# Etude de l'influence des forces de Van der Waals de couleur et d'effets non coulombiens dans la diffusion $^{208}$Pb+$^{208}$Pb par une experience de haute precision

Abstract : This work deals with the precise measurement of the absolute angular position of the elastic 208pb+208pb scattering cross section oscillations. The main objective is to verify if all of the elastic scattering ingredients are known even with an angular position precision of a few milli-degrees or if it is necessary to introduce new elements such as the color van der Waals force. This experiment was performed at Ganil. We obtained a precision of 0.004 deg. on the absolute cross section oscillation position and an angular shift of a few hundredths of degrees in relation to the expected position of a pure coulomb scattering. The attainment of this precision required particular precautions in the measurement of the absolute energy target position and scattering angle. First, the angular straggling on a thin target and the production of δ electrons during the scattering is studied. Next the origin of the angular shift is examined by the calculation of all the potentials that act during the scattering. The agreement between experimentation and theory allowed us to set a new limit on the color van der Waals interaction.
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Submitted on : Wednesday, February 24, 2016 - 2:14:26 PM
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### Identifiers

• HAL Id : in2p3-00008707, version 1

### Citation

J.M. Casandjian. Etude de l'influence des forces de Van der Waals de couleur et d'effets non coulombiens dans la diffusion $^{208}$Pb+$^{208}$Pb par une experience de haute precision. Physique Nucléaire Expérimentale [nucl-ex]. Université Paris Sud - Paris XI, 1996. Français. ⟨in2p3-00008707⟩

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