There is much excitement at the moment at the possible discovery of the Higgs boson and we are told that this particle confers mass to all other particles thus completes the missing piece of the Standard Model. However, on looking up Higgs in Wikipedia it says this. While the Higgs field is postulated to confer mass on quarks and leptons, it causes only a tiny portion of the masses of other subatomic particles, such as protons and neutrons. In these, gluons that bind quarks together confer most of the particle mass. So is finding the Higgs that important? Why can’t the theory of mass conference by gluons be expanded to cover all matter?
Do we actually know what the particle locks like , How do they identify it since in the collision there are 1000 of fragments , how do you label them. I understand there are 3D analyzers, what are the bases to say this particle verify the mass ?
The Higgs particle, its mass and what it does is predicted by the theory. The problem is finding it. The tracks of the smashed bits of the protons are caught in the dectetor and traced out on the screen. The system is calibrated so that observers know what the track of a Higgs boson, or actually it's decaying bits, would take so they know where to look.
We need the Higgs to give mass to elementary particles (leptons and quarks). The proton is a composite particle, therefore the mass is composite.
The Higgs plays an important role in the SM which the gluons alone can't do. The Higgs gives mass by it obtaining a vacuum expectation value (VEV), breaking a symmetry which would otherwise exist in the theory (no mass terms makes for great degrees of freedom). In the symmetric electroweak model there's no W+, W-, Z or photon particles! Instead you have 4 different fields. You then turn on the Higgs VEV and the 4 fields rearrange themselves to make the W+, W-, Z and photon fields. How much of the proton mass the Higgs makes is a different phenomenon to this. Gluon related things can replace the Higgs, it's known as technicolour. Instead of a fundamental scalar field (which the Higgs is) a composition scalar field is built from quarks and held together by gluons. Yukawa theory was the first step in the development of QCD and it basically describes scalar objects form from quarks and gluons (but we didn't realise that in the 40s/50s when it was developed). Something like a top-antitop state can play the role of the Higgs. It's less elegant and doesn't get away from the issues of how little the proton's mass is due to this symmetry breaking but it's the first place theorists would go if the Higgs were to be killed by the LHC. We understand particle physics below 100GeV extremely well, due to decades of work and experiments. As such we can say "Suppose no other particles exist. What would this 150GeV experimental collision look like?". That's basically what a lot of physicists have been doing for the last 10 years, banging out the predictions of various permutations of possible models so we can process LHC data quickly. If you don't include the Higgs or any other such mechanism (ie technicolour) our models say something impossible happens before you get to 500GeV (a violation of unitarity in electroweak decays involving W bosons). As such we expect something to come in and save the day. A Higgs mediated process would involve a lot of electroweak muguffins being thrown out from collisions. A technicolour one would involve quarks and gluons more. The results released by CERN this week show an elevation over the "No new particles" predictions in a particular range, in several collision types (ie more than one detector experiment sees something). So it seems there might be something there. The Hydrogen atom is composite but more than 99.999% of its mass is accounted for by the sum of the rest masses of the proton and electron. A proton is about 1GeV in mass, 1 billion eV. The electron is 0.5MeV, 500 thousand eV. The binding energy of said particles is 13.6eV. In a proton the individual quarks have rest masses about 5MeV*, so only 15 parts per 1000 are explained by the component rest masses. * Their precise rest masses are poorly understood precisely because you can't rip them out of the proton to measure them individually. It has to be computed non-perturbatively on a supercomputer you could crush an elephant with.
Thanks. I'm not just here to 'suppress the Truth' and slap down trolls, I sometimes come out with physics/maths.
