LHCP 2020
"The 8th LHC Physics Conference took place online on May 25-30. CERN has been issuing a series of media updates highlighting new results presented by the four experiments, which we update here"
The 2020 LHC Physics Conference was scheduled for May 25-30, 2020 in Paris. Due to the Covid-19 crisis, LHCP2020 took place entirely online. Nevertheless, it brought together many people, with the usual enthusiasm and large flow of new results. CERN issued a series of media updates highlighting new results presented at LHCP by the four experiments.
The ALICE, CMS and LHCb collaborations presented new results on particles with heavy quarks: a set of interesting measurements that show how these particles can serve as “messengers” through which physicists can learn more both about hadrons, which make up most of the visible matter in the present-day universe; and about the quark–gluon plasma, in which quarks and gluons are not confined within hadrons, and which is thought to have existed in the early universe and can be recreated in heavy-ion collisions at the LHC. LHCb obtained the most precise yet measurements of two properties of the exotic particle χc1(3872). As for CMS, the CMS-LIP group has been involved in new measurements concerning the B0s meson and shown at the Hard Probes conference, and a more detailed description is given in a dedicated news item here in the LIP website. The observation of the Bs in nuclear collisions and its exploration as a novel probe of the quark gluon plasma are reported. The decay of the particle B0s into the same χc1(3872) particle has been observed for the first time. Read the full CERN news item
On the antimatter front, the ALICE collaboration has presented new results on the production rates of antideuterons based on data collected at the highest collision energy delivered so far at the LHC. The new measurements are important because the presence of antideuterons in space is a promising indirect signature of dark matter candidates. In the future, these studies could be extended to heavier antinuclei. Read the full CERN news item
The ATLAS and CMS collaborations also presented their latest results on new signatures for detecting the Higgs boson at the PHC. These include searches for rare decays of the Higgs into a Z boson and a second particle. Observing and studying transformations that are predicted to be rare helps advance our understanding of particle physics and could also point the way to new physics if observations differ from the predictions. The results also included searches for signs of Higgs transformations into “invisible” particles, which could shine light on potential dark-matter particles. The Higgs boson continues to prove invaluable in helping test the Standard Model and seek physics that may lie beyond. Read the full CERN news item
ATLAS and CMS presented also new results on vector boson scattering: a vector boson is radiated from a quark in each proton and these vector bosons scatter off one another to produce a diboson final state. The observation and measurement of these rare processes is of particular interest, as they test in detail fundamental aspects of the Standard Model such as the electroweak symmetry breaking mechanism in a complementary way to the measurements of Higgs boson production and decay. ATLAS observed at 5.5 sigma ZZ production via this process, and CMS reported strong evidence. CMS reported the first observation of a W boson produced in association with a photon through vector boson scattering, as well as more precise measurements of the same-sign WW production, and an observation of the vector boson scattering production of a WZ pair. This April, CMS released a 5.7 sigma result, following the first evidence seen by ATLAS, of the production of three massive vector bosons. Besides being rare, such processes are extremely mimicked by background processes, making the analyses even more challenging. See the full CERN news item