Summary
We construct a multicluster model for\(\pi {\mathcal{N}}_{CEX} \) amplitude in the forward direction which, in contrast to conventional ρ-Regge models, reproduces within error bars the data for\(\sigma _{\pi ^ - p}^{tot} - \sigma _{\pi ^ + p}^{tot} \) and\(d\sigma _{CEX} /dt|_{t - 0} \) for 3 ≤p lab ≤ 60 GeV/e and fairly agrees with preliminary Batavia results. The model for the imaginary part shows an oscillation around a traditional ρ-pole value due to the onset of one large rapidity gap intermediate states. We propose that this oscillation, which fits well into Serpukhov enhancement, is the counter-part of similar threshold effects in\(\sigma _{\pi {\mathcal{N}}}^{tot} \) and\(\sigma _{{\mathcal{N}}{\mathcal{N}}}^{tot} \) arising at much higher energies. Absorptive corrections between clusters are considered to add consistency to the model.
Riassunto
Si costruisce un modello a molti addensamenti per l’ampiezza\(\pi {\mathcal{N}}_{CEX} \) nella direzione in avanti; modello che, all’opposto dei modelli con poli ρ di Regge, riproduce entro i limiti degli errori i dati sperimentali relativi a\(\sigma _{\pi ^ - p}^{tot} - \sigma _{\pi ^ + p}^{tot} \) e\(d\sigma _{CEX} /dt|_{t - 0} \) per 3 ≤p lab ≤ 60 GeV/c e concorda soddisfacentemente con i precedenti risultati di Batavia. Nel modello per la parte immaginaria si nota una oscillazione intorno a un tradizionale valore del polo ρ, dovuto all’intervento di stati intermedi con un notevole distacco in rapidità. Si avanza la proposta che questa oscillazione, che si approssima bene nell’ambito dell’innalzamento di Serpukhov, faccia da controparte a simili effetti di soglia in\(\sigma _{\pi {\mathcal{N}}}^{tot} \) e\(\sigma _{{\mathcal{N}}{\mathcal{N}}}^{tot} \) che si manifestano a valori molto superiori dell’energia. Si tiene conto di correzioni di assorbimento fra gli addensamenti per aumentare la consistenza del modello.
Реэюме
Мы конструируем многокластерную модель для\(\pi {\mathcal{N}}_{CEX} \) амплитуды в направлении вперед, которая, в противоположность обшепринятым ρ-Редже моделям, воспроиэводит в пределах ощибок данные для\(\sigma _{\pi ^ - p}^{tot} - \sigma _{\pi ^ + p}^{tot} \) и\(d\sigma _{CEX} /dt|_{t - 0} \) для 3 ≤\(\sigma _{\pi {\mathcal{N}}}^{tot} \) ≤ 60ГзB/c и довольно хорощо согласуется с предварительными реэулcтатами в Батавии. Предложенная модель для мнимой части обнаруживает осцилляции около эначения ρ-полюса, вследствие появления промежуточных состояний с больщим интервалом. Мы предполагаем, что укаэанная осцилляция, которая хорощо соответ-ствует серпуховскому увеличению, представляет соответствуюший аналог поро-говым зффектам в\(\sigma _{{\mathcal{N}}{\mathcal{N}}}^{tot} \) и\(\sigma _{{\mathcal{N}}{\mathcal{N}}}^{tot} \), которые воэникают при более высоких знергиях. Чтобы сделать рассматриваемую модель непротиворечивой, исследуются абсорб-ционные поправки между кластерами.
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García, A., Masperi, L. & Parga, N. Structure of the ρ-singularity in a multicluster model. Nuov Cim A 25, 377–394 (1975). https://doi.org/10.1007/BF02820852
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DOI: https://doi.org/10.1007/BF02820852