Soft-Gluon-Pole Contribution in Single Transverse-Spin Asymmetries of Drell-Yan Processes

We use multi-parton states to examine the leading order collinear factorization of single transverse-spin asymmetries in Drell-Yan processes. Twist-3 operators are involved in the factorization. We find that the so-called soft-gluon-pole contribution in the factorization must exist in order to make the factorization correct. This contribution comes from the corresponding cross-section at one-loop, while the hard-pole contribution in the factorization comes from the cross-section at tree-level. Although the two contributions come from results at different orders, their perturbative coefficient functions in the factorization are at the same order. This is in contrast to factorizations only involving twist-2 operators. The soft-gluon-pole contribution found in this work is in agreement with that derived in a different way. For the hard-pole contributions we find an extra contribution from an extra parton process contributing to the asymmetries. We also solve a part of discrepancy in evolutions of the twist-3 operator. The method presented here for analyzing the factorization can be generalized to other processes and can be easily used for studying factorizations at higher orders, because the involved calculations are of standard scattering amplitudes.Comment: typos eliminated. Published in JHEP 1104:062,201

The Spin Structure of the Nucleon

We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure

Oral fludarabine and cyclophosphamide as front-line chemotherapy in patients with chronic lymphocytic leukemia. The impact of biological parameters in the response duration

We tested the efficacy and safety of oral fludarabine and cyclophosphamide as front-line therapy in chronic lymphocytic leukemia (CLL) and assessed the influence of immunoglobulin variable region heavy chain (IgVH) gene mutation status, interphase cytogenetic abnormalities, and expression of ZAP-70 and CD38 on clinical outcome. Thirty-seven patients with previously untreated CLL received oral fludarabine (30 mg m(2)) and oral cyclophosphamide (250 mg m(2)) for three consecutive days every 4 weeks for six cycles. Eighteen patients had unmutated and 15 had mutated IgVH genes. Nine patients had the 'high risk' cytogenetic abnormality del(11q22.3) or del(17p13.1). Fifteen patients were ZAP-70-positive and eight patients were CD38-positive. Among the 35 valuable patients, 14 patients (40%) obtained a complete response and 13 (37%) a partial response. The median progression-free survival (PFS) was 23 months and median time to re-treatment (TTR) was 38 months. A significantly lower overall response rate (43% vs. 85%, p = 0.011), a shorter PFS (22 vs. 27 months, p = 0.015), and a shorter TTR (22 vs. 40 months, p = 0.031) were noticed in the 'high risk' cytogenetic abnormalities group; TTR was also shorter in IgVH-unmutated than in IgVH-mutated patients (26 vs. 41 months, p = 0.035). Hematologic toxicity included grade IV neutropenia (ten patients) and grade III/IV anemia (three patients). Gastrointestinal toxicity was mild and no patient required hospitalization. The oral combination of fludarabine and cyclophosphamide is an effective, safe, and well-tolerated regimen that, if confirmed with larger series, will be appropriate especially in patients with low risk biological parameters