Could dark baryons explain dark matter?

They are suggesting that instead of being Supersymetric WIMPs, they are
Technicolor Technibaryons.

Yousuf Khan

***
Could dark baryons explain dark matter?
"Sarkar is a Professor at the University of Oxford in England. Along
with Mads Frandsen, he has been working to show that asymmetric "dark
baryons" can be a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy 'supersymmetric'
particles that are very weakly interacting. Sarkar and Frandsen suggest
though that dark matter could be much lighter, asymmetric (i.e. just
particles and no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark Matter and the
sun.""
http://www.physorg.com/news198834411.html
***

Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much lighter than
the WIMP particles most dark matter hunters are looking for. Such
‘heavy’ particles are also their own antiparticles, so that when a WIMP
meets a WIMP they annihilate each other, making it puzzling that there’s
still so much dark matter around.

The Oxford team ask: what if, instead of being 100 times the mass of a
proton, dark matter particles were only 5 times heavier than a proton
but had the same asymmetry - excess of particles over antiparticles?

‘If it were five times heavier, it would get five times the abundance.
That’s what dark matter is,’ Subir Sarkar of Oxford University’s Rudolf
Peierls Centre for Theoretical Physics, who led the work with Mads
Frandsen, told Wired.com's Lisa Grossman. ‘That’s the simplest
explanation for dark matter in my view.’

Because these ‘light’ dark matter particles don’t annihilate each other,
Subir and Mads explain, they could be hoovered up by the gravity of a
star like our Sun and trapped there.

Subir comments: ‘The sun has been whizzing around the galaxy for 5
billion years, sweeping up all the dark matter as it goes.’"
http://www.physorg.com/news198221838.html

Dear Yousuf Khan:

On Jul 20, 9:49*am, Yousuf Khan wrote:
They are suggesting that instead of being Supersymetric
WIMPs, they are Technicolor Technibaryons.

* * * * Yousuf Khan

***
Could dark baryons explain dark matter?
"Sarkar is a Professor at the University of Oxford in
England. Along with Mads Frandsen, he has been
working to show that asymmetric "dark baryons" can be
a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy
'supersymmetric' particles that are very weakly interacting.
Sarkar and Frandsen suggest though that dark matter
could be much lighter, asymmetric (i.e. just particles and
no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark
Matter and the sun.""
http://www.physorg.com/news198834411.html
***

Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much
lighter than the WIMP particles most dark matter hunters
are looking for. Such ‘heavy’ particles are also their own
antiparticles, so that when a WIMP meets a WIMP they
annihilate each other, making it puzzling that there’s still
so much dark matter around.

The Oxford team ask: what if, instead of being 100 times
the mass of a proton, dark matter particles were only 5
times heavier than a proton but had the same asymmetry -
excess of particles over antiparticles?

‘If it were five times heavier, it would get five times the
abundance. That’s what dark matter is,’ Subir Sarkar of
Oxford University’s Rudolf Peierls Centre for Theoretical
Physics, who led the work with Mads Frandsen, told
Wired.com's Lisa Grossman. ‘That’s the simplest
explanation for dark matter in my view.’

Because these ‘light’ dark matter particles don’t annihilate
each other, Subir and Mads explain, they could be hoovered
up by the gravity of a star like our Sun and trapped there.

And take part in nuclear reactions. Baryons means a collection of
quarks, complete with strong and weak interactions.

Subir comments: ‘The sun has been whizzing around
the galaxy for 5 billion years, sweeping up all the dark
matter as it goes.’"
http://www.physorg.com/news198221838.html

Which if course does not explain its roughly 1 part in 10^14 loss of
mass due to radiation of fusion energy and solar wind ejecta. And if
these Dark baryons don't do friction, then they won't be "hoovered
up".

I don't see this as a significant improvement over Dark Matter as
something that is impossible to see in the lab, and is still not
predicted by any other branch of science. We've found some really
amazing collections of quarks, but they are all pretty short-lived...

David A. Smith

On 7/20/2010 11:57 PM, dlzc wrote:
Dear Yousuf Khan:

On Jul 20, 9:49 am, Yousuf wrote:
Because these ‘light’ dark matter particles don’t annihilate
each other, Subir and Mads explain, they could be hoovered
up by the gravity of a star like our Sun and trapped there.

And take part in nuclear reactions. Baryons means a collection of
quarks, complete with strong and weak interactions.

