Large Hadron Collider (LHC) News

Study matter and its motion through spacetime...

Moderators: Calilasseia, ADParker

Re: Large Hadron Collider (LHC) News

#501  Postby Microfarad » Jul 28, 2012 4:46 pm

DoctorE wrote:[youtube]http://www.youtube.com/watch?v=c8xUd7Myeuk[/youtube]

:lol: :lol:
Warning: the content of the post above may content inaccuracies, nonsense or insults to human intelligence. Read at your own risk.
User avatar
Microfarad
 
Posts: 1405
Age: 23
Male

Country: Italy
Italy (it)
Print view this post

Ads by Google


Re: Large Hadron Collider (LHC) News

#502  Postby CdesignProponentsist » Jul 29, 2012 4:57 am

Another awesome documentary hosted by Prof Jim Al-Khalli. Enjoy :D
[youtube]http://www.youtube.com/watch?v=IKmSHIh2YBY[/youtube]
"Things don't need to be true, as long as they are believed" - Alexander Nix, CEO Cambridge Analytica
User avatar
CdesignProponentsist
 
Posts: 12331
Age: 52
Male

Country: California
United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#503  Postby lpetrich » Oct 26, 2012 2:02 am

RÉSONAANCES: Higgs: New Deal
The new round of Higgs data will be presented on the 15th of November at a conference in Kyoto, and on blogs a few days earlier. The amount of data will increase by about 2/3 compared to what was available last summer. This means the errors should naively drop by 30%, or a bit more in the likely case of some improvements in the analyses. Here's a short guide to the hottest Higgs questions that may be answered.


Higgs -> photon-photon -- too high for the Standard Model

Higgs -> tau-tau -- too low for the SM

Higgs -> bottom-bottom -- too high for the SM

Higgs -> Z-photon -- not observed; SM says it's not common enough to be observed, at least not yet

Higgs spin? SM and SM extensions say it's zero. Evidence of nonzero spin: the particle-beam directions making an imprint on the directions of the Higgs particles' decay products. Zero spin: isotropic or zero-imprint decay.

Spin 1 is theoretically awkward for decaying into 2 photons. Spin 2 is the first plausible nonzero value.

So I'll keep an eye out for anything interesting that comes out.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#504  Postby Aca » Nov 01, 2012 1:40 pm

http://www.independent.co.uk/news/uk/cr ... 73751.html



British scientists have created a machine that can detect terrorist attempts to smuggle nuclear material through ports and airports - even if it has been shielded from giving off radiation.

The Independent understands that prototypes of the machine - developed using a technique first established by experiments using the Large Hadron Collider - have already been tested by researchers at Britain's Atomic Weapons Establishment.
on an island marooned in the Middle Ages
User avatar
Aca
 
Posts: 3422
Age: 43
Male

Country: Malta
Malta (mt)
Print view this post

Re: Large Hadron Collider (LHC) News

#505  Postby trubble76 » Nov 01, 2012 1:42 pm

Aca wrote:http://www.independent.co.uk/news/uk/crime/dirty-bomb-terror-threat-breakthrough-british-scientists-build-machine-to-detect-smuggling-of-nuclear-materials-8273751.html



British scientists have created a machine that can detect terrorist attempts to smuggle nuclear material through ports and airports - even if it has been shielded from giving off radiation.

The Independent understands that prototypes of the machine - developed using a technique first established by experiments using the Large Hadron Collider - have already been tested by researchers at Britain's Atomic Weapons Establishment.


God, those Brits are clever. Sexy too, vewy vewy sexy.

:shifty:
Freedom's just another word for nothin' left to lose,
And nothin' ain't worth nothin' but it's free.

"Suck me off and I'll turn the voltage down"
User avatar
trubble76
RS Donator
 
Posts: 11205
Age: 42
Male

United Kingdom (uk)
Print view this post

Re: Large Hadron Collider (LHC) News

#506  Postby THWOTH » Nov 01, 2012 11:26 pm

Aca wrote:http://www.independent.co.uk/news/uk/crime/dirty-bomb-terror-threat-breakthrough-british-scientists-build-machine-to-detect-smuggling-of-nuclear-materials-8273751.html

British scientists have created a machine that can detect terrorist attempts to smuggle nuclear material through ports and airports - even if it has been shielded from giving off radiation.

The Independent understands that prototypes of the machine - developed using a technique first established by experiments using the Large Hadron Collider - have already been tested by researchers at Britain's Atomic Weapons Establishment.

I'm telling you, it's Time Cops from the future!


