arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2004.03220hep-ph
收藏

$χ_{c1}$ and $χ_{c2}$ polarization as a probe of color octet channel

S. P. Baranov, A. V. Lipatov

英文摘要:

We analyze the first LHC data on $χ_{c1}$ and $χ_{c2}$ polarization obtained very recently by the CMS Collaboration at $\sqrt s = 8$~TeV. We describe the perturbative production of $c\bar c$ pair with $k_T$-factorization approach and use nonrelativistic QCD formalism for the formation of bound states. We demonstrate that the polar anisotropy of $χ_{c1}$ and $χ_{c2}$ mesons is strongly sensitive to the color octet contributions. We extract the long-distance matrix elements for $χ_{c1}$ and $χ_{c2}$ mesons from the first CMS polarization measurement %on the polarization parameters $λ_θ^{χ_{c1}}$ and $λ_θ^{χ_{c2}}$ obtained at $\sqrt s = 8$~TeV together with available LHC data on the $χ_{c1}$ and $χ_{c2}$ transverse momentum distributions (and their ratios) collected at $\sqrt s = 7$~TeV. Our fit points to unequal color singlet wave functions of $χ_{c1}$ and $χ_{c2}$ states.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