Nuclear physics|7 Article(s)
Deformed dispersion relation constraint with hydrogen atom 1S-2S transition *
Pu Jin, Li Guo-Ping, Jiang Qing-Quan, and Zu Xiao-Tao
Chinese Physics C
  • Publication Date: Jan. 01, 1900
  • Vol.44 Issue, 1 (2020)
Search for QCD critical point by transverse velocity dependence of anti-deuteron to deuteron ratio *
Yu Ning, Zhang Dingwei, and Luo Xiaofeng
We propose the transverse velocity ( ) dependence of the anti-deuteron to deuteron ratio as a new observable to search for the QCD critical point in heavy-ion collisions. The QCD critical point can attract the system evolution trajectory in the QCD phase diagram, which is known as the focusing effect. To quantify this effect, we employ the thermal and hadronic transport model to simulate the dynamical particle emission along a hypothetical focusing trajectory near the critical point. We found that the focusing effect can lead to anomalous dependence on , and ratios. We examined the dependence of and ratios of central Au+Au collisions at 7.7 to 200 GeV measured by the STAR experiment at RHIC. Surprisingly, we only observe a negative slope in dependence of ratio at 19.6 GeV, which indicates the trajectory evolution has passed through the critical region. In the future, we could constrain the location of the critical point and/or width of the critical region by conducting precise measurements on the dependence of the ratio at different energies and rapidity.
Chinese Physics C
  • Publication Date: Jan. 01, 1900
  • Vol.44 Issue, 1 (2020)
Measurement of the differential cross sections and angle-integrated cross sections of the 6Li(n, t)4He reaction from 1.0 eV to 3.0 MeV at the CSNS Back-n white neutron source *
Bai Huaiyong, Fan Ruirui, Jiang Haoyu, Cui Zengqi, Hu Yiwei, Zhang Guohui, Chen Zhenpeng, Jiang Wei, Yi Han, Tang Jingyu, Zhou Liang, An Qi, Bao Jie, Cao Ping, Chen Qiping, Chen Yonghao, Cheng Pinjing, Feng Changqing, Gu Minhao, Guo Fengqin, Han Changcai, Han Zijie, He Guozhu, He Yongcheng, He Yuefeng, Huang Hanxiong, Huang Weiling, Huang Xiru, Ji Xiaolu, Ji Xuyang, Jing Hantao, Kang Ling, Kang Mingtao, Li Bo, Li Lun, Li Qiang, Li Xiao, Li Yang, Li Yang, Liu Rong, Liu Shubin, Liu Xingyan, Luan Guangyuan, Ma Yinglin, Ning Changjun, Qi Binbin, Ren Jie, Ruan Xichao, Song Zhaohui, Sun Hong, Sun Xiaoyang, Sun Zhijia, Tan Zhixin, Tang Hongqing, Wang Pengcheng, Wang Qi, Wang Taofeng, Wang Yanfeng, Wang Zhaohui, Wang Zheng, Wen Jie, Wen Zhongwei, Wu Qingbiao, Wu Xiaoguang, Wu Xuan, Xie Likun, Yang Yiwei, Yu Li, Yu Tao, Yu Yongji, Zhang Jing, Zhang Linhao, Zhang Liying, Zhang Qingmin, Zhang Qiwei, Zhang Xianpeng, Zhang Yuliang, Zhang Zhiyong, Zhao Yingtan, Zhou Zuying, Zhu Danyang, Zhu Kejun, and Zhu Peng
The 6Li(n, t)4He reaction was measured as the first experiment involving neutron-induced charged particle emission reactions at the CSNS (China Spallation Neutron Source) Back-n white neutron source. The differential cross-sections of the 6Li(n,t)4He reaction at 15 detection angles ranging from 19.2° to 160.8° are obtained from 1.0 eV to 3.0 MeV at 80 neutron energy points; for 50 energy points below 0.1 MeV they are reported for the first time. The results indicate that the anisotropy of the emitted tritium is noticeable above En = 100 eV. The angle-integrated cross-sections are also obtained. The present differential cross-sections agree in general with the previous evaluations, but there are some differences in the details. More importantly, the present results indicate that the cross-sections of the 6Li(n, t)4He reaction might be overestimated by most evaluations in the 0.5 - 3.0 MeV region, although they are recommended as standards below 1.0 MeV.
Chinese Physics C
  • Publication Date: Jan. 01, 1900
  • Vol.44 Issue, 1 (2020)
Constituent quark number scaling from strange hadron spectra in pp collisions at TeV *
Zhang Jian-Wei, Li Hai-Hong, Shao Feng-Lan, and Song Jun
We show that the spectra of and at midrapidity in the inelastic events in collisions at 13 TeV exhibit a constituent quark number scaling property, which is a clear signal of quark combination mechanism at hadronization. We use a quark combination model with equal velocity combination approximation to systematically study the production of identified hadrons in collisions at = 13 TeV. The midrapidity spectra for protons, , , , and in the inelastic events are simultaneously fitted by the model. The multiplicity dependence of the yields of these hadrons are also well understood. The strong dependence of the ratio is well explained by the model, which further suggests that the production of two hadrons with similar masses is determined by their quark content at hadronization. The spectra of strange hadrons at midrapidity in different multiplicity classes in collisions at 13 TeV are predicted for further tests of the model. The midrapidity spectra of soft ( GeV/c) strange quarks and up/down quarks at hadronization in collisions at 13 TeV are extracted.
Chinese Physics C
  • Publication Date: Jan. 01, 1900
  • Vol.44 Issue, 1 (2020)
Antiproton production in heavy-ion collisions at subthreshold energies *
Feng Zhao-Qing
Within the framework of the Lanzhou quantum molecular dynamics model, the deep subthreshold antiproton production in heavy-ion collisions has been investigated thoroughly. The elastic scattering, annihilation and charge exchange reactions associated with antiproton channels are implemented in the model. The attractive antiproton potential extracted from the G-parity transformation of nucleon selfenergies reduces the threshold energies in meson-baryon and baryon-baryon collisions, and consequently enhances the antiproton yields to some extent. The calculated invariant spectra are consistent with the available experimental data. The primordial antiproton yields increase with the mass number of the colliding system. However, annihilation reactions reduce the antiproton production which becomes independent of the colliding partners. Anti-flow phenomena of antiprotons correlated with the mean field potential and annihilation mechanism is found by comparing them with the proton flows. Possible experiments at the high-intensity heavy-ion accelerator facility (HIAF) in China are discussed.
Chinese Physics C
  • Publication Date: Jan. 01, 1900
  • Vol.44 Issue, 1 (2020)