A IceCube search for the 'sterile neutrino' draws a blank

[kodama]

here's a link

https://www.sciencedaily.com/releases/2016/08/160808091101.htm

yet another null result for BSM physics

so just in 2016 ...
750 gev diphoton null
lux and panda x null
susy lhc null 13 tev @ 12.9 fb-1 (consistent with previous 8 tev 20 fb-1 null)
sterile neutrino null

so what are the ramification of all these null results for BSM physics?

apparently dark matter might not be WIMPS nor sterile neutrinos within bounds of sensitivity

what are ramifications specific to neutrino physics of a null result on sterile neutrinos?

 

[rootone]

Null results don't equate to having no value.
Effectively ruling out some hypothesis just means that the remaining as yet untested ideas need to be examined more seriously.

 

[kodama]

Null results don't equate to having no value.
Effectively ruling out some hypothesis just means that the remaining as yet untested ideas need to be examined more seriously.

examples please ty

 

[rootone]

Michelson-Morley experiment springs immediately to mind.
https://en.wikipedia.org/wiki/Michelson–Morley_experiment

 

[fresh_42]

Michelson-Morlely experiment springs immediately to mind.
https://en.wikipedia.org/wiki/Michelson–Morley_experiment

Exactly what I thought. You got me while I was looking for the link.
Proton decay may be considered as another example.

 

[kodama]

what i meant was, given the recent null results, what are more promising approaches specifically in bsm physics.
other than simply adjusting and fine tuning models to evade experimental bounds :( i am well aware that susy wimp, dark matter, etc can be fine tuned to evade any and every null result

hopefully ohwelike and mfmb can offer insights

 

[rootone]

Another example would be the many failed attempts to produce a heavier than air flying machine,
Eventually the wright brothers succeeded by thinking about aerodynamic principles, instead of previous notions like flapping wings, or having 12 wings stacked on top of each other.

 

[kodama]

is Seesaw mechanism still in alive?

 

[Chronos]

The null results achieved basically just further constrain the allowable parameter space for the model. Invalidating the model is no trivial matter, if fact it may be well nigh impossible if you have enough adjustable parameters. Science progresses using a Holmesian approach - eliminate the impossible and whatever remains is the truth.

 

[ohwilleke]

The sterile neutrino hypothesis was already on its death bed due to other results, and the statistical significance of the experimental anomalies that suggested the hypothesis in the first place has declined.

 

[kodama]

The null results achieved basically just further constrain the allowable parameter space for the model. Invalidating the model is no trivial matter, if fact it may be well nigh impossible if you have enough adjustable parameters. Science progresses using a Holmesian approach - eliminate the impossible and whatever remains is the truth.

what kind of dark matter is left?

 

[Chronos]

Basically, all of them. I'm not aware of any candidate that has been conclusively ruled out. PBH"s are probably closest at present. Nearly all of the available parameter space has been excluded.

 

[ohwilleke]

what kind of dark matter is left?

The most promising candidates for dark matter are (1) relict keV mass particles that don't interact via the weak force or strong force or electromagnetic force (i.e. warm dark matter), and (2) heavier dark matter particles that don't interact via any of the three SM forces but does have self-interactions via a boson with a mass in the MeV mass range and a coupling strength roughly comparable (to within a couple of orders of magnitude) to that of the electromagnetic (i.e. self-interacting dark matter).

Simulations the consider gravitational feedback of ordinary matter with dark matter, however, somewhat blur the distinction between warm dark matter and cold dark matter models with a bit heavier particles that don't interact via any of the three SM forces.

Any dark matter candidate needs to be very stable (hundreds of millions of years to billions of years at least), and to have a quite low propensity to annihilate into photons or cosmic rays (which name notwithstanding generally are made of highly energetic fermions).

Modifications of gravity in lieu of dark matter are also in the running.

