Exotic candidates with heavy quark(s)

In the last decades, the number of exotic candidates which are beyond the conventional quark model has grown dramatically. At the same time, numerous theoretical interpretations, such as tetraquark, hybrid, hadroquarkonium and hadronic molecule, have been proposed to understand their nature. In principle, all the configurations with the same quantum numbers can mix with each other. Thus at present we aim at identifying the prominent component. As an extended object, a hadronic molecule has some distinguishable features from other more compact configurations. In the end, the two $Z_b$ states are used to illustrate some features of the molecular scenario.Comment: XVII International Conference on Hadron Spectroscopy and Structure - Hadron201

A geometric perspective on the method of descent

We derive a representation formula for the tensorial wave equation \Box_\bg \phi^I=F^I in globally hyperbolic Lorentzian spacetimes (\M^{2+1}, \bg) by giving a geometric formulation of the method of descent which is applicable for any dimension

Mothers’ Perceptions of Stress, Parenting Self-Efficacy, and Permissive and Inconsistent Discipline: Insights from China, Japan, and the United States

Decades of parenting research has shown that heightened stress may interrupt the parenting process and negatively affect the child and the family. However, most existing studies have primarily focused on how stress can undermine parenting, and relatively few have attended to the role of cognitive appraisal in shaping the interpretation and ultimate effects of stressful conditions on parenting behavior. Following theoretical recommendations associated with social cognitive theory as well as transactional theory of stress and coping, the current study examined the association of psychological stress to mothers’ use of inconsistent and permissive discipline, focusing particularly on the mediating role of parenting self-efficacy (PSE) in the link between perceived stress and parental discipline. Separate path analyses were conducted with survey data collected from a total of 540 mothers of young children in China (n = 113), Japan (n = 262) and the United States (n = 165). Results indicated significant associations among mothers’ perceived stress, PSE, as well as permissive and inconsistent discipline in all three samples, with exceptions in the Chinese sample. Furthermore, path models supported the mediating effect of PSE in the link between mothers perceived stress and the inconsistent parenting in all three samples. In the US and Japanese samples, PSE also mediated the relationship between stress and permissiveness. Overall, these findings suggest the important role of PSE in parents’ stress and coping processes across diverse contexts as well but also underscore the importance of examining relevant sociocultural factors that might also contribute to the salience and strength of certain associations

Search for JPC=1−+J^{PC}=1^{-+} exotic state in e+e−e^+e^- annihilation

The charmed meson pair $(\frac{3}{2})^+$ and anti-$(\frac{1}{2})^-$, i.e. $D_1(2420)\bar D+c.c.$, $D_1(2420)\bar D^*+c.c.$, $D_2(2460)\bar D^*+c.c.$, can couple to states with vector quantum number $J^{PC}=1^{--}$ and exotic quantum number $J^{PC}=1^{-+}$ in a relative $S$ wave. Near threshold, the charmed meson pair may form hadronic molecules due to the strong $S$-wave coupling, and the mysterious vector state $Y(4260)$ could be such a state of the $D_1(2420)\bar D+c.c.$ molecule. This implies the possible existence of its exotic partner made of the same charmed mesons but with $J^{PC}=1^{-+}$. We evaluate the production rate of such exotic hadronic molecules and propose a direct experimental search for them in $e^+e^-$ annihilation. The confirmation of such exotic states in experiment will shed light on the spectrum in the heavy quark sector.Comment: 5 pages, 3 figure