Cern experiments on the anti-hydrogen production and the measure of antimatter gravity acceleration
Bibliographic record
Abstract
The speech reviews the Cern experiments AEgIS, ALPHA, ATRAP and ASACUSA for anti-hydrogen production and measure of its characteristics. They all use the Antiproton Decelerator at Cern. AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is a collaboration of physicists from Cern, France, Italy, Uk, Germany, Switzerland, Russia, Czech Republic, Norway, Qatar. The primary scientific goal of the AEgIS experiment is the direct measurement of the Earth's gravitational acceleration g on antihydrogen. In the first phase of the experiment, a gravity measurement with 1% precision will be carried out by sending an antihydrogen beam through a classical Moire deflectometer coupled to a position sensitive detector. This will represent the first direct measurement of a gravitational effect on an antimatter system. ALPHA is an international collaboration based at CERN, and whose aim is stable trapping of antihydrogen atoms, the antimatter counterpart of the simplest atom, hydrogen. By precise comparisons of hydrogen and antihydrogen, the experiment hopes to study fundamental symmetries between matter and antimatter. It is a collaboration of physicists from Cern, Denmark, Usa, Canada, UK, Israel, Japan, Brazil, Sweden. Alpha has successfully trapped antihydrogen atoms for at least 1000 seconds. ATRAP is an antimatter experiment at Cern whose long term goal is the precise laser or microwave spectroscopy of trapped antihydrogen to make the most stringent lepton and baryon CPT tests. It is a collaboration of physicists from Usa, Germany, Uk. ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) is an antimatter experiment studying: laser and microwave precision spectroscopy of antiprotonic helium atoms (i.e., antiproton+electron+helium nucleus) for testing the CPT (matter-antimatter) symmetry, and contributing to the fundamental physical constants, antihydrogen ground-state hyperfine splitting measurement, for testing the CPT symmetry, atomic and nuclear collision cross sections at extremely low energies. It is a collaboration of physicists from Cern, Austria, Denmark, Germany, Hungary, Italy, Japan, Uk, Northern Ireland.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.011 | 0.009 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".