Because of the strong beam-beam force at the interaction points in FCC-ee, the charge balance of two beams opposing each other is vitally important.
The injection of a high charge beam derives the imbalance of two beams, which causes the instability of the beams.
To avoid this imbalance, the bootstrapping injection has been adopted for the FCC-ee collider.
The conditioning of the...
The Geneva Basin consists of a variety of geological formations, including Mesozoic limestone, Cenozoic Molasse, and Quaternary moraines. A 3D ground model has been developed using existing geological data; however, significant uncertainties remain in several areas along the proposed FCC tunnel alignment due to the limited extent of previous site investigations.
This poster summarises...
The accelerator at the FACET-II National User Facility at SLAC National Accelerator Laboratory can test several elements of the design of the FCC-ee injector. To support the design of the injector we propose three experiments: measurement of emittance growth as a function of compression at high charge, characterization of jitter amplification of high-charge beams in s-band linacs at 25 ns...
The high-energy linac of the Future Circular Collider electron-positron (FCC-ee) injector complex requires high-performance RF accelerating structures to efficiently accelerate beams up to 20 GeV while ensuring operational stability. This study presents an analytical approach to the RF design of traveling-wave structures, incorporating a pulse compression system to enhance power efficiency and...
The electron-positron Future Circular Collider (FCC-ee) has challenging requirements for beam instrumentation, including the need for thousands of high-resolution beam position monitors (BPMs) presenting low impedance to the circulating beam. This poster details the requirements for the FCC-ee arc BPMs and presents the simulation results of BPM button pickups with various geometries, modelled...
Environmentally friendly detector refrigeration solutions for the FCC, inspired by ongoing LHC detector refrigeration research
In order to guarantee the foreseen lifetime operation of the FCC and its related experiments, environmental impact and machine performance are key elements to be considered, at a technical efficiency level as well as a global political level. New governmental...
At the LHC experiments, a variety of gas mixtures are used to operate different gaseous detectors. Some of these gases (C2H2F4, C4F10, CF4, SF6) are powerful Greenhouse Gases (GHGs) with a high Global Warming Potential (GWP). This raises the need for optimizing the GHG consumption, for which the gas team (EP-DT-FS) identified three key strategies. First, gas consumption is reduced through gas...
We study the potential of the FCCโ$ee$ to perform time-dependent $CP$ violation measurements in rare decays $B_s^0 \to \phi(\to K^+K^-)\mu^+\mu^-$ at the $Z$-pole, where large statistics can be achieved. These decays serve as sensitive probes for physics beyond the Standard Model (SM). In the SM, $CP$ violation enters only through loop processes and is therefore highly suppressed, so any...
Abstract
The FCC-ee at โs = 365 GeV provides a better environment to study Higgs boson production with high precision. This study focuses on single Higgs production via vector-boson fusion (VBF) and associated production (ZH), followed by its ฮ โ WW โ 2 l + MET decay. Using MadGraph5, event generation was performed for eโบ eโป โ ฮฝl ฮฝl~ H and eโบ eโป โ Z H. Parton-level events...
The LHC constitutes the first and currently only opportunity to perform precision measurements of $\Lambda_b^0$ baryons. These measurements provide useful information on flavour physics which complements the meson sector. Baryons stemming from the strong production mechanism at the LHC are unpolarized. At the FCC-ee however, the baryons are produced in the decay of $Z^0$-bosons which can lead...
The FCC holds a great opportunity for the discovery of dark matter. By achieving energy scales and collision frequencies surpassing the LHC, the FCC is expected to open new avenues for exploring candidate dark matter particles. The composite dark matter models are possible candidates for dark matter in the FCC. We focus our research on the composite dark matter models based on QCD-like...
Several key observables of the high-precision physics program at FCC-ee will critically depend on the knowledge of the absolute machine luminosity. The determination of the luminosity relies on the precise knowledge of some reference process, which is in principle not affected by unknown physics, so that its cross section can be computed within a well-established theory, like the Standard...
The efficacy of superconducting radio-frequency cavities in particle accelerators is predicated upon the quality of thin niobium films deposited onto complex copper substrates. Conventional direct-current magnetron sputtering (DCMS) often yields sub-optimal, porous columnar morphologies on intricate 3D geometries due to line-of-sight limitations. High-power impulse magnetron sputtering...
The top quark mass plays a fundamental role in verifying the stability of the Higgs vacuum. A more precise measurement allows us to determine whether the Universe is in a stable state or if it is destined, in the distant future, to decay. For this reason, high-precision measurements of the top quark mass are central to the scientific programs of present and future colliders. One of the primary...
The hadron collider phase of the Future Circular Collider (FCC-hh) is a proton-proton collider operating at a center-of-mass energy of 80-100 TeV. It is one of the most ambitious projects planned for the rest of this century and offers ample opportunities in the hunt for new physics, both through its direct detection reach as well as through indirect evidence from precision measurements.
This...
We investigate the non-standard ฮฝยฏฮฝ ฮณฮณ couplings parameterized by dimension-seven operators through the process e^+ e^-โฮฝยฏฮฝ ฮณ at the FCC-ee. A comprehensive Monte Carlo simulation is performed, where signal and relevant background events are generated within the MadGraph framework, incorporating the non-standard ฮฝยฏฮฝ ฮณฮณ interactions. Subsequent parton showering and hadronization are performed...
