The Standard Model

Results of direct searches for neutral, supersymmetric Higgs bosons at the LEP, in the case of maximum CP symmetry violation in the Higgs sector. The area of tested parameters is shown according to the mass of the lightest neutral boson, mH1, and tan(beta), parameter of the model.

Experiments using accelerators at the highest accessible energy can be used to perform precise tests on the Standard Model. At CERN, the LEP has obtained many results leading to more precise knowledge in this field. The degree of precision attained in measuring the mass of the W boson has been exploited to obtain an indirect upper bound for the mass of the Higgs boson through quantum corrections. The Tevatron accelerator at Fermilab (near Chicago) has yielded results on the physics and mass of the top quark. The HERA collider at the DESY research centre in Hamburg has obtained more precise measurements of inclusive cross sections, related to parton (i.e. quark and gluon) densities in the proton, offering vital physics data for the LHC. All these experiments have also included an extensive search for possible deviations from the Standard Model.


Last update : 10/18 2005 (598)


Union autour du boson de Higgs
Les collaborations ATLAS et CMS ont présenté pour la première fois leur mesure combinée de la masse du boson de Higgs, parvenant à une mesure précise à 0,2% près. Présentée lors de la 50e  édition des ... More »
Mass of the Higgs Boson: new limits of the Tevatron
The CDF and D0 experiments announce their new results in the search for the Higgs Boson
Physicist working on the CDF and D0 experiments using Fermilab's Tevatron accelerator in Chicago, including scientists from IN2P3/CNRS and IRFU/CEA, announced their latest results on 26 July at the International Conference on High-Energy Physics (ICHEP 2010) in Paris. Their measurement further ... More »
The DZero Physicists at Fermilab measure a significant asymmetry between matter and antimatter
The D0 experiment at the Tevatron accelerator at Fermilab (Chicago), in which physicists from CEA/IRFU and CNRS/IN2P3 are involved, has measured a significant matter-antimatter _asymmetry_ in the behaviour of particles containing b quarks, known as B mesons (or beauty mesons) beyond ... More »
Higgs Boson and supersymmetry: the Tevatron has nearly nailed it
Since researchers have been confronting the standard model of particle physics with experimentation, nothing has been able to shake it. Of all particles it describes, only the Higgs Boson has not yet been discovered. But the standard model is probably not the ultimate theory: it does not cover ... More »
Measurement of the mass of the top quark: the Tevatron on all fronts.
    Until the advent of the LHC, the Tevatron at the Fermi National Accelerator Laboratory, Fermilab (close to Chicago, USA), will remain the world's most powerful collider and the only location where the top1 quark can be produced. The DØ experiment recently published2 ... More »
BaBar discovers eta-sub-b
The ground state of bottomonium.
  η b is the name of the particle recently discovered by the physicists working on the BaBar experiment.This ground state of ‘bottomonium’, a collection of particles formed from a bottom quark and an anti-bottom quark, has been sought for over thirty years. It has now been ... More »
Joint CDF, DZero effort lands Fermilab in Higgs territory
Scientists from the CDF and DZero collaborations at the U.S. Department of Energy's Fermilab have combined Tevatron data from the two experiments to advance the quest for the long-sought Higgs boson. They have presented their results on August 3rd at the International Conference on High Energy ... More »
Tests and extensions of the Standard Model (SPP)
This program covers the experiments at accelerators with the top beam energy in the world. At Cern close to Geneva , the LEP was a large electron-positron collider, in operation from 1989 to 2000. It allowed a very detailed exploration of the Standard Model, with outstanding results, such as the ... More »




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