Ongoing experiments at JLAB investigate the nuclear transparency in exclusive rho0(770) electroproduction off nuclei. In this work we present transport model predictions for the attenuation of rho0s in nuclei and for color transparency (CT) effects as observable at CLAS with a 5 GeV electron beam energy. A full event simulation presented here permits to study the impact of actual experimental acceptance conditions and kinematical cuts. The exclusive (e,e'rho0) cross section off nucleons is described by diffractive and color string breaking mechanisms extended toward the onset of the deep inelastic regime. Different hadronization and CT scenarios are compared. We show that a detailed analysis of elementary cross section, nuclear effects and experimental cuts is needed to reveal the early onset of rho0-CT at present JLAB energies.
Color transparency occurs if a small-sized wave packet, formed in a high momentum transfer process, escapes the nucleus before expanding. The time required for the expansion depends on the masses of the baryonic components of the wave packet. Measured proton diffractive dissociation and electron deep inelastic scattering cross sections are used to examine and severely constrain the relevant masses. These constraints allow significant color transparency effects to occur at experimentally accessible momentum transfers.
Generalized Parton Distributions and Color Transparency
我们研究了广义部分子分布在碰撞参量空间中的结构，目的是确定小横向分离分量在夸克波函数中的大小和作用。分析了横向动量分量与横向分离的关系。具有大的横向动量分量的波函数可以同时再现狄拉克形状因子在大动量转移时的行为和Bjorken x -> 1时的深部非弹性结构函数的行为。然而，大动量分量的存在并不能保证在大x时小横向距离占优势。我们认为，测量强子在核介质中的衰减，或开始的颜色透明的实验，可以提供一个替代的信息来源广义部分子分布，通过映射出的行为的横向分量的波函数。
Evidence for Observation of Color Transparency in pa Collisions Using Global Fit and Scaling Law Analysis
本文综述了一种新的系统的色透明实验数据分析方法及其在质子核散射实验中的应用。该方法直接从数据中提取硬散射率以及质子穿过核的存活概率。该方法需要在一个有效的核子-核子截面方面的核衰减建模。我们可以通过引入一个新的标度律分析程序，可以产生相当多的信息，很少的理论输入，最大限度地减少这种模型的依赖。有了足够的数据，生存概率的函数形式以及硬散射可以提取没有任何理论建模。Carroll {\it et al}的BNL数据分析显示了观察颜色透明度的明确证据。
Non-universality of color transparency onset in pion and kaon electroproduction
Center for Exotic Nuclear Studies, Institute for Basic Science（基础科学研究所奇异核研究中心）；Research Institute of Basic Science, Korea Aerospace University（韩国航空大学基础科学研究所）；Department of Physics and Engineering Physics, Yonsei University（延世大学物理与工程物理系）
In the framework of soft-collinear effective theory with Glauber gluons, results and predictions for inclusive hadron suppression, based upon in-medium parton shower evolution, are presented for Au+Au and Pb+Pb collisions at RHIC and LHC energies $\sqrt{s}=200$ AGeV and $\sqrt{s}=2.76, \, 5.1$ ATeV, respectively. The $\rm SCET_G$ medium-induced splitting kernels are further implemented to evaluate the attenuation of reconstructed jet cross in such reactions and to examine their centrality and radius $R$ dependence. Building upon a previously developed method to systematically resum the jet sha…
The color transparency (CT) of a hadron, propagating with reduced absorption in a nucleus, is a fundamental property of QCD (quantum chromodynamics) reflecting its internal structure and effective size when it is produced at high transverse momentum, $Q$. CT has been confirmed in many experiments, such as semi-exclusive hard electroproduction, $e A \to e' πX$ for mesons produced at $Q^2 > 3 ~ {\rm GeV}^2$. However, a recent JLab (Jefferson Laboratory) measurement for a proton electroproduced in carbon $e\, {\rm C}\to e' p X$, where $X$ stands for the inclusive sum of all produced final states,…
Azimuthal Anisotropy Scaling for Identified Mesons and Baryons: Insights into Medium Transport Properties, Equation of State and Hadronic Re-scattering
Using a simple geometric framework with a realistic nuclear density distribution, we fit published HERMES data to determine fundamental properties of hadronization using the nuclear medium as a spatial analyzer. Our approach uses a fit to the transverse momentum broadening observable and the hadronic multiplicity ratio; the simultaneous fit to two different observables strongly constrains the outcome. Using the known sizes of the target nuclei, we extract the color lifetime, finding a z$\mathrm{_h}$-dependent range of values from 2 to 8 fm/c for these data. We also extract estimates for the $\…
The $12~$GeV electron beam energy at Jefferson Laboratory provides ideal electroproduction kinematics for many novel tests of QCD in both the perturbative and nonperturbative domains. These include tests of the quark flavor dependence of the nuclear structure functions; measurements of the QCD running coupling at soft scales; measurements of the diffractive deep inelastic structure function; measurements of exclusive contributions to the $T-$ odd Sivers function; the identification of ``odderon" contributions; tests of the spectroscopic and dynamic features of light-front holography, as well a…
