Observation of a Narrow Resonance in the D/S+ Pi^0 System at 2.32-GeV/C^2 with BABAR
Bibliographic record
Abstract
A new state with invariant mass near 2.32 GeV/c 2 has been observed by the BABAR Collaboration in the inclusive D + s π 0 mass distribution using 91 fb -1 of e + e -annihilation data taken at the PEP-II asymmetric-energy storage ring at energies near 10.6 GeV.The new state is narrow, with an observed width that is consistent with the experimental resolution.This narrow width combined with the quantum numbers of the final state imply that the decay is isospin-violating.The state has natural spin-parity, and its low mass suggests a J P = 0 + assignment.s 1 , the D * s (2112) + , the D s1 (2536) + , and the D s2 (2573) + [4].Two predicted but as yet unobserved states are expected to have masses in the 2.4-2.6 GeV/c 2 range.Expected to decay to D ( * ) K, these states should be very broad, with widths on the order of a few hundred MeV, making them difficult to observe.However, if their masses should be below D ( * ) K threshold, they could be much narrower.A new state, shown in Figure 1, decaying to D + s π 0 with mass near 2317 MeV/c 2 and experimental width Γ ≈ 10 MeV, was first noted by Antimo Palano, of the BABAR Collaboration, in early 2003 [5]. THE DATA SET, EVENT SELECTION, AND ANALYSISThe BABAR detector is a general purpose, solenoidal, magnetic spectrometer, and is described in detail elsewhere [6].A data set of 91.5 fb -1 of e + e -data taken near 1 Charge-conjugate states are implied throughout.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.008 | 0.002 |
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".