Pith. sign in

REVIEW 1 cited by

First Observation of the Direct Production of the $\chi_{c1}$ in $e^+e^-$ Annihilation

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2203.13782 v2 pith:I7WY6MIH submitted 2022-03-25 hep-ex

classification hep-ex
keywords gammaannihilationdatadirectfirstmathrmobservationobserved
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
abstract

We study the direct production of the $J^{PC}=1^{++}$ charmonium state $\chi_{c1}(1P)$ in electron-positron annihilation by carrying out an energy scan around the mass of the $\chi_{c1}(1P)$. The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process $e^+e^-\to \chi_{c1}(1P) \to \gamma J/\psi\to\gamma\mu^+\mu^-$ and the background processes $e^+e^-\to \gamma_{\mathrm{ISR}} J/\psi\to\gamma_{\rm{ISR}}\mu^+\mu^-$ and $e^+e^-\to\gamma_{\rm{ISR}}\mu^+\mu^-$ are observed by combining all the data samples. The $\chi_{c1}(1P)$ signal is observed with a significance of 5.1$\sigma$. This is the first observation of a $C$-even state directly produced in $e^+e^-$ annihilation. The electronic width of the $\chi_{c1}(1P)$ resonance is determined to be $\Gamma_{ee}=(0.12^{+0.13}_{-0.08})~\mathrm{eV}$, which is of the same order of magnitude as theoretical calculations.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Heavy quarkonia and new hadrons with two heavy quarks

    hep-ex 2025-08 accept novelty 1.0 of 10

    A literature review that compiles the current experimental landscape of charmonium, bottomonium, and XYZ exotic states; it contains no new measurements, derivations, or predictions.

Pith tools