Mon·Sep 6, 2021Monday·September 6, 2021

1. 01*

   Strange and charm contributions to nucleon charges and moments

   Rui Zhang🇺🇸 · Tanmoy Bhattacharya🇺🇸 · Rajan Gupta🇺🇸 · Huey-Wen Lin🇺🇸 · Santanu Mondal🇺🇸 · Sungwoo Park🇺🇸 · Boram Yoon🇺🇸

   We present preliminary results for strange and charm contributions to nucleon charges and moments. The scalar, axial and tensor charges, and unpolarized first moments are calculated using clover-on-HISQ formulation and cover four lattice spacings, $a=\{0.06,0.09,0.12,0.15\}$~fm, and three pion masses, $M_{\pi }=\{310,220,130\}$~MeV. The renormalization factors are calculated nonperturbatively using the RI-sMOM scheme. We carry out a chiral and continuum extrapolation to obtain physical results.

   hep-latPoS(2022)·0 citations
2. 02*

   Towards high partial waves in lattice QCD with a dumbbell-like operator

   Jia-Jun Wu🇨🇳 · Waseem Kamleh🇦🇺 · Derek B. Leinweber🇦🇺 · Yan Li🇨🇳 · Gerrit Schierholz🇩🇪 · Ross D. Young🇦🇺 · James M. Zanotti🇦🇺

   An extended two-hadron operator is developed to extract the spectra of irreducible representations (irreps) in the finite volume. The irreps of the group for the finite volume system are projected using a coordinate-space operator. The correlation function of this operator is computationally efficient to extract lattice spectra of the specific irrep. In particular, this new formulation only requires propagators to be computed from two distinct source locations, at fixed spatial separation. We perform a proof-of-principle study on a $24^3\times 48$ lattice volume with $m_{\pi }\approx 900$ MeV by isolating various spectra of the $\pi \pi$ system with isospin-2 including a range of total momenta and irreps. By applying the Lüscher formalism, the phase shifts of $S$-, $D$- and $G$-wave $\pi \pi$ scattering with isospin-2 are extracted from the spectra.

   hep-latPRD(2022)·5 citations
3. 03*

   Revisit the isospin violating decays of $X(3872)$

   Lu Meng🇩🇪 · Guang-Juan Wang🇯🇵 · Bo Wang🇨🇳 · Shi-Lin Zhu🇨🇳

   In this work, we revisit the isospin violating decays of $X(3872)$ in a coupled-channel effective field theory. In the molecular scheme, the $X(3872)$ is interpreted as the bound state of ${\bar{D}}^{\ast 0}{D}^0/{\bar{D}}^0{D}^{\ast 0}$ and $D^{\ast -}{D}^{+}/D^{-}{D}^{\ast +}$ channels. In a cutoff-independent formalism, we relate the coupling constants of $X(3872)$ with the two channels to the molecular wave function. The isospin violating decays of $X(3872)$ are obtained by two equivalent approaches, which amend some deficiencies about this issue in literature. In the quantum field theory approach, the isospin violating decays arise from the coupling constants of $X(3872)$ to two di-meson channels. In the quantum mechanics approach, the isospin violating is attributed to wave functions at the origin. We illustrate that how to cure the insufficient results in literature. Within the comprehensive analysis, we bridge the isospin violating decays of $X(3872)$ to its inner structure. Our results show that the proportion of the neutral channel in $X(3872)$ is over $80\%$. As a by-product, we calculate the strong decay width of $X(3872)\to {\bar{D}}^0{D}^0{\pi }^0$ and radiative one $X(3872)\to {\bar{D}}^0{D}^0\gamma$. The strong decay width and radiative decay width are about 30 keV and 10 keV, respectively, for the binding energy from $-300$ keV to $-50$ keV.

   ↳ hep-phhep-exhep-latnucl-thPRD(2021)·36 citations
4. 04*

   The QCD Equation of State in Small Systems

   W. A. Horowitz🇿🇦 · Alexander Rothkopf🇳🇴

   We present first results on finite system size corrections to the equation of state, trace anomaly, and speed of sound for two model systems: 1) free, massless scalar theory and 2) quenched QCD with periodic boundary conditions (PBC). We further present work-in-progress results for quenched QCD with Dirichlet boundary conditions.

   ↳ hep-phhep-latnucl-thSciPost Phys.Proc.(2022)·12 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.