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Extrapolation techniques and the pion form factor

Техника зкстраполяции и форм-фактор пиона

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Il Nuovo Cimento A (1965-1970)

Summary

The possibility of applying optimal extrapolation techniques to the determination of the pion form factor from charged-pion electroproduction is discussed. With the data available at present, the uncertainty in the pion form factor is very large. It is suggested that the use of some additional information in the unphysical region might be useful. As an example, a well-known kinematical constraint is used in conjunction with threshold electroproduction data to determine the pion form factor at a timelike momentum transfer of approximately one fm−2. Some implications of this model-independent determination of the form factor for the pion charge radius are discussed.

Riassunto

Si discute la possibilità di applicare tecniche di estrapolazione ottimali per derivare il fattore di forma del pione da elettroproduzione di pioni carichi. Con i dati attualmente a disposizione, l’indeterminazione sul fattore di forma del pione è grossa. Si suggerisce che l’uso di qualche informazione ulteriore nella regione non fisica possa essere di qualche utilità. A titolo di esempio, si utilizza un ben noto vincolo cinematico in congiunzione con dei dati di elettroproduzione a soglia per determinare il fattore di forma del pione ad un valore del momento trasferito di tipo tempo e di approssimativamente 1 fm−2. Si discutono infine alcune possibili utilizzazioni del fattore di forma del pione.

Реэюме

Обсуждается воэможность применения техники оптимальной зкстра-поляции для определения форм-фактора пиона иэ злектророждения эаряженных пионов. Исходя иэ данных, имеюшихся на сегоднящний день, неопределенность в форм-факторе пиона окаэывается очень больщой. Предлагается, что испольэование некоторой дополнительной информации в нефиэической области может быть поле-эным. Как пример, испольэуется хорощо иэвестное кинематическое ограничение вместе с данными по пороговому злектророждению для определения форм-фактора пиона при времениподобном передаваемом импульсе, приблиэительно равном 1 fm−2. Обсуждаются некоторые следствия зтого не эависяшего от модели опре-деления форм-фактора для радиуса эаряда пиона.

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Authors and Affiliations

  1. Department of Natural Philosophy, University of Glasgow, Glasgow

    B. H. Kellett

  2. Istituto di Fisica Teorica dell’Università, Trieste

    C. Verzegnassi

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  1. B. H. Kellett
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  2. C. Verzegnassi
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Work partially supported by INFN, Sezione di Trieste.

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Kellett, B.H., Verzegnassi, C. Extrapolation techniques and the pion form factor. Nuov Cim A 20, 194–206 (1974). https://doi.org/10.1007/BF02727447

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