The LHC Has Detected The Higgs Boson Again, This Time With a Massive Twist
Physicists working at the Large Hadron Collider have made a major new detection of the famous Higgs boson, this time catching details on a rare interaction with one of the heaviest fundamental particles known to physics – the top quark.
more…
Tau.Neutrino said:
The LHC Has Detected The Higgs Boson Again, This Time With a Massive TwistPhysicists working at the Large Hadron Collider have made a major new detection of the famous Higgs boson, this time catching details on a rare interaction with one of the heaviest fundamental particles known to physics – the top quark.
more…
> The top quark is heavy so has a strong interaction with the Higgs field. Catching this interaction requires having hints of a Higgs boson appearing together with a top quark in something called a ttH production. This is easier said than done. Neither particle exists long enough to be seen directly, and only 1 percent of Higgs bosons produced by the energies of the LHC appear alongside a top quark.
Nice work.
> Physicists needed to trawl through the data from two different collider experiments in search of signature combinations. The CMS and ATLAS Collaborations.
The two experimental teams are working together! That’s a more mind-blowing result than finding an interaction between the Higgs and Top. (TIC). But why did they have to work together on this one? The observations were done by CMS alone according to the abstract.
The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and 35.9 fb^-1 respectively. The data were collected with the CMS detector at the CERN LHC. An excess of events is observed, with a significance of 5.2 standard deviations, over the expectation from the background-only hypothesis. The resulting signal strength fits the standard model.
Full paper https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.120.231801
Tau.Neutrino said:
The LHC Has Detected The Higgs Boson Again, This Time With a Massive TwistPhysicists working at the Large Hadron Collider have made a major new detection of the famous Higgs boson, this time catching details on a rare interaction with one of the heaviest fundamental particles known to physics – the top quark.
more…
Sign of the times.
The list of authors takes up 11 and a half pages.
References a further page and a bit.
Full article including abstract is only 4 and a half pages.
mollwollfumble said:
Tau.Neutrino said:
The LHC Has Detected The Higgs Boson Again, This Time With a Massive TwistPhysicists working at the Large Hadron Collider have made a major new detection of the famous Higgs boson, this time catching details on a rare interaction with one of the heaviest fundamental particles known to physics – the top quark.
more…
Sign of the times.
The list of authors takes up 11 and a half pages.
References a further page and a bit.
Full article including abstract is only 4 and a half pages.
But that’s less than 1/2 a page of references per author.
Someone’s not pulling their weight I’d say.
In other news from CERN at the LHC. A record for the most powerful magnet.
The FRESCA2 magnet has set a new record of 14.6 teslas.
FRESCA2 magnet, a superconducting dipole magnet 1.5 metres long, 1 metre in diameter and with an aperture of 10 centimetres. FRESCA2 has recently reached a magnetic field of 14.6 teslas, a record for a magnet with a “free” aperture. To put this in context, the LHC magnets generate fields of 8.34 teslas in the centre of a 5-cm aperture.
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Formed by the superconducting niobium-tin compound and cooled to 1.9 kelvin. It which will serve as a test station for the superconductors of the future. FRESCA2 is indeed intended to test new superconducting cables in real situation, i.e. in an high magnetic field. Its free aperture provides a space in the centre of the magnet to accommodate samples of cables.
CERN and its partners are working on the development of magnets that could generate fields of 16 Tesla and beyond, as part of the Future Circular Collider study. To achieve this, the performance of the niobium-tin superconducting cables, which are already used for the new High Luminosity LHC magnets, must be increased. Coils formed of high-temperature superconductors are also under study.
Magnets from high temperature superconductors at CERN, That’s interesting. Picture of coils of high temperature superconducting magnets illustrated below. This is based on rare-earth barium-copper oxide (ReBCO). Not only can high temperature conductors retain superconducting behaviour up to around 100 Kelvin, but they can also bear a magnetic field much higher than 20 Tesla.
This is what the coil of a niobium-tin superconducting magnet looks like.
luminosities of up to 5.1, 19.7, and 35.9 fb^-1
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A barn (symbol: b) is a unit of area equal to 10 −28 m 2 .
.. needed a secretive unit to describe the approximate cross sectional area presented by the typical nucleus and decided on “barn.” This was particularly applicable because they considered this a large target for particle accelerators that needed to have direct strikes on nuclei and the American idiom “couldn’t hit the broad side of a barn” refers to someone whose aim is terrible. Initially they hoped the name would obscure any reference to the study of nuclear structure; eventually, the word became a standard unit in nuclear and particle physics.
Other related units are the outhouse and the shed.
Ian said:
luminosities of up to 5.1, 19.7, and 35.9 fb^-1—
A barn (symbol: b) is a unit of area equal to 10 −28 m 2 .
.. needed a secretive unit to describe the approximate cross sectional area presented by the typical nucleus and decided on “barn.” This was particularly applicable because they considered this a large target for particle accelerators that needed to have direct strikes on nuclei and the American idiom “couldn’t hit the broad side of a barn” refers to someone whose aim is terrible. Initially they hoped the name would obscure any reference to the study of nuclear structure; eventually, the word became a standard unit in nuclear and particle physics.
Other related units are the outhouse and the shed.
The LHC is off to a good start this year. This is the total integrated luminosity at Atlas and from CMS in fb^-1 each year. This year it’s way above the values for previous years at this time of year.
… and peak luminosity per day. Better this year than ever before.
