Singular and Regular Gauges in Soft Collinear Effective Theory: The Introduction of the New Wilson Line T
| Autor: | Idilbi, Ahmad, Scimemi, Ignazio |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | Phys.Lett.B695:463-468,2011 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.physletb.2010.11.060 |
| Popis: | Gauge invariance in soft-collinear effective theory (SCET) is discussed in regular (covariant) and singular (light-cone) gauges. It is argued that SCET, as it stands, is not capable to define in a gauge invariant way certain non-perturbative matrix elements that are an integral part of many factorization theorems. Those matrix elements involve two quark or gluon fields separated not only in light-cone direction but also in the transverse one. This observation limits the range of applicability of SCET. To remedy this we argue that one needs to introduce a new Wilson line as part of SCET formalism, that we call T. This Wilson line depends only on the transverse component of the gluon field. As such it is a new feature to the SCET formalism and it guarantees gauge invariance of the non-perturbative matrix elements in both classes of gauges. Comment: Version to appear in Phys. Lett. B. The discussion of the zero-bin subtraction is modified. Some typos corrected |
| Databáze: | arXiv |
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