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SUMMARY:Electro-weak production of pseudovector C-even heavy quarkonia in 
 electron-positron  collisions on Belle II and BES III
DTSTART;VALUE=DATE-TIME:20190226T083000Z
DTEND;VALUE=DATE-TIME:20190226T085000Z
DTSTAMP;VALUE=DATE-TIME:20260819T061238Z
UID:indico-contribution-606@indico.inp.nsk.su
DESCRIPTION:Speakers: Nikolay Achasov (Sobolev Institute for Mathematics)\
 nIt 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 lo
 ngitudinally polarized electron-positron\nbeams allows to study separately
  the $e^+e^-\\to Z\\to\\chi_{c1}/\\chi_{b1}$ and\n$e^+e^-\\to\\gamma^{\\as
 t}\\gamma^{\\ast}\\to\\chi_{c1}/\\chi_{b1}$.\n\nIn the discussed energy re
 gion the weak interaction grows with\nenergy increase $\\propto G_FE^2$\, 
 where $G_F=10^{-5}m_p^{-2}$ is\nthe Fermi constant. $G_FE^2=1.4\\times 10^
 {-4}$ for $\\chi_{c1}(1P)$\nand $G_FE^2=1.7\\times 10^{-4}$ for $\\chi_{c1
 }(3872)$. That is\,\n$G_FE^2\\sim \\alpha^2$ in the BES III energy region.
 \n$G_FE^2=1.1\\times 10^{-3}$ for $\\chi_{b1}(1P)$ and\n$G_FE^2=1.2\\times
  10^{-3}$ for $\\chi_{b1}(2P)$. That is\,\n$G_FE^2\\gg\\alpha^2$ in the Be
 lle II energy region.\n\nThe  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 d
 ay may be registered and  several of them in the channel $\\chi_{c1}(3872)
 \\to\\gamma\\psi(2S)$\, several tens of them in the channel $\\chi_{c1}(38
 72)\\to D^0\\bar D^{0\\ast}+c.c$.\n\nThe huge Belle II luminosity $8\\time
 s 10^{35} cm^{-2}s^{-1}$ gives possibilities to register near hundred thou
 sand of events each $e^+e^-\\to Z\\to\\chi_{b1}(1P)$ and\n$e^+e^-\\to Z\\t
 o\\chi_{b1}(1P)$ per day  and several tens of thousands of them in the wel
 l-known channels $\\chi_{b1}(1P)\\to\\gamma\\Upsilon(1S)$ and $\\chi_{b1}(
 2P)\\to\\gamma\\Upsilon(2S)$.\n\nhttps://indico.inp.nsk.su/event/15/contri
 butions/606/
LOCATION: Conference room
URL:https://indico.inp.nsk.su/event/15/contributions/606/
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