Production of e+ e- pairs accompanied by nuclear dissociation in ultra-peripheral heavy ion collision.

The STAR collaboration Adams, J. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 70 (2004) 031902, 2004.
Inspire Record 647869 DOI 10.17182/hepdata.98580

We present the first data on $e^+e^-$ pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED): the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, $p_T$, spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The $e^+$ and $e^-$ $p_T$ spectra are similar, with no evidence for interference effects due to higher-order diagrams.

5 data tables

(a) The pair mass distribution, (b) pair $p){T}$ , (c) pair rapidity and (d) pair cos($\theta′$) distributions. The data (points) are compared with predictions from the EPA (solid histogram) and lowest-order QED (dashed histogram) calculations. The error bars include both statistical and systematic errors.

(a) The pair mass distribution, (b) pair $p){T}$ , (c) pair rapidity and (d) pair cos($\theta′$) distributions. The data (points) are compared with predictions from the EPA (solid histogram) and lowest-order QED (dashed histogram) calculations. The error bars include both statistical and systematic errors.

(a) The pair mass distribution, (b) pair $p){T}$ , (c) pair rapidity and (d) pair cos($\theta′$) distributions. The data (points) are compared with predictions from the EPA (solid histogram) and lowest-order QED (dashed histogram) calculations. The error bars include both statistical and systematic errors.

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Mass identified particle production in proton anti-proton collisions at s**(1/2) = 300-GeV, 540-GeV, 1000-GeV, and 1800-GeV

The E735 collaboration Alexopoulos, T. ; Allen, C. ; Anderson, E.W. ; et al.
Phys.Rev.D 48 (1993) 984-997, 1993.
Inspire Record 363171 DOI 10.17182/hepdata.22669

The yields and average transverse momenta of pions, kaons, and antiprotons produced at the Fermilab p¯p collider at s=300, 540, 1000, and 1800 GeV are presented and compared with data from the energies reached at the CERN collider. We also present data on the dependence of average transverse momentum 〈pt〉 and particle ratios as a function of charged particle density dNcdη; data for particle densities as high as six times the average value, corresponding to a Bjorken energy density 6 GeV/fm3, are reported. These data are relevant to the search for quark-gluon phase of QCD.

11 data tables

PT RANGE FROM 0 TO INFINITY.

PT RANGE FROM 0 TO INFINITY.

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THE STUDY OF anti-n n INTERACTIONS AT 6.1-GeV/c

The Dubna-Bucharest-Yerevan-Kosice-Moscow-Prague-Sofiya collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.
Sov.J.Nucl.Phys. 48 (1988) 475, 1988.
Inspire Record 253864 DOI 10.17182/hepdata.9420

None

21 data tables

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DOUBLE CHARGE EXCHANGE OF NEGATIVE PIONS IN INCLUSIVE REACTIONS ON NUCLEI AT 40-GeV/c

Ananeva, M.A. ; Vishnyakov, V.V. ; Dikusar, N.D. ; et al.
EPL 4 (1987) 987, 1987.
Inspire Record 231157 DOI 10.17182/hepdata.9972

Inclusive production of π+ on four nuclear targets has been studied using a 40 GeV/c π- beam at the Serpukhov accelerator. No noticeable A-dependence has been found.

3 data tables

'CM' MEAN PION NUCLEON REST SYSTEM.

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Neutral Strange Particle Production in $K^+ p$ Interactions

The CERN-Soviet collaboration Ajinenko, I.V. ; Chliapnikov, P.V. ; Falaleev, V.P. ; et al.
Z.Phys.C 23 (1984) 307, 1984.
Inspire Record 193424 DOI 10.17182/hepdata.10722

The production properties ofKs0,\(\bar \Lambda\) andK+p interactions at 32 GeV/c are investigated using the final statistics of the experiment. We present total and semi-inclusive cross sections and aver-age multiplicities. Estimates are given of the diffractive dissociation contributions to total and differential cross sections. Thex-,pT−, and transverse mass dependence of inclusive and semi-inclusive distributions is discussed as well as properties of “prompt”Ks0's. The ratio of “prompt”K890+ (K8900) to “prompt”K0 cross sections is measured to be 1.03±0.12 (0.98±0.17). From a comparison of\(\bar \Lambda\) production inK±p interactions at 32 GeV/c, we estimate a strange sea-quark suppression of 0.26 ±0.02. The double differential cross sections ofKs0's is studied as a function of Feynman-x andpT2, and a Triple-Regge fit performed. The data are compared in detail to versions of the Lund-model for low-pT hadronic collisions.

27 data tables

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EXCLUSIVE REACTIONS IN pi+ p INTERACTIONS AT 32-GeV/c

Azhinenko, I.V. ; Belokopytov, Yu.A. ; Borovikov, A.A. ; et al.
Sov.J.Nucl.Phys. 34 (1981) 821, 1981.
Inspire Record 165497 DOI 10.17182/hepdata.41255

None

19 data tables

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Inclusive Production of Pions and $\rho^0$ in $\pi^+ p$ Interactions at 32-{GeV}/$c$

Azhinenko, I.V. ; Belokopytov, Yu.A. ; Chliapnikov, P.V. ; et al.
Sov.J.Nucl.Phys. 31 (1980) 628, 1980.
Inspire Record 143792 DOI 10.17182/hepdata.2720

None

48 data tables

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