264 research outputs found
Development of axion haloscopes for high-mass search at CAPP
No full textThe axion offers a well-motivated solution to two fundamental questions in modern physics: the strong CP problem and the dark matter mystery. Cavity haloscopes, exploiting resonant enhancement of photon signals, provide the most sensitive searches for axion dark matter in the microwave region. However, current experimental sensitivities are limited to the (Formula presented.) eV range, while recent theoretical predictions for the axion mass favor up to (Formula presented.) eV, suggesting the need of new experimental approaches that are suitable for higher mass regions. CAPP has developed/proposed several haloscopes effective for high-mass axion searches based on new cavity concepts and practical tuning mechanisms. They are characterized by large detection volumes and/or high quality factors at high frequencies, achieved by partitioning a single cavity into multiple cells, exploiting higher-order resonant modes, and constructing dielectric photonic crystal structures. Improving on the dish antenna haloscope scheme, a horn antenna array has also been proposed for volume-efficient broadband search in the THz region. We review these haloscope designs for sensitive search in the high-mass regions and discuss their impacts on future experiments. Copyright © 2024 Youn, Jeong and Semertzidis.11Ysciescopu
Storage ring proton EDM experiment
No full textI will give a overview of the present status of the electric dipole moment (EDM) experiments and then I will focus on the proton EDM method to be performed in an all-electric storage ring. In storage rings one has the chance to probe the EDM of the proton with unprecedented
sensitivity of 10^-29 e-cm.
The strength of the method originates from the fact that there are high intensity polarized proton beams available and the fact that the so-called geometric phase systematic error background cancels with clock-wise and counter-clock-wise storage possible in electric rings. The ultimate sensitivity of the method is 10^-30 e-cm. At this level it will either detect a non-zero EDM or it will eliminate electro-weak baryogenesis.</p
Axionic dark matter signatures in various halo models
No full textIn the present work we study possible signatures in the Axion Dark Matter searches. We focus on the dependence of the expected width in resonant cavities for various popular halo models, leading to standard velocity distributions, e.g. Maxwell–Boltzmann, as well as phase-mixed and non-virialized axionic dark matter (flows, caustic rings). We study, in particular, the time dependence of the resonance width (modulation) arising from such models. We find that the difference between the maximum (in June) and the minimum (in December) can vary by about 10% in the case of standard halos. In the case of mixed phase halos the variation is a bit bigger and for caustic rings the maximum is expected to occur a bit later. Experimentally such a modulation is observable with present technology
Electric dipole moments of fundamental particles
No full textElectric dipole moments (EDM) are at the fore-front of search for physics beyond the standard model. The next generation searches promise to improve by several orders of magnitude the current EDM sensitivity levels
The MECO experiment at BNL
No full textThe physics potential of the MECO experiment as well as the experimental method with some emphasis on extinction are described
Modulation, asymmetry and the diurnal variation in axionic dark matter searches
No full textIn the present work we study possible time dependent effects in Axion Dark Matter searches employing resonant cavities. We find that the width of the resonance, which depends on the axion mean square velocity in the local frame, will show an annual variation due to the motion of the Earth around the sun (modulation). Furthermore, if the experiments become directional, employing suitable resonant cavities, one expects large asymmetries in the observed widths relative to the sun’s direction of motion. Due to the rotation of the Earth around its axis, these asymmetries will manifest themselves as a diurnal variation in the observed width.
©2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license1111sciescopu
Spin and beam dynamics in the muon (g - 2) experiments
No full textA number of recent advances in the Physics of the Muon (g - 2) experiments are described outlining the expectations of future improvements of the statistical and systematic errors of the technique. A comparison between the spin and beam dynamics of the two muon (g - 2) experiments under preparation at FNAL and at J-PARC shows that they are both well under control. It may be possible to use magnetic focusing for the FNAL experiment, especially if a decision is made to run with negative muons. Finally, a polarized proton beam could be used to measure the B-field in case of magnetic focusing. © 2016 The Physical Society of Japan101sciescopu
Compton Back Scattering Polarimetry for Storage Ring Electron EDM Experiment
No full textIn this study, we present the result of feasibility study on the Compton polarimeter as a candidate for storage ring electron EDM experiment. The cross sections and analyzing powers of the scattered photons are calculated for both longitudinal and transverse electron polarizations. The optimum photon energy is calculated to be 8.9 keV for electrons with momentum of 15 MeV/c. The polarimeter figure of merit is calculated and compared with p-C interaction case
Analytical estimations of the chromaticity and corrections to the spin precession frequency in weak focusing magnetic storage rings
No full textUnderstanding beam and spin dynamics are fundamental in accelerator-based experiments concerning polarized beams. And there has been growing interest in having more precise estimations of the beam and spin dynamics variables, as more high precision particle physics experiments in the intensity frontier appear. This paper provides analytical estimations of some of the important variables such as beam transverse chromaticities and corrections to the spin precession frequency in the simplest type of particle accelerator: a circular magnetic storage ring with weak vertical focusing. We attempt to precisely obtain the next order approximations from the small betatron oscillations or the momentum dispersion, verified by high precision spin tracking simulation. We also discuss a potential way to suppress the corrections to the spin precession frequency, which relevant experiments may find beneficial.11Nsciescopu
Hybrid ring design in the storage-ring proton electric dipole moment experiment
No full textA new, hybrid design is proposed to eliminate the main systematic errors in the frozen spin, storage ring measurement of the proton electric dipole moment. In this design, electric bending plates steer the particles, and magnetic focusing replaces electric. The magnetic focusing should permit simultaneous clockwise and counterclockwise storage to cancel systematic errors related to the out-of-plane dipole electric field. Errors related to the quadrupole electric fields can be eliminated by successive runs of magnetic focusing with different strengths
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