Tue·Apr 13, 2021Tuesday·April 13, 2021

1. 01*

   Transport Estimations of Final State Interaction Effects on Short-range Correlation Studies Using the $(e,e^{\prime }p)$ and $(e,e^{\prime }pp)$ Reactions

   N. Wright🇺🇸 · A. Papadopoulou🇺🇸 · J.R. Pybus🇺🇸 · S. Gardiner🇺🇸 · M. Roda🇬🇧 · F. Hauenstein🇺🇸 · A. Ashkenazi🇮🇱 · L.B. Weinstein🇺🇸 · A. Schmidt🇺🇸 · O. Hen🇺🇸

   Short range correlated (SRC) nucleon-nucleon pairs in nuclei are typically studied using measurements of electron-induced hard nucleon-knockout reactions (e.g. $(e,e^{\prime }p)$ and $(e,e^{\prime }pN)$), where the kinematics of the knocked-out nucleons are used to infer their initial state prior to the interaction. The validity of this inference relies on our understanding of the scattering reaction, most importantly how rescattering of the detected nucleons (final state interactions or FSI) distort their kinematical distributions. Recent SRC measurements on medium to heavy nuclei have been performed at high-$x_B$ (i.e., anti-parallel kinematics) where calculations of light nuclei indicate that such distortion effects are small. Here we study the impact of FSI on recent ${}^{12}$C$(e,e^{\prime }p)$ and ${}^{12}$C$(e,e^{\prime }pp)$ measurements using a transport approach. We find that while FSI can significantly distort the measured kinematical distributions of SRC breakup events, selecting high-$x_B$ anti-parallel events strongly suppresses such distortions. In addition, including the effects of FSI improves the agreement between Generalized Contact Formalism-based calculations and data and can help identify those observables that have minimal sensitivity to FSI effects. This result helps confirm the interpretation of experimental data in terms of initial-state momentum distributions and provides a new tool for the study of SRCs using lepton-scattering reactions.

   ↳ nucl-thnucl-ex4 citations
2. 02*

   Effects of Proton Irradiation on Hole Carrier Transport in Hydrogen-Terminated Diamond Surfaces

   Ricardo Peterson🇺🇸 · Mohamadali Malakoutian🇺🇸 · Yongqiang Wang🇺🇸 · Srabanti Chowdhury🇺🇸 · Debbie G. Senesky🇺🇸

   In this letter, we report the effects of irradiating hydrogen-terminated diamond surfaces with protons. We study the electrical behavior of the two-dimensional hole gas that forms on the diamond surface as a result of hydrogen-termination. Four diamond samples, two of which were passivated with Al2O3 and the other two unpassivated, were irradiated with 2 MeV protons at two fluences, 0.5x10^14 and 1.0x10^14 /cm^2. The hole conductivity degraded at a higher proton fluence, which is attributed to the reduction of the mobility caused by enhanced hole scattering. Both passivated and unpassivated samples exhibited a reduction in the mobility, which can be explained by charging effects of the Al2O3 (for the passivated samples) and degradation of the hydrogen-terminated surface (for the unpassivated samples). To our knowledge, this is the first reported data on 2 MeV proton tolerance of hydrogen-terminated diamond surfaces.

   ↳ cond-mat.mtrl-scinucl-ex0 citations
3. 03*

   Nuclear Matrix Elements for Heavy Ion Sequential Double Charge Exchange Reactions

   Horst Lenske🇩🇪 · Jessica Bellone🇮🇹 · Maria Colonna🇮🇹 · Danilo Gambacurta🇮🇹

   The theoretical approach to a sequential heavy ion double charge exchange reaction is presented. A brief introduction into the formal theory of second-order nuclear reactions and their application to Double Single Charge Exchange (DSCE) reactions by distorted wave theory is given, thereby completing the theoretical background to our recent work [1]. Formally, the DSCE reaction amplitudes are shown to be separable into superpositions of distortion factors, accounting for initial and final state ion--ion interactions, and nuclear matrix elements. A broad space is given to the construction of nuclear DSCE response functions on the basis of polarization propagator theory. The nuclear response tensors resemble the nuclear matrix elements of $2\nu \beta \beta$ decay in structure but contain in general a considerable more complex multipole and spin structure. The QRPA theory is used to derive explicit expressions for nuclear matrix elements (NMEs). The differences between the NME of the first and the second interaction vertexes in a DSCE reaction is elucidated. Reduction schemes for the transition form factors are discussed by investigating the closure approximation and the momentum structure of form factors. DSCE unit strength cross sections are derived.

   ↳ nucl-thnucl-exUniverse(2021)·27 citations
4. 04*

   Interpreting the charge-dependent flow and constraining the chiral magnetic wave with event shape engineering

   Chun-Zheng Wang🇨🇳 · Wen-Ya Wu🇨🇳 · Qi-Ye Shou🇨🇳 · Guo-Liang Ma🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳

   The charge asymmetry (Ach) dependence of anisotropic flow serves as an important tool to search for the chiral magnetic wave (CMW) in heavy-ion collisions. However, the background effect, such as the local charge conservation (LCC) entwined with collective flow, has not yet been unambiguously eliminated in the measurement. With the help of two models, the AMPT with initial quadrupole moment and the blast wave (BW) incorporating LCC, we discuss the features of the LCC-induced and the CMW-induced correlations between Ach and the flow. More importantly, we first propose to use the Event Shape Engineering (ESE) technique to distinguish the background and the signal for the CMW study. This method would be highly desirable in the experimental search for the CMW and provides more insights for understanding the charge-dependent collective motion of the quark-gluon plasma.

   ↳ nucl-thnucl-exPLB(2021)·16 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.