These three alternatives are quite difficult to distinguish with observational evidence. http://arxiv.org/abs/1306.1364

 

[kodama]

The most promising candidates for dark matter are (1) relict keV mass particles that don't interact via the weak force or strong force or electromagnetic force (i.e. warm dark matter), and (2) heavier dark matter particles that don't interact via any of the three SM forces but does have self-interactions via a boson with a mass in the MeV mass range and a coupling strength roughly comparable (to within a couple of orders of magnitude) to that of the electromagnetic (i.e. self-interacting dark matter).

Simulations the consider gravitational feedback of ordinary matter with dark matter, however, somewhat blur the distinction between warm dark matter and cold dark matter models with a bit heavier particles that don't interact via any of the three SM forces.

Any dark matter candidate needs to be very stable (hundreds of millions of years to billions of years at least), and to have a quite low propensity to annihilate into photons or cosmic rays (which name notwithstanding generally are made of highly energetic fermions).

Modifications of gravity in lieu of dark matter are also in the running.

These three alternatives are quite difficult to distinguish with observational evidence. http://arxiv.org/abs/1306.1364

if they don't interact via weak force or strong force or electromagnetic force how are they produced?

#2 sounds a lot like Feng's 16.7 mev X-boson

 

[ohwilleke]

if they don't interact via weak force or strong force or electromagnetic force how are they produced?

Nobody knows. Presumably by some phenomena that is limited to the dark sector or emerges only at extremely high big bang class energy.

 

[1oldman2]

Is the x boson getting new attention or am I looking at old news in this article,
http://www.csmonitor.com/Science/20...iscovered-a-fifth-fundamental-force-of-nature

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.071803

 

[fresh_42]

Is the x boson getting new attention or am I looking at old news in this article,
http://www.csmonitor.com/Science/20...iscovered-a-fifth-fundamental-force-of-nature

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.071803

And here:
http://arxiv.org/abs/1604.07411 - (8 / 15 / 16 version 2; revision of 4 / 25 / 16 version 1)
http://arxiv.org/abs/1608.03591 - (8 / 11 / 16)

 

[1oldman2]

And here:
http://arxiv.org/abs/1604.07411 - (8 / 15 / 16 version 2; revision of 4 / 25 / 16 version 1)
http://arxiv.org/abs/1608.03591 - (8 / 11 / 16)

The closing line in http://arxiv.org/abs/1608.03591 "
"The models also contain vectorlike leptons at the weak scale that may be accessible to near future LHC searches." is intriguing, I would imagine the subject will be getting a lot of attention soon. If confirmed, the discovery of a "5th force" should be good for job security in the field, if not a Nobel. This has got to have the "Dark energy/matter" researchers working overtime.

 

[fresh_42]

The closing line in http://arxiv.org/abs/1608.03591 "
"The models also contain vectorlike leptons at the weak scale that may be accessible to near future LHC searches." is intriguing, I would imagine the subject will be getting a lot of attention soon. If confirmed, the discovery of a "5th force" should be good for job security in the field if not a Nobel. This has got to have the "Dark energy/matter" researchers working overtime.

I still have my doubts about this unconfirmed finding. The energy levels are so small that it makes me wonder why this wasn't detected at one of dozens of labs decades ago. I've read a possible explanation by the authors somewhere but it couldn't really convince me. Someone had to have stumbled over it before. I mean 17 MeV? This is what I really find exciting. If there is something unusual, how couldn't we know? Nevertheless, from my layman point of view (that's why I linked the arXiv sources, because they have a slightly better reputation here ) it's pretty exciting.

 

[Aaron8877]

WHAT! JOHN KERRY at SOUTH POLE on ELECTION DAY ! Something Is Not Right About This


Executive Order -- Coordinating Efforts to Prepare the Nation for Space Weather Events.
https://www.whitehouse.gov/the-pres...g-efforts-prepare-nation-space-weather-events
talks about "Solar flares" a lot.

