International Workshop on e+e- collisions from Phi to Psi

Electro-weak production of pseudovector C-even heavy quarkonia in electron-positron collisions on Belle II and BES III

26 Feb 2019, 15:30

20m

Conference room

Invited Oral Spectroscopy of light and heavy quarks Mesons of heavy quarks

Speaker

Prof. Nikolay Achasov (Sobolev Institute for Mathematics)

Description

It is shown that the $e^+e^-\to Z\to\chi_{c1}/\chi_{b1}$ and $e^+e^-\to\gamma^{\ast}\gamma^{\ast}\to\chi_{c1}/\chi_{b1}$ contributions do not interfere in the total cross sections. That is, the creation of longitudinally polarized electron-positron beams allows to study separately the $e^+e^-\to Z\to\chi_{c1}/\chi_{b1}$ and $e^+e^-\to\gamma^{\ast}\gamma^{\ast}\to\chi_{c1}/\chi_{b1}$. In the discussed energy region the weak interaction grows with energy increase $\propto G_FE^2$, where $G_F=10^{-5}m_p^{-2}$ is the Fermi constant. $G_FE^2=1.4\times 10^{-4}$ for $\chi_{c1}(1P)$ and $G_FE^2=1.7\times 10^{-4}$ for $\chi_{c1}(3872)$. That is, $G_FE^2\sim \alpha^2$ in the BES III energy region. $G_FE^2=1.1\times 10^{-3}$ for $\chi_{b1}(1P)$ and $G_FE^2=1.2\times 10^{-3}$ for $\chi_{b1}(2P)$. That is, $G_FE^2\gg\alpha^2$ in the Belle II energy region. The BESS III luminosity $10^{33} cm^{-2}s^{-1}$ gives possibilities to register near hundred of events $e^+e^-\to Z\to\chi_{c1}(1P)$ per day and near thirty of them in the well-known channel $\chi_{c1}(1P)\to\gamma\psi(1S)$. If $\chi_{c1}(3872)=\chi_{c1}(2P)$, then also near hundred of events $e^+e^-\to Z\to\chi_{c1}(3872)$ per day may be registered and several of them in the channel $\chi_{c1}(3872)\to\gamma\psi(2S)$, several tens of them in the channel $\chi_{c1}(3872)\to D^0\bar D^{0\ast}+c.c$. The huge Belle II luminosity $8\times 10^{35} cm^{-2}s^{-1}$ gives possibilities to register near hundred thousand of events each $e^+e^-\to Z\to\chi_{b1}(1P)$ and $e^+e^-\to Z\to\chi_{b1}(1P)$ per day and several tens of thousands of them in the well-known channels $\chi_{b1}(1P)\to\gamma\Upsilon(1S)$ and $\chi_{b1}(2P)\to\gamma\Upsilon(2S)$.

Summary

The new elegant experimental probes appear. In particular, they could find out whether is $\chi_{c1}(3872)=\chi_{c1}(2P)$ and search out the
$\chi_{b1}(2P)\to\rho\Upsilon(1S)$.

The work was supported by the program of fundamental scientific researches of the SB RAS No. II.15.1., project No. 0314-2016-0021.

The work also is partially supported by the Russian Foundation for Basic Research Grant No. 16-02-00065.

REFERENCES

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Presentation Materials

Slides

Achasov_26.02.2019.pdf

Peer reviewing

Paper

Accepted on 27 May 2019 by Fedor Ignatov

Paper files:

• NNAchasov_v2.tar.gz
• �.�._Achasov2019.zip
• 2019_������_�.�.pdf
• achasov2019_v2.pdf