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Production of Low Transverse Energy Clusters in anti-p p Collisions at s**(1/2) = 0.2-TeV to 0.9-TeV and their Interpretation in Terms of QCD Jets

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Nucl.Phys.B 309 (1988) 405-425, 1988.
Inspire Record 261009 DOI 10.17182/hepdata.33326

The production of transverse energy clusters in minimum bias proton-antiproton collisions at the CERN SPS Collider is studied with the UA1 detector over a new range of centre of mass energies (√ s = 0.2−0.9 TeV). This study is intended to investigate how low in transverse momentum perturbative QCD is able to describe the dynamics of hadron collisions. We observe that clusters with transverse energy in excess of a few GeV exhibit properties in agreement with QCD expectations for parton scattering, supporting their interpretation in terms of jet production. We find that the jet-event rate represents a sizeable fraction of the inelastic rate and is increasing with √ s over the measured energy range.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Diffraction Dissociation at the {CERN} Pulsed Collider at {CM} Energies of 900-{GeV} and 200-{GeV}

The UA5 collaboration Ansorge, R.E. ; Åsman, B. ; Booth, C.N. ; et al.
Z.Phys.C 33 (1986) 175, 1986.
Inspire Record 232615 DOI 10.17182/hepdata.15812

Cross-sections for diffractive particle production and pseudorapidity distributions of the decay products of diffractive states are presented. The data were obtained with the UA 5 streamer chamber detector at the CERNpp Collider operated in a new pulsed mode yieldingpp interactions at c.m. energies of 900 and 200 GeV. Data recorded with a special trigger designed to select a sample of events enriched in single-diffractive interactions clearly favour apt-limited fragmentation of diffractive states. The cross-section for single-diffractive particle production ϊ was found to be 7.8±0.5±1.1 mb at 900 GeV and 4.8±0.5±0.8 mb at 200 GeV (first error statistical, second systematic). From the pseudorapidity distribution of diffractive states we deduce the average number of charged particles to be 6.5±1.0 at 900 GeV and 4.1±1.1 at 200 GeV. Furthermore we report on our estimates for the cross-section of double-diffractive particle production at both Collider energies.

3 data tables
Table 1

Single diffractive cross sections.

Table 2

Average number of single diffractive charged particles.

Table 3

Estimate of the double diffractive cross sections.


Kaon Production at 200-{GeV} and 900-{GeV} Center-of-mass Energy

The UA5 collaboration Ansorge, R.E. ; Asman, B. ; Booth, C.N. ; et al.
Phys.Lett.B 199 (1987) 311-316, 1987.
Inspire Record 254608 DOI 10.17182/hepdata.30057

Results on inclusive kaon production at 200 and 900 GeV centre of mass (CM) energy obtained with the UA5 detector at the pulsed CERN SPS antiproton-proton Collider are presented and compared with our earlier data at 546 GeV. The average transverse momentum 〈 p t 〉 of kaons has been estimated to be (0.50±0.04) GeV/ c at 200 GeV and (0.63±0.03) GeV/ c at 900 GeV in the central region and shows an increase with CM energy that is smore rapid than that expected from previous ISR data. The yield of kaons per inelastic p p event is found to be (0.72±0.12) at 200 GeV and (1.31±0.14) at 900 GeV. Finally, the K/π ratio has been found to exhibit a very slow increase with CM energy.

1 data table
Table 1

No description provided.


Antiproton-proton cross sections at 200 and 900 {GeV} c.m. energy

The UA5 collaboration Alner, G.J. ; Ansorge, R.E. ; Asman, B. ; et al.
Z.Phys.C 32 (1986) 153-161, 1986.
Inspire Record 229896 DOI 10.17182/hepdata.15857

Data on antiproton-proton cross sections at the c.m. energies 200 and 900 GeV are presented. The data were obtained at the CERN antiproton-proton Collider operated in a new pulsed mode in which the same beams were accelerated and decelerated between beam energies of 450 and 100 GeV. The properties of the machine determine the ratio of the luminosities at the two energies to about 1% and thus an accurate measurement of the ratioR of the inelastic cross sections could be made. We findR (=σ900/σ200)=1.20±0.01±0.02, where the first error is statistical and the second systematic. Interpolating existing data to estimateσine1(200 GeV) this measurement ofR leads toσine1(900 GeV)=50.3+0.4+1.0 mb. Using an extrapolated value ofσe1/σtot we estimate the total cross section at 900 GeV to be 65.3±0.7±1.5 mb. Both the inelastic and total cross sections are compatible with a ln2s dependence. Comparisons are made with different fits to the total cross section energy dependence.

2 data tables
Table 1

Ratio of inelastic cross sections at 900 and 200 Gev.

Table 2

Estimate of 900 Gev total cross section based on a) interpolation to obtain total cross section at sqrt(s)=200 Gev (51.6 +- 0.4mb.) b) interpolation and extrapolation to obtain the ratio of elastic to total cross sections at 200 & 900 Gev (0.19 +- 0.01 and 0.23 +- 0.01 respectively).


