Charge radius the composite particle must be modeled as a sphere of negative rather than positive electric charge for the interpretation of electron scattering experiments. In these cases, the square of the charge radius of the particle is defined to be negative, with the same absolute value with units of length squared equal to the positive squared charge radius that it would have had if it was identical in all other respects but each quark in the particle had the opposite electric charge (with the charge radius itself having a value that is an imaginary number with units of length). It is
Cassidy (given name) Cassidy (given name) Cassidy is a given name derived from an Irish surname and ultimately from the Gaelic given name "Caiside", meaning "clever" or "curly-haired." The name "Caiside" comes from the Gaelic word element "cas", according to "Behindthename.com" Cassidy was the 244th most popular name for girls born in the United States in 2009. It was most popular in 1999, when it was the 99th most popular name for American girls. It first appeared among the 1,000 most popular names for American girls in 1981. Kassidy, an alternate spelling, was ranked as the 443rd most popular name for girls in