. Hi AlphaNumeric. Long time no see! I only registered here yesterday after a friend recommended a particular discussion thread involving variations of the theme of 'twin' etc 'time/clock' scenarios. I then also happened across this thread about the Higgs, and saw your informative post as quoted above. I bolded two sentences of particular interest to my own perspective on the speculations/hypotheses/models involved, and I would appreciate very much your own further views on them. I have two specific questions for you and anyone else interested/knowledgeable enough to answer them for me.... 1. Is the (putative) Higgs mechanism etc which is (hypothesised to be) responsible for the relevant 'symmetry breaking' active at all times ubiquitously and constantly?....or is there some 'frequency' to it?....that is, does there exist, in the 'lifetime' of Higgs-affected particles, any period where NO mass is being induced etc by the hyothetical Higgs (and hence NO 'rest mass' exists)? I hope you get the general as well as the specific thrust of this compound question? 2. What form does the 'binding energy' take?...and what is the nature/properties of the 'mass equivalent' feature/form called 'binding energy' quanta or quantum? Thanks in advance, mate. Back tomorrow! Cheers...and best wishes to you and yours (and also everyone here at sciforums) for a safe and happy time during "The Silly Season'! Please Register or Log in to view the hidden image! RealityCheck. . PS: for Trooper... Hi Trooper! Thanks and hope you are well. I should tell you that it was also your own recommendation (in a post at physforum to someone, but I can't remember when/who), as well as a (another) friend's email alert, that convinced me to register at sciforums. Cheers and see you around. Take care during the holiday madness, OK? From your friend, RealityCheck..... :wave: back at you, Trooper! .
Hi AlphaNumeric. Are you in a position to elucidate the matters/questions I asked/alluded to in my post above (#8) ? If not, perhaps rpenner or someone else can? Please Register or Log in to view the hidden image! I would appreciate it very much! Thanks. .
. prometheus, AlphaNumeric, rpenner. Can any of you answer my questions in post #8 above? If you have not yet come across it, I shall just repeat the relevant questions.... 1. Is the (putative) Higgs mechanism etc (hypothesised to be responsible for the relevant 'symmetry breaking') active at all times, ubiquitously and constantly?....or is there some 'frequency' to it?....that is, does there exist, in the 'lifetime' of Higgs-affected particles, any period where NO mass is being induced etc by the hyothetical Higgs (and hence NO 'rest mass' exists)? I hope you get the general as well as the specific thrust of this compound question? 2. What form does the 'binding energy' take?...and what is the nature/properties of the 'mass equivalent' feature/form called 'binding energy' quanta or quantum? [Please see post #8 above for the context in which this question arose.] Thanks in advance, guys! Cheers. Please Register or Log in to view the hidden image! .
I haven't had time today, I got back from work at 10pm and now I'm going to sleep (it being 11.30pm here in the UK). If no one beats me to it I'll answer some time tomorrow.
Since the Higg's Boson is a speculated subatomic particle is it permissible to make a non scientific speculation about it? Higgs confers mass to particle E = M C ^ 2 Could the Higgs be non-Energy type matter? (massless) Like the framework of a particle, on which the energy/mass associates as a particle.
This is all unscientific. Such hypotheses as Higgs are unfalsifiable If no Higgs is found, there will be no consequence. Another splint will be found to fix the model. If Higgs is found, it will be a miracle. It will be just weak evidence in favor of the Higgs boson and Higgs field hypothetical ad hoc band-aid to fix the standard model, but it will still be an ad hoc fix.
i actually didn't heard of the higgs boson before Please Register or Log in to view the hidden image! , but i'd like to know what is it...
