Physicists working at the Large Hadron Collider (LHC) have announced the discovery of what they called a “Higgs-like boson” — a particle that resembles the long sought-after Higgs.
“We have reached a milestone in our understanding of nature,” CERN director general Rolf Heuer told scientists and media at a conference near Geneva on July 4, 2012. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”
Two experiments, ATLAS and CMS, presented their preliminary results, and observed a new particle in the mass region around 125-126 GeV, the expected mass range for the Higgs Boson. The results are based on data collected in 2011 and 2012, with the 2012 data still under analysis. The official results will be published later this month and CERN said a more complete picture of today’s observations will emerge later this year after the LHC provides the experiments with more data.
“We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.”
The discovery of the Higgs is big, in that it is the last undiscovered piece of the Standard Model that describes the fundamental make-up of the universe.
Scientists believe that the Higgs boson, named for Scottish physicist Peter Higgs, who first theorized its existence in 1964, is responsible for particle mass, the amount of matter in a particle. According to the theory, a particle acquires mass through its interaction with the Higgs field, which is believed to pervade all of space and has been compared to molasses that sticks to any particle rolling through it.
And so, in theory, the Higgs would be responsible for how particles come together to form matter, and without it, the universe would have remained a formless miss-mash of particles shooting around at the speed of light.
“It’s hard not to get excited by these results,” said CERN Research Director Sergio Bertolucci. “We stated last year that in 2012 we would either find a new Higgs-like particle or exclude the existence of the Standard Model Higgs. With all the necessary caution, it looks to me that we are at a branching point: the observation of this new particle indicates the path for the future towards a more detailed understanding of what we’re seeing in the data.”
A CERN press release says that the next step will be to determine the precise nature of the particle and its significance for our understanding of the universe.
Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. – CERN press release
“We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”
Positive identification of the new particle’s characteristics will take more time and more experiments. But the scientists feel that whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.
Lead image caption: Event recorded with the CMS detector in 2012 at a proton-proton centre of mass energy of 8 TeV. The event shows characteristics expected from the decay of the SM Higgs boson to a pair of photons (dashed yellow lines and green towers). The event could also be due to known standard model background processes. Credit: CERN
Source: CERN
Well done to CERN and the European Union, and the many European countries who has financed its operations.
IT EXISTS! Proving all the decades of scientific and research has been worthwhile.
Now I know why my feet are so firmly planted to the earth!
Note: It was especially clever to announce it on the 4th of July! Chalk up one for the rest of us, I’d think!
A cavil: you know why you have mass, but you do not yet know why your feet remain planted; that would really require a verified quantum theory of gravity.
Don’t you hate language? I’m 100% wrong in my statement, but logically there is still some credence to it.
Before I was made of protons, neutrons, electrons (and quarks) but I knew not why they had mass. Hence, gravity to these particles interacting as ‘mass’ were unknown. If the Higgs is confirmed, then I now know Higgs reacts with gravity to confirm mass. Ergo. I have mass therefore gravity can hold me to the ground.
Your quite right pointing to my flawed statement. Thanks!
Well, mass is a mess.
Mass is an emergent phenomena* created by interaction energies, of which there are many. So your description, while it is perfectly correct – we need the Higgs mechanism to get bound systems started by way of fundamental particles having mass – isn’t allowing for that the Higgs mechanism isn’t dominant.
Our mass consists mainly of protons and neutrons, but they aren’t fundamental – quarks are. And when we look at a proton, only ~ 2 % is quark mass I hear. (See below how I don’t know how to estimate that myself – you need particle physics to do that!) The rest is then other interaction energies.
These interaction energies comes from quarks and gluons acting on each other to keep the proton together. Mind, there are way many quarks in a proton besides the 3 net quarks that aren’t balanced out by color forces.
——————–
* Similar to how spacetime and its gravitational curvature somehow emerges out of space and time.
