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n p + β + v - e size 12{n rightarrow p+β rSup { size 8{ - {}} } + { bar {v}} rSub { size 8{e} } } {}   becomes  udd uud + β + v - e size 12{ ital "udd" rightarrow ital "uud"+β rSup { size 8{ - {}} } + { bar {v}} rSub { size 8{e} } } {} .

We see that this is equivalent to a down quark changing flavor to become an up quark:

d u + β + v - e size 12{d rightarrow u+β rSup { size 8{ - {}} } + { bar {v}} rSub { size 8{e} } } {}

Quarks and antiquarks The lower of the ± size 12{ +- {}} {} symbols are the values for antiquarks.
Name Symbol Antiparticle Spin Charge B size 12{B} {} B size 12{B} {} is baryon number, S is strangeness, c size 12{c} {} is charm, b size 12{b} {} is bottomness, t size 12{t} {} is topness. S size 12{S} {} c size 12{c} {} b size 12{b} {} t size 12{t} {} Mass ( GeV / c 2 ) Values are approximate, are not directly observable, and vary with model.
Up u size 12{u} {} u - size 12{ { bar {u}}} {} 1/2 ± 2 3 q e size 12{ +- { {2} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 0 0 0 0 0.005
Down d size 12{d} {} d - size 12{ { bar {d}}} {} 1/2 1 3 q e size 12{ -+ { {1} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 0 0 0 0 0.008
Strange s size 12{s} {} s - size 12{ { bar {s}}} {} 1/2 1 3 q e size 12{ -+ { {1} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 1 size 12{ -+ 1} {} 0 0 0 0.50
Charmed c size 12{c} {} c - size 12{ { bar {c}}} {} 1/2 ± 2 3 q e size 12{ +- { {2} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 0 ± 1 size 12{ +- 1} {} 0 0 1.6
Bottom b size 12{b} {} b - size 12{ { bar {b}}} {} 1/2 1 3 q e size 12{ -+ { {1} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 0 0 1 size 12{ -+ 1} {} 0 5
Top t size 12{t} {} t - size 12{ { bar {t}}} {} 1/2 ± 2 3 q e size 12{ +- { {2} over {3} } q rSub { size 8{e} } } {} ± 1 3 size 12{ +- { {1} over {3} } } {} 0 0 0 ± 1 size 12{ +- 1} {} 173
Quark composition of selected hadrons These two mesons are different mixtures, but each is its own antiparticle, as indicated by its quark composition.
Particle Quark Composition
Mesons
π + size 12{π rSup { size 8{+{}} } } {} u d - size 12{u { bar {d}}} {}
π size 12{π rSup { size 8{ - {}} } } {} u - d size 12{ { bar {u}}d} {}
π 0 size 12{π rSup { size 8{0} } } {} u u - size 12{u { bar {u}}} {} , d d - size 12{d { bar {d}}} {} mixture These two mesons are different mixtures, but each is its own antiparticle, as indicated by its quark composition.
η 0 size 12{η rSup { size 8{0} } } {} u u - size 12{u { bar {u}}} {} , d d - size 12{d { bar {d}}} {} mixture These two mesons are different mixtures, but each is its own antiparticle, as indicated by its quark composition.
K 0 size 12{K rSup { size 8{0} } } {} d s - size 12{d { bar {s}}} {}
K - 0 size 12{ { bar {K}} rSup { size 8{0} } } {} d - s size 12{ { bar {d}}s} {}
K + size 12{K rSup { size 8{+{}} } } {} u s - size 12{u { bar {s}}} {}
K size 12{K rSup { size 8{ - {}} } } {} u - s size 12{ { bar {u}}s} {}
J / ψ size 12{J/ψ} {} c c - size 12{c { bar {c}}} {}
ϒ b b - size 12{b { bar {b}}} {}
Baryons Antibaryons have the antiquarks of their counterparts. The antiproton p - size 12{ { bar {p}}} {} is u - u - d - size 12{ { bar {u}} { bar {u}} { bar {d}}} {} , for example. , Baryons composed of the same quarks are different states of the same particle. For example, the Δ + size 12{Δ rSup { size 8{+{}} } } {} is an excited state of the proton.
p size 12{p} {} uud size 12{ ital "uud"} {}
n size 12{n} {} udd size 12{ ital "uud"} {}
Δ 0 size 12{Δ rSup { size 8{0} } } {} udd size 12{ ital "uud"} {}
Δ + size 12{Δ rSup { size 8{+{}} } } {} uud size 12{ ital "uud"} {}
Δ size 12{Δ rSup { size 8{ - {}} } } {} ddd size 12{ ital "ddd"} {}
Δ ++ size 12{Δ rSup { size 8{"++"} } } {} uuu size 12{ ital "uuu"} {}
Λ 0 size 12{Λ rSup { size 8{0} } } {} uds size 12{ ital "uds"} {}
Σ 0 size 12{Σ rSup { size 8{0} } } {} uds size 12{ ital "uds"} {}
Σ + size 12{Σ rSup { size 8{+{}} } } {} uus size 12{ ital "uus"} {}
Σ size 12{Σ rSup { size 8{ - {}} } } {} dds size 12{ ital "dds"} {}
Ξ 0 size 12{Ξ rSup { size 8{0} } } {} uss size 12{ ital "uss"} {}
Ξ size 12{Ξ rSup { size 8{ - {}} } } {} dss size 12{ ital "dss"} {}
Ω size 12{ %OMEGA rSup { size 8{ - {}} } } {} sss size 12{ ital "sss"} {}

This is an example of the general fact that the weak nuclear force can change the flavor of a quark . By general, we mean that any quark can be converted to any other (change flavor) by the weak nuclear force. Not only can we get d u size 12{d rightarrow u} {} , we can also get u d size 12{u rightarrow d} {} . Furthermore, the strange quark can be changed by the weak force, too, making s u size 12{s rightarrow u} {} and s d size 12{s rightarrow d} {} possible. This explains the violation of the conservation of strangeness by the weak force noted in the preceding section. Another general fact is that the strong nuclear force cannot change the flavor of a quark.

