Imagine a particle called an R boson, which is easily created in the laboratory.
ID: 2039752 • Letter: I
Question
Imagine a particle called an R boson, which is easily created in the laboratory. If it is created at rest, it is characterized by a charge Q, a mass M, and an average lifetime tA, after which it decays into another particle. Suppose another experiment creates an R boson which is traveling at 75% of the speed of light in the laboratory. How would the measured quantities Q, M, and tA differ for this rapidly moving particle?
1. Q and M would be the same, tA would be larger.
2. Q and M and tA would all be larger.
3. Q and M and tA would vary randomly.
4. Q would be the same, M and tA would be larger.
5. Q and M and tA would all be smaller.
Explanation / Answer
Answer would be 4.
As a particle speeds up, it's mass increases. Further, the decay time of the particle will remain the same in its own frame of reference. But from a stationary frame of reference of the laboratory, it would seem that its average lifetime has increased in accordance with time dilation principle. Charge of the boson will remain independent of speed.