But all particles feel curvature, even massless photons follow the geodesics of gravitational curvature. While Higgs is partial to some fundamental particles.
To see the data as presented go to
http://indico.cern.ch/conferenceDisplay.py?confId=197461
LC
An explanation of this conference appears at “The 36th International Conference on High Energy Physics will be held at the Melbourne Convention and Exhibition Centre, from 4–11 July.” http://www.scienceinpublic.com.au/media-releases/highenergyjuly (“The biggest questions in physics to be answered in Melbourne in July.”)
As said on this page; “Director General of CERN, Professor Rolf Heuer says “ICHEP is the most important conference in the particle physics calendar, and it’s great that it’s happening in Australia for the first time – a sign of that country’s growing stature in the field.”
Melbourne, Australia is the place to be. The final presented paper is going to be presented by Rolf Heuer himself on the afternoon of the 11th July 2012. See the site for details at; http://www.ichep2012.com.au/Home.aspx
(Also, I was sad to hear of your recent personal loss. Thinking of you and your family in clearly a difficult time.)
Thank you. Thinking of you as others here are, my sincere condolences and wishing you and your family well.
The historical timing of this is interesting to me. I wonder if there have been other civilizations to arrive at this point (surely there have – the universe is vast and old). It feels like this stage of our technological development also coincides with the possibility of our merging with that same technology. It’s like the simultaneous end and beginning of an era.
Boss on Europe. :d
The media are abuzz with this development and it is refreshing to witness science back on the public agenda. Thank you Nancy Atkinson.
Notice that the post on Dec 6, 2011 predicts a mass of 125.99 Gev/c sqr. with half a Z added to a W, as suggested initially by the sometimes controversial Lubos Motl on his blog earlier. When Maxwell discovered that 1/ sqr root of epsilon sub 0 times mu sub 0 equaled c, to ~ 5 sig figs…he recognized that couldn’t be a coincidence for a radio wave.
This “coincidence” is equally unlikely….SEE:http://www.bautforum.com/archive/index.php/t-125038.html?s=b7d9bb057e9b311ac239eec25319fd5e
pete
The reason the Higgs had to be painstakingly researched is precisely because you can’t predicts its own mass from the standard model – it doesn’t couple proportionally as it does with other particles – and of course you see a whole slew of more or less serious articles that retrodict the earlier LHC exclusion. Which range was always preferred for theoretical reasons (easier physics).
What if the Higgs we are looking for is the same the mysterious dark matter?
I think we can say from our armchair physics position that it can’t be, because:
– The Higgs out of the field itself is short lived, see how fast it makes the jet in the image above. And so are the ones that gives Z & Ws masses because these aggregate particles are short lived too.
– The Higgs field is a uniform scalar, or massive fundamental particles would have different masses in different places. But dark matter is denser around massive objects as seen by gravitational lensing.
What has been suggested, I have seen it before, is that the Higgs field could have been the inflation field too. By being responsible for inflation as well it would make a stronger and more predictive theory by that combo.
But see the “latest update” ref above how that can be almost certainly ruled out.
Do virtual particles have mass? Because, as space/time expands, I assume that the amount of Hadrons it contains remains constant, right? This suggests that the particles in the Universe are becoming more and more ‘diluted’ as they are ‘in’ more and more space… But what about the virtual particles created from, the Casimir–Polder field? The field, being a discrete part of space/time itself would expand with it, one would think, so wouldn’t that mean the number of these virtual particles is NOT static within the entire Universe, but indeed increasing with it? And if this is the case, could the mass of this increasing amount of virtual particles (foam) effect in some way the expansion rate? … Just shooting ducks in a pond, as my knowledge on this topic is I’d say slightly above a pedestrian level, so forgive any ridiculous notions. 😉
[Doubled comment. My browser has problems with this page.]
[Doubled comment.]
The expansion rate is affected over time, by dark energy. Expansion is accelerating.
To cut to the chase, the dark energy seems to be constant. So it looks nothing changes in relation to other things.
