Particle physics at accelerators in the United States and Asia

Abstract

Particle physics experiments in the United States and Asia have greatly contributed to the understanding of elementary particles and their interactions. With the recent discovery of the Higgs boson at CERN, interest in the development of next-generation colliders has been rekindled. A linear electron-positron collider in Japan and a circular collider in China have been proposed for precision studies of the Higgs boson. In addition to the Higgs programme, new accelerator-based long-baseline neutrino mega-facilities are being built in the UnitedStates and Japan. Here, we outline the present status of key particle physics programmes at accelerators and future plans in the United States and Asia that largely complement approaches being explored in the European Strategy for Particle Physics Update. We encourage the pursuit of this global approach, reaching beyond regional boundaries for optimized development and operations of major accelerator facilities worldwide, to ensure active and productive future of the field.The discovery [1,2] of the Higgs boson in 2012 completed the Standard Model (SM) of particle physics while also opening a new portal to the unknown. In the years since, the data samples accumulated by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) have grown 25-fold allowing for measurements of a range of properties of the Higgs boson and its couplings to many SM particles to 10-25% precision [3,4]. No evidence of any excursion from SM predictions has been found, but the hopes that the "Higgs portal" can be exploited to search for phenomena beyond the SM persist. The collision energy of the LHC is to be raised to 14 TeV in the next data-taking period scheduled for 2021-2023, aiming to double the data set for a total integrated luminosity of ~300 fb -1 .The high-luminosity upgrade of the LHC will increase the proton-proton collision data sets by an order of magnitude to 3000 fb -1 over the operation period 2027-2037. Most Higgs couplings will then be measurable to a few percent accuracy [5], allowing either discovery of deviations from SM predictions, -potentially evidence for new physics -or further show the SM to be accurate to an astonishing precision.The Higgs discovery has renewed interest worldwide in the development of next generation colliders. Due to the Higgs mass of 125 GeV, several proposals for an electron-positron Higgs Factory have been put forth: the 250 GeV International Linear Collider (ILC) [6][7][8] in Japan, the 380 GeV Compact Linear Collider (CLIC) [9] based on a novel two-beam acceleration technique at CERN, the Future Circular Collider [10] (FCC-ee) at CERN, and the Circular Electron-Positron Collider (CEPC) [11] in China. Both FCC-ee and CEPC are proposed to be followed by a proton-proton collider. Such an electron-positron machine is expected to provide exquisitely precise measurements of the Higgs boson couplings, in search of deviations from the SM. At higher energies, direct measurements of the Higgs self-coupling, essential to unravel the details of electrowe...

Future Collider Options for the US

“…After the remarkable discovery of the Higgs boson at the LHC in 2012, a global consensus for an e + e − Higgs factory as the next collider developed. The proposal for consideration of hosting the International Linear Collider (ILC) [1,2] in Japan has now been on the table for a decade [3]. While the international community has been studying the SRF-based ILC for decades, and significant progress has been made in accelerator technology, a decision on hosting the ILC in Japan still seems distant.…”

“…A phased Muon Collider project starting with a demonstrator and necessary R&D, followed by 125 GeV, 600 GeV, and later upgrades to a multi-TeV muon collider occurring in two stages (2)(3) TeV and then 8-10 TeV) is possible on the Fermilab site. The scenario is cost-efficient and has a high potential for physics at each stage.…”

A New Physics Theory About the Kinetic Force Mechanism of Energy Flow

“…At present, the study of physics has been very advanced, which is embodied in the perfect description of physical laws and the development of advanced technologies Bhat and Taylor (2020), Callahan (2000), Hey and Walters (2009), Lederman (1989), , . However, some physical problems are perfect in description by classical laws but are difficult to essentially explain with basic mechanisms.…”