English

A proposal to the '$\frac{1}{2}$ vs. $\frac{3}{2}$ puzzle'

High Energy Physics - Phenomenology 2023-07-25 v5

Abstract

We reconsider the semileptonic decays of BD1()lνˉlB\to D_1^{(\prime)}l\bar \nu_l. The previous theoretical calculations predict a significantly smaller rate for the semileptonic decay of BB to D1(Jl=12)D'_1(J_l=\frac{1}{2}) compared with that to the D1(Jl=32)D_1(J_l=\frac{3}{2}), which is not consistent with the current experimental data. This conflict is the so-called `12\frac{1}{2} vs. 32\frac{3}{2} puzzle'. In this work, we propose a simple scheme to fix this problem, where we suppose that the strong eigenstates D1()D_1^{(\prime)} do not coincide with the eigenstate of the weak interaction, since no experimental results show the weak and the strong interactions have to share the same eigenstates. Within the framework of this tentative scheme, meson BB first weakly decays to {the weak eigenstates} Dα(β)D_{\alpha(\beta)} and then the latter are detected as the D1()D_1^{(\prime)} by the strong products DπD^*\pi. We predict that there exist two new particles Dα(β)D_{\alpha(\beta)} with JP=1+J^P=1^+ which were not previously identified. The good performance of the new scheme in describing the experimental data may hint at new symmetry in the weak decays of BqB_{q} to 1+1^+ heavy-light mesons. To test the scheme proposed here, we suggest an experiment to detect the difference in the invariant mass spectra of D1D_1 reconstructed from the BB weak decay and from the strong decay products.

Keywords

Cite

@article{arxiv.2004.09925,
  title  = {A proposal to the '$\frac{1}{2}$ vs. $\frac{3}{2}$ puzzle'},
  author = {Qiang Li and Wei Feng and Guo-Li Wang},
  journal= {arXiv preprint arXiv:2004.09925},
  year   = {2023}
}

Comments

19 pages, 2 figures