[More detailed, the simplest prediction comes from vacuum energy being a “cosmological constant” dark energy. That ties back to the background which the resulting static and dynamic Casimir effects emerges from, somewhat like a van der Waal force analog. (They don’t emerge from a peculiar field, the known ones predicts this effect.)
The vacuum contains all particle fields, and so all virtual particles.
As for masses of virtual particles, it’s even a worse mess than other mass. See here. I haven’t studied quantum field theory, so I’m not the right person to ask.
I note early on: “The virtual particle forms of massless particles, such as photons, do
have mass (which may be either positive or negative) and are said to be
off mass shell. They are allowed to have mass … because they exist for only a temporary time, which in turn gives them a limited “range”.”
“For particles that do have a rest mass, their virtual forms still violate the energy-momentum relation of special relativity, in having a mass more or less than predicted by the relation:
E2 ? p2c2 = m2c4.”]
This remains to be tested further, naturally. There could still be new
physics here. But I think they get the cosmological constant dark energy
again and again every time they test.
I really love this website!
But if everywhere in the universe we have the same number of virtual particles per cubic meter then gravitationally they cancel each others gravitational force out.
But as have understood the Higgs boson, it explains mass, but it does not explain gravity and it does not explain the relationship mass to gravitational force.
Well, I am thinking that the colliding protons might have just hit the dark particles.
[Double post]
I am sorry, I don’t understand the context with the collider experiments and I don’t understand the context with the previous question.
Dark matter is dark because it interacts little or not at all with EM and so interacts little with everyday, baryonic, matter. Protons are baryonic matter.
(“The biggest questions in physics to be answered in Melbourne in July.”)
I think this is typical press overstatement. I think the biggest questions are yet to come, because this week’s announcement about a fundamental, universe pervading field causes more questions than answers.
Hippity Higgs, Hurrah!
Some early reflections from an outside view:
– They did really well, better than expected, as both experiments achieved 5 sigma or just shy of it. No need to aggregate the data, and the Tevatron 2-3 sigma results released this week too are also suggestive.
– What they didn’t handle well was the press release. Apparently they put up press videos leaking the result yesterday and press releases before the talks were finished, as well as collaboration members leaking.
– The production rates and the different combinations of observed particles produced by the Higgs, the “channels”, are still somewhat rickety statistics. But they are all consistent with a standard Higgs.
– If it is a standard Higgs with 125-126 GeV mass, it suggests new physics right away!
Several analyses concludes that such a Higgs makes a quasistable vacuum at ~ 3 sigma. Improving on Higgs results would be informative here.
More than that, the latest update I have seen found that the Higgs field parameters conspires to get there, suggesting criticality of a dynamical system.
At the same time it favors supersymmetry at a low energy. (Also noteworthy is that they find that there may be hints into Planck scale physics in this.)
“Figure 8 shows not only how Mh ~= 125 GeV disfavors supersymmetry broken at a very high scale, but also the well know fact that the usual scenario of weak-scale supersymmetry can account for the Higgs mass only for extreme values of the parameters (such as large tan β, heavy stops, maximal stop mixing).”
“… we find that the values of the Higgs mass, hinted by the first LHC results (125 – 126 GeV), lie right at the edge between EW stability and instability regions, …”
“The observation that both parameters in the Higgs potential are quasi-critical
may be viewed as evidence for an underlying statistical system that approaches criticality. The multiverse is the most natural candidate to play the role of the underlying statistical system for SM parameters.”
Of course also a finite but sufficiently long lifetime of a universe with a quasistable vacuum (~10^100 years) to cover life appearing and disappearing support an anthropic multiverse.
Since I just found the above today, I was hit by the correspondence with another recent paper on similar physics.
The father of modern string theory Susskind, on the past-eternal physics of eternal inflation, finds that simple multiverse models favors a frozen in dynamic statistic (akin to criticality) by way of a first order tree model.
