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arXiv 1411.2004hep-phhep-lat
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格点量子色动力学耦合$πK, ηK$散射的共振

Resonances in coupled $πK, ηK$ scattering from lattice QCD

David J. Wilson, Jozef J. Dudek, Robert G. Edwards, Christopher E. Thomas

摘要:

通过研究由动态格点量子色动力学计算得到的有限体积能谱,确定了耦合道$πK$和$ηK$散射振幅。使用大量的插值算子,包括类似于$q\bar{q}$结构的算子和类似于具有相对动量的介子对的算子,可以得到可靠的激发态谱。在${m_π=391\,\mathrm{MeV}}$工作时,我们发现$J^P=0^+$ $πK$相移逐渐增加,这可以用强耦合到$πK$和弱耦合到$ηK$的宽标量共振来识别。这种振幅的低能量行为表明可能与$κ$共振有关的虚拟束缚态。与$J^P=1^-$的束缚态被发现非常接近的$πK$的阈值能量,其耦合到$πK$通道是兼容的实验$K^\star(892)$。在$J^P=2^+$中发现了窄共振的证据。还研究了同位旋3/2 $πK$散射,得到了跨越整个弹性散射区的非共振相移。

英文摘要:

Coupled-channel $πK$ and $ηK$ scattering amplitudes are determined by studying the finite-volume energy spectra obtained from dynamical lattice QCD calculations. Using a large basis of interpolating operators, including both those resembling a $q\bar{q}$ construction and those resembling a pair of mesons with relative momentum, a reliable excited-state spectrum can be obtained. Working at ${m_π=391\,\mathrm{MeV}}$, we find a gradual increase in the $J^P=0^+$ $πK$ phase-shift which may be identified with a broad scalar resonance that couples strongly to $πK$ and weakly to $ηK$. The low-energy behavior of this amplitude suggests a virtual bound-state that may be related to the $κ$ resonance. A bound state with $J^P=1^-$ is found very close to the $πK$ threshold energy, whose coupling to the $πK$ channel is compatible with that of the experimental $K^\star(892)$. Evidence is found for a narrow resonance in $J^P=2^+$. Isospin--3/2 $πK$ scattering is also studied and non-resonant phase-shifts spanning the whole elastic scattering region are obtained.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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