The Higgs mechanism is nothing to do with E=mc^2 mass-energy relations. It's to do with turning a massless description into massive descriptions. To give you an example (one which cuts corners and tells half truths but there's no point in doing too nuts here) the following is the massless QED Lagrangian (without U(1) invariance) : \(\mathcal{L} = i\bar{\psi}\gamma^{a}\partial_{a}\psi\) This, a kinetic term, is what you write down if you want to describe a massless, non-interacting spinor field, massless, chargeless electrons for instance. If you want to include mass, as real electrons have then you need to include a term of the following form, \(m\bar{\psi}\psi\), where m is the mass. For technical reasons no one wants me to get into it's better not to put this in by hand. Instead you say the massless electron interacts with a Higgs field, H. Such an interaction looks like \(g H \bar{\psi}\psi\), where g is the coupling between them. The Higgs has its own kinetic term but never mind that. So we have \(\mathcal{L} = i\bar{\psi}\gamma^{a}\partial_{a}\psi + g H \bar{\psi}\psi\). So how do we get mass? We say the Higgs gains a 'vacuum expectation value', a VEV, by writing it as \(H = \langle H \rangle + h\) where h is some small perturbation about the VEV (like doing a Taylor expansion about some non-zero x for those who know what I mean). We now have \(\mathcal{L} = i\bar{\psi}\gamma^{a}\partial_{a}\psi + g \Big( \langle H \rangle + h \Big) \bar{\psi}\psi = i\bar{\psi}\gamma^{a}\partial_{a}\psi + g \langle H \rangle \bar{\psi}\psi + g h \bar{\psi}\psi\). h is still some field but \(g \langle H \rangle\) is a number, what you get if you combine the coupling constant with the VEV. Well let's just write it as a single term, say .... m. Now we have a term \(m\bar{\psi}\psi\). Oh look, it's the mass term for a massive electron-like particle! We've given the electron mass by giving the Higgs a VEV! We explain the mass term in terms of another field. In fact we explain ALL mass terms like that, using the same field. That is how the Higgs gives things mass. Now for RC... The mass giving properties are always 'on', they don't fluctuate. However, the way in which the Higgs is produced is to give the system enough energy to overcome the VEV. Have a look on Wiki for 'mexican hat potential'. The Higgs field behaves according to that potential. Normally it bobs around the circular trough but pump enough energy in and it'll be able to rise up to the top of the mound easily. This means processes involving electroweak particles get altered due to the way the Higgs dictates how they combine, but the electron always has the mass it has in any of this. As for binding energy it's gluons mostly. They can carry a hell of a punch and the tight binding they form with one another requires vasts amount of energy to pull apart. So many you make new quarks and gluons so it's impossible to isolate them in simple experiments. If you pump enough energy into the system then it's possible to 'melt' mesons (quark anti-quark pairings). This allows you to construct systems where strong charge flows without resistance, its the strong force version of superconduction. It's hypothesised this can happen in the core of neutron stars, which compress things enough to break normal 'colour locking'. Unfortunately its poorly understood as you can't do standard methods on it, unlike the Higgs mechanism, you need to use a supercomputer. There's been serious theoretical development in the last 5~10 years using string theory. Despite the whining of some, string theoretic models have lead to an understanding of gravity/gauge duality which allows us to examine colour locking and meson properties using standard methods, by mapping all this strongly coupled stuff in 4 dimensions into weak coupled gravity (but in 10 dimensions). This might never have been discovered without string theory (and it's not the only real world thing string theory has helped us understand!). One of the most cited papers in modern times is the paper which put forth this duality. Both Prom and I have written papers (not together) on the subject so it's something we're going to support a bit Please Register or Log in to view the hidden image!
AN Quote: Both Prom and I have written papers (not together) on the subject so it's something we're going to support a bit . . . ever heard of 'self-fulfilling prophecies' . . . .
How so? I can't speak for Prom but I worked on it because it was interesting, close to my main area of research, provided plenty of new insight into field theory and still had plenty of interesting unanswered questions. I don't support it in the sense of "If it's proven nonsense then my career is doomed!", I support people looking into it because I have seen sufficiently many good reasons (as just listed) to make it worth looking at. The worth of looking into it wouldn't be completely removed if it turned out not to be completely valid. Electromagnetism isn't completely accurate but it's still something every single physicist should know something about. Likewise Newtonian mechanics or pretty much anything else pre 1900. Quite a lot of the time people don't do theoretical research using the reasoning "I'm certain this is the true model" but rather "A better understanding of this would help in the grand scheme of things". If it turns out to be accurate then that's an added bonus. Currently we struggle to understand some areas of non-perturbative field theory and gravity-gauge dualities provide insight into some parts of that. That is why its worth looking into, IMO. So if you're thinking we defend it for fear disproof might harm our careers then you're just flat out wrong.
Hi, RC. I think Alphanumeric misunderstood your question. Binding energy is negative, it doesn't take on any form of its own. Maybe you should ask a slightly different question involving an electron and a proton, or a cannonball and the earth, or capturing a massless photon in a mirror-box.
