Charge is conserved. Components are = other than the charge parity is approximate. Don't think this would prevent a 'flip-flop' of the charge component. Just a guess. http://en.wikipedia.org/wiki/Antiparticle
You seem to have missed the point! neutron -> proton(+ charge) + electron (- charge) + neutrino (no charge). Call proton "matter". One of the leptons is called "matter", the other is called "antimatter". Which?
Most likely I did if you say so. You want to know neutrino or anti-neutrino? Probably got that wrong to. Based on my lack of any real knowledge I'd go with symmetry. Maybe this can reveal something for you. Antihydrogen (H¯) and muonic antihydrogen (H¯μ) formation in low energy three-charge-particle collisions http://arxiv.org/abs/1304.2434
The terms matter and antimatter are misleading, because atoms, made of pure matter, with an imbalance in the ratio of protons to neutrons, can emit positrons. This matter based process is called positron emission which turns a proton into a neutron. There are also cases where atoms can bind one or more positrons outside the nucleus. http://prl.aps.org/abstract/PRL/v109/i22/e223401
Electrons and neutrinos are a bit special, since the left-handed part of the electron sits in an SU(2) doublet along with the corresponding electron-neutrino. They are "the same particle", in a manner of speaking. I think it would therefore not make sense to trying to separately switch the "matter"-"antimatter" labels for them. I think you could independently switch the right-handed part of the electron to being "antimatter" if you liked, because it sits by itself in the singlet representation of SU(2), so that the physical mass eigenstate of the electron would be a mix of left-handed "matter" and right-handed "antimatter". I think there is no reason you couldn't re-label the quarks separately as well. However, if there is grand unification or some such, then none of that may be possible, because then all the standard model fields would sit together in some representation of the GUT group, i.e. all be just different components of one big GUT field. The fact that most of the "stuff" that survived the early universe seems to be clearly label-able as "matter" seems to indicate that it might be linked together in some way like this. Oh, also, I guess the Standard Model does have some non-perturbative features that violate lepton and baryon numbers, i.e. high-temperature phenomenon that may be at least partially responsible for the observed matter-antimatter asymmetry, sphalerons ands whatnot (though I don't think they generally can generate a big enough asymmetry...), which I think also strongly motivates the "natural" categorisation of fields into matter and antimatter. p.s. also to answer the quoted question more directly, you can call either the electron or the anti-neutrino "matter", but the other has to then be called antimatter, since it has to be the time-reversed SU(2) partner of the (left-handed) electron which is emitted along with the electron. The time-reversal makes it "anti" whatever the electron is. But like I said, this is a weak process so it creates a left-handed electron, but it quickly starts oscillating between left and right handed states due to having mass, and the right handed piece I think should be allowed to be labelled separately. View attachment 6820
Mathman: From your Post #20: The only critical issue relating to definitions is that they be consistent. If you wanted to say that our universe consists of antimatter, the semantics could be made consistent. Would you consider it a sensible definition? If a universe with atoms made of negative nuclei & a cloud of positrons were discovered, it would be called a matter universe. The semantics would be consistent. It would seem a bit backwards. It seems a bit strange to call electrons in our universe antimatter. I think the definition can be made consistent, but requires positrons to be called matter instead of antimatter. Does it seem sensible to make definitions such that matter atoms in our universe are made of matter protons & neutrons with a cloud of antimatter electrons? It requires that antimatter atoms be defined as consisting of negatrons (word coined by me) & neutrons with a cloud of matter positrons. The above definitions are consistent, making the Semantics valid. It just seems silly to call one constituent of our matter an antimatter particle when more reasonable definitions could have been chosen. I think there are several particles called neutrinos (not sure of this & too lazy to look it up). Until more information is discovered via accelerator experiments, I am betting that there is one basic type of neutrino which is its own antiparticle.
I don't think mathman cares if it is sensible, just whether it is logically allowed by the structure of the Standard Model. The important thing is the math after all, not so much the words we happen to choose to talk about it with. There are 3; one for each charged lepton. They come in pairs together; electron/electron-neutrino, muon/muon-neutrino, tau/tau-neutrino. Each of these pairs sits in an SU(2) doublet, so before electroweak symmetry breaking you could have done an SU(2) transformation on them (basically swapping them for each other) and the universe would remain unchanged. This is why I said they are kind of "the same particle", and why the definition of their matter/antimatter-ness is linked together. Neutrinos are definitely not their own antiparticles. The chirality of neutrinos is left-handed, while anti-neutrinos are right handed. This is an experimentally observable difference.
From http://en.wikipedia.org/wiki/Neutrino: While I would not bet serious money on the validity of data from Wikipedia, they are usually correct. Apparently, there must be cases for which opposite chirality does not imply two different particles.