Now from what this guy is saying Mcmurdo deals with a lot of stuff but one thing stuck out and is related Mcmurdo studies
https://www.nsf.gov/mobile/funding/pgm_summ.jsp?pims_id=13420
Antarctic Astrophysics and Geospace Sciences The polar regions have been called Earth's window to outer space. This term originally applied to study of the aurora and other phenomena related to interaction of solar wind (ionized plasma blown from the Sun) with the Earth's magnetosphere. In this context, the polar upper atmosphere is a screen on which the results of such interaction can be viewed and through which other evidence of space physics processes can pass. Today, the concept of Earth's polar atmosphere as a window also includes research in other fields. For example, favorable atmospheric conditions and the unique location of Amundsen-Scott South Pole Station on the high Antarctic plateau enable astronomers and astrophysicists to use this window to understand better the internal structure of the Sun, to study our Milky Way and other galaxies, and to probe the early Universe with unprecedented precision. Antarctica's deep, clear ice sheet also is a window, providing a transparent medium for detection of neutrinos - elusive particles that fill space and easily pass through Earth.

ICE CUBE @ the South Pole
https://icecube.wisc.edu/
IceCube is a particle detector at the South Pole that records the interactions of a nearly massless subatomic particle called the neutrino. IceCube searches for neutrinos from the most violent astrophysical sources: events like exploding stars, gamma-ray bursts, and cataclysmic phenomena involving black holes and neutron stars. The IceCube telescope is a powerful tool to search for dark matter and could reveal the physical processes associated with the enigmatic origin of the highest energy particles in nature. In addition, exploring the background of neutrinos produced in the atmosphere, IceCube studies the neutrinos themselves; their energies far exceed those produced by accelerator beams. IceCube is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.

I think were headed into Gravity wave/belt that will effect the sun. Ibex did some research into this

NASA’s IBEX Observations Pin Down Interstellar Magnetic Field
https://www.nasa.gov/feature/goddar...rvations-pin-down-interstellar-magnetic-field

A Major Step Forward in Explaining the Ribbon in Space Discovered by NASA's IBEX Mission
http://www.nasa.gov/mission_pages/ibex/news/ribbon-explained.html

Mysterious Energy Ribbon at Solar System's Edge a 'Cosmic Roadmap
'http://www.space.com/24692-mysterious-energy-ribbon-solar-system.html

Its affecting the Earth and sun.

 

[nikkkom]

The sterile neutrino hypothesis was already on its death bed due to other results, and the statistical significance of the experimental anomalies that suggested the hypothesis in the first place has declined.

Neutrino mass still needs to be explained, you can't just leave only LH neutrinos in SM.

The most simple "vanilla" SM extension is to add RH neutrinos, giving the same mass generation mechanism as other fermions have. These RH neutrinos would be light, just like LH ones are (which are currently estimated to be below 200 meV, IIRC).

Unless I'm missing something, IceCube result does not exclude this part of parameter space.

 

[kodama]

Neutrino mass still needs to be explained, you can't just leave only LH neutrinos in SM.

The most simple "vanilla" SM extension is to add RH neutrinos, giving the same mass generation mechanism as other fermions have. These RH neutrinos would be light, just like LH ones are (which are currently estimated to be below 200 meV, IIRC).

Unless I'm missing something, IceCube result does not exclude this part of parameter space.

would this work,
LH neutrinos couple to protophobic x-boson 17 MeV, gaining mass and thus oscilation

 

[nikkkom]

Then charged leptons would couple to this boson too, which is not observed.

 

[kodama]

Then charged leptons would couple to this boson too, which is not observed.

maybe muons and tau are electrons that coupled to this force

 

[nikkkom]

I meant that (sufficiently energetic) lepton collisions would emit these bosons, and this would be discovered long ago.

 

[kodama]

I meant that (sufficiently energetic) lepton collisions would emit these bosons, and this would be discovered long ago.

well if the couplings are weak enough to evade experimental bounds

 

[nikkkom]

Electron interactions by now are measured to precisions on the order of ~10^-9, and they agree with theoretical predictions. This means that such hypothetical couplings are weaker than that, and can only induce neutrino masses below ~1 meV.

