arXiv subjects

Na-Na Ma

Publications and source records attributed to Na-Na Ma.

4 recordsLinked to original sources

arXiv2024

A sign of three-nucleon short-range correlation from an analysis of nuclear mass and short-range correlation probability

Three-nucleon short-range correlation ($3N$ SRC) represents a rare and intriguing part of the nuclear dynamics at short distance, beyond the two-nucleon short-range correlation ($2N$ SRC). To search its existence is a hot topic in the ongoing and future high-energy nuclear experiments and the developments of nuclear theory. In this study, we found a positive sign of $3N$ SRC in nuclei, by analyzing the correlation between the per-nucleon nuclear mass and the probability of a nucleon in $2N$ SRC state, with the current experimental measurements of $^2$H, $^3$He, $^4$He, $^9$Be, $^{12}$C, $^{27}$Al, $^{56}$Fe, Cu, $^{197}$Au and $^{208}$Pb from SLAC, CLAS, and JLab Hall C collaborations. The effective masses of the nucleons in $2N$ SRC and $3N$ SRC are also extracted from the analysis, which provide some references for the nuclear medium effect study. The probability of $3N$ SRC is much smaller than that of $2N$ SRC, thus requiring high-luminosity experiments to confirm its existence.

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arXiv2024

The European Muon Collaboration effect from short-range correlated nucleons in a nucleon swelling model

The relation between the nuclear EMC effect and the nucleon-nucleon short-range correlation is a hot topic in high-energy nuclear physics, ever since a peculiar linear correlation between these two phenomena discovered. In this paper, the contribution to the nuclear EMC effect arising from the short-range correlated nucleons is examined in a nucleon-swelling model. We find that the structure modifications of the N-N SRC nucleons reproduce more or less the measured EMC ratios of light nuclei, while they are not enough to explain the measured EMC ratios of heavy nuclei. We speculate that the hypothesis of causal connection between SRC and the EMC effect is not exact, or the universality of the inner structure of SRC nucleon is violated noticeably from light to heavy nuclei, or there are other origins for the EMC effect.

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arXiv2023

The European Muon Collaboration effect from short-range correlated nucleons in a $x$-rescaling model

In this paper, we examine the hypothesis that the nuclear EMC effect comes merely from the N-N SRC pairs inside the nucleus and that the properties of N-N SRC pair are universal among the various nuclei, using the conventional $x$-rescaling model for the EMC effect. With the previously determined effective mass of the short-range correlated nucleon and the number of N-N SRC pairs estimated, we calculate the EMC effect of various nuclei within the $x$-rescaling approach. From our calculations, the nuclear EMC effect due to the mass deficits of the SRC nucleons is not enough to reproduce the observed EMC effect in experiments. We speculate that the internal structure of the mean-field single nucleon is also obviously modified, or there are more origins of the EMC effect beyond the N-N SRC configuration (such as the $α$ cluster), or the universality of N-N SRC pair is violated noticeably from light to heavy nuclei.

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arXiv2021

Nuclear Fermi Momenta of $^{2}$H, $^{27}$Al and $^{56}$Fe from an Analysis of CLAS data

Nuclear Fermi momentum is a basic property of a nucleus where many nucleons dwell. However, in experiments only the nuclear Fermi momenta of just a few nuclei are measured using quasielastic electron scattering on the nuclear targets so far. Particularly, we still do not know experimentally the Fermi momentum of the lightest nucleon composite -- the deuteron. In this paper, we apply both gaussian distribution and Cauchy distribution to describe the quasielastic peak in the cross section of electron-nucleus scattering. The dip of the cross-section ratio at about $x_{\rm B}=1$ is explained with the nuclear Fermi momentum. By performing the least-square fits to the published CLAS data in the narrow kinematic region of quasielastic scattering, we obtain the nuclear Fermi momenta of $^{2}$H, $^{27}$Al and $^{56}$Fe, which are $116\pm 7$ MeV/c, $232\pm 27$ MeV/c, and $244\pm 28$ MeV/c respectively. The extracted nuclear Fermi momenta are compared to the simple calculations based on Fermi gas model, and the consistencies are found.

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