BaBar experiment data hint at cracks in the Standard Model

Jun 18, 2012
The latest results from the BaBar experiment may suggest a surplus over Standard Model predictions of a type of particle decay called “B to D-star-tau-nu.” In this conceptual art, an electron and positron collide, resulting in a B meson (not shown) and an antimatter B-bar meson, which then decays into a D meson and a tau lepton as well as a smaller antineutrino. Credit: Image by Greg Stewart, SLAC National Accelerator Laboratory

(Phys.org) -- Recently analyzed data from the BaBar experiment may suggest possible flaws in the Standard Model of particle physics, the reigning description of how the universe works on subatomic scales. The data from BaBar, a high-energy physics experiment based at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory, show that a particular type of particle decay called "B to D-star-tau-nu" happens more often than the Standard Model says it should.

In this type of decay, a particle called the B-bar meson decays into a D meson, an and a tau lepton. While the level of certainty of the excess (3.4 sigma in statistical language) is not enough to claim a break from the Standard Model, the results are a potential sign of something amiss and are likely to impact existing theories, including those attempting to deduce the properties of Higgs bosons.

"The excess over the Standard is exciting," said BaBar spokesperson Michael Roney, professor at the University of Victoria in Canada. The results are significantly more sensitive than previously published studies of these decays, said Roney. "But before we can claim an actual discovery, other experiments have to replicate it and rule out the possibility this isn't just an unlikely statistical fluctuation."

The BaBar experiment, which collected particle collision data from 1999 to 2008, was designed to explore various mysteries of particle physics, including why the universe contains matter, but no . The collaboration's data helped confirm a matter-antimatter theory for which two researchers won the 2008 Nobel Prize in Physics.

Researchers continue to apply BaBar data to a variety of questions in . The data, for instance, has raised more questions about Higgs bosons, which arise from the mechanism thought to give their mass. Higgs bosons are predicted to interact more strongly with heavier particles – such as the B mesons, D mesons and tau leptons in the BaBar study – than with lighter ones, but the Higgs posited by the Standard Model can't be involved in this decay.

"If the excess decays shown are confirmed, it will be exciting to figure out what is causing it," said BaBar physics coordinator Abner Soffer, associate professor at Tel Aviv University. Other theories involving new physics are waiting in the wings, but the BaBar results already rule out one important model called the "Two Higgs Doublet Model."

"We hope our results will stimulate theoretical discussion about just what the data are telling us about new physics," added Soffer.

The researchers also hope their colleagues in the Belle collaboration, which studies the same types of particle collisions, see something similar, said Roney. "If they do, the combined significance could be compelling enough to suggest how we can finally move beyond the ."

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More information: The results have been presented at the 10th annual Flavor Physics and Charge-Parity Violation Conference in Hefei, China, and submitted for publication in the journal Physical Review Letters. The paper is available on arXiv in preprint form.

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julianpenrod
1.7 / 5 (23) Jun 18, 2012
Sonme points that many, if not most, even "science" devotees will unknowingly or willingly overlook.
Among other things consider that reference to a level of certainty of 3.4 sigma, the refence to sigma being the standard deviation. It has become the vogue of those shilling for "science" to trundle out sigma to con the unwitting into thinking first that the "conclusions" must be reliable and that the person using the unfamiliar terminology must be trustworthy in what they sayu. In fact, sigma is not a level of certainty. It is a measure of the spread of a distribution! Even if the Standard Model was right, there would be errant instances when the decay would occur 3.4 standard deviations beyond the expected number.
Also, note the illustration pointedly does not show a B meson. Why? How much trouble would it be to include the depiction of a B meson there?
HannesAlfven
2 / 5 (21) Jun 18, 2012
We need not look to mathematics to undermine the Standard Model. This conversation distracts from the more important and fundamental *conceptual* criticisms which any layperson can understand. After all, another uncertainty here pertains to the inference that we can figure out how to build atoms by smashing things together. This methodology is a departure from most of the other more common ways which people try to understand their surroundings. It's clearly conceivable that subatomic particles can simply possess transient states which say very little about the stable states.

Another even more important source of uncertainty is that there remain many orders of magnitude which we still cannot make direct measurements of. This zone of uncertainty extends downwards from 10^-19 to 10^-35 meters. To claim that we have certainty of what's happening at the quantum scales, and yet not be able to witness all of this, is arguably just human ego on display.
slack
4.2 / 5 (6) Jun 18, 2012
To claim that we have certainty of what's happening at the quantum scales, and yet not be able to witness all of this, is arguably just human ego on display.

