Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userCharting the European Course to the High-Energy Frontier
69
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We review the capabilities of two projects that have been proposed as the next major European facility, for consideration in the upcoming update of the European Strategy for Particle Physics: CLIC and FCC. We focus on their physics potentials and emphasise the key differences between the linear or circular approaches. We stress the uniqueness of the FCC-ee programme for precision electroweak physics at the $Z$ peak and the $WW$ threshold, as well as its unequalled statistics for Higgs physics and high accuracy for observing possible new phenomena in Higgs and $Z$ decays, whereas CLIC and FCC-ee offer similar capabilities near the $t overline t$ threshold. Whilst CLIC offers the possibility of energy upgrades to 1500 and 3000 GeV, FCC-ee paves the way for FCC-hh. The latter offers unique capabilities for making direct or indirect discoveries in a new energy range, and has the highest sensitivity to the self-couplings of the Higgs boson and any anomalous couplings. We consider the FCC programme to be the best option to maintain Europes place at the high-energy frontier during the coming decades.
rate research
Read More
We respond to points raised in the recent discussion note arXiv:1912.13466, Charting the European course to the high-energy frontier, which compares the CLIC and FCC programmes.
The long-term prospect of building a hadron collider around the circumference of a great circle of the Moon is sketched. A Circular Collider on the Moon (CCM) of $sim$11000 km in circumference could reach a proton-proton center-of-mass collision energy of 14 PeV -- a thousand times higher than the Large Hadron Collider at CERN -- optimistically assuming a dipole magnetic field of 20 T. Siting and construction considerations are presented. Machine parameters, powering, and vacuum needs are explored. An injection scheme is delineated. Other unknowns are set down. Through partnerships between public and private organizations interested in establishing a permanent Moon presence, a CCM could be the (next-to-) next-to-next-generation discovery machine and a natural successor to next-generation machines, such as the proposed Future Circular Collider at CERN or a Super Proton-Proton Collider in China, and other future machines, such as a Collider in the Sea, in the Gulf of Mexico. A CCM would serve as an important stepping stone towards a Planck-scale collider sited in our Solar System.
Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spallation Source currently under construction in Lund, Sweden to deliver, in parallel with the spallation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spallation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few $mu$s with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 $sigma$ significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 $sigma$ if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.
Building upon the PDFSense framework developed in Ref. [1], we perform a comprehensive analysis of the sensitivity of present and future high-energy data to a number of quantities commonly evaluated in lattice gauge theory, with a particular focus on the integrated Mellin moments of nucleon parton distribution functions (PDFs), such as $langle x rangle_{u^+ - d^+}$ and $langle x rangle_{g}$, as well as $x$-dependent quark quasi-distributions -- in particular, that of the isovector combination. Our results demonstrate the potential for lattice calculations and phenomenological quark distributions informed by high-energy experimental data to cooperatively improve the picture of the nucleons collinear structure. This will increasingly be the case as computational resources for lattice calculations further expand, and QCD global analyses continue to grow in sophistication. Our sensitivity analysis suggests that a future lepton-hadron collider would be especially instrumental in providing phenomenological constraints to lattice observables.
The opportunities which are offered by a next generation and multi-purpose fixed-target experiment exploiting the proton and lead LHC beams extracted by a bent crystal are outlined. In particular, such an experiment can greatly complement facilities with lepton beams by unraveling the partonic structure of polarised and unpolarised nucleons and of nuclei, especially at large momentum fractions.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