Oh, I don't know, if they are Technibaryons, then they might be made up
of "Techniquarks"?

Subir comments: ‘The sun has been whizzing around
the galaxy for 5 billion years, sweeping up all the dark
matter as it goes.’"
http://www.physorg.com/news198221838.html

Which if course does not explain its roughly 1 part in 10^14 loss of
mass due to radiation of fusion energy and solar wind ejecta. And if
these Dark baryons don't do friction, then they won't be "hoovered
up".

Apparently they do a little friction.

I don't see this as a significant improvement over Dark Matter as
something that is impossible to see in the lab, and is still not
predicted by any other branch of science. We've found some really
amazing collections of quarks, but they are all pretty short-lived...

I'm reserving my judgement about this.

Yousuf Khan

Yousuf Khan wrote:

They are suggesting that instead of being Supersymetric WIMPs, they are
Technicolor Technibaryons.

Yousuf Khan

***
Could dark baryons explain dark matter?

I wholly imagine 'dark baryons' is an equally meaningless buzzword like
'dark fluid' that has no relation to the words used.

"Sarkar is a Professor at the University of Oxford in England. Along
with Mads Frandsen, he has been working to show that asymmetric "dark
baryons" can be a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy 'supersymmetric'
particles that are very weakly interacting.

By who? Different folks have different opinions and models to match. The
only unifying details are the bulk properties of the subject.

Sarkar and Frandsen suggest
though that dark matter could be much lighter, asymmetric (i.e. just
particles and no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark Matter and the
sun.""
http://www.physorg.com/news198834411.html
***

Sure why not?

There's no way to observationally distinguish between the dozens of models
of dark matter at this moment in time.

The idea of using the presumed mechanism of creation for the prevalence of
matter over antimatter as the mechanism for making dark matter isn't a bad
idea. Two problems with that, though :

1) We don't actually know what did it. This is closely related to why I
think there's more to discover in particle physics.
2) There is literally no evidence to distinguish his proposal from any of
the others.


Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much lighter than
the WIMP particles most dark matter hunters are looking for. Such
?heavy? particles are also their own antiparticles, so that when a WIMP
meets a WIMP they annihilate each other, making it puzzling that there?s
still so much dark matter around.

I wonder what part of 'weakly interacting' confused the author. We know that
the interaction cross section of dark matter is something within an order of
magnitude or two of neutrinos.

Borrowing the representative statistic, a neutrino can go through roughly a
light year of lead and stand a 50% chance of interacting. Why on Earth would
it be expected that dark matter self interactions would be more powerful
than that?


The Oxford team ask: what if, instead of being 100 times the mass of a
proton, dark matter particles were only 5 times heavier than a proton
but had the same asymmetry - excess of particles over antiparticles?

Minor problem with that, on several fronts:

1) Protons and antiprotons are symmetric. Parity violations have not - to my
knowledge - been observed of them. K mesons and something new that's quite
recent, yes. Baryons, no.
2) Parity inversions need _charge_. Dark matter is overwhelmingly understood
to be charge free. Once again, 'weakly interacting'. So assuming dark matter
with nonzero amounts of electronic charge sounds like a poor start.


?If it were five times heavier, it would get five times the abundance.

I suggest gentle readers parse the above statement and its' curious
implication _very slowly_.

That?s what dark matter is,? Subir Sarkar of Oxford University?s Rudolf
Peierls Centre for Theoretical Physics, who led the work with Mads
Frandsen, told Wired.com's Lisa Grossman. ?That?s the simplest
explanation for dark matter in my view.?

Because these ?light? dark matter particles don?t annihilate each other,
Subir and Mads explain, they could be hoovered up by the gravity of a
star like our Sun and trapped there.

Let's play "order of magnitudes". I think Feynman used to do this.

The required density for dark matter in the Milky Way rounds out to about
10^12 solar masses which in turn gives an equivalent mass-energy equivalent
density of about 1 hydrogen atom per cm^3 or 10^6 / m^3.

Say the Sun is 10^6 meters wide, and has been alive 5 billion years, while
traveling about the galaxy with a speed of 10^6 m/s.

That's forms a volume of 3 * (10^6m)^2 * (10^6m/s * 10^17s) = 10^35 m^3,
with a density of 10^41 hydrogen-atoms equivalent.

