Электронный каталог

Статья

Matsumura, Y.
Direct Measurement of the In-Medium *h' Mass Spectrum Through the *g*g Decay Channel / Y.Matsumura, E.A.Strokovsky, [a.o.]. – Text : electronic // Physical Review Letters. – 2026. – Vol. 137, No. 5. – P. 051901. – URL: https://doi.org/10.1103/x414-n6g9. – Bibliogr.: 39.

We measured the invariant mass of the 𝜂′⁡(958) meson through the 𝜂′→𝛾⁢𝛾 decay channel to search for possible character change of 𝜂′ in a nuclear medium. The measured invariant-mass spectra were analyzed by fitting realistic spectral functions. An enhancement was observed in the lower tail of the 𝜂′ mass peak for low-momentum (𝑃&sub(𝛾⁢𝛾)<1  GeV/c) events. Three statistical methods were applied to assess the significance of the enhancement. All methods yield a statistical significance above 3.7⁢𝜎. The spectral fitting indicates a mass reduction of 57.5&sup(+5.7)&sub( −27.8 )MeV/c2. Our result provides the first evidence for an in-medium spectral modification of the 𝜂′ meson obtained through a direct measurement of its invariant mass.



ОИЯИ = ОИЯИ (JINR)2026