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喷注中的夸克碎裂

Quark Fragmentation within an Identified Jet

Massimiliano Procura, Iain W. Stewart

备注：
26 pages, 2 figures; v3: small correction to eq.(72)
发表信息：
Phys.Rev.D81:074009,2010; Erratum-ibid.D83:039902,2011
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摘要：

我们推导出一个因式分解定理，描述了一个充满活力的强子h从一个喷流产生的部分子i，其中喷流不变质量的测量分裂。分析得到一个“碎裂喷流函数”G_i^h（s，z），它依赖于喷流不变质量s和碎裂强子的能量分数z。我们表明，G^h_i可以计算的微扰计算系数，J_{ij}（s，z/x），对标准的非微扰碎裂功能，D_j^{h}（x）集成。我们还证明了z G_i^h（s，z）在z上的积分在h上的和由标准包含喷流函数J_i（s）给出，该喷流函数J_i（s）在QCD中是可微扰计算的。我们使用软共线有效理论，为了简单起见，我们推导了一个单喷流过程，B -> X h l nu，质量不变，m_{X h} ^2>> λ_QCD ^2。我们的分析给出了一个简单的替换规则，它允许任何依赖于包含喷流函数J_i的因式分解定理转化为包含分裂强子h的半包含过程.我们应用这一规则导出了B -> X K γ的因式分解定理，它是在b -> s γ中分裂成K介子，以及e^+e^->（双射）+h的因式分解定理，其中测量了半球双射不变质量。

英文摘要：

We derive a factorization theorem that describes an energetic hadron h fragmenting from a jet produced by a parton i, where the jet invariant mass is measured. The analysis yields a "fragmenting jet function" G_i^h(s,z) that depends on the jet invariant mass s, and on the energy fraction z of the fragmentation hadron. We show that G^h_i can be computed in terms of perturbatively calculable coefficients, J_{ij}(s,z/x), integrated against standard non-perturbative fragmentation functions, D_j^{h}(x). We also show that the sum over h of the integral over z of z G_i^h(s,z) is given by the standard inclusive jet function J_i(s) which is perturbatively calculable in QCD. We use Soft-Collinear Effective Theory and for simplicity carry out our derivation for a process with a single jet, B -> X h l nu, with invariant mass m_{X h}^2 >> Lambda_QCD^2. Our analysis yields a simple replacement rule that allows any factorization theorem depending on an inclusive jet function J_i to be converted to a semi-inclusive process with a fragmenting hadron h. We apply this rule to derive factorization theorems for B -> X K gamma which is the fragmentation to a Kaon in b -> s gamma, and for e^+e^- -> (dijets)+h with measured hemisphere dijet invariant masses.

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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