One gram of hydrogen is ~10^23 atoms. So that's 10^18 grams - 10^15 kg - of
mass-energy equivalent. The sun is 10^30 kg or so. Absent a gross error in
my numbers or assumptions, this idea is rated 'not even close' on the scale
of correctness.

Long story short, dark matter amounts to an abundant '**** all' in terms of
mass increase even integrated over the ENTIRE LIFETIME OF THE STAR using the
_generous_ notion that it captures everything that touches the solar radius.

Can this idea please die?


Subir comments: ?The sun has been whizzing around the galaxy for 5
billion years, sweeping up all the dark matter as it goes.?"
http://www.physorg.com/news198221838.html

Yeah, and would have picked up - optimistically - 0.001% of an Earth mass
while doing so. Color me unimpressed.

Yousuf Khan wrote:

They are suggesting that instead of being Supersymetric WIMPs, they are
Technicolor Technibaryons.

Yousuf Khan

***
Could dark baryons explain dark matter?

I wholly imagine 'dark baryons' is an equally meaningless buzzword like
'dark fluid' that has no relation to the words used.

"Sarkar is a Professor at the University of Oxford in England. Along
with Mads Frandsen, he has been working to show that asymmetric "dark
baryons" can be a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy 'supersymmetric'
particles that are very weakly interacting.

By who? Different folks have different opinions and models to match. The
only unifying details are the bulk properties of the subject.

Sarkar and Frandsen suggest
though that dark matter could be much lighter, asymmetric (i.e. just
particles and no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark Matter and the
sun.""
http://www.physorg.com/news198834411.html
***

Sure why not?

There's no way to observationally distinguish between the dozens of models
of dark matter at this moment in time.

The idea of using the presumed mechanism of creation for the prevalence of
matter over antimatter as the mechanism for making dark matter isn't a bad
idea. Two problems with that, though :

1) We don't actually know what did it. This is closely related to why I
think there's more to discover in particle physics.
2) There is literally no evidence to distinguish his proposal from any of
the others.


Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much lighter than
the WIMP particles most dark matter hunters are looking for. Such
?heavy? particles are also their own antiparticles, so that when a WIMP
meets a WIMP they annihilate each other, making it puzzling that there?s
still so much dark matter around.

I wonder what part of 'weakly interacting' confused the author. We know that
the interaction cross section of dark matter is something within an order of
magnitude or two of neutrinos.

Borrowing the representative statistic, a neutrino can go through roughly a
light year of lead and stand a 50% chance of interacting. Why on Earth would
it be expected that dark matter self interactions would be more powerful
than that?


The Oxford team ask: what if, instead of being 100 times the mass of a
proton, dark matter particles were only 5 times heavier than a proton
but had the same asymmetry - excess of particles over antiparticles?

Minor problem with that, on several fronts:

1) Protons and antiprotons are symmetric. Parity violations have not - to my
knowledge - been observed of them. K mesons and something new that's quite
recent, yes. Baryons, no.
2) Parity inversions need _charge_. Dark matter is overwhelmingly understood
to be charge free. Once again, 'weakly interacting'. So assuming dark matter
with nonzero amounts of electronic charge sounds like a poor start.


?If it were five times heavier, it would get five times the abundance.

I suggest gentle readers parse the above statement and its' curious
implication _very slowly_.

That?s what dark matter is,? Subir Sarkar of Oxford University?s Rudolf
Peierls Centre for Theoretical Physics, who led the work with Mads
Frandsen, told Wired.com's Lisa Grossman. ?That?s the simplest
explanation for dark matter in my view.?

Because these ?light? dark matter particles don?t annihilate each other,
Subir and Mads explain, they could be hoovered up by the gravity of a
star like our Sun and trapped there.

Let's play "order of magnitudes". I think Feynman used to do this.

The required density for dark matter in the Milky Way rounds out to about
10^12 solar masses which in turn gives an equivalent mass-energy equivalent
density of about 1 hydrogen atom per cm^3 or 10^6 / m^3.

Say the Sun is 10^6 meters wide, and has been alive 5 billion years, while
traveling about the galaxy with a speed of 10^6 m/s.

That's forms a volume of 3 * (10^6m)^2 * (10^6m/s * 10^17s) = 10^35 m^3,
with a density of 10^41 hydrogen-atoms equivalent.

One gram of hydrogen is ~10^23 atoms. So that's 10^18 grams - 10^15 kg - of
mass-energy equivalent. The sun is 10^30 kg or so. Absent a gross error in
my numbers or assumptions, this idea is rated 'not even close' on the scale
of correctness.