The associated production of a Higgs boson with a Z boson decaying into leptons and the Higgs boson mostly decays to b b~ pair can be measured in the high transverse momentum regime of dileptons, ranging 50 - 70 GeV, with the IDEA detector. The recoil mass distributions from the signal (HZ, Z-> l+ l-) and the backgrounds (mainly ZZ, WW and other backgrounds) have been analyzed using the...
We present an overview and update for the {\tt KKMCee 5.00.2} Monte Carlo event generator for lepton and quark pair production in high-energy electron-positron annihilation processes. We note that it is still the most sophisticated event generator for such processes. Its entire source code is rewritten in the modern C++ language and it reproduces all features of the older KKMC code in Fortran...
Calorimeters based on liquified noble gases have demonstrated excellent performance over the past decades in various particle physics experiments, offering good energy resolution, linearity, uniformity, and stability. To achieve the goals of FCCโs ambitious physics programme, future detector technologies must meet stringent performance requirements.
As part of an extensive R&D programme,...
The iron-based superconductor $\mathrm{Ba}_{1-x}\mathrm{K}_x\mathrm{Fe}_2\mathrm{As}_2$ (Ba122), with a critical temperature around 38 K and a very high upper critical field (Hc2), is a promising candidate for high-field magnet applications, including those envisioned in future particle accelerator technologies. In this context, CNR-SPIN and CERN have initiated a joint collaborationโwithin the...
To achieve the desired experimental outcomes at the FCC-ee, precise control of linear and non-linear optics is essential. Amplitude dependent tune shifts, higher order chromaticity and resonant driving terms (RDTs) are examples of non-linear optics parameters which must be understood and controlled. Two key figures of merit for the collider ring are the dynamic aperture (DA) and momentum...
Measuring the Yukawa couplings of the Higgs boson remains one of the most critical and unresolved tasks since its discovery. The FCC-ee, with its extremely high integrated luminosity, provides a rare chance to probe the electron Yukawa coupling via s-channel Higgs production at a centre-of-mass energy of 125โฏGeVโon the condition that the energy spread can be reduced from 50โฏMeV to match the...
Collider rings all around the world need to have several sensors all around the ring to operate. One kind of these sensors is the Beam Position Monitors (BPMs), that allows operators to measure if the beam travelling in their apparatus is well centered in the different magnets.
One specific category of BPMs, standing out by its very high aquisition rate, is called the Turn-by-turn BPMs...
The Future Circular lepton Collider (FCC-ee) is a proposed e+eโ collider covering a beam energy range from 45.6 GeV to 182.5 GeV. In Z-mode operation, it will achieve the highest luminosity ever reached by any lepton collider, with a stored beam energy of up to 18 MJ. Due to synchrotron radiation damping, the vertical beam size will shrink to a few tens of micrometers, resulting in a maximum...
The FCC-ee arc half-cell mock-up project team is currently developing a Short Straight Section demonstrator, combining experimental measurements and simulations to evaluate the vibrational budget of various elements including the feet, the support, the magnets, etc. The results of this study have shown that vibrations will have a non-negligible effect on the stability of the magnet's magnetic...
Although the stored beam energy in the FCC-ee will be lower than in the LHC, the extremely small vertical beam size leads to a high energy density. This poses a risk of damaging accelerator components, making machine protection essential. A Beam Loss Monitoring (BLM) system capable of quickly detecting and localizing beam losses is therefore needed to protect the machine by triggering the beam...
Various magnetic septa devices and topologies are foreseen in the FCC-ee complex, from the injector to the collider. While some of the proposed topologies, such as direct-drive septa, are well known and mastered, others require in-depth consideration of their design. The Lambertson half-vacuum topology, designed to reduce the area exposed to vacuum, or the low-power topology, which...
The identification of jets initiated by a strange quark and discriminating them against jets initiated by other flavours of partons is a crucial piece of measuring the Higgs Yukawa coupling to strange quarks. While ML-based taggers have been trained on simulation to provide such simulation, its unclear which features of the simulation they are using in their discrimination and how this might...
The design of the FCC-ee positron source based on the conversion of bremsstrahlung photons into e-/e+ pairs in the tungsten target has been carried out and integrated into the FCC Feasibility Study report. An alternative scheme exploiting lattice coherent effects in oriented crystals has been proposed. This contribution presents the conceptual design of this approach and preliminary results...
Beam profile diagnostics will play a crucial role in the commissioning and efficient operation of the electronโpositron Future Circular Collider (FCC-ee). Non-invasive techniques are essential to avoid beam perturbations during regular physics operations. As is customary in high-energy lepton colliders, transverse diagnostics at FCC-ee will primarily rely on synchrotron radiation. Given the...
The FCC-ee is a collider, proposed after the LHC era, based on a ring of approximately 90 km of circumference. It will have to be able to accommodate beams running at half the z-pole and tt ฬ -pole with vertical Interaction point beam size less than 40 nanometer at the z. In the present studies, coherent ground motions are being explored with particle tracking tools such as MAD-X and analytics...
FCC-ee luminosity optimization relies on measuring realistic signals from Bhabha scattering, beamstrahlung, and radiative Bhabha photons. Initial assessments of beamstrahlung signals examine the change in luminosity, beamstrahlung power and vertex detector hits in response to waist shifts, vertical dispersion and skew coupling at the collision point. These ongoing studies aim to extract...
This study provides an overview of integration and space requirements for fast pulsed kicker magnets, septa and their power converters and controls for the FCC-ee booster and collider injection, extraction and dump systems.
The position of the magnet, septa in the tunnel is defined by the optics, then their technology selection is based on the required pulse parameters; rise time, flat top...