Again, from [link] , we see that the π + size 12{π rSup { size 8{+{}} } } {} meson (one of the three pions) is composed of an up quark plus an antidown quark, or u d - size 12{u { bar {d}}} {} . Its total charge is thus + 2 3 q e + 1 3 q e = q e size 12{+ left ( { {2} over {3} } right )q rSub { size 8{e} } + left ( { {1} over {3} } right )q rSub { size 8{e} } =q rSub { size 8{e} } } {} , as expected. Its baryon number is 0, since it has a quark and an antiquark with baryon numbers + 1 3 1 3 = 0 size 12{+ left ( { {1} over {3} } right ) - left ( { {1} over {3} } right )=0} {} . The π + size 12{π rSup { size 8{+{}} } } {} half-life is relatively long since, although it is composed of matter and antimatter, the quarks are different flavors and the weak force should cause the decay by changing the flavor of one into that of the other. The spins of the u size 12{u} {} and d - size 12{ { bar {d}}} {} quarks are antiparallel, enabling the pion to have spin zero, as observed experimentally. Finally, the π size 12{π rSup { size 8{ - {}} } } {} meson shown in [link] is the antiparticle of the π + size 12{π rSup { size 8{+{}} } } {} meson, and it is composed of the corresponding quark antiparticles. That is, the π + size 12{π rSup { size 8{+{}} } } {} meson is u d - size 12{u { bar {d}}} {} , while the π size 12{π rSup { size 8{ - {}} } } {} meson is u - d size 12{ { bar {u}}d} {} . These two pions annihilate each other quickly, because their constituent quarks are each other’s antiparticles.

Two general rules for combining quarks to form hadrons are:

  1. Baryons are composed of three quarks, and antibaryons are composed of three antiquarks.
  2. Mesons are combinations of a quark and an antiquark.

Questions & Answers

Calculate the work done by an 85.0-kg man who pushes a crate 4.00 m up along a ramp that makes an angle of 20.0º20.0º with the horizontal. (See [link] .) He exerts a force of 500 N on the crate parallel to the ramp and moves at a constant speed. Be certain to include the work he does on the crate an
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What is thermal heat all about
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why uniform circular motion is called a periodic motion?.
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what is distance of A to B of the stations and what is the time taken to reach B from A
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the information provided is not enough
aliyu
Hmmmm maybe the question is logical
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where are the parameters for calculation
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mistake, there is enough information to calculate an average velocity
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what is the unit of momentum
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what are the types of radioactivity
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what is static friction
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It is the opposite of kinetic friction
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static fiction is friction between two surfaces in contact an none of sliding over on another, while Kinetic friction is friction between sliding surfaces in contact.
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I don't get it,if it's static then there will be no friction.
author
It means that static friction is that friction that most be overcome before a body can move
kingsley
static friction is a force that keeps an object from moving, and it's the opposite of kinetic friction.
author
It is a force a body must overcome in order for the body to move.
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If a particle accelerator explodes what happens
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why we see the edge effect in case of the field lines of capacitor?
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what is wave
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what is force
Muhammed
force is something which is responsible for the object to change its position
MINDERIUM
more technically it is the product of mass of an object and Acceleration produced in it
MINDERIUM
wave is disturbance in any medium
iqra
energy is distributed in any medium through particles of medium.
iqra
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we have to first figure out .... wats a particle accelerator first
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The resistive force of surface.
iqra
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on both a string and peldulum?
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spring*
Anya
Yea
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Which is
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teach him SHM init
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Simple harmonic motion
yusuf
how.an.equipotential.line is two dimension and equipotential surface is three dimension ?
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definition of mass of conversion
umezurike Reply
Force equals mass time acceleration. Weight is a force and it can replace force in the equation. The acceleration would be gravity, which is an acceleration. To change from weight to mass divide by gravity (9.8 m/s^2).
Marisa
how many subject is in physics
Adeshina Reply
the write question should be " How many Topics are in O- Level Physics, or other branches of physics.
effiom
how many topic are in physics
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Praise what level are you
yusuf
If u are doing a levels in your first year you do AS topics therefore you do 5 big topic i.e particles radiation, waves and optics, mechanics,materials, electricity. After that you do A level topics like Specific Harmonic motion circular motion astrophysics depends really
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Yeah basics of physics prin8
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Heat nd Co for a level
yusuf
yh I need someone to explain something im tryna solve . I'll send the question if u down for it
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hallow
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please send the answer
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I don't know please give the answer
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Source:  OpenStax, College physics. OpenStax CNX. Jul 27, 2015 Download for free at http://legacy.cnx.org/content/col11406/1.9
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