Battiston, R.
DSIG/DCOSTHETA
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Measurement of Jet Production Properties at the CERN anti-p p Collider

The UA2 & Bern-CERN-Copenhagen-Orsay-Pavia-Saclay collaborations Bagnaia, P. ; Banner, M. ; Battiston, R. ; et al.
Phys.Lett.B 144 (1984) 283-290, 1984.
Inspire Record 202658 DOI 10.17182/hepdata.30516

Jet production properties at s = 540 GeV have been measured in the UA2 detector at the CERN p p Collider. Results on the total transverse momentum of the jet system, on the parton density in the nucleon (structure function) and on the two-jet angular distributions are reported. The data are compared with QCD predictions and extrapolations from lower energy experiments.

2 data tables
Table 1

DISTRIBUTION OF THE SCATTERING ANGLE OF THE 2-JET AXIS IN THE 2-JET COM FRAME WITH A NORMALISATION FIXED AT 1 FOR COS(THETA*) = 0.

Table 2

STRUCTURE FUNCTION IS DEFINED AS F(X) WHERE D3(SIG)/DX1/DX2/DCOS(THETA) = (F(X1)/X1)*(F(X2)/X2)*D(SIG)/DCOS(THETA).


Inclusive Production of Vector and Tensor Mesons in anti-Proton-Proton Annihilation and Nonannihilation Interactions at 9.1-GeV/c

The LIVERPOOL-STOCKHOLM collaboration Markytan, M. ; Johnson, P. ; Mason, P. ; et al.
Nucl.Phys.B 143 (1978) 263-284, 1978.
Inspire Record 136559 DOI 10.17182/hepdata.8198

Cross sections have been determined for the inclusive production of vector (ϱ 0 , ω, K ∗ ) and tensor (f, A 2 ± ) mesons in p p reactions at 9.1 GeV/c for both annihilation and non-annihilation processes. Distributions in the Feynman variable x and transverse momentum squared, p T 2 , have been examined for the ϱ 0 , ω and f mesons. The slopes for p T 2 appear to be exponential and decrease with increasing particle mass for both annihilation and non-annihilation reactions, furthermore the slopes have consistently higher values for non-annihilation reactions. Comparisons with other data indicate that the ratio ϱ 0 / π − is independent of antiproton momentum in annihilation processes.

13 data tables
Table 1

NON-ANNIHILATION EVENTS.

Table 2

No description provided.

Table 3

No description provided.

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A STUDY OF e+ e- ANNIHILATION IN THE 1400-MeV TO 2250-MeV ENERGY RANGE WITH THE MAGNETIC DETECTOR DM2 AT DCI

Augustin, J.E. ; Ayach, L. ; Calcaterra, A. ; et al.
LAL-83-21, 1983.
Inspire Record 192321 DOI 10.17182/hepdata.13242

None

5 data tables
Table 1

ASSUMING ABS(GE)=ABS(GM).

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
>A Measurement of $e^+ e^- \to \bar{p} p$ for 1975-{MeV} $\le \sqrt{s} \le$ 2250-{MeV}

Bisello, D. ; Limentani, S. ; Nigro, M. ; et al.
Nucl.Phys.B 224 (1983) 379, 1983.
Inspire Record 190558 DOI 10.17182/hepdata.33935

The e + e − → p p cross section has been measured in the energy interval (1975 ⩽ 2 E ⩽ 2250) MeV for |cos θ | < 0.7. The measurement is based on ∼ 100 events, thus improving by a factor 3 on the previous existing statistics in this energy interval. The form factor | G | 2 is given as a function of energy under the assumption | G E | = | G M |. We also give the first measurement of the differential cross section, averaged over the energy interval, and estimate the ratio G M |/| G E | from it.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Exclusive Production of Hadron Pairs at Large Momentum Transfer in Photon-photon Interactions

The PLUTO collaboration Berger, Christoph ; Deuter, A. ; Genzel, H. ; et al.
Phys.Lett.B 137 (1984) 267-271, 1984.
Inspire Record 194772 DOI 10.17182/hepdata.30576

We report on the exclusive production of π, K and proton pairs from photon-photon interactions at momentum transfers | t |⩾1 GeV 2 . Using the PLUTO detector at the e + e − storage ring PETRA, we have observed 15 events in an integrated luminosity of 41.7 pb −1 . The data lie far below the expectations for point-like hadrons, and are in reasonable agreement with the QCD-based predictions of Brodsky and Lepage.

