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北美退伍军人节(Veterans Day),12 日无更新
arXiv 0908.4405nucl-thhep-phnucl-ex
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来自IR手性EFT的PDKEEPAAA电位

NN potentials from IR chiral EFT

Renato Higa

摘要:

手征微扰论是目前一种将手征约束引入量子色动力学的成熟方法。然而,对于包含一个重子的系统,决定可观测量手征序的幂次计数并不像纯介子情况那样简单和一致。重子方法依赖于无限重重子极限附近的非相对论展开,恢复了通常的功率计数,但破坏了散射振幅的某些分析性质。几年前,Becher和Leutwyler提出了一种洛伦兹不变的手征微扰理论,它保持了所需的分析性质,但代价是不太直观的功率计数。意识到重子形式主义的缺点,圣保罗小组根据贝歇和洛伊特韦勒的工作导出了核子-核子势的2 π交换分量。一个引人注目的结果是,势的长距离性质是由重子展开失效的π-核子散射振幅的特定低能区决定的。在这次演讲中,我将讨论这种失败的起源,以及它如何反映在核子-核子相互作用的渐近性中。一些结果的相移和氘核的性质将显示,然后与重子的预测进行比较。

英文摘要:

Chiral perturbation theory is nowadays a well-established approach to incorporate the chiral constraints from QCD. Nevertheless, for systems involving one baryon, the power counting which dictates the chiral order of observables is not as simple and consensual as in the purely mesonic case. The heavy baryon approach, which relies on a non-relativistic expansion around the limit of infinitely heavy baryon, recovers the usual power counting but destroys some analytic properties of the scattering amplitude. Some years ago, Becher and Leutwyler proposed a Lorentz-invariant formulation of chiral perturbation theory that maintains the required analytic properties, but at the expense of a less intuitive power counting. Aware of the shortcomings of the heavy baryon formalism, the São Paulo group derived the two-pion exchange component of the nucleon-nucleon potential in line with the works of Becher and Leutwyler. A striking result was that the long distance properties of the potential is determined by the specific low energy region of the pion-nucleon scattering amplitude where the heavy baryon expansion fails. In this talk I will discuss the origin of such failure and how it reflects in the asymptotics of the nucleon-nucleon interaction. Some results for phase shifts and deuteron properties will be shown, followed by a comparison with the heavy baryon predictions.

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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