SR problem in book seems to be faulty

[Mr.Miyagi]

Homework Statement

The problem in question is 11.10 of "A traveler's guide to spacetime" by Moore. It goes as follows (by the way, the unit of distance that is used in the book is the lightsecond):

"A neutral boson of mass m traveling with v=4/5 in the +x direction strikes a snoozon of mass M=3m at rest. The interaction of these particles produces a previously undiscovered particle (which we will call a "rayon") and a photon with energy 2m. Assume that the photon is emitted in the -x direction.
a. What is the four-momentum of the rayon?"

Homework Equations

$$E=\frac{m}{\sqrt{1-v^2}}$$
$$p_x=v_xE$$
$$p_y=v_yE$$
$$p_y=v_yE$$

The Attempt at a Solution

I calculate the following values:
$$E_{boson}=5m/3$$
$$p_{x, boson}=4m/3$$
$$E_{snoozon}=3m$$
$$p_{x, snoozon}=0$$
$$E_{foton}=2m$$
$$p_{x, foton}=-2m$$
All the y- and z-components of p are 0.

With this I calculate the components of the four-momentum of the rayon, using the fact that the four-momentum of the system of particles is conserved:
$$E_{rayon}=E_{boson}+E_{snoozon}-E_{foton}=5m/3+3m-2m=8m/3$$
$$p_{x, rayon}=p_{x, boson}+p_{x, snoozon}-p_{x, foton}=4m/3+0+2m=10m/3$$
And again, the y- and z-components are 0.

The four-momentum then, is $$\left[ \begin{array}{cccc} 8m/3 \\ 10m/3 \\ 0 \\ 0 \end{array} \right]$$
But this doesn't make any sense, since E should always be qreater or equal to p.

Have I made a mistake somewhere or is the question just not right?

 

[Mr.Miyagi]

Should I, perhaps, explain my solution in more detail?

 

[nlightner]

I would say that there is likely an error in the question or in the calculations provided. It is possible that the question is not properly framed or that there is a typo in the given values. It is also possible that there is a mistake in the equations used to calculate the four-momentum.

In order to properly address the issue, I would suggest double-checking all of the values and equations used in the calculations. If the error cannot be identified, it may be helpful to consult with a colleague or the author of the book for clarification. It is important to ensure that all calculations and assumptions are accurate in order to arrive at a valid solution.