTAL INCLUSIVE CHARMED LAMBDA CROSS SECTION IS DERIVED FROM THE OBSERVED PRODUCTION RATE VIA THE <P K- PI+> CHANNEL USING THE STEP IN INCLUSIVE PROTON PRODUCTION AT THE CHARMED-BARYON THRESHOLD AND REASONABLE ASSUMPTIONS. THE BRANCHING RATIO (LAMBDA/C+ --> P K- PI+) IS THEN 2.2 +- 1.0 PCT.

Table 2

ACTUALLY TWICE THE INCLUSIVE ANTI-PROTON CROSS SECTION (EACH BARYON PAIR IS COUNTED TWICE).

Table 3

EACH BARYON PAIR PRODUCED IS OF COURSE COUNTED TWICE IN THIS CROSS SECTION.