Search for a new 17 MeV resonance via e+e− annihilation with the PADME experiment
A bstract The PADME Experiment at the Frascati DAΦNE linear accelerator has searched for a hypothetical particle with mass around 17 MeV, commonly referred to as the X17, using a positron beam incident on a fixed target. The beam energy was varied between 262 and 296 MeV, corresponding to center-of-mass energies $$\sqrt{s}$$ between 16.4 and 17.4 MeV. The X17 should be produced resonantly via e + e − annihilation when $$\sqrt{s}$$ approaches its mass, inducing an excess of events with a two-body final state over the background expectation. The beam energy spacing was fixed to less than half the expected width of the resonance’s line shape. Uncertainties below 1% per $$\sqrt{s}$$ point were achieved. A blind analysis has been performed. The data are consistent with the expected background in most of the explored energy range, and limits are set in previously unexplored regions of the available parameter space. The most significant deviation is found for $$\sqrt{s}\approx 16.90$$ MeV, corresponding to a global significance of approximately 2 standard deviations over the null hypothesis expectation.
Authors
- E. Leonardi (ORCID: https://orcid.org/0000-0001-8728-7582)
- Kalina Dimitrova (ORCID: https://orcid.org/0000-0003-4953-9667)
- A. Frankenthal (ORCID: https://orcid.org/0000-0002-2583-5982)
- C. Taruggi (ORCID: https://orcid.org/0000-0002-9921-7132)
- C. Di Giulio (ORCID: https://orcid.org/0000-0002-0597-4547)
- P. Valente (ORCID: https://orcid.org/0000-0002-5413-0068)
- M. Garattini (ORCID: https://orcid.org/0000-0002-8605-2228)
- E. Di Meco (ORCID: https://orcid.org/0000-0003-1236-551X)
- R. de Sangro (ORCID: https://orcid.org/0000-0002-3808-5455)
- L. Foggetta (ORCID: https://orcid.org/0000-0002-6389-1280)
- M. Raggi (ORCID: https://orcid.org/0000-0002-7448-9481)
- E. Long (ORCID: https://orcid.org/0000-0002-7192-2235)
- I. Sarra (ORCID: https://orcid.org/0000-0002-5037-5316)
- M. Mancini (ORCID: https://orcid.org/0000-0002-3615-5560)
- G. Finocchiaro (ORCID: https://orcid.org/0000-0002-3936-2151)
- V. Kozhuharov (ORCID: https://orcid.org/0000-0002-0669-7799)
- T. Spadaro (ORCID: https://orcid.org/0000-0002-7101-2389)
- R. Simeonov (ORCID: https://orcid.org/0000-0001-7729-5503)
- F. Bossi (ORCID: https://orcid.org/0000-0001-5669-1603)
- Giovanni Organtini (ORCID: https://orcid.org/0000-0002-3229-0781)
- Danilo Domenici (ORCID: https://orcid.org/0000-0002-3000-7663)
- S.A. Ivanov (ORCID: https://orcid.org/0000-0003-2442-7351)
- S. Ivanov (ORCID: https://orcid.org/0000-0003-3937-6227)
- F. Ferrarotto (ORCID: https://orcid.org/0000-0001-5464-0378)
- P. Gianotti (ORCID: https://orcid.org/0000-0003-4167-7176)
- E. Vilucchi (ORCID: https://orcid.org/0000-0002-4839-6281)
- K. Kostova (ORCID: https://orcid.org/0009-0001-1739-3109)
Institutions
- University of California System (US)
- Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati (IT)
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma I (IT)
- Sofia University "St. Kliment Ohridski" (BG)
- Sapienza University of Rome (IT)
Publication Details
- Journal
- Journal of High Energy Physics
- Published
- 2025-11-04
- DOI
- https://doi.org/10.1007/jhep11(2025)007
- Citations
- 4
- Primary Topic
- Nuclear physics research studies
- Type
- article
- Field-Weighted Citation Impact
- 7.48
Funders
- Strong
- European Commission
- Bulgarian National Science Fund
- Istituto Nazionale di Fisica Nucleare