:D
"No-one is exempt from speaking nonsense – the only misfortune is to do it solemnly."
Michel de Montaigne, Essais, 1580
User avatar
THWOTH
RS Donator
 
Name: Penrose
Posts: 37064
Age: 54

Country: Untied Kingdom
United Kingdom (uk)
Print view this post

Re: Large Hadron Collider (LHC) News

#507  Postby lpetrich » Nov 02, 2012 11:52 am

It uses muon scattering. Muons are a flavor of electron that is about 200 times more massive than an ordinary electron. That makes them dragged much less by the material that they pass through, meaning that they can pass through shielding material relatively easily.

The article does not mention how the muons are produced, since they have a mean lifetime of a few microseconds. I think that they'd be produced by a mini particle accelerator that shoots electrons at some target material. With enough energy, it will make pairs of muons, + and - ones.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Ads by Google


Re: Large Hadron Collider (LHC) News

#508  Postby lpetrich » Nov 15, 2012 1:13 pm

RÉSONAANCES: Higgs: what's new
Higgs at HCP2011 « viXra log
Higgs Results at Kyoto | Of Particular Significance
Summary of New Higgs Results | Of Particular Significance
Higgs: New ATLAS And CMS Results
CMS And ATLAS: Higgs To Tau Pairs!

The putative Higgs particle's mass is around 126 GeV with uncertainties around 0.4 GeV.

Nothing new on Higgs -> photon-photon or Higgs -> ZZ -> 4-charged-lepton

However, we have some results on some other decays.

Higgs -> tau-tau
ATLAS: 0.7 +- 0.7 Standard Model
CMS: 0.72 +- 0.52 SM
(Quantum Diaries)

Higgs -> bottom-bottom
ATLAS: "large negative fluctuation"
CMS: 1.3 - 0.6 + 0.7 SM
(Résonaances)

Also a test of spin-parity: 0+ (SM prediction) vs. 0-: better fit to 0+ by about 2.5 standard deviations.
(Quantum Diaries, Of Particular Significance)

To sum up, the putative Higgs particle is even more like the Standard-Model Higgs particle than had been reported earlier.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#509  Postby Little Idiot » Dec 01, 2012 1:42 pm

So still no mini black holes then?
Its all OK.
Little Idiot
 
Posts: 6546

Print view this post

Re: Large Hadron Collider (LHC) News

#510  Postby lpetrich » Dec 02, 2012 1:44 am

No.

Search for Black Holes in pp Collisions at sqrt(s) = 8 TeV - CERN Document Server
A search for microscopic black holes in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 3.7 fb^(−1) recorded by the CMS experiment at the LHC in 2012. Events with large total transverse energy have been analyzed for the presence of multiple energetic jets, leptons, and photons, which are typical signals of evaporating semiclassical and quantum black holes, and string balls. Agreement with the expected standard model backgrounds, which are dominated by QCD multijet production, has been observed for various combined multiplicities of jets and other reconstructed objects in the final state. Model-independent limits are set on new physics processes producing high-multiplicity, energetic final states. In addition, new model-specific indicative limits are set excluding semiclassical black holes with masses below 4.1 to 6.1 TeV. The analysis has a substantially increased sensitivity compared to previous searches due to higher collision energy.

(Record created 2012-07-09, last modified 2012-07-09)

Also The search for microscopic black holes, as of March 2012 | CMS Experiment
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#511  Postby Pulsar » Dec 18, 2012 12:34 am

http://resonaances.blogspot.be/2012/12/twin-peaks-in-atlas.html

Twin Peaks in ATLAS

For the annual December CERN council meeting the ATLAS experiment provided an update of the Higgs searches in the γγ and ZZ→4 leptons channels. The most interesting thing about the HCP update a month ago was why these most sensitive channels were *not* updated (also CMS chose not to update γγ). Now we can see why. The ATLAS analyses in these channels return the best fit Higgs masses that differ by more than 3 GeV: 123.5 GeV for ZZ and 126.6 GeV for γγ, which is much more than the estimated resolution of about 1 GeV. The tension between these 2 results is estimated to be 2.7σ. Apparently, ATLAS used this last month to search for the systematic errors that might be responsible for the discrepancy but, having found nothing, they decided to go public.

