GATE 2026 PH – Question 24
Given $Q$ is the electromagnetic charge and $S$ is the strangeness quantum number, identify the particle(s) for which $(Q-S)=0$ is satisfied.
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Correct answer: (A) $\Sigma^{*-}$; (B) $K^+$
Explanation
Compute $Q-S$ for each particle.
| Particle | Quark content | $Q$ | $S$ | $Q-S$ |
|---|---|---|---|---|
| $\Sigma^{*-}$ | $dds$ | $-1$ | $-1$ | **0** ✓ |
| $K^+$ | $u\bar s$ | $+1$ | $+1$ | **0** ✓ |
| $\Omega^-$ | $sss$ | $-1$ | $-3$ | $+2$ |
| $\Delta^{++}$ | $uuu$ | $+2$ | $0$ | $+2$ |
Answer **$\Sigma^{*-}$ and $K^+$** (A and B).