(PhysOrg.com) -- Results presented by the LHCb collaboration this evening at the annual Rencontres de Moriond conference, held this year in La Thuile, Italy, have put one of the most stringent limits to date on the current theory of particle physics, the Standard Model. LHCb tests the Standard Model by measuring extremely rare processes, in this case a decay pattern predicted to happen just three times out of every billion decays of a particle known as the Bs (B-sub-s) meson.
Read More »Tag Archives: standard-model
Feed SubscriptionNew measurements of W boson mass point to Higgs mass and test Standard Model
(PhysOrg.com) -- The world’s most precise measurement of the mass of the W boson, one of nature’s elementary particles, has been achieved by scientists from the CDF and DZero collaborations at the Department of Energy’s Fermi National Accelerator Laboratory. The new measurement is an important, independent constraint of the mass of the theorized Higgs boson
Read More »Fermilab results add to confidence in explaining less antimatter amounts
(PhysOrg.com) -- The Standard Model of Physics suggests that shortly after the Big Bang there should have been the same amount of antimatter in existence as there was matter. As time passed, both should have decayed roughly equally, leaving roughly the same amounts of each today.
Read More »Physicists propose search for fourth neutrino
(PhysOrg.com) -- Physicists know that neutrinos (and antineutrinos) come in three flavors: electron, muon, and tau. In several experiments, researchers have detected each of the neutrino flavors and even watched them oscillate back and forth between flavors. But starting in the early 90s, some experiments have also revealed a nagging anomaly: muon antineutrinos oscillate into electron antineutrinos at a 3% higher rate than predicted.
Read More »The Discovery of the Top Quark [From the Archive]
Editor's note: This article was originally published in the September 1997 issue of Scientific American (a PDF version of the original is available for purchase below). We have resurfaced this article to commemorate the end of the Tevatron
Read More »Fermilab experiment discovers a heavy relative of the neutron
(PhysOrg.com) -- Scientists of the CDF collaboration at the Department of Energy's Fermi National Accelerator Laboratory announced the observation of a new particle, the neutral Xi-sub-b (Ξb0). This particle contains three quarks: a strange quark, an up quark and a bottom quark (s-u-b). While its existence was predicted by the Standard Model, the observation of the neutral Xi-sub-b is significant because it strengthens our understanding of how quarks form matter
Read More »Garrett Lisi responds to criticism of his proposed unified theory of physics
This past December Jim Weatherall and I wrote " A Geometric Theory of Everything " for Scientific American , describing progress on unified geometric theories of gravitation and the Standard Model of particle physics. My personal contribution to this progress, a developing model called E8 Theory, was introduced three years ago in a paper titled " An Exceptionally Simple Theory of Everything ." Almost immediately after this paper appeared, physicists and the interested public began a lengthy process of considering and discussing this new theory's merits and faults. Not surprisingly, the initial response was largely critical, with most commenters encountering some unfamiliar mathematical structures in the paper and responding with appropriate skepticism
Read More »U.S. Collider Offers Physicists a Glimpse of a Possible New Particle
Physicists sifting through data generated by the Tevatron particle collider in Illinois have uncovered a signal that neither they nor the long-standing Standard Model of particle physics can explain. [More]
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