Recent content by B4cklfip

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    Integrating Factor: Need Help Solving Excersice?

    I'm not sure if that is the right way to solve this excersice. Can someone maybe help and tell me if this calculation proofs the statement ?
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    I Isospin Operator: Act on |ud> State

    How does the isospin operator I_3 act on a state |ud>, where u ist an up- and d a Down quark?
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    A Electromagnetic transitions of ##\psi(2S)##

    When the ##\psi(2s)## particle decays also the following two transitions are observed $$\psi(2S) \rightarrow \gamma + \eta({1}^S_0)$$ $$\psi(2S) \rightarrow \gamma + \chi_{c0}({3}^P_0)$$ The branching fraction for the first decay is about ##3.4*10^{-3}## while it's ##9.7*10^{-2}## for the...
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    I What is the Minimum Neutron Energy Required for Lithium Fission?

    Whats the minimum kinetic energy a neutron must have in order to trigger the fission of for example a lithium core ?
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    What is the value of the second term in the commutator for an N particle system?

    I have insertet the equations for H and P in the relation for the commutator which gives $$[H,P] = [\sum_{n=1}^N \frac{p_n^2}{2m_n} +\frac{1}{2}\sum_{n,n'}^N V(|x_n-x_n'|),\sum_{n=1}^N p_n] \\ = [\sum_{n=1}^N \frac{p_n^2}{2m_n},\sum_{n=1}^N p_n]+\frac{1}{2}[\sum_{n,n'}^N...
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    Determining Radiation Length in Air

    The radiaton length for air is about $$X_0 = 30420cm$$. This is the length at which the electron has decreased to 1/e of it´ s initially value. I also know that the maximal value of interactions for a specific energy is given by $$ n_{max} = \frac{ln(\frac{E_0}{E_c})}{ln(2)} $$, where E_c is...
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    WKB method transmission coefficient

    No, everything should be correct. After substituting x=sin(Theta) one gets $$ p(x) = \frac{1}{a} \int_{-a}^{a} \sqrt{y-V_0*sin^2(\Theta)}* cos(\theta)dx $$ that can be substituted by $$u = sin(\Theta)$$ which gets one $$ p(x) = \frac{1}{a} \int_{-a}^{a} \sqrt{y-V_0*u^2}du $$ finally one can...
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    WKB method transmission coefficient

    E is smaller than the potential V(x). I´ m at the moment trying to solve the integral by substituting $$x = sin(\Theta)$$
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    WKB method transmission coefficient

    Not yet. I´ m also not sure which one to use. I´ ve now written the equation as $$ p(x) = \frac{1}{a} \int_{-a}^{a} \sqrt{V_0(a^2-x^2)-E} dx $$ but have now idea how to go further.
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    WKB method transmission coefficient

    Not quite, there´ s missing one bracket. It should be: $$p(x)=\frac{1}{\hbar} \int_{-a}^{a}\sqrt{2m(V_0(1-(\frac{x}{a})^2)-E)}dx$$ with the potential $$ V(x) = \begin{cases} V_0(1-(\frac{x}{a})^2) & \text{for -a $\leq x \leq $a} \\0 & \text{otherwise} \end{cases}$$
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    WKB method transmission coefficient

    Homework Statement: The Task is to calculate the Transmission coefficient with the WKB Approximation of following potential: V(x) = V_0(1-(x/a)²) |x|<a ; V(x) = 0 otherwise Homework Equations: ln|T|² = -2 ∫ p(x) dx I have inserted the potential in the equation for p(x) and recieved p(x) =...
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    Fourier transformation of the Wavefunction in QM

    Thanks for the hint, I now tried to solve it and got following result: $$\tilde{\phi}(x) = \begin{cases} 0 & x < -L \\ \frac{A_0}{\sqrt{2pi}k} \cdot 2sin(kL)\ & -L \leq x \leq L \\ 0 & x > L\end{cases}$$ I have integrated from -L to L for the second interval. Is it correct ? And how can I...
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    Fourier transformation of the Wavefunction in QM

    \phi(k) = \frac{1}{\sqrt{2\pi}}\int_{-\infty}^\infty e^{ikx} \phi(x)\,dx is the Fouriertransformation of \phi(x). It changes the dependence of the wavefunction from position x to momentum p.
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    Fourier transformation of the Wavefunction in QM

    Hello Physics Forum, I am not sure what to to in this task, because the wavefunction is only given as A_0. Maybe someone can explain it to me. Thanks in Advance, B4ckflip
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