Hmm ok I must be wrong about the chirality itself producing some measurable effect, at least in this neutrino case. As for wikipedia, well I think it is correct but it is a little tricky. It is referring to the possibility that neutrinos might be Majorana particles. As I understand it, if this is the case, then the real physical mass eigenstate of neutrinos would be a mixture of left-handed (flavour, or weak) eigenstates v and right handed anti-neutrino eigenstates v_c, that is, v_m = v + v_c, roughly speaking. It would be this physical neutrino which was its own antiparticle, not the state that is directly involved in weak interactions. edit: actually maybe I'm not wrong. It is the left/right handed weak eigenstate that is produced in reactions after all, so you may still be able to measure whether you are producing left or right handed particles. It is just that I guess they would quickly oscillate into the other chirality particle just the same as the other massive fermions do. The difference is that the physical electron mass eigenstate, a mixture of a left handed (weakly interacting) piece and a right handed (non weakly interacting) piece, is definitely not its own antiparticle (the positron being a mixture of a right-handed (weakly interacting) piece and a left handed (non weakly interacting) piece), while the physical Majorana neutrino mass eigenstate would in fact be the same as its antiparticle.
I was thinking more along the lines of the coupled Majorana equation, but hey, I think your reply was better. I didn't fully understand the OP question.
I know what you're asking, and I believe the answer is yes. All "matter" behaves together in a certain way and cannot be freely swapped out with its respective "antimatter" part, expecting the same results (unless of course ALL matter is swapped out for antimatter). My belief is that, physically, there is an extremely low-level chirality of sorts which differentiates between the two flavors...
You still don't get my point! I was not switching parts, only labels! The electron remains an electron and the positron remains a positron. The question I am raising (repeatedly) is which will have the LABEL "matter".
Mathman: You are essentially asking that we define our universe as consisting of antimatter. As far as I know, it would cause no semantic or logical problems if we called the matter in our universe antimatter & defined matter as having a negative nucleus surrounded by a cloud of positive particles. The most important issue is semantic & logical consistency, with other considerations being minor. Still: Since it is logically & semantically consistent, why not make the definitions result in assigning the shorter definition to the most used term? BTW: Consider my having children from a first marriage & marrying a woman who also has children from a previous marriage. It would be logically & semantically consistent for me to call my offspring natural sons & natural daughters, while calling her children my sons & daughters. Of course before I married for the second time, I would have to introduce my children using the qualifier to make sure that strangers understood they were my progeny, rather than being the progeny of a second wife. Would it be sensible to use a qualifier for my natural children & not use a qualifier for her children? Sensibility & convenience are worth something in assigning defining terms/phrases.
You still don't get my point. Does calling protons, neutrons, etc. (quark stuff) matter require calling electrons matter or can the definitions in reference to leptons be switched but leave the quark stuff label as is?
It is not easy to answer the following question: Note the bold part of my reply in a previous Post: The bold part of my Post indicates that I agree that your view is logically & semantically consistent. That Post also included the following, which should be considered to have merit:
This is an example of the cart being placed before the horse. It assumes all these things are true before the experiment proves it. This is how you support premises that begin with no proof and generate need for research dollars. The moon is made of cheese. If we can capture the piece of the moon cheese we cold explain how the cheese is made. Say the universe began with matter and anti-matter, due to energy spilt, with a slight asymmetric excess of matter. To end with only matter, that would mean most of the original matter/antimatter reformed energy. Do we observe a universe with 99% energy or whatever the slight asymmetry proportion was in favor of matter? If matter and antimatter combine, to get rid of the anti-matter, and form energy, this energy can separate to form matter and antimatter. To remove all the anti-matter, the energy has to persist and not reverse. With space-time expanding faster than the speed of light, according to other assumptions, this 99% percent plus energy universe should be easy to see. Do we see it? As far as I know, we don't see that much energy. This would imply equilibrium favors matter; matter is more stable. As an analogy if we react hydrogen and oxygen we get water but also an assortment of radicals. One can do this over and over in the lab, but water is the most stable so no matter how many times you do it, water is left standing. Besides, atoms can capture anti-matter, such as positrons without blowing up, since both are matter. If they were not both matter these could never combine, without releasing all their energy. The nomenclature was design for sales.
Close, only 4% of the universe is composed of normal matter. The above statement is just silly, the apparent problem is that you are clearly ignorant of matter / antimatter interactions.
These is a little method to my madness. My hypothesis (which it has to remain as such, since we don't know what happened to the antimatter) is that antimatter hadron decay left behind an excess of electrons. Until the antimatter deficit is explained, the point I make is of interest.
Mathman:From your Post #38 The mainstream explanation for the antimatter deficit is that there was mutual annihilation of matter/antimatter. Originally, there was an excess of matter. That excess is what was left after the mutual annihilation. I do not understand your claiming that there is an excess of electrons. As far as I know our universe is charge neutral: There is the same (exact/approximately?) number of positively charged particles as negatively charged particles. I wonder about your reference to hadron decay & excess electrons. Antiimatter is composed of a negative nucleus surrounded by a cloud of positrons. Matter is composed of a positive nucleus surrounded by a cloud of electrons (negative). Mutual annihilation of matter & antimatter results in antimatter atoms & matters atoms being totally converted to energy. If there is an excess of matter, some matter atoms will survive, resulting in a matter universe/region. If there is an excess of antimatter, some antimatter atoms will survive, resulting in an antimatter universe/region. The resulting universe will be charge neutral. There will be an excess of either matter or antimatter atoms, with neither excess of positive hadrons nor an excess of electrons/postitrons. Am I missing something or not understanding what you are Posting?
My point is that the universe may have started with an equal amount of matter and antimatter, but they have slight different decay patterns. As a result the matter we see consists of protons and neutrons, while the antimatter consists of electrons, with neutrinoes keeping the accounts equal.
