My picture should be here...

Daniel M. Kaplan, Professor Emeritus

Mailing Address: Physics Department
3101 South Dearborn St.
Chicago, IL 60616
Office Address: Tech South, room 1A8-1
3424 S. State St.
Chicago, IL 60616
Phone: 312.567.3389
Fax: 312.567.3494
Other URL: My "official" web page

Fermilab Muonium R&D Workshop (July 14, 2022)

Some background documents (more are on the workshop Indico page):

  • D. M. Kaplan et al., Snowmass2021 LoI SNOWMASS21-RF0-AF0-005 on Muonium Gravity Experiment (7/29/2020)
  • K. Kirch, "Testing Gravity with Muonium," arXiv:physics/0702143 (2008)
  • A. Antognini et al., "Studying Antimatter Gravity with Muonium," Atoms 6 (2018) 17
  • D. Taqqu, "Ultraslow Muonium for a Muon beam of ultra high quality," Physics Procedia 17 (2011) 216–223

  • Physics Demonstrations manual

    In 1998 I assembled a manual on Physics Demonstrations in Mechanics available in the IIT Physics Dept.

    Recent presentations on the work of my collaborations:

    Selected research from my group at IIT on the Muon Ionization Cooling Experiment, the national Muon Accelerator Program, the Fermilab NOvA neutrino experiment, and NASA space-telescope R&D:

    See also complete list of my papers with the NOvA collaboration.

    At NuFact 2021 held online and in Cagliari, Italy, I presented an invited talk on

    At COOL'19 in Novosibirsk, Russia, I presented an invited talk on

    At CAARI 2018 in Grapevine, TX, I presented an invited talk on

    At CIPANP 2018 in Indian Wells, CA, I presented a poster on

    At COOL'15 at Jefferson Laboratory I presented the invited talk

    At ICNFP2014 in Crete, Greece, I presented the invited talk

    as well as a poster on Measuring Antimatter Gravity with Muonium (see below).

    Novel research initiative:

    With a small group, I'm now investigating the feasibility of a novel measurement of antimatter gravity!

    Does antimatter fall up??? This "science fiction" idea is being taken seriously by a number of researchers.

    You may have heard about antimatter as the fuel for the Starship Enterprise, or as the weapon of mass destruction in Angels and Demons. Although rare in nature, antimatter is real, and is studied at particle accelerator laboratories around the world and used everyday in positron-emission tomography (PET) scans at hospitals.

    Einstein's General Theory of Relativity, the accepted theory of gravity, predicts no difference between the gravitational behavior of antimatter and that of matter. While well established experimentally, General Relativity is fundamentally incompatible with quantum mechanics, and finding a quantum alternative has been a longstanding quest of physics.

    Since all available experimental evidence on which to base a quantum theory of gravity concerns matter-matter or matter-light interactions, matter-antimatter measurements could play a key role in this quest. Indeed, the most general candidate theories include the possibility that the force between matter and antimatter will be different — perhaps even of opposite sign! — from that of matter on matter.

    So if antimatter falls up in the gravitational field of the Earth — or even if it falls down, but at a different rate from matter — it will be a really big deal!

    But so far no experiment has been sensitive enough to make this very difficult measurement. The first problem is to _make_ some neutral antimatter. This can only be done in tiny quantities. The second is to build a sensitive enough device to detect the tiny effect of gravity on a single atom. Four teams of physicists at the CERN laboratory, in Geneva, Switzerland (where the Higgs boson was discovered) are all competing to make the first measurement using antihydrogen.

    I'm leading a group of IIT physicists looking into a new and different approach: make a beam of unstable "muonium" atoms (perhaps at Fermilab, in Batavia, 40 miles west of IIT, or at the Paul Scherrer Institute in Switzerland), and put it through a precision interferometer to measure its trajectory with picometer precision. We don't know yet whether this is just hard, or impossible, but we're keen to work through the details and find out.

    For more, see our recent papers, my physics colloquium, and poster presented at CPT'16.

    [IIT Home] Last Update June 16, 2022 by kaplan AT