 

[kodama]

Electron interactions by now are measured to precisions on the order of ~10^-9, and they agree with theoretical predictions. This means that such hypothetical couplings are weaker than that, and can only induce neutrino masses below ~1 meV.

maybe neutrino masses are below ~1 meV, or like the higgs, its couplings to neutrinos are higher than for charged leptons

the feng boson or light neutral boson, is also postulated to solve anomalous magnetic dipole moment muon and muon radius puzzle

 

[nikkkom]

maybe neutrino masses are below ~1 meV, or like the higgs, its couplings to neutrinos are higher than for charged leptons

Higgs-like coupling (IOW: fermion to scalar field coupling) would require existence of RH neutrinos.

 

[kodama]

Higgs-like coupling (IOW: fermion to scalar field coupling) would require existence of RH neutrinos.

feng proposes his boson is a spin-1 vector boson with axial and vectorlike currents

my point about the higgs is that it couples to top quarks is quite different from electrons

 

[nikkkom]

feng proposes his boson is a spin-1 vector boson with axial and vectorlike currents

Nonzero-spin fields with nonzero VEV break Lorentz invariance.

 

[kodama]

Nonzero-spin fields with nonzero VEV break Lorentz invariance.

perhaps this boson has zero VEV to preserve Lorentz invariance

 

[nikkkom]

Then how it generates neutrino mass?

 

[kodama]

Then how it generates neutrino mass?

if there is more than 1 higgs field, perhaps neutrinos couple to a second set of higgs

 

[ohwilleke]

Higgs-like coupling (IOW: fermion to scalar field coupling) would require existence of RH neutrinos.

Depends on how "Higgs-like" it has to be. I don't see anything wrong in principle with a scalar field that couples only to left handed particles and thereby generates mass. It wouldn't be very Higgs-like, compared to the SM, but shouldn't be mathematically impossible.

 

[Urs Schreiber]

what kind of dark matter is left?

Fuzzy dark matter.

W. Hu, R. Barkana, and A. Gruzinov, “Cold and fuzzy dark matter,” Phys. Rev. Lett. 85, 1158–1161 (2000), https://arxiv.org/abs/astro-ph/0003365

One of the big conundrums is that the assumption of dark matter works extremely well on large scales for explaining the structure of the cosmos, but seems to fail to work on the scale of galaxies. One interesting idea how to fix this (without giving up on the established theory of gravity as MOND does) is to assume that dark matter consists of massive but extremely light particles, whose de Broglie wavelength is of the order of thousands of parsecs. This has the consequence that at around the scale of that wavelength the behaviour of this dark matter changes.

Now Edward Witten et al. have argued in more detail that this works really well, and consistent with existing null results on direct detection:

Lam Hui, Jeremiah P. Ostriker, Scott Tremaine, Edward Witten, "On the hypothesis that cosmological dark matter is composed of ultra-light bosons" https://arxiv.org/abs/1610.08297

 

[kodama]

Fuzzy dark matter.

W. Hu, R. Barkana, and A. Gruzinov, “Cold and fuzzy dark matter,” Phys. Rev. Lett. 85, 1158–1161 (2000), https://arxiv.org/abs/astro-ph/0003365

One of the big conundrums is that the assumption of dark matter works extremely well on large scales for explaining the structure of the cosmos, but seems to fail to work on the scale of galaxies. One interesting idea how to fix this (without giving up on the established theory of gravity as MOND does) is to assume that dark matter consists of massive but extremely light particles, whose de Broglie wavelength is of the order of thousands of parsecs. This has the consequence that at around the scale of that wavelength the behaviour of this dark matter changes.

Now Edward Witten et al. have argued in more detail that this works really well, and consistent with existing null results on direct detection:

Lam Hui, Jeremiah P. Ostriker, Scott Tremaine, Edward Witten, "On the hypothesis that cosmological dark matter is composed of ultra-light bosons" https://arxiv.org/abs/1610.08297

does this fuzzy dark matter couple to higgs?