One may be tempted to interpret the twin peaks as 2 separate Higgs-like particles. However in this case they most likely signal a systematic problem rather than interesting physics. First, it would be quite a coincidence to have two Higgs particles so close in mass (I'm not aware of a symmetry that could ensure it). Even if the coincidence occurs, it would be highly unusual that one Higgs decays dominantly to ZZ and the other dominantly to γγ, each mimicking pretty well the standard Higgs rate in the respective channel. Finally, and most importantly, CMS does not see anything like that; actually their measurements give a reverse picture. In the ZZ→4l channel CMS measures mh=126.2±0.6 GeV, above (but well within the resolution) the best fit mass they find in the γγ channel which is 125.1±0.7 GeV GeV. That makes us certain that down-to-earth reasons are responsible for the double vision in ATLAS, the likely cause being an ECAL calibration error, an unlucky background fluctuation, or alcohol abuse.


Image
"The longer I live the more I see that I am never wrong about anything, and that all the pains that I have so humbly taken to verify my notions have only wasted my time." - George Bernard Shaw
User avatar
Pulsar
 
Posts: 4617
Age: 41
Male

Country: Belgium
Belgium (be)
Print view this post

Re: Large Hadron Collider (LHC) News

#512  Postby CdesignProponentsist » Dec 18, 2012 12:53 am

Pulsar wrote:http://resonaances.blogspot.be/2012/12/twin-peaks-in-atlas.html

Twin Peaks in ATLAS

For the annual December CERN council meeting the ATLAS experiment provided an update of the Higgs searches in the γγ and ZZ→4 leptons channels. The most interesting thing about the HCP update a month ago was why these most sensitive channels were *not* updated (also CMS chose not to update γγ). Now we can see why. The ATLAS analyses in these channels return the best fit Higgs masses that differ by more than 3 GeV: 123.5 GeV for ZZ and 126.6 GeV for γγ, which is much more than the estimated resolution of about 1 GeV. The tension between these 2 results is estimated to be 2.7σ. Apparently, ATLAS used this last month to search for the systematic errors that might be responsible for the discrepancy but, having found nothing, they decided to go public.

One may be tempted to interpret the twin peaks as 2 separate Higgs-like particles. However in this case they most likely signal a systematic problem rather than interesting physics. First, it would be quite a coincidence to have two Higgs particles so close in mass (I'm not aware of a symmetry that could ensure it). Even if the coincidence occurs, it would be highly unusual that one Higgs decays dominantly to ZZ and the other dominantly to γγ, each mimicking pretty well the standard Higgs rate in the respective channel. Finally, and most importantly, CMS does not see anything like that; actually their measurements give a reverse picture. In the ZZ→4l channel CMS measures mh=126.2±0.6 GeV, above (but well within the resolution) the best fit mass they find in the γγ channel which is 125.1±0.7 GeV GeV. That makes us certain that down-to-earth reasons are responsible for the double vision in ATLAS, the likely cause being an ECAL calibration error, an unlucky background fluctuation, or alcohol abuse.


Image


It's the God particle, and she must be a woman because her boobs are starting to show.
"Things don't need to be true, as long as they are believed" - Alexander Nix, CEO Cambridge Analytica
User avatar
CdesignProponentsist
 
Posts: 12331
Age: 52
Male

Country: California
United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#513  Postby lpetrich » Dec 18, 2012 4:24 pm

This discrepancy could be due to the vagaries of statistics or due to unmodeled or incorrectly-modeled systematic effects.

But that blog entry reports on another result: the putative Higgs particle's spin. It's consistent with zero to within experimental limits. A common benchmark spin-2 model was ruled out to a confidence limit of 90%.

Also,

The first LHC protons run ends with new milestone | CERN press office
Geneva, 17 December 2012. This morning CERN completed the first LHC proton run. The remarkable first three-year run of the world’s most powerful particle accelerator was crowned by a new performance milestone. The space between proton bunches in the beams was halved to further increase beam intensity. ...

To put this into context, of the 6 million billion proton-proton collisions generated by the LHC, the ATLAS and CMS experiments have each recorded around 5 billion collisions of interest over the last three years. Of these, only around 400 produced results compatible with the Higgs-like particle whose discovery was announced in July. ...

At the beginning of 2013, the LHC will collide protons with lead ions before going into a long maintenance stop until the end of 2014. Running will resume in 2015 with increased collision energy of 13 TeV and another increase in luminosity.

Image
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#514  Postby lpetrich » Dec 18, 2012 4:31 pm

The results, side by side:

ATLAS:
Higgs mass from ZZ: 123.5 GeV
Higgs mass from photon-photon: 126.6 GeV
About 2.7 stdevs.

