I. Pomerantz, N. Bubis, K. Allada, A. Beck, S. Beck, B. L. Berman, W. Boeglin, A. Camsonne, M. Canan, K. Chirapatpimol, E. Cisbani, F. Cusanno, C. W. de Jager, … 展开作者
I. Pomerantz, N. Bubis, K. Allada, A. Beck, S. Beck, B. L. Berman, W. Boeglin, A. Camsonne, M. Canan, K. Chirapatpimol, E. Cisbani, F. Cusanno, C. W. de Jager, C. Dutta, F. Garibaldi, O. Geagla, R. Gilman, J. Glister, D. W. Higinbotham, X. Jiang, A. T. Katramatou, E. Khrosinkova, B. Lee, J. J. LeRose, R. Lindgren, E. McCullough, D. Meekins, R. Michaels, B. Moffit, G. G. Petratos, E. Piasetzky, X. Qian, Y. Qiang, I. Rodriguez, G. Ron, A. Saha, A. J. Sarty, B. Sawatzky, E. Schulte, R. Shneor, N. Sparveris, R. Subedi, S. Strauch, V. Sulkosky, Y. Wang, B. Wojtsekhowski, X. Yan, H. Yao, X. Zhan, X. Zheng
备注:
7 pages, 3 figures, for submission to Phys. Lett. B
We present a study of high energy photodisintegration of proton-pairs through the gamma + 3He -> p+p+n channel. Photon energies from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair with high relative momentum and a neutron nearly at rest. The s-11 scaling of the cross section, as predicted by the constituent counting rule for two nucleon photodisintegration, was observed for the first time. The onset of the scaling is at a higher energy and the cross section is significantly lower than for deuteron (pn pair) photodisintegration. For photon energies below the scaling region, the scaled cross section was found to present a strong energy-dependent structure not observed in deuteron photodisintegration.
为了理解强相互作用从强子描述到夸克胶子描述的转变动力学,人们对氘核的硬光致蜕变进行了广泛的研究。在这项工作中,我们讨论了这个程序的扩展到硬光衰变的$pp$对在$^3$ He核。实验证实了这里所预言的反应的新特征,将促进我们对硬核反应的理解。一个主要的预测,与低能量的观测结果相比,是$pp$破碎截面并不比$pn$破碎截面小得多。在一些模型中,$pp$散射的能量依赖振荡被预测出现在$γ^3{\rm He} \to p p + n$反应中。这将为硬核反应中颜色相干现象的研究开辟一个全新的领域。我们还表明,除了能量的依赖性,反冲中子的光锥动量分布的测量提供了一个独立的测试硬解体的基本动力学。
Observation of inverse diproton photodisintegration at intermediate energies
用COSY-Juelich的ANKE谱仪,在T_p=0.353,0.500和0.550 GeV的质子束能量下,观测到了pp → {pp}_sγ反应,其中{pp}_s是激发能E_{pp} <3 MeV的质子对。这等价于光子能量为Eγ~ Tp/2的自由1S_0双质子的光衰变。测量的微分截面为c.m.角度0度<θ_{pp} <20 deg. exhibit a steep increase with angle that is compatible with E1 and E2 multipole contributions. The ratio of the measured cross sections to those of np->dγ在10^{-3}-10 ^{-2}水平。pp->{pp}_sγ截面随T_p的增加可能反映了Delta(1232)激发的影响。
A measurement of the differential cross section for the two-body photodisintegration of 3He at theta_LAB = 90deg using tagged photons in the energy range 14 -- 31 MeV
First Measurements of Spin-Dependent Double-Differential Cross Sections and the GDH Integrand from \vec{^3He}(\vecγ,n)pp at Incident Photon Energies of 12.8 and 14.7 MeV
在三角大学核实验室(TUNL)的高强度γ射线源(HIγS)装置中,首次测量了圆偏振γ射线束对圆偏振^3He的三体光致衰变。给出了自旋相关的双微分截面和三体光致衰变对^3 He GDH被积函数的贡献,并与入射光子能量为12.8和14.7 MeV时的最新三体计算结果进行了比较。这些数据揭示了在三体计算中考虑质子间库仑相互作用的重要性。
Measurement of the dependence of transverse energy production at large pseudorapidity on the hard-scattering kinematics of proton-proton collisions at $\sqrt{s} = 2.76$ TeV with ATLAS
利用LHC ATLAS探测器记录的$\sqrt{s} = 2.76$ TeV $pp$的4.0 pb $^{-1}$碰撞数据,研究了中心区喷流产生与伪快度分离区潜在事件活动之间的关系。的基本事件的特征在于通过测量的横向能量的总和的平均值在大的伪快度下游的质子,这是报告在这里作为硬散射运动学变量的函数。硬散射的特点是平均横向动量和赝快度的两个最高的横向动量射流的事件。双喷流运动学被用来估计,在事件的基础上,标度的纵向动量的硬散射部分子在目标和弹丸束质子移动朝向和远离测量横向能量的区域,分别。在大赝快度的横向能量生产被观察到减少与目标质子的纵向动量分数的线性依赖,并依赖于只有弱的抛射体质子。的结果进行比较的各种Monte Carlo事件发生器,定性再现数据中观察到的趋势,但一般underpredict的整体水平的横向能量在前进的伪快度的预测。
Measurement of $\mathrm{D}$-meson production as a function of charged-particle multiplicity in proton--proton collisions at $\sqrt{s} = 13$ TeV with ALICE at the LHC
Hard exclusive pion electroproduction at backward angles with CLAS
我们报告的第一次测量的横截面独家深虚拟π电生产的质子,$e p \to e^\prime n π^+$,以上的共振区在向后π质心角。测量了$φ^*_π$依赖的截面,从中我们提取了质子的三种结构函数组合。我们的结果与基于核子到π介子跃迁分布振幅(TDAs)的计算结果是一致的,并为核子结构提供了新的解释。