The news out of Geneva gives a tantalizing first gustatory perception of really discovering the Higgs Boson . Is this for real ? In this hebdomad ’s “ require a Physicist , ” we do a round - up of all things Higgs - related .
Top image mention : CERN
If you fall out in some of the nerdier websites ( including this one ) , you probably could n’t help but get unrestrained aboutyesterday ’s newsregarding the Higgs Boson . If you somehow missed it , here ’s the equipment failure .
https://gizmodo.com/physicists-reveal-compelling-evidence-for-the-god-part-5867512
As you belike know , one of the bragging goals – - arguably the big goal — of the LHC is to regain the elusive Higgs Boson . The two biggest experiment in the Large Hadron Collider , ATLAS and CMS , announced their datum updates yesterday . Both ATLAS and CMS have found a signal with comparatively mellow significance suggest that the Higgs Boson is real and that it has a mint of around 135 times the mass of a proton ( or , to you experts , around 125 GeV ) . This is a giving bargain because 1 ) The Higgs Boson is the last undetected subatomic particle in the Standard Model of natural philosophy , and 2 ) The Higgs field is what gives other atom their masses .
I did a column a while ago aboutwhy discovering the Higgswould be so exciting , but surely you must have more questions . In fact , I be intimate you do since we put out acall for questionsyesterday and you guys post andemaileddozens of question about what it all means . Thanks to everyone who sent in questions .
What ’s the Matter with the Higgs Boson ?
https://gizmodo.com/do-you-have-questions-about-the-higgs-boson-discovery-5867650
The Ultimate Field Guide to Subatomic Particles
Credit : ATLAS Collaboration .
Credit : CMS Collaboration .
Did they really detect the Higgs ?
permit me get this out of the way from the kickoff . By the standards of the particle physics residential district ( and almost certainly by the measure of the Nobel prize citizens committee ) the Higgs has not formally been get wind . Why not ? That takes a little explaining . This involve number , which mean that the numerically squeamish may want to expect forth , and it also take a few back - of - the envelope calculation so the numerical experts may also need to look out .
I usually do n’t post data in my pillar , but as you could see above , I ’ve made an exception today . The two plots are from the ATLAS experiment and the CMS experiment , severally . In each , the square line is the data for different possible value of the Higgs boson mass ( the hug drug - bloc ) . The dashed personal credit line is what you ’d look if there were no Higgs at a particular pot . The strong and scare away lines obviously do n’t match up . When you do an experiment , you do n’t carry to get exactly the void result ( no Higgs ) with every measurement . There ’s always a scattering .
If there were no Higgs , then just about 95 % of the metre the substantial line should be within the white-livered bend . This is have it off , mathematically , as “ 2 - sigma . ” You only have about a 2.5 % of finding yourself 2 - sigma above the void value by random fortune . Both the ATLAS and CMS experiment have more than a 2 - sigma result around 125 GeV ( 135 clock time the stack of the proton ) in their data .
There are a few complications , however . For one matter , if you take care at enough data you wouldexpect to seea few random wavering . Even after correcting for that , the ATLAS result is about 2.3 sigma and the CMS effect is about 1.9 . Alone , neither is such a large deal BUT ( and here ’s the important compass point ) since the results are sovereign , you get to combine them giving you a 3 - sigma result , or only about a 1 in 700 chance of seeing a signal like this anywhere in the experiments . Provided the team have been careful about their error analysis ( and there ’s no good reason to theorise they have n’t ) this is a fairly convincing result . Let me put it this way : criminal convictions , which expect proof “ beyond a sensible uncertainty ” almostnever rise to this level of certainty .
But particle physicist care to be more heedful before they say something has been officially “ give away . ” They normally demand a 5 - sigma detection — with less than a one in a million prospect of being wrong . It makes sense to place a high bar , but for my part , I ’m convinced that the Higgs is material and that we know its close together mass . The remaining work will be to make it prescribed .
Oh , and one more thing . These resultant role are totally consistent with therange limitfound by the Fermilab Tevatron . They only saw a 1 - sigma result , but unite all of it , the betting odds fall to something like 1 in 1100 against seeing all three measuring by staring hazard .
Are the results consistent with what we expect ?
Yup . This is very much in line with what was predicted by the stock theoretical account . In that respect , it ’s kind of bore to see what you expect .
However , this Higgs mass would be a flake above what is typically predicted bysupersymmetry , giving one hint that while the stock model of particle physical science is correct , supersymmetry ( or at least certain var. of it ) may not be .
Why do we have to “ create ” the Higgs to detect it ? I think it was all around us , giving particles their peck .
There are a lot of affair call “ Higgs ” but the two most relevant are the Higgs particle and the Higgs field . It ’s straight that the Higgs field is all around us ; it is the field of operations that gives at least some of the particles mass . That ’s very much like saying that there is an electromagnetic field all around . A photon can be think of as something like a congealed lump of the electromagnetic bailiwick . Likewise , the Higgs boson could be cerebrate of as a hunk of the Higgs field . The tough part is slamming particles together with enough energy to rive out one of those lout , even for a short full point of time .
There ’s another important breaker point here . Even under the best of circumstances , we still do n’t in reality detect the Higgs boson itself . What happen is that a Higgs is created and ( like so many monumental particles do ) it decay into lighter particles ; two photon for example . By measuring the energies of the photons , you could get the lot of the Higgs , but decay into photons are quite uncommon . More commonly , the Higgs decays into abottom quarkand an anti - bottom ( not the same as a top ! ) , but this is really tough to measure . It ’s all very indirect , you see , which is why “ discovering ” a particle like the Higgs does n’t quite signify what most mass think it means .
