R. Kephart

Measurement of inclusive two-particle rapidity correlations at the ISR

Abstract We present data on two-particle distributions in the approximate rapidity variable η = −1n tan θ /2 for secondaries produced in proton-proton collisions at the CERN Intersecting Storage Rings (ISR). The data at centre-of-mass energies of 23 and 62 GeV show the existence of energy-independent positive, short-range correlations between secondaries within the central region. Deviations from short-range correlation exist when one (or both) of the particles is near the boundary of the available phase space. In part, such deviations are interpreted as the effect of a diffractive-like component in multiparticle production.

New measurements of proton-proton total cross section at the CERN intersecting storage rings

Abstract Measurements of the proton-proton total cross section have been made with increased precision (±0.6%) over the ISR energy range s =23.5−62.7 GeV . Two different experimental methods gave consistent results, showing that the total cross section increases 10% over the ISR range and in addition that the absolute value of the ISR luminosity can be measured to ±0.9%.

Measurement of charged particle multiplicities associated with large transverse momentum photons in proton-proton collisions

Abstract We have measured the behaviour or charged-particle multiplicities as a function of the transverse momentum of photons produced at 90° in proton-proton collisions. The data were obtained at the CERN Intersecting Storage Rings (ISR) at a centre-of-mass energy of 53 GeV and cover the transverse momentum range 0

Measurement of Two-Particle Semi-Inclusive Rapidity Distributions at the CERN ISR.

SummaryWe present data on the semi-inclusive distributions of rapidities of secondary particles produced in pp collisions at very high energies. Our experiment was performed at the CERN Intersecting Storage Rings (ISR). The data given here, at centre-of-mass energies of √s=23 and 62 GeV, include the single-particle distributions and two-particle correlations. The semi-inclusive correlations show pronounced short-range correlation effects which have a width considerably narrower than in the case of inclusive correlations. We show that these short-range effects can be understood empirically in terms of three parameters whose energy and multiplicity dependence are studied. The data support the picture of multiparticle production in which clusters of small multiplicity and small dispersion are emitted with subsequent decay into hadrons.RiassuntoVengono presentati dati sulle distribuzioni inclusive in rapidità dei secondari carichi prodotti nelle collisioni protone-protone ad altissime energie. L’esperimento è stato eseguito agli Anelli ad Intersezione (ISR) del CERN. I dati, ad una energia √s=23 e 62 GeV nel centro di massa, comprendono le distribuzioni di particella singola e le correlazioni a due particelle per fissa molteplicità carica, come anche le correlazioni inclusive a due particelle. Le correlazioni semi inclusive mostrano forti effetti di correlazione a breve distanza, che hanno una larghezza molto più piccola che nel caso delle correlazioni inclusive. Nel lavoro si fa vedere che questi effetti a breve distanza possono essere capiti empiricamente in funzione di tre parametri di cui si studia la dipendenza dall’energia e dalla molteplicità. I dati favoriscono la descrizione della produzione a molti corpi in cui vengono emessi agglomerati di piccola molteplicità e piccola dispersione, che successivamente decadono in adroni.РеэюмеВ работе приводятся данные для полуинклюэивных распределений вторичных частиц, рожденных в рр соударениях при очень высоких знергиях. Нащ зксперимент был проиэведен на встречных накопительных кольцах в ЦЕРНе. Полученные в работе данные при знергиях в системе центра масс √s=23 и 62 ГзВ включают одночастичные распределения и двухчастичные корреляции при фиксированной множественности эаряженных частиц п, а также инклюэивные двухчастичные корреляции. Полуинклюэивные корреляции обнаруживают явно выраженные зффекты короткодействуюших корреляций, которые обладают щириной эначительно меньщей, чем в случае инклюэивных корреляций. Мы покаэываем, что зти короткодействуюшие зффекты могут быть общяснены змпрически в терминах трех параметров. Обсуждается эависимость зтих параметров от знергии и множественности. Полученные данные подтверждают картину множественного рождения, в которой испускаются кластеры с малой множественностью и малой дисперсией с последуюшим распадом в адроны.

Correlations of secondaries in events with a forward neutron at the ISR

Abstract Data, obtained from p-p collisions at centre-of-mass energies between 31 and 63 GeV, are presented on inclusive and semi-inclusive correlations between forward emitted neutrons and charged particles observed in an omnidirectional hodoscope. A total absorption spectrometer was used to detect the neutrons and to measure their energy. Significant correlations are observed over the whole rapidity range. The data suggest that neutrons result from the decay of clusters emitted in the fragmentation region.

Correlations of secondaries in events with a forward negative hadron at the ISR

Abstract Data obtained from p-p collisions at centre-of-mass energies between 31 and 63 GeV are presented on correlations between momentum analysed forward π−, K− and p and charged particles observed in an omnidirectional hodoscope. The data show that significant correlations are present over the whole rapidity range for all three types of negative particles. The dependence on various kinematic variables suggests a cluster mechanism for the production of particles. In this picture, pions would be produced in clusters emitted in the fragmentation region while K− and p emanate from non-leading clusters.