Long story short, dark matter amounts to an abundant '**** all' in terms of
mass increase even integrated over the ENTIRE LIFETIME OF THE STAR using the
_generous_ notion that it captures everything that touches the solar radius.

Can this idea please die?


Subir comments: ?The sun has been whizzing around the galaxy for 5
billion years, sweeping up all the dark matter as it goes.?"
http://www.physorg.com/news198221838.html

Yeah, and would have picked up - optimistically - 0.001% of an Earth mass
while doing so. Color me unimpressed.

Dear Yousuf Khan:

On Jul 20, 11:41*am, Yousuf Khan wrote:
On 7/20/2010 11:57 PM, dlzc wrote:

Dear Yousuf Khan:

On Jul 20, 9:49 am, Yousuf *wrote:
Because these ‘light’ dark matter particles don’t annihilate
each other, Subir and Mads explain, they could be hoovered
up by the gravity of a star like our Sun and trapped there.

And take part in nuclear reactions. *Baryons means a
collection of quarks, complete with strong and weak
interactions.

Oh, I don't know, if they are Technibaryons, then they might
be made up of "Techniquarks"?

Unlikely.

Subir comments: ‘The sun has been whizzing around
the galaxy for 5 billion years, sweeping up all the dark
matter as it goes.’"
http://www.physorg.com/news198221838.html

Which if course does not explain its roughly 1 part in 10^14
loss of mass due to radiation of fusion energy and solar
wind ejecta. *And if these Dark baryons don't do friction,
then they won't be "hoovered up".

Apparently they do a little friction.

I don't see this as a significant improvement over Dark
Matter as something that is impossible to see in the lab,
and is still not predicted by any other branch of science.
*We've found some really amazing collections of quarks,
but they are all pretty short-lived...

I'm reserving my judgement about this.

It is just Dark Matter, with a fancier name. It is still not seen in
the lab, and if it does friction, it is obviated by observation.

I'm still on the quest... AND thank you for posting this.

David A. Smith

On 7/21/2010 2:15 AM, dlzc wrote:
Dear Yousuf Khan:

On Jul 20, 11:41 am, Yousuf wrote:
On 7/20/2010 11:57 PM, dlzc wrote:

Dear Yousuf Khan:

On Jul 20, 9:49 am, Yousuf wrote:
Because these ‘light’ dark matter particles don’t annihilate
each other, Subir and Mads explain, they could be hoovered
up by the gravity of a star like our Sun and trapped there.

And take part in nuclear reactions. Baryons means a
collection of quarks, complete with strong and weak
interactions.

Oh, I don't know, if they are Technibaryons, then they might
be made up of "Techniquarks"?

Unlikely.

I don't know enough about the Technicolor theory to agree or disagree,
one way or another. All I remember hearing about it before was that it
was an alternative to Supersymmetry back in the 70's or 80's, but had
somehow fallen out of favor. Actually, as I remember it, Susy itself had
fallen out of favor back then, until it was revived & integrated into
String theory, thus giving it the name of Superstring theory.

It is just Dark Matter, with a fancier name. It is still not seen in
the lab, and if it does friction, it is obviated by observation.

I'm still on the quest... AND thank you for posting this.

Well, I'm still a firm believer of the fluidic universe theory. But for
those who still believe in Dark matter, this might be interesting to
them. I don't see this as an alternative to the entire field of Dark
matter, but as an alternative to the current obsession with WIMPs. Other
alternatives include Axions, sterile neutrinos, etc. WIMPs are really
the Susy/String people trying to put their stake in the ground to lay
claim to some kind of a prediction.

Yousuf Khan

On 7/21/2010 1:05 AM, eric gisse wrote:
Yousuf Khan wrote:
"Sarkar is a Professor at the University of Oxford in England. Along
with Mads Frandsen, he has been working to show that asymmetric "dark
baryons" can be a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy 'supersymmetric'
particles that are very weakly interacting.

By who? Different folks have different opinions and models to match. The
only unifying details are the bulk properties of the subject.

I think they are trying to set themselves apart from the usual WIMP
assumptions by saying that these types of dark matter will have some
light-duty frictional interactions, and be immune to collisional
annihilation if they are not their own anti-particles. A lightly
frictional model might help explain some of the anomalies of the dark
matter model at the supercluster scales. Not being your own
anti-particle would help explain why we still see them after the Big Bang.

