# Impact Parameter

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## impact parameter

[′im‚pakt pə‚ram·əd·ər]
(nuclear physics)
In a nuclear collision, the perpendicular distance from the target nucleus to the initial line of motion of the incident particle.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

## Impact Parameter

in the classical theory of particle scattering, the perpendicular distance between the scattering center of force and the original line of motion of the scattering particle.

References in periodicals archive ?
For small angles, the deflection of the wave (which far away from the lens is null and where r is the impact parameter) is
where [omega] is the electron impact parameter (nm) that can be found in the standard tables [N.sub.r] is the reference electron density which equal to [10.sup.16] (c[m.sup.-3]) for neural atoms and [10.sup.17] (c[m.sup.-3]) for singly charged ions, [DELTA][[lambda].sub.1/2] is the FWHM of Stark broadening lines.
Here r is the distance of the ghost galaxy to the Milky Way (the Milky Way being located at the focus of the orbit), p is the distance of closest approach (impact parameter), e is the eccentricity of the orbit, [theta] is the angle of radius vector with respect to the x axis, and [v.sub.r], [v.sub.[theta]] are the parallel and perpendicular components of the velocity with respect to the radial position vector.
He extended the standard theory of light deflection, his method being equivalent to minimising the action integral for a light ray with small impact parameter starting from infinity; for orbits in the plane [phi] = [pi]/2,
Extensive studies have been done over the past three decades on the sensitivity of collective transverse flow towards the nuclear EoS, nn cross-section, and entrance channel parameters such as incident energy of projectile, size of the system ([A.sub.TOT] = [A.sub.T] + [A.sub.P]), and colliding geometry (i.e., impact parameter) [1-9].
The relationship between the target change in the current account balance and the target change in the REER is established by equalising the former to the latter, modified by an "impact parameter".
The non-dimensional impact parameter is calculated as
This article introduces an alternative impact parameter for group-based RCTs with student mobility--the survivor average causal effect ("SACE")--that pertains to the subpopulation of original cohort students who would remain in their baseline study schools in either the treatment or control condition.
In this study, for quantitative comparison between pre and post-project conditions, the numerical value of above impact indicator (hereafter referred to as impact parameter) has been used.
[[DELTA].sub.Hurst,frame_type] is defined as the self-similarity impact parameter. A positive value of the self-similarity impact parameter means that the specified frame traffic weakens the self-similarity of aggregated frame traffic, and vice versa.
The average of the scores of the individual impact parameter ratings gave the CEI for each mode.

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