Summary
Bubble chamber data on pn interactions at 19 GeV/c are used to investigate the effects of nucleon diffraction and resonance production on the inclusivex- andp 2T -distributions of protons and pions. We determine the differential distributions of p, π− and π+ due to neutron and proton diffraction and similarly the distributions from the decay of the strong resonances Δ++(1232) and Δ−(1232) and from ρ0(770). Thex-distributions of the protons in the two c.m. hemispheres become quite similar when the effect of diffraction and Δ++ is subtracted. Thep 2T -distributions can then be described by a single exponential in the whole kinematic region. The net effect on the shapes of thex-distributions of the pions due to diffraction, Δ++/Δ− and ρ0 production is rather small. The separate effects of these processes on the particle ratio π−/π+ is investigated. By excluding the diffraction and Δ++/Δ− production, the strength of the low-p 2T component of thep 2T -distributions of the pions is reduced, but it seems that diffraction and resonance production cannot account for all oft hislow-p 2T enhancement.
Riassunto
Si usano i dati della camera a bolle sulle interazioni pn a 19 GeV/c per studiare gli effetti della diffrazione di nucleoni e la produzione di risonanze sulle distribuzioni inclusivex ep 2T di protoni e pioni. Si determinano le distribuzioni differenziali di p, π− e π+ dovute alla diffrazione di neutroni e protoni e analogamente le distribuzioni che derivano dal decadimento delle risonanze forti Δ++(1232) e Δ−(1232) e da ρ0(770). Le distribuzionix dei protoni nei due emisferi del centro di massa diventano abbastanza simili quando si sottrae l'effetto della diffrazione e Δ++. Le distribuzioni dip 2T si possono descrivere mediante una singola esponenziale nell'intera regione cinematica. L'effetto netto sugli andamenti delle distribuzionix dei pioni dovuti a diffrazione, alla produzione di Δ++/Δ− e di ρ0 è abbastanza piccolo. Si studiano gli effetti separati di questi processi sul rapporto tra particelle π−/π+. Escludendo la diffrazione e la produzione di Δ++/Δ−, l'intensità della componente a bassop 2T delle distribuzionip 2T dei pioni è ridotta, ma sembra che la diffrazione e la produzione di risonanze non possano spiegare tutto questo incremento a bassop 2T .
Резуме
Данные с пузырьковой камеры, касающиеся pn взаимодействий при 19 ГэВ/с, используются для исследования влияния дифракции нуклонов и резонансного рождения на инклюзивныеx- иp 2T -распределения протонов и пионов. Мы опредедяем дифференциаьные распределения р, π− и π+, обусловленные дифракцией нейтрона и протона, и аналогично распределения из распада сильных резонансов Δ++(1232) и Δ−(1232) и из ρ0(770).x-распределения для протонов в двух полусфераш системы центра масс становятся похожими, когда вычитается эффект дифракции и Δ++.p 2T -распределения могут быть описаны с помощью одной экспоненты во всей кинематической области. Влияние дифракции, Δ++/Δ− и ρ0 на формуx-распределений оказывается довольно слабым. Исследуются влияния этих процессов на отношение частиц π−/π+. Исключая дифракцию и Δ++/Δ−, определяется величина компоненты с малымp 2T вp 2T -распределениях пионов. По-видимому, дифракция и рождение резонансов не позволяют объяснить указанное возрастание при малыхp 2T .
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The Scandinavian Bubble Chamber Collaboration., Bakken, V., Breivik, F.O. et al. The effect of resonance production and diffraction on the inclusive spectra of pions and protons in 19 GeV/c pn interactions. Nuov Cim A 79, 73–99 (1984). https://doi.org/10.1007/BF02831080
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DOI: https://doi.org/10.1007/BF02831080