If the Higgs field gives mess to other atom , how can it be so much more monolithic than a proton ?
This goes back to the distinction between the Higgs corpuscle and a Higgs boson . It ’s not like a Higgs boson is hiding inside a proton , for case . Rather , molecule interact with the Higgs field , and the interaction creates get-up-and-go . Just as E = mc^2 , the effective deal created is m = E / c^2 , where E is the vim of the fundamental interaction .
Energy and mass really are the same matter . If you do n’t believe me , debate this . proton are made of quarks , but if you supply up the masses of the individual quark , they only add up to a per cent or so of the full proton mass . The rest is interaction energy . From the exterior , you could not tell the difference between “ real mint ” and mass with is really energy . There is no difference .
Why does n’t the Higgs field give mountain to photon ?
For one thing , it ’s not only the photon that gets off the draw , mass - knowing , but also the gluon ( the particle for the strong force ) , and ( if it exist ) the graviton . The substantial question might be , “ Why do theW and Z bosonshave mass , but not the other mediators ? ”
Once upon a time there were 4 particles carrying the “ electroweak ” force . Two of them were charged molecule ( which finally became the W^+ and W^- ) , and two of them were neutral . In the very beginning , all four of them were massless . This was a long time ago , about the first trillionth of a second after the big bang . As the existence chill , the interactions of these particleschanged , and the Higgs field was created . In many regard , it ’s kind of like an water ice crystal forming when water supply sink below a certain temperature . The whole structure of the electroweak particles changed .
call back , the Higgs field creates an interaction energy , but one manner of thinking about it is that the 4 electroweak particles got “ mixed - up ” with the photon being the massless combination of the two old neutral molecule , and the izzard being the massive compounding . In the end , three of these particles ( the W^+ , W^- , and Z ) interact with the Higgs field , give them mass , and one of them , the photon .
There will be those of you who will point out that all I ’ve done here is say the photon does n’t interact with the Higgs because that ’s how the mathematical model forge . Yup . That ’s exactly what I ’ve done , but I ’m afraid in this grammatical case , it does n’t get any simpler than that .
I should mention that while the Higgs mechanism does name how the W and ezed corpuscle get their plenty , it does n’t really explain how the quark cheese and negatron get their mass . We assume that it ’s due to the Higgs , but we really do n’t know , and we really ca n’t say anything predictive . With the W and Z particles , on the other hired man , we ’re capable to compute the proportion of the masses to insane preciseness .
Would discover the Higgs tells us anything about graveness ?
No . The Higgs does n’t tell us anything about how gravity works , but since gravity responds to mass , fundamental interaction with the Higgs field produces gravitational orbit , as does any form of slew or energy . Not only does n’t the Higgs tell us about gravity , there ’s nothing in the stock model at all that includes sobriety . Our current right hypothesis of gravity is general relativity , and one of the big goals of physics is to figure out a room to unify gravitation with the other force .
Does the Higgs have an antiparticle ?
Nope . An antiHiggs and a Higgs are one and the same . Some molecule are their own antiparticle , but they have to be neutral kick , because antimatter always has the diametric charge of regular matter . Photons , for example , are their own antiparticle . There are no “ antiphotons . ” The Higgs boson is the same way .
What ’s the hard-nosed wallop of bring out the Higgs ?
Practical ? Who knows ? just know how mass is mother for some speck does n’t really allow us to pull strings masses any more than sympathise how gravity works allows us to ramp up black hollow . Remember the warnings about black maw being father in the LHC ? Yeah . That did n’t go on .
Personally , I thinkbasic science is worth doing for its own rice beer . But the question of why the great unwashed should care is a good enough one that the Imperial College , London , has a contest for educatee asking thisvery enquiry .
Of course , this being io9 , I ’m trusted people will add up up with Day of Judgment devices built around the Higgs atom . Remember , though , that even if you make a Higgs , you do n’t get to keep it for very long . They break down in less than a quintillionth of a second .
Would discovering the Higgs mean the end of Physics ?
Not a luck . For one thing , the Higgs only tells us , at best , about ordinary matter in the macrocosm . We still do n’t understand much aboutdark matterordark energy , which combined represent about 95 % of the total energy . sure models of supersymmetry , which might have shed light on dark-skinned topic actually seem less likely now , which mean that we have a circumstances of study to do .
Ask A Physicist : Why Believe In Dark Matter ?
Are physicists just making up drab energy ?
While the received model does a great job distinguish the fusion of electromagnetics and the watery force , we still do n’t have a “ Grand Unified Theory ” which also combine the strong force . We do n’t bang how any of these effect combine with gravity in a way that would leave us to distinguish the commencement of time or the nerve center of black hole in a useful way . We do n’t sleep with why the parameter of the universe are what they are or why there are 3 sets of quarks , 3 sets of neutrinos , and 3 sets of chargedleptonsor even why neutrino really have mass or why they are specifically leave - handed . We just know , in all of these cases , that they are , and not why they are .
I could go on and on , but the stop should be clear . If the Higgs mechanics is right then this merely intend that we have found one musical composition of the puzzle — a utile corner spell , to be trusted , but still just a bit . There ’s still scads to do .
Dave Goldbergis the author , with Jeff Blomquist , of“A User ’s scout to the Universe . ”(follow us ontwitter , facebook , twitterorour blog . ) He is an Associate Professor of Physics at Drexel University and is presently mold on “ The Universe in the Rearview Mirror , ” a new book all about balance that will be published by Dutton in 2013 . Please send electronic mail to[email protected]with any question about the universe .
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