M. Basile

A large-area modular electromagnetic shower detector for the CERN intersecting storage rings

Abstract We describe the design and performances of a large-area (13 m 2 ) shower detector built for an experiment at the CERN ISR to detect electrons and gamma rays with energies up to 4 GeV. The main characteristics of the detector are: a) linearity of the energy response from 0.5 to 4 GeV; b) good energy, time and space resolutions; c) modularity of the mechanical assembly; d) low cost of construction.

The leading effect explains the charged-particle multiplicity distributions observed at the cern pp collider

SummaryThe assumption that the leading effect, and the charged-particle multiplicity distributions, measured at the ISR, scale with energy, and that the mean charged multiplicity, measured at the ISR, can be extrapolated up to Collider energy using the leading subtraction method, allows a prediction of the charged multiplicity distribution at the CERN pp Collider. This prediction is found to be in excellent agreement with the experimental data obtained at the Collider by the UA5 group.

Universality Features in (pp), (e+e−), and Deep Inelastic Scattering Processes

SummaryThe use of the correct variables in (pp), (e+e−), and deep-inelastic scattering (DIS) processes allows universality features to be established in these—so far considered—different ways of producing multihadronic states.RiassuntoLuso delle variabili corrette, nei processi (pp), (e+e−) e scattering inelastico profondo (DIS), permette di mettere in evidenza lesistenza di caratteristiche universali in tali interazioni, considerate sinora modi molto differenti di produrre stati multiadronici.РезюмеИспользование правильных переменных в (p, p), (e+e−) и процессах глубоко неупругого рассеяния позволяет установить универсальные особенности в этих реаксиях.

Search for fractionally charged particles produced in proton-proton collisions at the highest ISR energy

SummaryThe results of an experiment to search for quarks at the CERN ISR, at a total centre-of-mass energy √s=62.2 GeV, are reported. The experiment was sensitive to fractionally charged particles with 0.035e≤|Q|≤0.67e, β=v/c≥0.1 and masses up to 26 GeV/c2. The 90% confidence level on the ratio «quark flux/charged flux» is 1.78·10−9 forQ=+(1/3)e and 1.05·10−9 forQ=−(1/3)e. These values hold true for production processes with transverse momentap⊥≃0.4 GeV/c.RiassuntoSi presentano i risultati di un esperimento per la ricerca di quarks presso gli ISR del CERN, ad un valore dellenergia totale nel centro di massa √s=62.2 GeV. Lesperimento era sensibile a particelle con carica frazionaria nellintervallo 0.035e≤|Q|≤0.67e, con β=v/c≧0.1 e masse fino a 26 GeV/c2. Il valore del rapporto «flusso di quarks/flusso di particelle cariche», con un livello di confidenza del 90%, è 1.78·10−9 perQ=+(1/3)e, e 1.05·10−9 perQ=−(1/3)e. Questi valori si applicano a processi di produzione con impulsi trasversip⊥≃0.4 GeV/c.

Scaling in the charged-particle multiplicity distributions at the ISR and comparison with (e+e-) data

SummaryThe distribution of the charged-particle multiplicities at the ISR are studied in terms of the effective energy available for particle production in (pp) interactions. These distributions are found to scale once the effective energy, obtained via the leading subtraction method, is used. A comparison with the charged particle distributions measured in (e+e-) annihilation shows a clear difference. This could be interpreted in terms of gluon-induced and quark-induced jets; where the gluoninduced jets are characterized by a wider multiplicity distribution with respect to quarkinduced jets.

The present knowledge of | F π | and the value of a low-energy (e + e − ) storage ring

SummaryThe present knowledge of the modulus of the pion electromagnetic form factor |Fπ| in the spacelike and timelike regions is reviewed. The interest in studying the low-energy range of the e+e− annihilation into pions is discussed as well as a possible storage ring.RiassuntoSi passa in rassegna lattuale conoscenza del modulo del fattore di forma electtromagnetico del pione |Fπ| nelle regioni spaziali e temporali. Si discute sia linteresse dello studio dellannichilazione e+e− a basse energie sia un possibile anello daccumulazione.

Search for quarks in proton-proton interactions at √ s = 52.5 GeV

SummaryThe results of an experiment to search for quarks in pp collisions, at a total centre-of-mass energy √s = 52.5 GeV, are reported. The experiment was sensitive to fractionally charged particles with 0.035e ⩽ |Q| ⩽ 0.67e,β =v/c ⩾ 0.1, and masses up to 21 GeV/c2. The 90% confidence level on the ratio «quark flux/charged-particle flux» is 5.11 · 10−11 for |Q| = 1/3e. This value holds true for particles produced with a mean transverse momentum of 0.4 GeV/c.RiassuntoSi presentano i risultati di un esperimento per la ricerca di quark con carica frazionaria nell’interazione protone-protone, ad un’energia totale nel centro di massa √s = 52.5 GeV. L’esperimento era sensibile a particelle con carica nell’intervallo 0.035e ⩽ |Q| ⩽ 0.67e, velocitàβ =v/c ⩾ 0.1 e masse fino a 21 GeV/c2. Il valore del limite superiore sul rapporto «flusso di quark/flusso di particelle cariche» è 5.11 · 10−11 per |Q| = 1/3e, con un livello di confidenza del 90%. Questo limite è valido per particelle prodotte con un impulso trasverso medio di circa 0.4 GeV/c.РеэюмеПредлагаются реэультаты зксперимента по поиску кварков в протон-протонных соударениях при полной знергии в системе центра масс √s = 52.5 ГзВ. Эксперимент является чувствительным к дробно эаряженным частицам с 0.035e ⩽ ⩽ |Q| ⩽ 0.67e,β =v/c ⩾ 0.1 и с массами вплоть до 21 ГзВ/с2. С 90% степенью достоверности отнощение « поток кварков/поток эаряженных частиц » составляет 5.11·10−11 для |Q| = 1/3e. Эта величина справедлива для частиц, обраэованных со средним поперечным импульсом 0.4 ГзВ/с.

A search for quarks in the CERN SPS neutrino beam

SummaryQuarks and leptons are the only pointlike particles known so far. However, a search for a proton-breaking mechanism in high-energy neutrino-nucleon interactions had never been performed. We present here the results of the first experiment in this field.RiassuntoLe uniche particelle puntiformi finora conosciute sono i quark ed i leptoni. Tuttavia non è mai stata effettuata una ricerca intesa a mettere in evidenza un meccanismo di rottura del protone nelle interazioni di neutrini ad alta energia su nucleoni. In questo lavoro sono presentati i risultati del primo esperimento realizzato in questo campo.РеэюмеКварки и лептоны являются единственными точечно-подобными частицами, иэвестными до сих пор. Однако поиск механиэма, приводяшего к раэвалу протона, при высоких знергиях в нейтрино-нуклонных вэаимодействиях никогда не был проведен. В зтой работе мы приводим реэультаты первого зксперимента в зтой области.

The End of A Myth: High-pT Physics

So far, the main picture of hadronic physics has been based on a distinction between high-pT and low-pT phenomena.

Two-body correlations in high-energy proton-proton interactions

SummaryA study of about 105 proton-proton interactions atn