Lattice QCD study of the $χ_{c1}\to J/ψ\, γ$ decay
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909654286598144 |
|---|---|
| author | Bečirević, D. Di Palma, R. Frezzotti, R. Gagliardi, G. Lubicz, V. Sanfilippo, F. Tantalo, N. |
| author_facet | Bečirević, D. Di Palma, R. Frezzotti, R. Gagliardi, G. Lubicz, V. Sanfilippo, F. Tantalo, N. |
| contents | We present the results of our lattice QCD computation of the electric ($E_{1}$) and magnetic $(M_{2})$ form factors relevant to the $χ_{c1}\to J/ψ\,γ$ decay by using the gauge field configurations produced by the Extended Twisted Mass Collaboration with $N_{f}=2+1+1$ dynamical Wilson-Clover twisted mass fermions at four different lattice spacings with physical dynamical $u$ , $d$, $s$ and $c$ quark masses (except for the coarsest lattice for which the lightest sea quark corresponds to a pion with $m_π\simeq 175~\mathrm{MeV}$). In the continuum limit, we obtain $Γ( χ_{c1}\to J/ψ γ) = 0.3265(79)~\mathrm{MeV}$, which agrees to $(1÷2) σ$ with the experimental results and disagrees with a previous (unquenched) lattice QCD calculation. Our result for the magnetic quadrupole fractional transition amplitude, $a_{2} =M_{2}/\sqrt{E_{1}^{2}+M_{2}^{2}} = -0.0666(22)$, is in agreement with the experiment and represents an improvement by a factor of about $30$ with respect to the only existing (quenched) lattice QCD result. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2506_17030 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Lattice QCD study of the $χ_{c1}\to J/ψ\, γ$ decay Bečirević, D. Di Palma, R. Frezzotti, R. Gagliardi, G. Lubicz, V. Sanfilippo, F. Tantalo, N. High Energy Physics - Lattice High Energy Physics - Phenomenology We present the results of our lattice QCD computation of the electric ($E_{1}$) and magnetic $(M_{2})$ form factors relevant to the $χ_{c1}\to J/ψ\,γ$ decay by using the gauge field configurations produced by the Extended Twisted Mass Collaboration with $N_{f}=2+1+1$ dynamical Wilson-Clover twisted mass fermions at four different lattice spacings with physical dynamical $u$ , $d$, $s$ and $c$ quark masses (except for the coarsest lattice for which the lightest sea quark corresponds to a pion with $m_π\simeq 175~\mathrm{MeV}$). In the continuum limit, we obtain $Γ( χ_{c1}\to J/ψ γ) = 0.3265(79)~\mathrm{MeV}$, which agrees to $(1÷2) σ$ with the experimental results and disagrees with a previous (unquenched) lattice QCD calculation. Our result for the magnetic quadrupole fractional transition amplitude, $a_{2} =M_{2}/\sqrt{E_{1}^{2}+M_{2}^{2}} = -0.0666(22)$, is in agreement with the experiment and represents an improvement by a factor of about $30$ with respect to the only existing (quenched) lattice QCD result. |
| title | Lattice QCD study of the $χ_{c1}\to J/ψ\, γ$ decay |
| topic | High Energy Physics - Lattice High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2506.17030 |