## GR0877 Problem 88

**PROBLEM STATEMENT**: *This problem is still being typed*.

**SOLUTION**: (**D**) Let us first determine the normalization constant : . Now, , where represents spin up and is spin down. When you measure on a particle in the state , you could get with probability or with probability . Thus, the probability of finding the particle with spin projection is . For more on this, see section 4.4 of Griffiths’ “Introduction to quantum mechanics” (2nd ed.) and, in particular, identical Example 4.2.

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I think you’re missing a ‘b’ term in your spinor equation, should be X= aX(+) + bX(-)

how you guys get a or b?

I think the a and b are just constants . Their squared value gives the probability for either spin up or spin down. You get the full picture after decomposing the matrix into a + and a – . I am not sure if I made much sense, but if you still have trouble let me know.