A Study of the Energy Dependence of the Underlying Event in Proton-Antiproton Collisions

The CDF collaboration Aaltonen, Timo Antero ; Amerio, Silvia ; Amidei, Dante E ; et al.
Phys.Rev.D 92 (2015) 092009, 2015.
Inspire Record 1388868 DOI 10.17182/hepdata.70787

We study charged particle production in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of eta-phi space; toward, away, and transverse. The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the underlying event. The transverse region is divided into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

24 data tables

Average charged particle multiplicity for charged particles with pT > 0.5 GeV and |eta| < 0.8 in the TransMAX region as defined by the leading charged particle, as a function of the transverse momentum of the leading charged-particle pTmax, at 1.96 TeV.

Average charged particle multiplicity for charged particles with pT > 0.5 GeV and |eta| < 0.8 in the TransMIN region as defined by the leading charged particle, as a function of the transverse momentum of the leading charged-particle pTmax, at 1.96 TeV.

Average charged particle multiplicity for charged particles with pT > 0.5 GeV and |eta| < 0.8 in the TransAVE region as defined by the leading charged particle, as a function of the transverse momentum of the leading charged-particle pTmax, at 1.96 TeV.

More…

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.

More…

INCLUSIVE gamma PRODUCTION IN anti-p p INTERACTIONS AT 12-GeV/c

Chakrabarti, S. ; Banerjee, S. ; Ganguli, S.N. ; et al.
Z.Phys.C 27 (1985) 1, 1985.
Inspire Record 202797 DOI 10.17182/hepdata.16116

The inclusive production of photons in\(\bar pp\) interactions has been studied at incident momentum of 12 GeV/c. Topological cross section has been presented and KNO distribution for\(\bar pp\) interactions has been studied. Inclusive cross section for γ production has been measured to be 149.5±8.8 mb. Bulk of these photons come from π0 decays whose cross section has been evaluated independently to be 60.4±7.9 mb. Signals of η and ω have been seen in γγ and π+π-π0 decay modes and their inclusive cross sections have been estimated to be 14.9±8.8 mb and 14.6±7.0 mb respectively. Results on average multiplicities of γ and two particle correlation parameters are presented. Neutral pions seem to be more strongly correlated than the charged pions. The inclusive distributions of the Feynmanx andpT/2 of the photons are compared with expectation from charged pions on the basis of charge independence. Energy dependence of the normalised invariant distributions has been studied. The distribution of the scaling variablez of photons ine+e− and\(\bar pp\) interactions has been compared.

8 data tables
More…

Pseudorapidity distribution of charged particles in anti-p p collisions at s**(1/2) = 630-GeV

Harr, R ; Liapis, C ; Karchin, P ; et al.
Phys.Lett.B 401 (1997) 176-180, 1997.
Inspire Record 440823 DOI 10.17182/hepdata.28295

Using a silicon vertex detector, we measure the charged particle pseudorapidity distribution over the range 1.5 to 5.5 using data collected from PbarP collisions at root s = 630 GeV. With a data sample of 3 million events, we deduce a result with an overall normalization uncertainty of 5%, and typical bin to bin errors of a few percent. We compare our result to the measurement of UA5, and the distribution generated by the Lund Monte Carlo with default settings. This is only the second measurement at this level of precision, and only the second measurement for pseudorapidity greater than 3.

1 data table

No description provided.


phi meson production from p anti-p collisions at s**(1/2) = 1.8-TeV

The E735 collaboration Alexopoulos, T. ; Allen, C. ; Anderson, E.W. ; et al.
Z.Phys.C 67 (1995) 411-416, 1995.
Inspire Record 405368 DOI 10.17182/hepdata.14115

Fermilab experiment E735 located at the CO intersection region of the\(\sqrt s= 1.8\) TeV\(p\bar p\) collider analysed over 900 Φ→K+K− events. Measured were the transverse momentum spectrum, the correlation between the average transverse momentum <pt> and the charged particle multiphcityNc, as well as the probability of Φ production per charged track,NΦ/Nc, versusNc. We have also made an estinate of the total inclusive cross section for Φ mesons,\(\sigma (p\bar p \to \phi X) = 7.3 \pm 2.2 mb\).

3 data tables

Corrected phi meson transverse momentum distribution at rapidity = 0.

Total inclusive cross section.

Ratio of phi to rho0 production in high and low charged particle multiplicity events.


Transverse momentum spectra of charged particles in p anti-p collisions at s**(1/2) = 630-GeV

Bocquet, G. ; Norton, A. ; Wang, H.Q. ; et al.
Phys.Lett.B 366 (1996) 434-440, 1996.
Inspire Record 403649 DOI 10.17182/hepdata.48062

We have analysed a sample of 2.36 million minimum bias events produced in p p collisions at s =630 GeV in the UA1 experiment at the CERN collider. We have studied the production of charged particles with transverse momenta ( p T ) up to 25 GeV/c. The results are in agreement with QCD predictions. The rise of 〈 p T 〉 with charged particle multiplicity may be related to changing production of low p T particles.

11 data tables

No description provided.

No description provided.

No description provided.

More…

Jet fragmentation properties of anti-p p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.Lett. 65 (1990) 968-971, 1990.
Inspire Record 297585 DOI 10.17182/hepdata.19919

The charged-particle fractional momentum distribution within jets, D(z), has been measured in dijet events from 1.8-TeV p¯p collisions in the Collider Detector at Fermilab. As expected from scale breaking in quantum chromodynamics, the fragmentation function D(z) falls more steeply as dijet invariant mass increases from 60 to 200 GeV/c2. The average fraction of the jet momentum carried by charged particles is 0.65±0.02(stat)±0.08(syst).

1 data table

No description provided.


Annihilation and Topological Cross-sections for $P P$ and $\bar{P} P$ Interactions at 200-{GeV}/c

The NA5 collaboration Allday, J. ; Fry, J.R. ; Mason, P. ; et al.
Z.Phys.C 40 (1988) 29-39, 1988.
Inspire Record 268872 DOI 10.17182/hepdata.15563

The results of an analysis of streamer chamber data from the NA5 experiment are presented. Topological cross sections forpp and\(\bar p\)p interactions and strange neutral particle production at 200 GeV/c have been measured and (\(\bar p\)p−pp) difference cross sections have been determined. Multiplicity moments were calculated.

1 data table

No description provided.


STUDY OF INCLUSIVE AND SEMIINCLUSIVE TRANSVERSE MOMENTUM DISTRIBUTIONS OF THE CHARGED HADRONS IN anti-p p INTERACTIONS AT 32-GeV/c

Bogolyubsky, M.Yu. ; Borovikov, A.A. ; Bumazhnov, V.A. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 455, 1988.
Inspire Record 239546 DOI 10.17182/hepdata.2439

None

57 data tables

No description provided.

No description provided.

No description provided.

More…

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

Single diffractive cross sections.

Average number of single diffractive charged particles.

Estimate of the double diffractive cross sections.