Talk:Pseudorapidity

Untitled
The table should be extended to $$\theta = 180^\circ$$

{Relation to rapidity in limit} The following statement: "...in the approximation that the mass of the particle is nearly zero, pseudorapidity is numerically close to the experimental particle physicist's definition of rapidity" is too vague. In this limit pseudorapidity _equals_ rapidity. Just plug in m=0 in the formula — Preceding unsigned comment added by 83.89.32.26 (talk) 19:17, 16 May 2012 (UTC)

{Correction} If one express
 * $$\tan\frac{\theta}{2}=\frac{\sin\frac{\theta}{2}}{\cos\frac{\theta}{2}} = \sqrt{\frac{1-\cos\theta}{1-\sin\theta}}$$

while the longitudinal and trasversal components of momentum $$ \mathbf{p} $$ are
 * $$ p_T=|\mathbf{p}|\sin\theta $$

and
 * $$ p_L=|\mathbf{p}|\cos\theta $$

the result for $$\eta$$ is
 * $$\eta=\frac{1}{2}\ln\left[\frac{|\mathbf{p}|-p_L}{|\mathbf{p}|-p_T}\right]$$ — Preceding unsigned comment added by 200.1.26.102 (talk) 18:54, 29 April 2013 (UTC)

Hyperbolic geometry
This article is about an application of angle of parallelism, a key metric concept in hyperbolic geometry. The equations find the angle of parallelism based on a leg of an ideal triangle in the hyperbolic plane. Today the reference to Chiochia was added, but we need a reference that tells how the particle scientists came to exploit hyperbolic geometry this way. — Rgdboer (talk) 22:01, 6 October 2015 (UTC)