Photoproduction of heavy quarkonium at the ILC
Photoproduction of heavy quarkonium at the ILC
复制标题
ILC 重夸克氮的照片制作
DOI：
10.1103/physrevd.90.034004
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发表时间：
2014-07
影响因子：
5
通讯作者：
Sun, Zhan
中科院分区：
文献类型：
--
作者：
Wu, Xing-Gang;Fu, Hai-Bing;Han, Hua-Yong;Sun, Zhan
我们用非相对论QCD理论研究了未来国际直线对撞机(ILC)上重夸克素光产生的问题。我们通过子过程$\Gamma\Gamma\to|[q\bar{q‘}]_{\bf1}(N)>；+q’+\bar{q}$来关注生产通道，其中$q$和$q‘$分别代表重的$c$-或$b$-夸克。$|[q\bar{q‘}]_{\bf 1}(N)>；$表示色单重态$S$-波夸克，即$\eta_{c}(|[c\bar{c}]_{\bf 1}(^1s_0)>；)$，$J/\psi(|[c\bar{c}]_{\bf 1}(^3s_1)>；)$，$B_{c}(|[c\bar{b}]_{\bf 1}(^1s_0)>；))$、$B^*_{c}(|[c\bar{b}]_{\bf 1}(^3s_1)>；)$、$\eta_{b}(|[b\bar{b}]_{\bf 1}(^1s_0)>；)$和$\upsilon(|[b\bar{b}]_{\bf 1}(^3s_1)>；)$。为了提高计算效率，我们采用了改进的螺旋度振幅方法，解决了在夸克质量不可忽略的情况下计算产额表达式的困难。给出了光生产物的总截面和微分截面及其不确定度。值得注意的是，ILC可以产生相当数量的$|c\bar{c}>；$-charmonium和$|c\bar{b}>；$-夸克事件。更具体地说，我们预测$(2.8^{+1.0}_{-0.7})\×10^{6}$\ETA_c$，$(5.4^{+1.9}_{-1.3})\×10^{6}$$J/\psi$，$(8.3^{+2.2}_{-1.8})\×10^{4}$$B_c$，$(4.3^{+1.1}_{-0.9})\×10^{5}$B_c^*$，$(9.0^{+1.7}_{-1.4})\倍10^{3}$\eta_b$和$(1.6\pm0.3)\倍10^{4}$$\Upsilon$在ILC一个运营年内产生的事件，条件是$\sqrt{S}=500$GeV和${cal L}\simeq 10^{36}$cm$^{-2}$S$^{-1}$。
We study the photoproduction of the heavy quarkonium at the future International Linear Collider (ILC) within the nonrelativistic QCD theory. We focus on the production channel via the subprocess $\gamma\gamma \to |[Q\bar{Q'}]_{\bf 1}(n)>+Q'+\bar{Q}$, where $Q$ and $Q'$ stand for heavy $c$- or $b$-quark, respectively. $|[Q\bar{Q'}]_{\bf 1}(n)>$ stands for color-singlet $S$-wave quarkonium, i.e., $\eta_{c}(|[c\bar{c}]_{\bf 1}(^1S_0)>)$, $J/\psi(|[c\bar{c}]_{\bf 1}(^3S_1)>)$, $B_{c}(|[c\bar{b}]_{\bf 1}(^1S_0)>)$, $B^*_{c}(|[c\bar{b}]_{\bf 1}(^3S_1)>)$, $\eta_{b}(|[b\bar{b}]_{\bf 1}(^1S_0)>)$, and $\Upsilon(|[b\bar{b}]_{\bf 1}(^3S_1)>)$, respectively. To improve the calculation efficiency, we adopt the improved helicity amplitude approach to deal with the difficulty of calculating the expressions for the yields when the quark masses cannot be neglected. Total and differential photoproduction cross sections, together with their uncertainties, have been presented. It is noted that sizable amount of $|c\bar{c}>$-charmonium and $|c\bar{b}>$-quarkonium events can be generated at the ILC. More specifically, we predict $(2.8^{+1.0}_{-0.7})\times 10^{6}$ $\eta_c$, $(5.4^{+1.9}_{-1.3})\times 10^{6}$ $J/\psi$, $(8.3^{+2.2}_{-1.8})\times 10^{4}$ $B_c$, $(4.3^{+1.1}_{-0.9})\times 10^{5}$ $B_c^*$, $(9.0^{+1.7}_{-1.4})\times 10^{3}$ $\eta_b$, and $(1.6\pm0.3)\times 10^{4}$ $\Upsilon$ events to be generated in one operation year at the ILC under the condition of $\sqrt{S}=500$ GeV and ${\cal L}\simeq 10^{36}$cm$^{-2}$s$^{-1}$.