Thu·Jul 13, 2023Thursday·July 13, 2023

1. 01*

   Transverse Single-Spin Asymmetry for Inclusive and Diffractive Electromagnetic Jets at Forward Rapidity in $p^{\uparrow }$+p Collisions at $\sqrt{s}=200$ GeV and $510$ GeV at STAR

   Xilin Liang (for the STAR Collaboration)🇺🇸

   There have been numerous attempts, in the last decades, to understand the origin of the unexpectedly large transverse single-spin asymmetry ($A_N$) observed in inclusive hadron productions at forward rapidities in transversely polarized $p^{\uparrow }$+$p$ collisions at different center-of-mass energies ($\sqrt{s}$). The current theoretical frameworks aimed at explaining this puzzle include the twist-3 contributions in the collinear factorization framework, as well as the transverse-momentum-dependent contributions from the initial-state quark and gluon Sivers functions, and/or final-state Collins fragmentation functions. Besides, there are indications that the diffractive processes may contribute to the large $A_N$. We present the detailed investigations into the $A_N$ for electromagnetic jets (EM-jets) produced in inclusive processes using the Forward Meson Spectrometer with transversely polarized $p^{\uparrow }$+ $p$ data at $\sqrt{s}=$ 200 GeV collected in 2015 at STAR. We observe a negative value for the $A_N$ of EM-jets in diffractive processes. This finding shows a different sign for $A_N$ in inclusive processes and needs further theoretical input in order to be understood. Finally, we present the statistical projections of the $A_N$ for inclusive and diffractive EM-jets utilizing $p^{\uparrow }$+ $p$ data at $\sqrt{s}=$ 510 GeV collected in 2017 at STAR. This dataset allows for a substantial enhancement in statistical precision.

   nucl-ex1 citation
2. 02*

   Searching for universality of dineutron correlation at the surface of Borromean nuclei

   A.Corsi🇫🇷 · Y.Kubota🇯🇵 · J. Casal🇪🇸 · M.Gomez-Ramos🇪🇸 · A. M. Moro🇪🇸 · G. Authelet🇫🇷 · H. Baba🇯🇵 · C. Caesar🇩🇪 · D. Calvet🇫🇷 · A. Delbart🇫🇷 · M. Dozono🇯🇵 · J. Feng🇨🇳 and 56 other authors

   The dineutron correlation is systematically studied in three different Borromean nuclei near the neutron dripline, 11Li, 14Be and 17B, via the (p, pn) knockout reaction measured at the RIBF facility in RIKEN. For the three nuclei, the correlation angle between the valence neutrons is found to be largest in the same range of intrinsic momenta, which can be associated to the nuclear surface. This result reinforces the prediction that the formation of the dineutron is universal in environments with low neutron density, such as the surface of neutron-rich Borromean nuclei.

   nucl-exnucl-thPLB(2023)·14 citations
3. 03*

   Empirical radius formulas for canonical neutron stars from bidirectionally selecting EOS features in extended Bayesian analyses of observational data

   Jake Richter🇺🇸 · Bao-An Li🇺🇸

   Given the significant advancement in Bayesian inference of nuclear Equation of State (EOS) from gravitational wave and X-ray observations of neutron stars (NSs), especially since GW170817, is there a data-driven and robust empirical formula for the radius $R_{1.4}$ of canonical NSs in terms of the characteristic EOS parameters (features)? What is the single most important but currently poorly known EOS parameter for determining the $R_{1.4}$? We study these questions by extending the traditional Bayesian analysis which normally ends at presenting the marginalized posterior probability distribution functions (PDFs) of individual EOS parameters and their correlations (or sometimes only the Pearson correlation coefficients which are only reliably useful when the variables are linearly correlated while they are actually often not). Using three regression model-building methodologies: bidirectional step-wise feature selection, Least Absolute Shrinkage Selection Operator (LASSO) regression, and neural network regression on a large set of posterior EOSs and the corresponding $R_{1.4}$ values inferred from earlier comprehensive Bayesian analyses of NS observational data, we systematically and rigorously develop the most probable $R_{1.4}$ formulas with varying statistical accuracy and technical complexity. The most important EOS parameters for determining $R_{1.4}$ are found consistently in each of the feature/model selection processes to be (in order of decreasing importance): curvature $K_{sym}$, slope $L$, skewness $J_{sym}$ of nuclear symmetry energy, skewness $J_0$, incompressibility $K_0$ of symmetric nuclear matter, and the magnitude $E_{sym}({\rho }_0)$ of symmetry energy at the saturation density ${\rho }_0$ of nuclear matter.

   ↳ nucl-thastro-ph.HEnucl-exPRC(2023)·20 citations
4. 04*

   State dependence of tunneling processes and thermonuclear fusion

   Roberto Onofrio🇺🇸 · Carlo Presilla

   We discuss the sensitivity of tunneling processes to the initial preparation of the quantum state. We compare the case of Gaussian wave packets of different positional variances using a generalised Woods-Saxon potential for which analytical expressions of the tunneling coefficients are available. Using realistic parameters for barrier potentials we find that the usual plane wave approximation underestimates fusion reactivities by an order of magnitude in a range of temperatures of practical relevance for controlled energy production.

   ↳ quant-phnucl-exnucl-thNPA(2024)·1 citation

* 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.