Many universes would have supersymmetry at low energies and cosmological constants at low energy, as they tend towards a “master vacuum” (dominant vacuum). Those are also the livable universes (the dominant isn’t), which explains the selection.
“At first sight it would seem attractive to predict that we live in the master vacuum. However, that is not feasible – such a highly supersymmetric state would not be anthropically viable. Both for anthropic and observational reasons a period of slow-roll inflation is necessary, and to get to the slow-roll plateau the local universe must have tunneled from a nearby ancestor state. Thus one should look for that ancestor state which allows tunneling to the inflationary plateau, and which has the largest projection onto the dominant eigenvector.
Douglas argues that the neighborhood of the master vacuum may be very rich with enough vacua to provide numerous anthropically allowable cases, and also candidates for ancestor vacua to decay to the anthropic vacua. Given the proximity to the almost supersymmetric vacuum d, one may expect that the vacuum favored by the dominant eigenvector hypothesis will also have a relatively low supersymmetry breaking scale. The same argument may also favor a low inflationary scale.”
Of course, Susskind is anthropic theory perhaps #1 fan. But if the particle is a standard Higgs then it might be interesting to see what the Planck probe will have to say on inflation later this year. It might be interesting in _any_ case.
Excellent post Torbjorn, informative and a good read -Thanks
Wezley
Indeed! Thanks for the added info. I’m on pins and needles for more info updates on the ramifications.
What will the results be, now that we know that mass?
What kind of hypothesis can no be thrown in the garbage can?
Does this have an effect on string theory and different types of models like holographic universe?
“Can not or can now is the question.”
Good questions all. I suggested some consequences below. I don’t know if this is an exhaustive list, so I hope people pitch in:
– They have to see if it is a standard Higgs by way of its parameters, hopefully before they shut down at year’s end for energy upgrade.
– They need to check if it interacts proportionally with Standard Model particle’s energy.
– All that is also informative on the question if we live in a future eternal or a long-lived universe. And if the latter case, which seems likely, on the dynamics responsible.
– Such a standard Higgs suggest a supersymmetry scale just shy of the weak scale. So they will have to look at that.
– Such a supersymmetry would solve dark matter properties.
– Supersymmetry is as much a prediction as a requirement for string theory, so I would think this strengthens it in the short term. If they don’t find supersymmetry in the next decade, who knows what will happen?
– String theory has a good grip on gravitation and is suggestive on a graviton, at least in the landscape theory.
– Higgs predicts some of its own mass but not all. (I.e. it is not proportional here. Meaning it differs from gravity, fortunately.) The remainder will lead to new physics.
I’m more curious about how neutrino physics fits into the picture. Who ordered that?
[Unless of course neutrinos predict matter-antimatter symmetry. Which of course gets me back to anthropic scenarios right now – we need matter.]
maybe its funding polotics time
Why does Higgs only interact with some particles and not others?
Shouldn’t that question be: Why do some particles interact with the Higgs field and others don’t so much?
Some particles are more rough and causes more drag.
Other particles are more smooth and have almost no drag.
Ok I admit particles do not have a surface, but you get the idea.
One could also imagine it as having a parachute. Some particles have a big parachute others have a tine one, and some have none.
About Higgs Particle.
According to CERN report:
the mass of Higgs particle is 12Gev. This was published as”Tantalizing Hints of
Elusive Higgs Particle Announced {Update}, The
long-sought Higgs boson is tied to the leading theory of how quarks, electrons
and other particles get their mass , By Davide Castelvecchi | December
13, 2011 — — — “the LHC detectors
have now reduced the allowed range further: Tonelli said that according to CMS
data its mass cannot be greater than 127 GeV. That was not for lack of data—in
fact, quite the opposite. “We were not able to exclude the range below 127
GeV because of excesses,” or more of certain particle by-products than
would be expected in the absence of the Higgs, he remarked during his seminar
talk—which was an understated way of saying that the CMS experiment had
actually seen hints of a Higgs existing and having a mass of 124 GeV or so.
