TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
Phys Rev Lett. 2013 Oct 4;111(14):143402. doi: 10.1103/PhysRevLett.111.143402. Epub 2013 Oct 3.
Stimulated by the proton radius conundrum, measurements of the Lamb shift in various light muonic atoms are planned at PSI. The aim is to extract the rms charge radius with high precision, limited by the uncertainty in the nuclear polarization corrections. We present an ab initio calculation of the nuclear polarization for μ(4)He(+) leading to an energy correction in the 2S-2P transitions of δ(pol)(A)=-2.47 meV ±6%. We use two different state-of-the-art nuclear Hamiltonians and utilize the Lorentz integral transform with hyperspherical harmonics expansion as few-body methods. We take into account the leading multipole contributions, plus Coulomb, relativistic, and finite-nucleon-size corrections. Our main source of uncertainty is the nuclear Hamiltonian, which currently limits the attainable accuracy. Our predictions considerably reduce the uncertainty with respect to previous estimates and should be instrumental to the μ(4)He(+) experiment planned for 2013.
受质子半径佯谬的刺激，计划在 PSI 对各种轻μ子原子的兰姆位移进行测量。目的是通过不确定的核极化修正来高精度地提取均方根电荷半径。我们提出了一种μ(4)He(+)的核极化的从头计算，导致在 2S-2P 跃迁中能量修正为δ(pol)(A)=-2.47 meV ±6%。我们使用了两种不同的最先进的核哈密顿量，并利用了带有超球谐展开的洛伦兹积分变换作为少体方法。我们考虑了主要的多极贡献，加上库仑、相对论和有限核大小修正。我们的不确定性主要来源是核哈密顿量，这目前限制了可达到的精度。我们的预测大大降低了与以前估计的不确定性，并应有助于计划于 2013 年进行的μ(4)He(+)实验。
