Normalization Constant for Gaussian

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Homework Help Overview

The discussion revolves around finding the normalization constant \( N \) for a Gaussian wave packet described by the function \( \psi (x) = N e^{-(x-x_{0})^{2}/2 K^{2}} \). Participants are analyzing the normalization condition involving an integral of the square of the wave function.

Discussion Character

  • Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to derive the normalization constant by setting up the integral of the squared wave function and making substitutions. They question the presence of \( x_{0} \) in their final expression for \( N \). Other participants point out potential flaws in the substitutions and clarify the role of \( K \) in the calculations.

Discussion Status

Participants are actively engaging in correcting each other's reasoning regarding the substitutions made in the integral. There is recognition of a mistake concerning the inclusion of \( x_{0} \) in the final expression for \( N \), and some participants confirm the adjustments needed to arrive at the correct form.

Contextual Notes

There is an ongoing examination of the substitutions made during the integration process, particularly regarding the transformation of variables and the implications for the normalization constant. The discussion reflects a collaborative effort to clarify the mathematical steps involved.

atomicpedals
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Homework Statement



Find the normalization constant N for the Gaussian wave packet
\psi (x) = N e^{-(x-x_{0})^{2}/2 K^{2}}

Homework Equations


1 = \int |\psi (x)|^{2} dx

The Attempt at a Solution


1 = \int |\psi (x)|^{2} dx = N^{2} \int e^{-(x-x_{0})^{2}/K^{2}} dx
Substitute y=(x-x_{0})
N^{2} \int e^{-y^{2}/K^{2}} dy
Substitute again z = y/|K|
N^{2} \int e^{-z^{2}} dz = N^{2} x_{0} K \sqrt{\pi}
N= ( \frac{1}{K x_{0} \sqrt{\pi}})^{1/2}
Where my question lies is with the x_{0} in N. Should that be there?
 
Last edited:
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Actually... that first substitution may be flawed.
 
Ok, I think I see where I went wrong. The x_{0} doesn't belong in the final answer.
 
yes, you've figured it out.

P.S. on this line, on the left hand side, there should be K since you have changed dy for dz:
N^{2} \int e^{-z^{2}} dz = N^{2} x_{0} K \sqrt{\pi}
But after that you've remembered the K, so I guess you just forgot to type the K here, but you understand the right answer.
 
Yeah, I forgot about the K, so what I should end up with is:
N^{2} K \int e^{-z^{2}} dz = N^{2} K \sqrt{\pi}
 
yep, looks right to me :)
 

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