Funds from this grant support an effort by Professor Eric Hessels at York University, Professor Amar Vutha at the University of Toronto, and Assistant Professor Jaideep Singh at Michigan State University to build advanced instrumentation capable of detecting new fundamental particles through precision measurement of the distortions these particles cause to the distribution of electric charge in an electron.К Hessels, Vutha, and SinghХs primary detection strategy is to trap barium fluoride molecules in a matrix of solid argon. Once held, the electrons in these trapped molecules can be measured for distortions in the distribution of their electric charge. This methodology has several significant theoretical benefits over competing methods. First, holding molecules still, as a solid matrix would, allows the molecules to be measured for thousands of times longer than using molecules in motion. Second, molecules can be very densely packed in a solid matrixСthe York University team will aim to trap a few billionСthereby increasing the number of detection measurements that can be made per unit of space. The method faces obstacles as there is uncertainty about whether a precision measurement can be performed on molecules embedded in a solid matrix. Phonon vibrations of the solid or other effects could make precision measurement of the trapped molecules impractical. The York team will implant the barium fluoride molecules into a solid argon matrix while it is being grown, and then perform spectroscopic measurements on the embedded molecules to see if a precision measurement is practical. In situdiagnostics will probe the growth and implantation process and different growth and annealing schedules will be followed to optimize the platform. If successful, the method could improve our detection capabilities by a factor of 200. The project will lead to six papers, talks and posters at relevant conferences, and training for 30 students and postdoctoral researchers over the project's three-year arc.

Funds from this grant support efforts by researchers led by Professor Michael Tarbutt and Professor Edward Hinds, both at Imperial College London, to build advanced instrumentation capable of detecting new fundamental particles through precision measurement of the distortions these particles cause to the distribution of electric charge in an electron.К Tarbutt and HindsХs primary detection strategy is to use intersecting lasers to create an electromagnetic ТlatticeУ that holds diatomic molecules at a fixed point in space. The held molecules can then be measured for perturbations in their electrical charge. The approach, called optical trapping, has significant theoretical advantages over other methods. First, optical traps can hold neutral molecules and neutral molecules can be packed very denselyСcharged particles disrupt one another when they are too close togetherСallowing for more measurements to be made per unit of space. Second, holding molecules still, as optical trapping does, allows the molecules to be measured for thousands of times longer than efforts using molecules in motion. The technical challenge is that only very cold molecules can be caught in an optical trap. Tarbutt and HindsХs primary activities over the grant period will be to see if ytterbium fluoride (YbF) molecules can be cooled to the microkelvin temperatures needed to make them candidates for optical trapping. They plan to bring YbF molecules into collision with a super-cold cryogenic buffer gas, which will cool the molecules sufficiently to allow laser-based techniques to take over and cool the molecules to the appropriate temperature. If successful, this would put the team in position to improve existing detection methods by a factor of 1,000, representing a significant leap in detection technology. The project will produce several papers on laser slowing and cooling of an EDM relevant molecule, as well as training for two postdoctoral and two graduate students.

Funds from this grant support ACME III, the third-generation Advanced Cold Molecule Electron electric dipole moment (EDM) search. ACME III is a Yale-Harvard-Northwestern collaboration to build advanced instrumentation capable of detecting new fundamental particles through precision measurement of the distortions these particles cause to the distribution of electric charge in an electron.К Led by Professor David DeMille at Yale, Professor John Doyle at Harvard, and Professor Gerald Gabrielse at Northwestern, the ACME team will attempt to measure the electrical charge of electrons present in a dense beam of thorium oxide molecules, made super-cold by colliding the molecules with a cryogenic buffer gas. The technique proved successful in the first and second iterations of the ACME experiment, and phase III looks to build on this record of success. ACME III will increase both the number of molecules measured and the duration of each measurement, boosting the overall sensitivity of the experiment, compared to ACME II, by a factor of 30. The project will produce high-profile publications, talks, and posters at major conferences, training for two postdoctoral and six Ph.D. students each year, and at least four Ph.Ds. during the grant period.

