Tue·Oct 25, 2022Tuesday·October 25, 2022

1. 01*

   Hunting for an EMC-like effect for antiquarks

   Massimiliano Alvioli🇮🇹 · Mark Strikman🇺🇸

   We argue that the Drell-Yan process in the $x_A\ge 0.15$ kinematics recently studied at FNAL by the E906/SeaQuest experiment may allow to observe an analogous of the EMC effect for antiquarks. The effects of Fermi motion and energy loss are considered. The preliminary E906/SeaQuest data are inconsistent with the growth of the ${\sigma }_A/A{\sigma }_N$ ratio expected in the Fermi motion scenario at $x_A\ge 0.25$. The pattern of the $x_A$ dependence of the ratio seems also inconsistent with a scenario in which the dominant nuclear effect is a suppression of the cross section due to the energy loss experienced by a quark of the projectile proton involved in the Drell-Yan process. All together the data suggest the possibility of a modification of the antiquark parton distributions in nuclei, with a pattern similar to the one observed in the EMC effect. We argue that optimal kinematics to look for an antiquark EMC-like effect would be to measure the ${\sigma }_A^{DY}/A{\sigma }_N^{DY}$ ratios for $x_A$ = 0.2-0.4 and $x_p$ $\approx$ constant.

   ↳ hep-phhep-exnucl-exnucl-thPLB(2023)·1 citation
2. 02*

   Further understanding the nature of $a_0(1710)$ in the $D_s^{+}\to {\pi }^0{K}^{+}{K}_S^0$ decay

   Xin Zhu🇨🇳 · Hao-Nan Wang🇨🇳 · De-Min Li🇨🇳 · En Wang🇨🇳 · Li-Sheng Geng🇨🇳 · Ju-Jun Xie🇨🇳

   Based on our previous work about the role of $a_0(1710)$ in the $D_s^{+}\to {\pi }^{+}{K}_S^0{K}_S^0$ decay [Phy. Rev. D 105, 116010 (2022)], we perform a further theoretical study of $a_0(1710{)}^{+}$ in the process $D_s^{+}\to {\pi }^0{a}_0(1710{)}^{+}\to {\pi }^0{K}^{+}{K}_S^0$. In addition to $a_0(1710)$, the contributions of $K^{\ast }$ and $a_0(980)$ are also taken into account. Firstly, we consider the contributions from the tree diagrams of $K^{\ast +}\to K^{+}{\pi }^0$ and ${\bar{K}}^{\ast 0}\to {\pi }^0{\bar{K}}^0$. Secondly, we describe the final state interaction of $K\bar{K}$ in the chiral unitary approach to study the contribution of $a_0(980)$, while the $a_0(1710)$ state is dynamically generated from the $K^{\ast }{\bar{K}}^{\ast }$ interaction, and then decays into $K^{+}{\bar{K}}^0$. Since the final $K^{+}{K}_S^0$ state is in pure isospin $I=1$, the $D_s^{+}\to {\pi }^0{K}^{+}{K}_s^0$ decay is an ideal process to study the $a_0(1710{)}^{+}$ and $a_0(980{)}^{+}$ resonances. Based on our theoretical calculations, it is found that the recent experimental measurements on the $K^{+}{K}_S^0$, ${\pi }^0{K}^{+}$, and ${\pi }^0{K}_S^0$ invariant mass distributions can be well reproduced, which supports the molecular $K^{\ast }{\bar{K}}^{\ast }$ nature of the scalar $a_0(1710)$ resonance.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2023)·32 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.