Evidence for the Cusp Effect in ?0 Decays into ??0?0
Küçük Resim Yok
Tarih
2023
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Physical Soc
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Using a sample of 4.3 x 105 eta' -> eta pi 0 pi 0 events selected from the ten billion J=psi event dataset collected with the BESIII detector, we study the decay eta' -> eta pi 0 pi 0 within the framework of nonrelativistic effective field theory. Evidence for a structure at pi+pi- mass threshold is observed in the invariant mass spectrum of pi 0 pi 0 with a statistical significance of around 3.5 sigma, which is consistent with the cusp effect as predicted by the nonrelativistic effective field theory. After introducing the amplitude for describing the cusp effect, the pi pi scattering length combination a0 - a2 is determined to be 0.226 10.060stat 10.013syst, which is in good agreement with theoretical calculation of 0.2644 10.0051.
Açıklama
Anahtar Kelimeler
Electromagnetic Corrections, Pi, 3-Pi(0), Tof
Kaynak
Physical Review Letters
WoS Q Değeri
N/A
Scopus Q Değeri
Q1
Cilt
130
Sayı
8
