论文标题
NRQCD中的底部生产和两极分化，并具有$ k_t $ -Factorization。 iii：$υ（1s）$和$χ_b（1p）$ MESON
Bottomonium production and polarization in the NRQCD with $k_T$-factorization. III: $Υ(1S)$ and $χ_b(1P)$ mesons
论文作者
论文摘要
在$ K_T $ -Factorization方法的框架内研究了$υ（1s）$ MESON生产和高能化的两极分化。我们的考虑是基于针对硬性党派子过程的约束状态形成和外壳生产幅度的非权益QCD形式主义。从$υ（3s）$和$υ（2s）$衰减的辐射$χ_b（MP）$衰减和捐款的直接生产机制，捐赠的捐款。质子中的横向动量依赖性（TMD）Gluon密度源自ciafaloni-catani-fiorani-marchesini进化方程和金伯 - 马丁 - ryskin的处方。通过以多极辐射理论为角度来处理非扰动色彩八位位转变，我们从$υ（1s）$和$χ_b（1p）$ erson的相应的非扰动矩阵元素中提取了从组合拟合到在各种LHC实验下测得的横向分布的组合。然后，我们应用提取的值来研究偏振参数$λ_θ$，$ λ_ϕ $和$λ_{θϕ} $，该$ nsuke $υ（1s）$ spin limepenty矩阵。我们的预测与当前可用的Tevatron和LHC数据在理论和实验不确定性中具有相当良好的一致性。
The $Υ(1S)$ meson production and polarization at high energies is studied in the framework of the $k_T$-factorization approach. Our consideration is based on the non-relativistic QCD formalism for a bound states formation and off-shell production amplitudes for hard partonic subprocesses. The direct production mechanism, feed-down contributions from radiative $χ_b(mP)$ decays and contributions from $Υ(3S)$ and $Υ(2S)$ decays are taken into account. The transverse momentum dependent (TMD) gluon densities in a proton were derived from the Ciafaloni-Catani-Fiorani-Marchesini evolution equation and the Kimber-Martin-Ryskin prescription. Treating the non-perturbative color octet transitions in terms of multipole radiation theory, we extract the corresponding non-perturbative matrix elements for $Υ(1S)$ and $χ_b(1P)$ mesons from a combined fit to transverse momenta distributions measured at various LHC experiments. Then we apply the extracted values to investigate the polarization parameters $λ_θ$, $λ_ϕ$ and $λ_{θϕ}$, which determine the $Υ(1S)$ spin density matrix. Our predictions have a reasonably good agreement with the currently available Tevatron and LHC data within the theoretical and experimental uncertainties.
