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# particle STRANGENESS - can anyone explain for me please? watch

1. i have no clue and do not understand strangeness at all in regard to particle physics. I would be really grateful if someone could just briefly explain what it is, what effect it has on particles and it only affects muons doesn't it??

2. from what I've learnt, it relates to the strange quark.
If a particle has 1 strange quark, its strangeness is -1, if it has 1 antistrange quark its strangeness is +1.
So 2 strange quarks give a strangeness of -2, and vice versa.
Strangeness is only conserved through the strong interaction, not weak.
3. (Original post by Mr Nonsense)
i have no clue and do not understand strangeness at all in regard to particle physics. I would be really grateful if someone could just briefly explain what it is, what effect it has on particles and it only affects muons doesn't it??

Strangeness is what we call a charge.
A charge is just a number that doesn't change (or at least tends not to change). We don't know why, or how, or that that 'charge' means. But its relatively constant.
Seriously, its the same with electric charge, and with mass.
Physicists like giving names to random numbers like energy, momentum etc etc...

So...if you are comfortable with that we can get onto strangeness.
Initially in particle physics, we found certain particles tended to refuse decay as quickly as they were created.
It was postulated that strangeness was conserved in their creation. So of every particle with S = 1 was produced, a particle with S = -1 was also produced. Easy to see how that works.

But these particles headed away from each other. So their decay must violate Strangeness (since its almost imposible for these particles to find another strange particle in its short lifetime).

What we 'know' now is that strangeness comes from the Strange quark, which has a Strangeness of -1 (yes I know that sentence made no logical sense). That strangeness is conserved in Strong interactions (that is the strong nuclear force) but is broken by the Weak interaction.

A very very similar situation exists with a charge known as Charmness.

In conclusion what you actually need to know (possibly) is that Strangeness is conserved in Strong interactions but not in the weak.
That is Strangeness commutes with Strong interactions but not Weak interactions.
4. thank you soooo much!!
what a thorough response
definite +rep for you
thanks again
5. (Original post by Mr Nonsense)
i have no clue and do not understand strangeness at all in regard to particle physics. I would be really grateful if someone could just briefly explain what it is, what effect it has on particles and it only affects muons doesn't it??

Mehh has it right.

I remember when I learnt about that last year. It confused me too. Just remember that strangeness is a quality of the particle, but that it could just as easily have been called anything else. It works in a similar way to charge in the calculations (well, sort off). It seems so much more complicated than it is from the outside.
6. (Original post by Mehh)
Strangeness is what we call a charge.
A charge is just a number that doesn't change (or at least tends not to change). We don't know why, or how, or that that 'charge' means. But its relatively constant.
Seriously, its the same with electric charge, and with mass.
Physicists like giving names to random numbers like energy, momentum etc etc...

So...if you are comfortable with that we can get onto strangeness.
Initially in particle physics, we found certain particles tended to refuse decay as quickly as they were created.
It was postulated that strangeness was conserved in their creation. So of every particle with S = 1 was produced, a particle with S = -1 was also produced. Easy to see how that works.

But these particles headed away from each other. So their decay must violate Strangeness (since its almost imposible for these particles to find another strange particle in its short lifetime).

What we 'know' now is that strangeness comes from the Strange quark, which has a Strangeness of -1 (yes I know that sentence made no logical sense). That strangeness is conserved in Strong interactions (that is the strong nuclear force) but is broken by the Weak interaction.

A very very similar situation exists with a charge known as Charmness.

In conclusion what you actually need to know (possibly) is that Strangeness is conserved in Strong interactions but not in the weak.
That is Strangeness commutes with Strong interactions but not Weak interactions.
one more thing sorry....

what are the characteristics of a strange particle?
7. Strange quark-
charge=-1/3
strangeness= -1
baryon number= +1/3
and the opposite for antiquarks.

(Original post by Mr Nonsense)
one more thing sorry....

what are the characteristics of a strange particle?
8. (Original post by zafaru123)
Strange quark-
charge=-1/3
strangeness= -1
baryon number= +1/3
and the opposite for antiquarks.
sorry, i should have been clearer. What i really meant was what is the effect of having a strangeness of -1? Just like having a charge of +1 say makes a proton behave in a certain way, how does being a strange particle affect its behaviour?

thanks again
9. (Original post by Mr Nonsense)
sorry, i should have been clearer. What i really meant was what is the effect of having a strangeness of -1? Just like having a charge of +1 say makes a proton behave in a certain way, how does being a strange particle affect its behaviour?

thanks again

They are strange.

They are expected to decay as fast as they are created yet they do not, therefore it is said they are strange.

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