Sarkar and Frandsen suggest
though that dark matter could be much lighter, asymmetric (i.e. just
particles and no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark Matter and the
sun.""
http://www.physorg.com/news198834411.html
***

Sure why not?

There's no way to observationally distinguish between the dozens of models
of dark matter at this moment in time.

The idea of using the presumed mechanism of creation for the prevalence of
matter over antimatter as the mechanism for making dark matter isn't a bad
idea. Two problems with that, though :

1) We don't actually know what did it. This is closely related to why I
think there's more to discover in particle physics.
2) There is literally no evidence to distinguish his proposal from any of
the others.

Regarding #1, I think that's exactly what they're hoping for. There's a
lot of camps within particle physics which have a stake in making sure
that their particular theories are searched for during the LHC
collisions. So far, SUSY is looking for WIMPs, while Technicolor is
probably going to be looking for these Technibaryons.

Regarding #2, at the astrophysical or cosmological level, there should
not be any difference between his theory and any number of other dark
matter theories, obviously. So he's staking his claim within the Sun,
saying we should be able to tell from differences within the Sun's
burning patterns.

Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much lighter than
the WIMP particles most dark matter hunters are looking for. Such
?heavy? particles are also their own antiparticles, so that when a WIMP
meets a WIMP they annihilate each other, making it puzzling that there?s
still so much dark matter around.

I wonder what part of 'weakly interacting' confused the author. We know that
the interaction cross section of dark matter is something within an order of
magnitude or two of neutrinos.

Borrowing the representative statistic, a neutrino can go through roughly a
light year of lead and stand a 50% chance of interacting. Why on Earth would
it be expected that dark matter self interactions would be more powerful
than that?

As I said, it's the Technicolor camp vs. the Susy camp, they are marking
out their territories. For whatever reason, they are saying
Technibaryons have stronger interactions with themselves than they do
with regular baryons -- beyond that I don't know enough about it. A WIMP
which interacts with itself should annihilate in a matter/anti-matter
sense, which should send out gamma rays. A Technibaryon won't leave such
a trail.

Looking through the literature, I've seen some papers on Arxiv
discussing Technibaryons as possible dark matter candidates going back
to 1993. But they were already stating back then that they don't think
there would be enough Technibaryons around after the Big Bang to account
for CDM. Maybe there has been some new research into the issue, and the
Technicolor folks believe they can revive the theory, and get equal time
at the LHC?

The Oxford team ask: what if, instead of being 100 times the mass of a
proton, dark matter particles were only 5 times heavier than a proton
but had the same asymmetry - excess of particles over antiparticles?

Minor problem with that, on several fronts:

1) Protons and antiprotons are symmetric. Parity violations have not - to my
knowledge - been observed of them. K mesons and something new that's quite
recent, yes. Baryons, no.

Well apart from the one big parity violation that the number of protons
exceeded anti-protons during the BB.

2) Parity inversions need _charge_. Dark matter is overwhelmingly understood
to be charge free. Once again, 'weakly interacting'. So assuming dark matter
with nonzero amounts of electronic charge sounds like a poor start.

Neutrinos and anti-neutrinos are charge-free, but we still distinguish
them. So I'm not getting what you're trying to say here.

That?s what dark matter is,? Subir Sarkar of Oxford University?s Rudolf
Peierls Centre for Theoretical Physics, who led the work with Mads
Frandsen, told Wired.com's Lisa Grossman. ?That?s the simplest
explanation for dark matter in my view.?

Because these ?light? dark matter particles don?t annihilate each other,
Subir and Mads explain, they could be hoovered up by the gravity of a
star like our Sun and trapped there.

Let's play "order of magnitudes". I think Feynman used to do this.

The required density for dark matter in the Milky Way rounds out to about
10^12 solar masses which in turn gives an equivalent mass-energy equivalent
density of about 1 hydrogen atom per cm^3 or 10^6 / m^3.

Say the Sun is 10^6 meters wide, and has been alive 5 billion years, while
traveling about the galaxy with a speed of 10^6 m/s.

That's forms a volume of 3 * (10^6m)^2 * (10^6m/s * 10^17s) = 10^35 m^3,
with a density of 10^41 hydrogen-atoms equivalent.

