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I understand that composite particles with integer spin form a boson. For example a helium nucleus is a boson because it has 2 protons and 2 neutrons.

If all of the components on their own are fermions, which mean they can not occupy the same space, how can combining them allow them to now occupy the same space?

I guess my question is: Is there an "intuitive" explanation for this behavior, or is the answer just the integer spin always equals boson?

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The Pauli exclusion principle applies to the constituent fermions of the composite bosons. For example, many atoms of helium can be in the same lowest energy state forming a superfluid. However, they cannot be squeezed to a zero volume, because the Pauli exclusion principle holds for protons and neutrons, as well as for their constituent quarks.

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  • $\begingroup$ Ok, so only elementary particles that are bosons do not follow the Pauli exclusion formula? $\endgroup$ – jminardi Sep 24 at 0:12
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    $\begingroup$ @jminardi Correct, elementary bosons (e.g. photons) do not follow the Pauli exclusion principle. $\endgroup$ – safesphere Sep 24 at 2:53

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