CMS:
Higgs mass from ZZ: 126.2 +- 0.6 GeV
Higgs mass from photon-photon: 125.1 +- 0.7 GeV

ATLAS ZZ seems like the odd one out.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#515  Postby lpetrich » Dec 19, 2012 1:29 am

CMS, ATLAS experiments report Higgs-like particle close to the 7 sigma level -- that's that putative Higgs particle that they had discovered.

12 matter particles suffice in nature reporting on Phys. Rev. Lett. 109, 241802 (2012): Impact of a Higgs Boson at a Mass of 126 GeV on the Standard Model with Three and Four Fermion Generations
The authors analyzed LHC and Tevatron data, and they found that a fourth generation of elementary fermions is excluded to within 5.3 standard deviations.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Ads by Google


Re: Large Hadron Collider (LHC) News

#516  Postby Microfarad » Dec 20, 2012 9:52 am

lpetrich wrote:
Image

An official annoncement. :smile:
Image
Warning: the content of the post above may content inaccuracies, nonsense or insults to human intelligence. Read at your own risk.
User avatar
Microfarad
 
Posts: 1405
Age: 23
Male

Country: Italy
Italy (it)
Print view this post

Re: Large Hadron Collider (LHC) News

#517  Postby lpetrich » Feb 15, 2013 11:25 pm

First three-year LHC running period reaches a conclusion | CERN press office
Geneva 14 February 2013. At 7.24am, the shift crew in the CERN1 Control Centre extracted the beams from the Large Hadron Collider, bringing the machine’s first three-year running period to a successful conclusion.

The LHC thus enters "Long Shutdown 1", when it wlll be upgraded to run at its full operating energy of 7 TeV per proton or 14 TeV collision energy. It had been at 3.5 to 4 TeV per proton for its initial run.

It should restart in 2015.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#518  Postby CdesignProponentsist » Feb 16, 2013 1:14 am

trubble76 wrote:
Aca wrote:http://www.independent.co.uk/news/uk/crime/dirty-bomb-terror-threat-breakthrough-british-scientists-build-machine-to-detect-smuggling-of-nuclear-materials-8273751.html



British scientists have created a machine that can detect terrorist attempts to smuggle nuclear material through ports and airports - even if it has been shielded from giving off radiation.

The Independent understands that prototypes of the machine - developed using a technique first established by experiments using the Large Hadron Collider - have already been tested by researchers at Britain's Atomic Weapons Establishment.


God, those Brits are clever. Sexy too, vewy vewy sexy.

:shifty:


Not sensing any bias here at all. Moving on.
"Things don't need to be true, as long as they are believed" - Alexander Nix, CEO Cambridge Analytica
User avatar
CdesignProponentsist
 
Posts: 12331
Age: 52
Male

Country: California
United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#519  Postby lpetrich » Feb 16, 2013 12:46 pm

The link: Dirty bomb terror threat breakthrough: British scientists build machine to detect smuggling of nuclear materials - Crime - UK - The Independent

From the looks of it, it makes muons, which are a flavor of electron about 207 times more massive than familiar electrons.

I'm guessing that it works by accelerating electrons at a target, where colliding electrons make muons by pair production. Other products are then filtered out with shielding and/or magnetic fields, and the muons continue to what they will be probing.

I can't tell from the description how it will work. Will the muons simply scatter off the electric fields of the nuclei like some glorified Rutherford experiment? Or will the muons cause some spallation on the nuclei themselves? Spallation could produce gamma rays from decaying nuclei, and also neutrons, both of which are relatively penetrating.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Re: Large Hadron Collider (LHC) News

#520  Postby lpetrich » Mar 08, 2013 9:50 am

Higgs-particle news!

Quantum Diaries - Latest news on the Higgs boson
Quantum Diaries - The Standard Model passes with flying colors
Moriond Higgs Update | viXra log
So far, the putative Higgs particle behaves much like the Standard-Model one. Its interactions are less than a factor of 2 from Standard-Model predictions, and it most likely has spin 0.

HiggsPublicResults < AtlasPublic < TWiki - scroll down to " Animations". There are 4 animated GIFs of graphs that show how the Higgs-particle bump emerged as the ATLAS detector collected more data.

To get to the source, you can check out Rencontres de Moriond EW 2013 (02-09 March 2013) It has collections of slides presented at that conference as PDF's. It may warn about an untrusted security certificate; you can go ahead anyway.
lpetrich
 
Posts: 712
Age: 58
Male

United States (us)
Print view this post

Previous

Return to Physics

Who is online

Users viewing this topic: No registered users and 1 guest