Totally agree HA.
However,I'm not sure anyone is claiming certainty...
Parsec
4.6 / 5 (11) Jun 18, 2012
Sonme points that many, if not most, even "science" devotees will unknowingly or willingly overlook.
Among other things consider that reference to a level of certainty of 3.4 sigma, the refence to sigma being the standard deviation. It has become the vogue of those shilling for "science" to trundle out sigma to con the unwitting into thinking first that the "conclusions" must be reliable and that the person using the unfamiliar terminology must be trustworthy in what they sayu. In fact, sigma is not a level of certainty. It is a measure of the spread of a distribution! Even if the Standard Model was right, there would be errant instances when the decay would occur 3.4 standard deviations beyond the expected number.
Also, note the illustration pointedly does not show a B meson. Why? How much trouble would it be to include the depiction of a B meson there?

You do realize of course that the researchers repeatedly acknowledge that 3.4 sigma isn't certainty?
dschlink
4.9 / 5 (9) Jun 18, 2012
In statistical analysis, sigma indicates the level of probability of a data set being due to chance. At 3.4 sigma there is less than a 0.1% chance of being a false signal. 5 sigma is the gold standard.
julianpenrod
1.6 / 5 (16) Jun 18, 2012
Among other things in Parsec's attempted attack on my statements, I did not see any "repeated" assertion that 3.4 sigma is not certainty. However, that is not even what I said! I said that standard deviation is not a level of certainty! And it's the article that applied the word "certainty" to sigma! Standard deviation is a measure of how spread out results of an experiment or test are, it does not assure, to any degree, that a "conclusion" is true or not. Such things as hypothesis testing are used for that. I said standard deviation itself is not a measure used for certainty, whereas Parsec changed the meaning to 3.4 sigma supposedly meaning absolute, unequivocal truth. Either Parsec is trying to pretend my statements have no validity or they don't under stand the very terminology they prate about.
dschlink
3.7 / 5 (9) Jun 18, 2012
"my statements have no validity " - precisely.
julianpenrod
1.7 / 5 (11) Jun 18, 2012
dschlink's "description" of the statistical suggestion of sigma has as little veracity as so many others.
In a given experiment, there is always the possibility that occurrences of individual types of result will fall outside several standard deviations of the mean. Even five standard deviations. But that says nothing. Anything can happen, supposedly. There is significance if the occurrences are repeated over several different experiments and the standard deviation of those repeated occurrences falls several standard deviations outside the expected number.
Parsec
3.8 / 5 (8) Jun 18, 2012
Among other things in Parsec's attempted attack on my statements, I did not see any "repeated" assertion that 3.4 sigma is not certainty. However, that is not even what I said! I said that standard deviation is not a level of certainty! And it's the article that applied the word "certainty" to sigma! Standard deviation is a measure of how spread out results of an experiment or test are, it does not assure, to any degree, that a "conclusion" is true or not. Such things as hypothesis testing are used for that. I said standard deviation itself is not a measure used for certainty, whereas Parsec changed the meaning to 3.4 sigma supposedly meaning absolute, unequivocal truth. Either Parsec is trying to pretend my statements have no validity or they don't under stand the very terminology they prate about.

Something is either true, or it isn't true. A particular sigma value indicates how often an untrue event will show up true, and visa versa. That's all.
julianpenrod
1.7 / 5 (11) Jun 19, 2012
To begin with, an event is true because, by definition, an event is something that definitely occurred. And an event is an event, it's an interpretation or a conclusion, a statement, that can be true or untrue! Standard deviation says nothing whatsoever long lasting about an event or what that event is supposed to imply, it is only a descriptor of the one run of events. And, again, very indicative that illegitimate statements like Parsec's get five out of five stars.
boater805
5 / 5 (10) Jun 19, 2012
... Standard deviation says nothing whatsoever long lasting about an event or what that event is supposed to imply, it is only a descriptor of the one run of events....

