<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Z</mml:mi><mml:mrow><mml:mi>c</mml:mi><mml:mi>s</mml:mi></mml:mrow></mml:msub></mml:math> states from the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>*</mml:mo></mml:msubsup><mml:msup><mml:mover accent="true"><mml:mi>D</mml:mi><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mo>*</mml:mo></mml:msup></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>J</mml:mi><mml:mo stretchy="false">/</mml:mo><mml:mi>ψ</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>*</mml:mo></mml:msup></mml:math> coupled channels: Signal in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>B</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:mo stretchy="false">→</mml:mo><mml:mi>J</mml:mi><mml:mo stretchy="false">/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>ϕ</mml:mi><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math> decay
Natsumi Ikeno, R. Molina, E. Oset
Abstract
We study the ${D}_{s}^{*}{\overline{D}}^{*}$ system in connection with the $J/\ensuremath{\psi}{K}^{*}$ in coupled channels and observe that, within reasonable values of the cutoff used to regularize the loops, the system does not develop a bound state. However, the ${J}^{P}={2}^{+}$ channel has enough attraction to create a strong cusp structure that shows up in the $J/\ensuremath{\psi}{K}^{+}$ invariant mass distribution in the ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}{K}^{+}$ decay at the ${D}_{s}^{*}{\overline{D}}^{*}$ threshold. Such structure is visible in the experimental ${B}^{+}\ensuremath{\rightarrow}J/\ensuremath{\psi}\ensuremath{\phi}{K}^{+}$ and ${\overline{B}}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{+}{K}^{\ensuremath{-}}$ decays, with small statistics, and our results should stimulate further measurements around this region, given the fact that cusp effects provide as valuable information on hadron dynamics as resonances themselves.