L. Votano

The inclusive transverse-momentum distribution in hadronic systems produced in proton-proton collisions

Summary. The single.particle inclusive transverse-momentum distribution in the multiparticle systems produced in low-1~T proton-proton interactions at ~- 30 and 62 GoV has been studied. The analysis was performed removing from the final state the leading proton and redefining the effective hadronie energy available for particle production. Excellent agreement for effective hadronic energies up to 13 GoV is found between (pp) and (e+e-). At higher energy the (pp) data show a less pronounced growth than the (e+e -) data.

Analysis of the reaction γ+n→p+π − in the first and second resonance regions

SummaryThe final results of an experimental investigation of the reaction γ+n→p+π− performed with a deuterium bubble chamber at the 1 GeV Frascati electrosynchrotron are presented. Total and differential cross-sections on neutrons are extracted by means of the spectator model, the reliability of which has been checked by numerous tests and is extensively discussed. The problems of a possible isotensor component in the electromagnetic current, the time-reversal invariance of the electromagnetic interactions and the photoproduction of the Roper resonance are considered in detail.RiassuntoSi presentano i risultati finali di unindagine sperimentale della reazione γ+n→p+π− eseguita con una camera a bolle a deuterio presso lelettrosincrotrone da 1 GeV di Frascati. Le sezioni durto totali e differenziali sono ricavate usando il modello dello spettatore la cui validità è stata sottoposta a numerosi controlli ed è discussa in dettaglio. Sono considerati in particolare i problemi riguardanti una possibile componente isotensoriale della corrente elettromagnetica, linvarianza per inversione rispetto al tempo delle interazioni elettromagnetiche e la fotoproduzione della risonanza di Roper.РезюмеПриводятся окончательные результаты экспериментального исследования реакции γ+n→p+π−, проведенного на дейтериевой пузырьковой камере при цнергии 1 ГэВ на электронном синхотроне фраскати. вычисляются полные и дифференциаляные поперечные сечения на нейтроне, испольэуя модель наблюдателя, надежность которой подробно обсуждается и била проверена с помощью численных расчетов. Подробно рассматриваются проблемы возможной изотензорной компоненты в электромагнитном токе, инвариантность электромагнитных взаимодействий относительно обращения времени и фоторождение резонанса Ропера.

Dimethyl ether as a drift-chamber gas

Abstract We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether.

The leading effect explains the forward-backward multiplicity correlations in hadronic interactions

SummaryThe multiplicity correlations between forward and backward hemispheres observed since a long time in (pp) interactions at the CERN Intersecting Storage Rings (ISR), are shown to be due to the leading effect. These multiplicity correlations are reproduced following our method of classifying each (pp) interaction in terms of the effective hadronic energy available. It is this energy, and not the long-range correlation, which produces low or high multiplicities in both hemispheres of a (pp) collision. The (logs)-dependence of the correlation strength follows from the energy dependence of the multiplicity. The (logs)-dependence is shown to follow our prediction from FNAL and SPS, to ISR, and up to Collider energies.

Dimethyl ether reviewed: New results on using this gas in a high-precision drift chamber

Abstract Two years ago, dimethyl ether (DME) was presented, for the first time, as a suitable gas for high-precision drift chambers. In fact our tests show that resolutions can be obtained which are better by at least a factor of 2 compared to what one can get with conventional gases. Moreover, DME is very well quenched. The feared formation of whiskers on the wires has not occurred, at least after months of use with a 10 μCi 106 Ru source.

Transverse properties of jets at Collider energies from ISR data

SummaryThe universality features observed in comparing ISR data with (e+e−) and deep-inelastic scattering (DIS), prompt a comparison, at Collider energies, of high-pT and low-pT jets with constantnn

New results on charmed and beautiful baryon production at the ISR

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Results of the quark search experiment in high-energy neutrino interactions

nn. The expectations of the transverse properties of the particles in the jets are discussed.