TOTAL, ELASTIC AND INCLUSIVE SINGLE DIFFRACTIVE CROSS-SECTIONS IN ALPHA-ALPHA COLLISIONS AT THE CERN INTERSECTING STORAGE RINGS

Lloyd Owen, D. ; Paternoster, G. ; Patricelli, S. ; et al.
Nucl.Phys.B 274 (1986) 685-706, 1986.
Inspire Record 227125 DOI 10.17182/hepdata.33694

We present measurements of the total interaction cross section and of the single-diffractive dissociation cross section in αα collisions at √ s = 126 GeV. The result obtained for the total cross section, σ tot = (315±18) mb, is a substantial improvement on the precision of earlier measurements. Earlier elastic data were re-analysed, incorporating, through the optical theorem, the present σ tot measurement, resulting in improved determinations of the forward slope, b − t <0.07 = (87±4) GeV −2 , and of the integrated elastic cross section, σ el = (58±6) mb. The single-diffractive differential cross section falls exponentially with momentum transfer at small values of t with a slope b sd = (19.3 ± 0.6) GeV −2 . The integrated single-diffractive cross section is σ sd = (16.6±2.5) mb. The topology of charged tracks resulting from the disintegration of the α in single-diffractive events reveals a two-component distribution. The cross section data are compared with multiple-scattering models.

2 data tables
Table 1

Total cross section by total rate method. Systematic errors included.

Table 2

Reanalysis using data from ISR experiments R-418, and R-807.


Scaling Violations in Multiplicity Distributions at 200-GeV and 900-GeV

The UA5 collaboration Alner, G.J. ; Ansorge, R.E. ; Asman, B. ; et al.
Phys.Lett.B 167 (1986) 476-480, 1986.
Inspire Record 220002 DOI 10.17182/hepdata.30284

New data are presented on charged particle multiplicity distributions for non single-diffractive events produced at CM energies s = 200 and 900 GeV . The data were obtained at the CERN antiproton-proton collider operated in a new pulsed mode. The multiplicity distributions are very well described by a negative binomial distribution. The highest energy data show no sign of approaching scaling, confirming our earlier results on the breaking of KNO scaling. The energy variation of the average charged multiplicity can be fitted to a quadratic in ln s or a s 0.13 dependence.

3 data tables
Table 1

Figure gives uncorrected multiplicity distributions. Here we give the corrected distributions. Data supplied by D. Ward.

Table 2

Results for multiplicity moments based on negative binomial fit to corrected data. Errors reflect both statistical and systematic effects. Results from earlier data at 546 Gev cm energy are also given.

Table 3

C moments for corrected data where CQ=<N**Q>/<N>**Q.


A MEASUREMENT OF ALPHA-ALPHA ELASTIC SCATTERING AT THE CERN ISR

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 152 (1985) 140-144, 1985.
Inspire Record 206315 DOI 10.17182/hepdata.30430

We present measurements of the αα elastic scattering differential cross section at √ s = 126 GeV in the range 0.05 ⩽ ‖ t ‖

3 data tables
Table 1

ERRORS ARE STATISTICAL ONLY.

Table 2

EXPONENTIAL FIT TO CROSS SECTION BELOW T = 0.075 GEV**2.

Table 3

OPTICAL THEOREM CALCULATION OF THE TOTAL CROSS SECTION ASSUMING RHO IS ZERO.


Measurement of $\alpha \alpha$ and $\alpha p$ Elastic Scattering at the {CERN} {ISR}

Bell, W. ; Braune, K. ; Claesson, G. ; et al.
Phys.Lett.B 117 (1982) 131-134, 1982.
Inspire Record 177982 DOI 10.17182/hepdata.30868

Differential cross sections for αα and αp scattering have been measured at √ s =125 and 88 GeV, respectively, in the t range from −0.2 to −0.8 (GeV/ c ) 2 using the Split-Field Magnet detector at the CERN Intersecting Storage Rings. Comparison with theoretical calculations using the Glauber model confirms the importance of including inelastic shadowing effects in very high energy nucleus-nucleus elastic scattering.

2 data tables
Table 1

No description provided.

Table 2

PLAB IS CALCULATED ASSUMING STATIONARY HELIUM TARGET.


Measurements of Elastic Scattering in $\alpha^- \alpha$ and $\alpha$ - Proton Collisions at the {CERN} Intersecting Storage Rings

The CERN-Naples-Pisa-Stony Brook collaboration Ambrosio, M. ; Anzivino, G. ; Barbarino, G. ; et al.
Phys.Lett.B 113 (1982) 347-352, 1982.
Inspire Record 176959 DOI 10.17182/hepdata.30919

We measured the elastic scattering of αα at s = 126 GeV and of α p at s = 89 GeV . For αα , the differential cross section d σ /d t has a diffractive pattern minima at | t | = 0.10 and 0.38 GeV 2 . At small | t | = 0.05−0.07 GeV 2 , this cross section behaves like exp[(100 ± 10) t ]. Extrapolating a fit to the data to the optical point, we obtained for the total cross section α tot ( αα ) = 250 ± 50 mb and an integrated elastic cross section σ e1 ( αα ) = 45 ± mb. Another method of estimating σ tot ( αα ), based on measuring the interaction rate, yielded 295 ± 40 mb. For α p, d σ /d t has aminimum at | t | = 0.20 GeV 2 , and for 0.05 < | t | < 0.18 GeV 2 behaves like exp[(41 ± 2) t ]. Extrapolating this slope to | t | = 0, we found σ tot ( α p) = 130 ± 20 and σ e1 ( α p) = 20 ± 4mb. Results on pp elastic scattering at s = 63 GeV agree with previous ISR experiments.

5 data tables
Table 1

Axis error includes +- 15/15 contribution.

Table 2

Axis error includes +- 15/15 contribution.

Table 3

METHOD 1 FOR SIG IS USING OPTICAL THEOREM. METHOD 2 FOR SIG IS BASED ON THE MEASURED LUMINOSITY-MONITOR CROSS SECTIONS.

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

Chilingarov, A. ; Clark, A.G. ; Darriulat, P. ; et al.
Nucl.Phys.B 151 (1979) 29-45, 1979.
Inspire Record 133024 DOI 10.17182/hepdata.34778

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.