One gram of hydrogen is ~10^23 atoms. So that's 10^18 grams - 10^15 kg - of
mass-energy equivalent. The sun is 10^30 kg or so. Absent a gross error in
my numbers or assumptions, this idea is rated 'not even close' on the scale
of correctness.

Long story short, dark matter amounts to an abundant '**** all' in terms of
mass increase even integrated over the ENTIRE LIFETIME OF THE STAR using the
_generous_ notion that it captures everything that touches the solar radius.

Can this idea please die?

Searching through their paper, it looks like they are not saying that
every particle of Technibaryon is going to get hoovered up by the Sun,
just a certain percentage.

Yousuf Khan

Yousuf Khan wrote:

On 7/21/2010 1:05 AM, eric gisse wrote:
Yousuf Khan wrote:
"Sarkar is a Professor at the University of Oxford in England. Along
with Mads Frandsen, he has been working to show that asymmetric "dark
baryons" can be a candidate for cold dark matter. This is a different
approach, since dark matter is assumed to be heavy 'supersymmetric'
particles that are very weakly interacting.

By who? Different folks have different opinions and models to match. The
only unifying details are the bulk properties of the subject.

I think they are trying to set themselves apart from the usual WIMP
assumptions by saying that these types of dark matter will have some
light-duty frictional interactions

Unobserved.

, and be immune to collisional
annihilation if they are not their own anti-particles.

A solution in search of a problem. With _required_ low interaction rates and
an _observed_ lack of a solid omnidirectional radiation glow, dark matter
not only interacts weakly but annihilates rarely if at all.


A lightly
frictional model might help explain some of the anomalies of the dark
matter model at the supercluster scales.

Such as, and supporting references? Running out of interesting reading
material.

Not being your own
anti-particle would help explain why we still see them after the Big Bang.

Sarkar and Frandsen suggest
though that dark matter could be much lighter, asymmetric (i.e. just
particles and no antiparticles) and interact more strongly. Their work
is published in Physical Review Letters: "Asymmetric Dark Matter and the
sun.""
http://www.physorg.com/news198834411.html
***

Sure why not?

There's no way to observationally distinguish between the dozens of
models of dark matter at this moment in time.

The idea of using the presumed mechanism of creation for the prevalence
of matter over antimatter as the mechanism for making dark matter isn't a
bad idea. Two problems with that, though :

1) We don't actually know what did it. This is closely related to why I
think there's more to discover in particle physics.
2) There is literally no evidence to distinguish his proposal from any of
the others.

Regarding #1, I think that's exactly what they're hoping for. There's a
lot of camps within particle physics which have a stake in making sure
that their particular theories are searched for during the LHC
collisions. So far, SUSY is looking for WIMPs, while Technicolor is
probably going to be looking for these Technibaryons.

Their parameter space will be appropriately crushed and be forced to make
excuses or find new models.


Regarding #2, at the astrophysical or cosmological level, there should
not be any difference between his theory and any number of other dark
matter theories, obviously. So he's staking his claim within the Sun,
saying we should be able to tell from differences within the Sun's
burning patterns.

A dubious enterprise.


Using the Sun as an experiment for these Dark Baryons:

***
Sun's dark matter trap
"The work looks at the possibility that dark matter is much lighter than
the WIMP particles most dark matter hunters are looking for. Such
?heavy? particles are also their own antiparticles, so that when a WIMP
meets a WIMP they annihilate each other, making it puzzling that there?s
still so much dark matter around.

I wonder what part of 'weakly interacting' confused the author. We know
that the interaction cross section of dark matter is something within an
order of magnitude or two of neutrinos.

Borrowing the representative statistic, a neutrino can go through roughly
a light year of lead and stand a 50% chance of interacting. Why on Earth
would it be expected that dark matter self interactions would be more
powerful than that?

As I said, it's the Technicolor camp vs. the Susy camp, they are marking
out their territories. For whatever reason, they are saying
Technibaryons have stronger interactions with themselves than they do
with regular baryons -- beyond that I don't know enough about it. A WIMP
which interacts with itself should annihilate in a matter/anti-matter
sense, which should send out gamma rays. A Technibaryon won't leave such
a trail.

And has the Fermi gamma ray observatory seen such a background?


Looking through the literature, I've seen some papers on Arxiv
discussing Technibaryons as possible dark matter candidates going back
to 1993.

