Subtleties in triangle loops for D s plus <i> →</i><i> ρ</i> plus <i> η</i><i> →</i><i> π</i> plus <i> π</i> 0<i> η</i> in a 0 (980) production

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Bayar M., Molina R., Oset E., Liu M., Geng L.

PHYSICAL REVIEW D, cilt.109, sa.7, 2024 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 109 Sayı: 7
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1103/physrevd.109.076027
  • Dergi Adı: PHYSICAL REVIEW D
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, INSPEC, zbMATH
  • Kocaeli Üniversitesi Adresli: Hayır

Özet

We address a general problem in the evaluation of triangle loops stemming from the consideration of the range of the interaction involved in some of the vertices, as well as the energy dependence of the width of some unstable particles in the loop. We find sizeable corrections from both effects. We apply that to a loop relevant to the D + s -> pi + pi 0 eta decay, and find reductions of about a factor of 4 in the mass distribution of invariant mass of the pi eta in the region of the a 0 ( 980 ) . The method used is based on the explicit analytical evaluation of the q 0 integration in the d 4 q loop integration, using Cauchy 's residues method, which at the same time offers an insight on the convergence of the integrals and the effect of form factors and cutoffs.