WIMPs AWOL Yet Again

On Monday, August 1, 2016 at 2:36:26 AM UTC-4, Phillip Helbig (undress to reply) wrote:

Note also that one of the main motivation for the MACHO and similar
collaborations was to find a substantial fraction of the dark matter in
compact objects in our galactic halo. After 25 years of data, no show.


Astounding!

Most of the dark matter research literature and the majority of the
astrophysical community state that MACHOs have been detected and that
they could contribute at least 10% of the dark matter.

See the paper by B. Carr above.

You say: "no show". How do you explain this? No other scientist known to
me has made such a statement.

RLO
http://www3.amherst.edu/~rloldershaw

In article ,
"Robert L. Oldershaw" writes:

On Monday, August 1, 2016 at 2:36:26 AM UTC-4, Phillip Helbig (undress to reply) wrote:

Note also that one of the main motivation for the MACHO and similar
collaborations was to find a substantial fraction of the dark matter in
compact objects in our galactic halo. After 25 years of data, no show.

Astounding!

Most of the dark matter research literature and the majority of the
astrophysical community state that MACHOs have been detected and that
they could contribute at least 10% of the dark matter.

There is not only a lower limit ("at least 10%") but also a quite strict
upper limit.

Of course, one does observations and sees what Nature has to offer. As
Robert Pirsig wrote, the television scientist who says "Our experiment
is a failure; we didn't find what we were looking for" is suffereing
mainly from a bad script writer. If you already KNOW what you will
find, then there is no need to do the experiment.

Nevertheless, such an observational programme costs money, and has to be
justified somehow, and the "hope" was that MACHOs would turn out to be
THE dark matter, i.e. essentially all dark matter in MACHOs. That is
not how it turned out.

People once thought that massive neutrinos could be dark matter. Now,
that looks very improbable, though SOME fraction of non-baryonic matter
is indeed composed of neutrinos. So, neutrinos are not THE dark matter,
but they contribute to it.

You say: "no show". How do you explain this? No other scientist known to
me has made such a statement.

"No show" refers to the fact that it didn't turn out that all of the
dark matter is in MACHOs, which was conceivable when they started out.

Also, all MACHOs could be baryonic, but we know that most of the dark
matter can't be.

On 8/1/16 1:36 AM, Phillip Helbig (undress to reply) wrote:

Note also that one of the main motivation for the MACHO and similar
collaborations was to find a substantial fraction of the dark matter in
compact objects in our galactic halo. After 25 years of data, no show.
Any reasonable Beer-Lambert law calculation
of object number and size
in galactic halo optical transparency
below instrumental observation capability
can account for dark matter fraction.

Richard D Saam

On Tuesday, August 2, 2016 at 4:08:24 AM UTC-4, Richard D. Saam wrote:

below instrumental observation capability

Uh, oh! More bad news from the particle physics community.

https://profmattstrassler.com/2016/0...-flickers-out/

Who would have guessed?

[[Mod. note -- I fail to see how this qualifies as "bad news". In fact,
I see no evidence in this blog entry that the blogger (Matt Strassler)
sees this as "bad news" either.
-- jt]]

On Thursday, August 4, 2016 at 11:29:11 PM UTC-4, Robert L. Oldershaw wrote:

[[Mod. note -- I fail to see how this qualifies as "bad news". In fact,
I see no evidence in this blog entry that the blogger (Matt Strassler)
sees this as "bad news" either.
-- jt]]

You may add to the loss hyped 750 Gev boson (The Cheshire Cat
particle?), the newest negative results regarding sterile neutrinos
in what theoretical physicists thought was the most desired mass
range.

http://www.nature.com/news/icy-teles...theory-1.20382

Also, I note that my post answering your query about the 750 Gev
bad news has failed to appear. Oversight or selective moderating?

RLO
http://www3.amherst.edu/~rloldershaw

[[Mod. note -- I haven't seen the post you ask about. Perhaps one
of the other moderators has it?

Another possibility: about a week ago (I don't recall the exact date)
my university's main email servers were down for about 12 hours. I
think/hope that all incoming email during that time was queued and
later delivered, but it's possible that some misconfigured software
didn't retry properly and some email was lost then.
-- jt]]

On Thursday, August 4, 2016 at 11:29:11 PM UTC-4, Robert L. Oldershaw wrote:

[[Mod. note -- I fail to see how this qualifies as "bad news". In fact,
I see no evidence in this blog entry that the blogger (Matt Strassler)
sees this as "bad news" either.
-- jt]]

Well, one could take a "What Me Worry" attitude.

The alternative view, and we do like alternative views in science,
might go something like this:

Since the first "hint" of a new 750 Gev particle, approximately 500
papers have been written explaining the meaning of this 2-sigma
bump. Was there really sufficient cause for physicists to "go into
a frenzy"?

Does this tell us something about the state of particle physics?
Steven Weinberg's "Nightmare Scenario", i.e., nothing discovered
at the LHC beyond the Standard Model of Particle Physics, which has
a number of problems signifying its provisional character, continues
without letup. Physics has suffered through 45 years of failure to
find a single "string", "sparticle" or "WIMP" despite heroic
experimental efforts.

You might not see this as bad news, but I can tell you that the
particle physics community is embarrassed and getting very nervous
about where this is headed.

RLO
http://www3.amherst.edu/~rloldershaw

On Tuesday, August 9, 2016 at 12:54:18 AM UTC-4, Robert L. Oldershaw wrote:
[[Mod. note -- 23 excessively-quoted lines snipped here. -- jt]]

----------------------------------------------

Now yesterday's post seems to have "gone missing" too. Let me try again.

On 8/9/16 the ATLAS Collaboration presented new results from the
upgraded LHC (13 Tev) search for particle dark matter.

http://arxiv.org/abs/1608.02372

Bottom Line: particle dark matter still AWOL.

RLO
http://www3.amherst.edu/~rloldershaw

On Thursday, August 11, 2016 at 3:14:29 AM UTC-4, Robert L. Oldershaw wrote:

Well, one could take a "What Me Worry" attitude.


Yawn. Another No-Show for WIMPs and the "WIMP miracle". This time
from the upgraded LUX experiment.

http://arxiv.org/abs/1608.07648