33.5 Quarks: is that all there is?  (Page 2/20)

 Page 2 / 20

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

$d\to u+{\beta }^{-}+{\stackrel{-}{v}}_{e}$

Quarks and antiquarks The lower of the $±$ symbols are the values for antiquarks.
Name Symbol Antiparticle Spin Charge $B$ $B$ is baryon number, S is strangeness, $c$ is charm, $b$ is bottomness, $t$ is topness. $S$ $c$ $b$ $t$ Mass $\left(\text{GeV}/{c}^{2}\right)$ Values are approximate, are not directly observable, and vary with model.
Up $u$ $\stackrel{-}{u}$ 1/2 $±\frac{2}{3}{q}_{e}$ $±\frac{1}{3}$ 0 0 0 0 0.005
Down $d$ $\stackrel{-}{d}$ 1/2 $\mp \frac{1}{3}{q}_{e}$ $±\frac{1}{3}$ 0 0 0 0 0.008
Strange $s$ $\stackrel{-}{s}$ 1/2 $\mp \frac{1}{3}{q}_{e}$ $±\frac{1}{3}$ $\mp 1$ 0 0 0 0.50
Charmed $c$ $\stackrel{-}{c}$ 1/2 $±\frac{2}{3}{q}_{e}$ $±\frac{1}{3}$ 0 $±1$ 0 0 1.6
Bottom $b$ $\stackrel{-}{b}$ 1/2 $\mp \frac{1}{3}{q}_{e}$ $±\frac{1}{3}$ 0 0 $\mp 1$ 0 5
Top $t$ $\stackrel{-}{t}$ 1/2 $±\frac{2}{3}{q}_{e}$ $±\frac{1}{3}$ 0 0 0 $±1$ 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
${\pi }^{+}$ $u\stackrel{-}{d}$
${\pi }^{-}$ $\stackrel{-}{u}d$
${\pi }^{0}$ $u\stackrel{-}{u}$ , $d\stackrel{-}{d}$ mixture These two mesons are different mixtures, but each is its own antiparticle, as indicated by its quark composition.
${\eta }^{0}$ $u\stackrel{-}{u}$ , $d\stackrel{-}{d}$ mixture These two mesons are different mixtures, but each is its own antiparticle, as indicated by its quark composition.
${K}^{0}$ $d\stackrel{-}{s}$
${\stackrel{-}{K}}^{0}$ $\stackrel{-}{d}s$
${K}^{+}$ $u\stackrel{-}{s}$
${K}^{-}$ $\stackrel{-}{u}s$
$J/\psi$ $c\stackrel{-}{c}$
$\Upsilon$ $b\stackrel{-}{b}$
Baryons Antibaryons have the antiquarks of their counterparts. The antiproton $\stackrel{-}{p}$ is $\stackrel{-}{u}\stackrel{-}{u}\stackrel{-}{d}$ , for example. , Baryons composed of the same quarks are different states of the same particle. For example, the ${\text{Δ}}^{+}$ is an excited state of the proton.
$p$ $\text{uud}$
$n$ $\text{udd}$
${\text{Δ}}^{0}$ $\text{udd}$
${\text{Δ}}^{+}$ $\text{uud}$
${\text{Δ}}^{-}$ $\text{ddd}$
${\text{Δ}}^{\text{++}}$ $\text{uuu}$
${\text{Λ}}^{0}$ $\text{uds}$
${\text{Σ}}^{0}$ $\text{uds}$
${\text{Σ}}^{+}$ $\text{uus}$
${\text{Σ}}^{-}$ $\text{dds}$
${\text{Ξ}}^{0}$ $\text{uss}$
${\text{Ξ}}^{-}$ $\text{dss}$
${\Omega }^{-}$ $\text{sss}$

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 $d\to u$ , we can also get $u\to d$ . Furthermore, the strange quark can be changed by the weak force, too, making $s\to u$ and $s\to d$ 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 ${\pi }^{+}$ meson (one of the three pions) is composed of an up quark plus an antidown quark, or $u\stackrel{-}{d}$ . Its total charge is thus $+\left(\frac{2}{3}\right){q}_{e}+\left(\frac{1}{3}\right){q}_{e}={q}_{e}$ , as expected. Its baryon number is 0, since it has a quark and an antiquark with baryon numbers $+\left(\frac{1}{3}\right)-\left(\frac{1}{3}\right)=0$ . The ${\pi }^{+}$ 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 $u$ and $\stackrel{-}{d}$ quarks are antiparallel, enabling the pion to have spin zero, as observed experimentally. Finally, the ${\pi }^{-}$ meson shown in [link] is the antiparticle of the ${\pi }^{+}$ meson, and it is composed of the corresponding quark antiparticles. That is, the ${\pi }^{+}$ meson is $u\stackrel{-}{d}$ , while the ${\pi }^{-}$ meson is $\stackrel{-}{u}d$ . 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.

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
What is thermal heat all about
why uniform circular motion is called a periodic motion?.
when a train start from A & it returns at same station A . what is its acceleration?
what is distance of A to B of the stations and what is the time taken to reach B from A
BELLO
the information provided is not enough
aliyu
Hmmmm maybe the question is logical
yusuf
where are the parameters for calculation
HENRY
there is enough information to calculate an AVERAGE acceleration
Kwok
mistake, there is enough information to calculate an average velocity
Kwok
~\
Abel
what is the unit of momentum
Abel
wha are the types of radioactivity ?
what are the types of radioactivity
Worku
what is static friction
It is the opposite of kinetic friction
Mark
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.
MINDERIUM
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.
Eboh
If a particle accelerator explodes what happens
Eboh
why we see the edge effect in case of the field lines of capacitor?
Arnab
what is wave
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
If a particle accelerator explodes what happens
we have to first figure out .... wats a particle accelerator first
Teh
What is surface tension
The resistive force of surface.
iqra
Who can tutor me on simple harmonic motion
on both a string and peldulum?
Anya
spring*
Anya
Yea
yusuf
Do you have a chit-chat contact
yusuf
I dont have social media but i do have an email?
Anya
Which is
yusuf
Where are you chatting from
yusuf
I don't understand the basics of this group
Jimmy
teach him SHM init
Anya
Simple harmonic motion
yusuf
how.an.equipotential.line is two dimension and equipotential surface is three dimension ?
definition of mass of conversion
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
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
Praise
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
Anya
Yeah basics of physics prin8
yusuf
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
a ripple tank experiment a vibrating plane is used to generate wrinkles in the water .if the distance between two successive point is 3.5cm and the wave travel a distance of 31.5cm find the frequency of the vibration
Tamdy
hallow
Boniface
Boniface
the range of objects and phenomena studied in physics is
Boniface By By    By     By Edward Biton 