This grant supports theoretical work in particle physics by Professor Matthew Reece of Harvard University. Dr. ReeceХs funded work will focus on better understanding the theoretical implications of the detection or nondetection of small asymmetries in the distribution of electrical charge in an electron. Distortions in the distribution of the electrical charge of an electron can be caused by the presence of fundamental particles, with the magnitude of the distortion inversely proportional to the mass of the intruding particle. The larger the particleХs mass, the smaller the distortion it causes. Theory tells us, however, that this only holds for particles that participate in so-called CP-violating interactions. Electron measurement experiments therefore do not put significant limits on these types of particles and it is important to understand which kinds of possible particles fall into this category, that is, to know which kinds of particles electron measurement experiments constrain. Professor ReeceХs research will categorize the types of particles and interactions that weakly violate CP-symmetry and therefore that could explain a tiny but nonzero distortion of an electronХs electrical charge. This will, in turn, provide help in interpreting the results of the experiments that aim to detect new particles through measuring the charge of electrons.К

Funds from this grant support an effort by Assistant Professor Nicholas Hutzler at Caltech and Professor John Doyle at Harvard to build advanced instrumentation capable of detecting new fundamental particles through precision measurement of the distortions these particles cause to the distribution of electric charge in an electron.К Hutzler and DoyleХs primary detection strategy is to use intersecting lasers to create an electromagnetic ТlatticeУ that holds polyatomic molecules at a fixed point in space. The held molecules can then be measured for perturbations in their electrical charge. The approach has significant theoretical advantages over other methods. First, optical traps can hold neutral molecules and neutral molecules can be packed very denselyСcharged particles disrupt one another when they are too close togetherСallowing for more measurements to be made per unit of space. Second, holding molecules still, as optical trapping does, allows the molecules to be measured for thousands of times longer than efforts using molecules in motion. While other experiments of this type aspire to laser-cool diatomic molecules, diatomic molecules have limits. They donХt offer the same powerful suppression of experimental noise as the molecules used in the leading experiments of this field. Polyatomic molecules should, however, and this experiment proposes using laser-cooled polyatomic molecules as an experimental platform with strong noise suppression and ultralow temperature via laser cooling. Both effects contribute to the promise of an ultraprecise measurement. The project will produce high-profile publications, talks, and posters at major conferences, and training for two postdoctoral and six Ph.D. students each year.

Funds from this grant support the third iteration of an effort by researchers at JILA/University of Colorado, Boulder to build advanced instrumentation capable of detecting new fundamental particles through precision measurement of the distortions these particles cause to the distribution of electric charge in an electron.К A team led by JILA Fellows Eric Cornell and Jun Ye will attempt to use laboratory-generated electric fields to trap and hold molecular ions, which can then be measured to detect deformations in their electrical charge. Held still, ions can be monitored for thousands of times longer than if they were in motion, thereby increasing the probability of a successful detection of a charge-distorting particle. Cornell and YeХs third-generation experiment will seek to improve on their prior efforts in several ways. First, they will switch from hafnium fluoride (HfF+) to thorium fluoride ions (ThF+) as the primary ion used for detection. This will result in greater sensitivity, as thorium is known to be more sensitive to the sorts of electrical distortions the group is attempting to measure. Second, Cornell and Ye will redesign their experimental apparatus to boost the number of ions that can be measured at one time from a few thousand to a few hundred thousand. Taken together, the improvements are expected to increase the sensitivity of their experiments by a factor of 10. This project will produce high-profile publications, talks at major conferences, public lectures, and training for six Ph.D. students.

This grant to the National Academy of Sciences (NAS) supports the research, production, and dissemination of a consensus study, Understanding the Aging Workforce and Employment at Older Ages. Conducted by the National AcademiesХ Committee on Population (CPOP) in collaboration with the Committee on National Statistics (CNSTAT) in the Division of Behavioral and Social Sciences and Education, the NAS will convene a multidisciplinary committee of nine experts from economics, sociology, demography, organizational psychology, and statistics/methodology, who will meet over the course of four meetings and 18 months to produce their final consensus report. The committee will review and assess the existing research and data on the labor market activities of older workers, including individual-level human capital and demographic characteristics associated with decisions to continue working at older agesСwork history, occupation, cognitive abilities, financial literacy, and financial resourcesСas well as the social and structural factors that inhibit or enable employment, such as economic insecurity, family structure, workplace and personnel practices, policy levers, and available opportunities for self-employment. The report will then lay out conclusions and recommendations for future work by researchers, policymakers, and funding organizations and will be disseminated to key stakeholders, including relevant federal funding agencies, Congressional staff, academic researchers, and media.