Which combination of quarks produces a neutral baryon? 1) cts 2) dsb 3) uds 4) uct
The correct answer and explanation is:
The correct answer is 3) uds.
Explanation:
Baryons are particles made of three quarks. Each quark has an electric charge measured in units of the elementary charge. The charges for the common quarks involved here are:
- Up (u): +2/3
- Down (d): -1/3
- Strange (s): -1/3
- Charm (c): +2/3
- Bottom (b): -1/3
- Top (t): +2/3 (but top quarks decay very quickly and do not form baryons in normal matter)
To determine which combination of quarks produces a neutral baryon, add their charges and check if the total charge equals zero.
- c t s
- c: +2/3
- t: +2/3
- s: -1/3
Sum: 2/3 + 2/3 – 1/3 = 1 (not neutral, charge +1)
- d s b
- d: -1/3
- s: -1/3
- b: -1/3
Sum: -1/3 -1/3 -1/3 = -1 (charge -1, not neutral)
- u d s
- u: +2/3
- d: -1/3
- s: -1/3
Sum: 2/3 – 1/3 – 1/3 = 0 (neutral)
- u c t
- u: +2/3
- c: +2/3
- t: +2/3
Sum: 2/3 + 2/3 + 2/3 = +2 (not neutral)
The uds combination corresponds to the well-known neutral baryon called the Lambda (Λ) particle or the neutron-like baryon. This is a neutral baryon because the total charge is zero.
Baryons form part of the family of hadrons and are subject to the strong interaction. The quark content determines the baryon’s properties such as mass, charge, and spin. The uds combination is significant because it is the quark composition of the Lambda baryon, which is stable enough to be observed and studied. In contrast, combinations with top quarks are rare or nonexistent in stable baryons due to the extremely short lifetime of the top quark.
Thus, the uds quark set is the only option that produces a neutral baryon.