What's this? An attempt to redefine what standard deviation is?
"an event" has no standard deviation at all, standard deviation only applies to a collection of events & describes how far any statistical population of those events tend to spread from the mean when analyzing the ENTIRE POPULATION of events data is available for. Further, various theories indeed predict mean values and possible deviation from means. If a theories range of possibles lays outside the entire range of 5 sigma then its deemed so unprobable as to not be worthy of considering possible for now. If it falls inside the range then still something can be said about the likelyhood of validiy based o the probablilty of that overlap area intersects. Saying their data population has 3.4 sigma is a quantative statement. Nada more needed.
TkClick
Jun 19, 2012
This comment has been removed by a moderator.
TkClick
1 / 5 (5) Jun 19, 2012
The elusive nature of CP violation effect confused the physicists many times in the past. The memo of this high level model is, it has no meaning to attempt to improve the signal/noise ratio with increasing of collision energy and with building of larger colliders, because the universe is random in AWT and the CP violation effects will disappear again at large energies (after all, in the same way, like at the case of large galaxies and galactic clusters, which are as irregular, as the smallest observable particles).
TkClick
1 / 5 (5) Jun 19, 2012
IMO the high level explanation of CP symmetry violation can be as follows: every sufficiently dense object attracts the fluctuations of vacuum of the opposite curvature. But these fluctuations are concentrated at its surface instead of its center as so called dark matter. When this object is rotating, it generates an axial flux of finely divided "antimatter", which deforms the shape of object axially. When such object decomposes, it decays particles in one axial direction preferentially. This effect is indeed most prominent at the case of large dense black holes. The similar effect can be observed at the case of vortex ring formed with compressible fluid: due the gradient of fluid density toward the center of vortex, the flux of fluid in one axial direction is preferred and it leads to the propulsion force. For example, when 60-Co atom nuclei in magnetic field decay in one direction, it means that the radioactive decay of magnetized sample will accelerate it in the opposite direction.
birmas
4.7 / 5 (3) Jun 19, 2012

Something is either true, or it isn't true. A particular sigma value indicates how often an untrue event will show up true, and visa versa. That's all.


Does that mean that the cat is dead or alive? *confused*
davhaywood
5 / 5 (5) Jun 19, 2012
Mr. Penrod is a useful tool. He helps me reinforce what I know, while at the same time getting a laugh out of how full of shit he is. Please, continue to make a fool of yourself.
TkClick
Jun 20, 2012
This comment has been removed by a moderator.
TkClick
Jun 20, 2012
This comment has been removed by a moderator.
TkClick
Jun 20, 2012
This comment has been removed by a moderator.
TkClick
1 / 5 (2) Jun 20, 2012
BaBar experiment data hint at cracks in the Standard Model
Scientific journalism is based on exaggeration of cognitive gradients: everything in it is phenomenal finding or spectacular crush, nothing inbetween. If the BaBar asymetry hints to crack in the Standard Model, then the things like the (positive) neutrino mass, existence of dark matter, electroweak symmetry breaking, absence of violation of unitarity with WW cross-section above 1 TeV or hiearchy problem of Higgs boson's mass (i.e. why it doesn't blow up from quadratic loop corrections) cracked the Standard Model already before time. The scientific theories are like tools: each of them is good for certain purpose, for which it was designed - outside of this scope it becomes fringe like every other model. The fact hammer cannot be used for slicing of wood doesn't mean, it's a wrong tool. The fact, the media are seeking for sensations doesn't contribute to the holistic understanding of scientific theories very much.
Nikstlitselpmur
2 / 5 (4) Jun 21, 2012
Aahaa, just as I thought.
Osiris1
not rated yet Jun 21, 2012
solution to 'problem' of standard model denyers: just like the solution to the 'relativity denyer marginalization and elimination as a class' problem...... vilify, lie, discredit unfairly, eliminate research grants, fire, whatever it takes till the denyers recant a la Galileo and the Pope.
Anda
5 / 5 (1) Jun 21, 2012
U talk too much for nothing.
No one thinks the standard model is the holy grail of physics.
It's a tool, the result of experimentation.
It's not complete, and always improving, as our understanding of the universe.
We still have a long way to go in this fascinating journey. That's science.
slayerwulfe
1 / 5 (1) Jun 22, 2012
i do not want to engage in an argument with anyone i come here for education only. the statement 'something is either true, or it isn't true" is not valid no one can prove or disprove the existence of God and that pretty much describes our current situation, why make a choice one way over another. there always exist the undecided alternative. not happy also in seeing multiple comments from any individual wanting to be leader of the comment forum.
alan_mindbender
1 / 5 (1) Jun 24, 2012
Do remember, many such "discussions" led to the experiments upon which this very discourse is based. I'm not sure how the name calling helps here, but the very nature of debate reveals truths and untruths, and are a necessary part of advancement in any field. To swallow the information presented by media sources (nearly always sensationalized) without a discussion strangles the very nature of discovery.

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