up quark
- noun
- /ʌp kwɑrk/
- Specialized
:
quark up
- An up quark has an electric charge of +2/3, making it one of the essential components of protons.
- one up quark
- two up quarks
- up quarks and one down
And when this down quark emits this W boson, what happens is it switches to an up quark.
- And when this down quark emits this W boson, what happens is it switches to an up quark.
Examples
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There's a down an up quark and a down bar quark.
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That up quark remains bound to the others by the strong interaction, the three quarks together forming a proton.
Academic text (2012) -
The up-quark contribution Delta u, for example, is given by
Academic text (1995) -
There's the the up quark, which is these red triangles.
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And then there is a precise symmetry relating up quarks to down quarks.
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Now, to form a proton, we're going to need an up quark, another up quark, and a down quark.
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So the proton is made of two up quarks, which are these red triangles, and one down quark.
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Quarks, Those are the particles, the up quarks and the down quarks we found in the proton.
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One example is pion which is made out of up quarks and down quarks that can be charged in neutral pions.
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And now because it's an up, down, up quark, it's no longer a neutron, it's a proton, because protons are made of up, down, up quarks.
Surface Forms
Morphology
up + quark
A learner who knows 'quark' as an elementary particle and the word 'up' will reasonably infer that an 'up quark' is a particular type or subtype of quark (the modifier 'up' signals a label/classification). However, the specific physical properties (e.g. the +2/3 charge and role in the Standard Model) are conventional domain knowledge and not directly predictable from the constituents, so full meaning requires specialist knowledge.
Etymology
Up quark uses up as a simple image to contrast with down: think of up as having a small 'positive' electric charge and down as the opposite. So up quark names a tiny particle with a small 'positive' charge that helps make protons and neutrons.
