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

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

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.

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


Scaling Violation Favoring High Multiplicity Events at 540-GeV CMS Energy

The UA5 collaboration Alner, G.J. ; Alpgard, K. ; Ansorge, R.E. ; et al.
Phys.Lett.B 138 (1984) 304-310, 1984.
Inspire Record 199419 DOI 10.17182/hepdata.30571

New data are presented on the charged multiplicity distribution for non single-diffractive events produced in pp̄ interactions at a CM energy s = 540 GeV . The distribution in the full pseudorapidity range is compared with data from the ISR. Using the scaling variable z = n 〈n〉 a change of shape is observed. The effect is manifested as an increase from 2% to 6% in the proportion of high multiplicity ( z > 2) events. For the central pseudorapidity range, | η | ⪅ 1.5, scaling is approximately valid up to s = 540 GeV .

5 data tables

THE SCALING VARIABLE Z IS N/MEAN(N). THE ERRORS ARE HIGHLY CORRELATED AND ARE BASED ON THE SQUARE ROOT OF THE NUMBER OF EVENTS IN THE BIN. IN THE CASE OF MULTIPLICITIES 2,4, AND 6, ADDITIONAL SYSTEMATIC ERRORS HAVE BEEN INCLUDED. ABOVE MULTIPLICITY 96 BINS HAVE BEEN COMBINED - THE VALUE IN THE TABLE IS THE AVERAGE OVER THE RANGE - NOT THE SUM. NOTE ALSO THAT IN FIG. 1 THE "Y-VALUE" IS MULTIPLIED BY THE MEAN MULTIPLICITY (29.1).

CHARGED MULTIPLICITY (NON-CORRECTED) FOR EVENTS WHICH HAVE AT LEAST ONE TRACK WITH ABS(ETARAP) <1.5.

CHARGED MULTIPLICITY (NON CORRECTED) FOR EVENTS WHICH HAVE AT LEAST ONE TRACK WITH ABS(ETARAP) <1.3.

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