Model hunting is a nigh-meaningless pursuit when there is no evidence that
can _distinguish_ between the models. It is like saying observation shows x
+ y = 3, and my model predicts x = 1 and y = 2 and another model predicts x
= 6 and y = -1. Without a way to _tell_, the enterprise is worthless.

Given the lack of anomalies in the CMB power spectrum even in the 7 year
WMAP data, there is nothing out there to pick between competing models.

But they were already stating back then that they don't think
there would be enough Technibaryons around after the Big Bang to account
for CDM. Maybe there has been some new research into the issue, and the
Technicolor folks believe they can revive the theory, and get equal time
at the LHC?

A proton is a proton, an anti-proton is an anti-proton. I wonder in what
form 'accelerator time' manifests as when the atom smashing is the same
every time.


The Oxford team ask: what if, instead of being 100 times the mass of a
proton, dark matter particles were only 5 times heavier than a proton
but had the same asymmetry - excess of particles over antiparticles?

Minor problem with that, on several fronts:

1) Protons and antiprotons are symmetric. Parity violations have not - to
my knowledge - been observed of them. K mesons and something new that's
quite recent, yes. Baryons, no.

Well apart from the one big parity violation that the number of protons
exceeded anti-protons during the BB.

Do not confuse cause and effect.

The _effect_ is there are protons instead of photon soup, the _cause_ is
currently unknown. But the efficiency of the process was hellaciously large
given that matter dominates over photons at this epoch.


2) Parity inversions need _charge_. Dark matter is overwhelmingly
understood to be charge free. Once again, 'weakly interacting'. So
assuming dark matter with nonzero amounts of electronic charge sounds
like a poor start.

Neutrinos and anti-neutrinos are charge-free, but we still distinguish
them. So I'm not getting what you're trying to say here.

http://en.wikipedia.org/wiki/CP_violation

I do remember that violation of C, P, or T results in a violation of the
set. But I'm now not quite sure if charge is required to be present for a
CPT violation.

Not a particle physicist but regardless, that requires a _massive_ violation
of the CPT theorem instead of a subtle one with the Kaon.


That?s what dark matter is,? Subir Sarkar of Oxford University?s Rudolf
Peierls Centre for Theoretical Physics, who led the work with Mads
Frandsen, told Wired.com's Lisa Grossman. ?That?s the simplest
explanation for dark matter in my view.?

Because these ?light? dark matter particles don?t annihilate each other,
Subir and Mads explain, they could be hoovered up by the gravity of a
star like our Sun and trapped there.

Let's play "order of magnitudes". I think Feynman used to do this.

The required density for dark matter in the Milky Way rounds out to about
10^12 solar masses which in turn gives an equivalent mass-energy
equivalent density of about 1 hydrogen atom per cm^3 or 10^6 / m^3.

Say the Sun is 10^6 meters wide, and has been alive 5 billion years,
while traveling about the galaxy with a speed of 10^6 m/s.

That's forms a volume of 3 * (10^6m)^2 * (10^6m/s * 10^17s) = 10^35 m^3,
with a density of 10^41 hydrogen-atoms equivalent.

One gram of hydrogen is ~10^23 atoms. So that's 10^18 grams - 10^15 kg -
of mass-energy equivalent. The sun is 10^30 kg or so. Absent a gross
error in my numbers or assumptions, this idea is rated 'not even close'
on the scale of correctness.

Long story short, dark matter amounts to an abundant '**** all' in terms
of mass increase even integrated over the ENTIRE LIFETIME OF THE STAR
using the _generous_ notion that it captures everything that touches the
solar radius.

Can this idea please die?

Searching through their paper, it looks like they are not saying that
every particle of Technibaryon is going to get hoovered up by the Sun,
just a certain percentage.

Yousuf Khan

Thus the idea is made even worse by using a realistic capture rate.

The only way something in the neighborhood of a millionth of an Earth mass
in the solar core could be relevant to burn rates is if it interacted
meaningfully at core densities. Which is rather unlikely - remember how
neutrinos stream right out of the solar core?

Besides, if the interaction is at all meaningful the dark baryons would have
been burnt away in the fusion process eons ago, leaving only the ****-all
per cm^3 it picks up now.

It would probably still not explain the type of motion that suns have
in galaxies,
which might be pressurized gravity generated hardening of galactic
mass. The
unique pressure can be explained to rise between gravity and
centrifugal forces.

According to Einstein no centrifugal forces would be applicable in
spacetime,
but special force driven pressure fields might rise.