ATLAS saw excesses in a similar range of energies, although the graphs did not
quite line up—the ATLAS data favor a Higgs around 126 GeV.”
It was not confirmed
result, the confusion was their. Declaration of present mass given as 126 Gev which was published December, 13,
2011. I am giving thanks to all scientists. But I want to say that this mass
126 Gev as Higgs particle is not the mass of creation of the universe which
will obey all fundamental rule. There are lot of particles in this range. Curie
particle is interlinked to all sub-atomic particles even Higgs. I calculated
the mass of many sub-atomic particles and results tallied with experimental
results. I described all in my book “Complete Unified Theory”, ( page- 234
to 246, Published on 1998). Higgs
particle is a part of sub-atomic stage. If science developed in future, then
scientists will realize this — how the Universe created. It is not possible
to write all in this small paper. The
complete unified theory can describe ——
why universe, how it created ? Complete
unified theory is single theory. It is applicable from the particle to
universe.
Nirmalendu Das.
Dated: 05-07-2012.
About Higgs Particle.
According to CERN report:
the mass of Higgs particle is 126Gev. This was published as”Tantalizing Hints of
Elusive Higgs Particle Announced {Update}, The
long-sought Higgs boson is tied to the leading theory of how quarks, electrons
and other particles get their mass , By Davide Castelvecchi | December
13, 2011 — — — “the LHC detectors
have now reduced the allowed range further: Tonelli said that according to CMS
data its mass cannot be greater than 127 GeV. That was not for lack of data—in
fact, quite the opposite. “We were not able to exclude the range below 127
GeV because of excesses,” or more of certain particle by-products than
would be expected in the absence of the Higgs, he remarked during his seminar
talk—which was an understated way of saying that the CMS experiment had
actually seen hints of a Higgs existing and having a mass of 124 GeV or so.
ATLAS saw excesses in a similar range of energies, although the graphs did not
quite line up—the ATLAS data favor a Higgs around 126 GeV.”
It was not confirmed
result, the confusion was their. Declaration of present mass given as 126 Gev which was published December, 13,
2011. Repeated this result. Whatever it may. I am giving thanks to all scientists. But I
want to say that this mass 126 Gev as Higgs particle is not the mass of
creation of the universe which will obey all fundamental rules from particle to
the universe. . There are lot of particles in this range. Curie particle is
interlinked to all sub-atomic particles even Higgs. I calculated the mass of
many sub-atomic particles and results tallied with experimental results. I
described all in my book “Complete Unified Theory”, ( page- 234 to 246, Published on 1998). Higgs particle is a
part of sub-atomic stage. If science developed in future, then scientists will realize
this — how the Universe created. It is not possible to write all in this small
paper. The complete unified theory can describe
—— why universe, how it created ? Complete unified theory is single
theory. It is applicable from the particle to universe.
Nirmalendu Das.
Dated: 05-07-2012.
Ok I saw some quacks now claiming faster than light speed and time travel because of this. Facepalm
All the discussions I have seen has brought several questions to mind. As I understand it the Higgs Boson (particle) is very heavy or massive. It must have a field surrounding it for ordinary matter to interact with to gain the property of mass. This field must pervade the universe as all detectable matter in it has mass (other than photons). Since the universe is expanding one would think that the Higgs field must also be expanding and thus becoming less concentrated per unit of volume. Wouldn’t this result in decreasing mass of all particles interacting with the Higgs field? What might the nature of this field be? Electro-magnetic or something altogether different? Just suppose a device could be invented to mask or null the Higgs field in a small space, would the mass of particles in this masked volume be reduced to zero? Imagine a space craft that could mask the field. Would it (the spacecraft, become mass-less? Would it cease to exist? If not could it accellerate ot the speed of light (w/o mass) and hopefully decellerate?
Perhaps a type of warp engine ??? Pure speculation and comments will be appreciated.