We consider a possible resummation of subleading effects in two-body systems with a large scattering length as described by a short-range effective field theory (EFT). In particular, we investigate the consequences of a resummation of part of the range corrections. Explicit calculations of the two-body phase shifts and charge form factor indicate that, except for extreme choices, resummations do not alter the convergence of the EFT expansion and are often beneficial at lowest orders. We have considered the expansion when the regulator cutoff is removed as well as when it is finite, and find that the cutoff is not an important factor for resummations. Our results connect with other works where the partial resummation is induced by potentials with finite cutoffs or interaction ranges.
Two-body and Three-body Contacts for Identical Bosons near Unitarity
在最近的超冷囚禁Rb-85原子的实验中，Makotyn等人研究了量子简并玻色气体在幺正极限下的散射长度无限大。我们发现，所观察到的动量分布是兼容的一个普遍的关系，表示高动量尾巴的2体和3体接触。我们确定了数密度n约为20 n ^{4/3}和2 n ^{5/3}的幺正玻色气体的两体和三体接触密度。我们还表明，所观察到的原子损失率与3原子非弹性碰撞的损失率是一致的，它的贡献与三体接触成正比，但与2原子非弹性碰撞的损失率是不一致的，它的贡献与2体接触成正比.指出在么正性附近和么正性处利用维里定理可以独立地测量接触。
Partial-wave decomposition of isospin-projected subleading three-nucleon contact interactions
European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT ∗ ) and Fondazione Bruno Kessler（欧洲核物理及相关领域理论研究中心和布鲁诺·凯塞尔基金会）；Department of Mathematics and Physics “E. De Giorgi”, University of Salento（萨莱托大学“E. 德乔治”数学与物理系）；Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Lecce（意大利国家核物理研究所莱切分部）
