barn

• Nom désignant principalement un bâtiment agricole servant au stockage des grains, du foin ou à l'hébergement du bétail. En physique nucléaire, il désigne aussi une unité de mesure de section efficace, valant 10⁻²⁸ mètre carré, représentant la surface effective d'une cible pour une interaction entre particules.

A noun with two distinct meanings: a farm building used for storing grain or housing animals, and a unit of nuclear cross section in physics representing the effective target area for particle interactions.

1. Farm buildingA2formal

   A large outbuilding on a farm used for storing grain, hay, or animal feed, and for housing livestock.

   grange

   • The farmer stored the hay in the barn for winter.
   • Cows were kept in the barn during the cold night.
   • They painted the old barn red to match the farmhouse.

2. Unit of nuclear cross sectionC2formalscientific

   A unit of area used in nuclear physics to measure the effective cross-sectional area of an atomic nucleus for scattering or absorption.

   Barn (unité de surface)

   • The cross section for this reaction is measured in barns.
   • One barn equals 10^-28 square meters.
   • The experiment recorded a cross section of 2.5 barns.