3 data tables
Table 1

THIS METHOD OF ANALYSIS OF THE OBSERVED RATIO OF HADRON TO MUON PAIRS, IS TIED TO THE SPECIFIC DETECTOR ACCEPTANCE, BUT HAS THE ADVANTAGE OF BEING VIRTUALLY INDEPENDENT OF THE HADRON MASSES.

Table 2

SEE COMMENT IN PREVIOUS TABLE.

Table 3

THIS METHOD OF ANALYSIS OF THE CROSS SECTION AT 90 DEG IN THE CM AS A FUNCTION OF PCM IS MORE EASILY COMPARED WITH THEORETICAL PREDICTIONS BUT MORE DEPENDENT ON THE SPECIFIC HADRON MASSES.


Production of the F(0) Meson in Photon-photon Collisions

The CELLO collaboration Behrend, H.J. ; Fenner, H. ; Schachter, M.J. ; et al.
Z.Phys.C 23 (1984) 223, 1984.
Inspire Record 199731 DOI 10.17182/hepdata.16320

The production of thef0 in two photon collisions, with the subsequent decayf0→π+π− has been observed in the CELLO detector at PETRA. Thef0 peak was found to lie on a dipion continuum and to be shifted downwards in mass by ≃50 MeV/c2. The ππ mass spectrum from 0.8 to 1.5 GeV/c2 was well fitted by the model of Mennessier using only a unitarised Born amplitude and helicity 2f0 amplitude. The previously observed mass shift and distortion of thef0 peak are explained by strong interference between the Born andf0 amplitudes. The only free parameter in the fit of the data to the model is the radiative widthΓγγ(f0). It was found that:Γγγ(f0)=2.5±0.1±0.5 keV where the first (second) quoted errors are statistical (systematic).

2 data tables
Table 1

Data read from graph.

Table 2

Data read from graph.


rivet Analysis
Pion Pair Production in Photon-photon Interactions

The PLUTO collaboration Berger, Christoph ; Deuter, A. ; Genzel, H. ; et al.
Z.Phys.C 26 (1984) 199, 1984.
Inspire Record 204487 DOI 10.17182/hepdata.16198

The processγγπ+π− has been measured with complete particle identification. Cross-sections are presented from near threshold up to the region of thef(1270). In the mass range 0.5–0.7 GeV, crosssections are lower than the Born term predictions and show no evidence for an ε(600). The two-photon width of thef(1270) is found to be in agreement with previous results.

1 data table
Table 1

Data for W > 1 GeV read from graph.. Additional overall systematic error 10% for W < 1 GeV, rising to 20% for the 4 lowest W points.


A Test of Universality of Charged Leptons

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 1915, 1979.
Inspire Record 142012 DOI 10.17182/hepdata.20759

Measurements of the reactions e++e−→e++e−, μ++μ−, and τ++τ− at PETRA energies (s12=13,17,27.4,30 and 31.6 GeV) are reported. The results show that these reactions agree well with the predictions of quantum electrodynamics thus determining that all the known charged leptons are pointlike particles to a distance < × 10−16 cm.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


rivet Analysis
A Summary of Recent Experimental Results From Mark-$J$: High-energy $e^+ e^-$ Collisions at {PETRA}

The Mark-J collaboration Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rept. 109 (1984) 131, 1984.
Inspire Record 196567 DOI 10.17182/hepdata.30997

None

6 data tables
Table 1

DATA ARE CORRECTED FOR TWO-PHOTON AND TAU PRODUCTION EFFECTS, ACCEPTANCE AND QED RADIATIVE EFFECTS UP TO ORDER ALPHA**3. THERE IS ALSO A 6 PCT NORMALISATION ERROR NOT INCLUDED. THE OVERALL AVERAGE VALUE OF R FROM THIS DATA IS 3.88 +- 0.04 +- 0.22.

Table 2

No description provided.

Table 3

SEE PRL 55, 665 FOR MOST RECENT VALUES OF THE MU+ MU- CROSS SECTIONS.

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Formation of Delta (980) and A2 (1320) in Photon-photon Collisions

The Crystal Ball collaboration Antreasyan, D. ; Aschman, D. ; Besset, D. ; et al.
Phys.Rev.D 33 (1986) 1847, 1986.
Inspire Record 217547 DOI 10.17182/hepdata.23518

The reaction γγ→π0η has been investigated with the Crystal Ball detector at the DESY storage ring DORIS II. Formation of δ(980) and A2(1320) has been observed with γγ partial widths Γγγ(A2)=1.14±0.20±0.2 6 keV and Γγγ(δ)B(δ→πη)=0.19±0.07 −0.07+0.10 keV.

2 data tables
Table 1

No description provided.

Table 2

No description provided.