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arXiv 1407.0437nucl-thhep-phnucl-ex
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有效场论中接触区电流的功率计算

Power Counting of Contact-Range Currents in Effective Field Theory

M. Pavón Valderrama, Daniel R. Phillips

摘要:

本文分析了核有效场论(EFT)中的二体电流功率计数。我们发现,在低能量的非微扰物理的存在,这是表现在存在的氘核和1S0 NN虚拟束缚态,结合出现在版本的核EFT,将手征对称性,修改与接触算子,涉及核子核子对和外场的耦合的重整化群流的奇异位。这些耦合的顺序,从而提高相对于朴素的维度分析估计。因此,短程电流进入手征EFT的阶数比迄今为止所认识到的要低,它们对低能可观测量的影响也随之更大。我们说明了一些低能量的过程,涉及外部探针和几个核子系统,包括电子-氘核弹性散射和辐射中子质子捕获的功率计数的变化。

英文摘要:

We analyze the power counting of two-body currents in nuclear effective field theories (EFTs). We find that the existence of non-perturbative physics at low energies, which is manifest in the existence of the deuteron and the 1S0 NN virtual bound state, combined with the appearance of singular potentials in versions of nuclear EFT that incorporate chiral symmetry, modifies the renormalization-group flow of the couplings associated with contact operators that involve nucleon-nucleon pairs and external fields. The order of these couplings is thereby enhanced with respect to the naive-dimensional-analysis estimate. Consequently, short-range currents enter at a lower order in the chiral EFT than has been appreciated up until now, and their impact on low-energy observables is concomitantly larger. We illustrate the changes in the power counting with a few low-energy processes involving external probes and the few-nucleon systems, including electron-deuteron elastic scattering and radiative neutron capture by protons.

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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