迈向质子形状因子问题的解决：新的电子与正电子散射数据
核实验
2015-06-23 v1
摘要
利用非极化和极化电子散射提取的质子电荷形状因子 数值之间存在显著差异。理论计算预测，微小的双光子交换 (TPE) 贡献会显著影响从非极化电子 - 质子截面中提取 的结果。我们通过使用同时产生的次级电子 - 正电子束流轰击液氢靶，并在 Jefferson Lab CLAS 探测器中探测散射粒子，测量了正电子 - 质子与电子 - 质子弹性散射截面的比值，从而确定了 TPE 贡献。这种新技术使我们能够同时覆盖广泛的虚光子极化 () 和动量转移 () 范围，并抵消与亮度相关的系统误差。在 时，截面比值随 的减小而增加。该测量结果与 GeV 处的形状因子差异大小一致，也与包含核子和 中间态的强子计算一致，后者已被证明可解决高达 GeV 的差异。
引用
@article{arxiv.1411.6908,
title = {Towards a resolution of the proton form factor problem: new electron and positron scattering data},
author = {D. Adikaram and D. Rimal and L. B. Weinstein and B. Raue and P. Khetarpal and R. P. Bennett and J. Arrington and W. K. Brooks and K. P. Adhikari and A. V. Afanasev and M. J. Amaryan and M. D. Anderson and J. Ball and M. Battaglieri and I. Bedlinskiy and A. S. Biselli and J. Bono and S. Boiarinov and W. J. Briscoe and V. D. Burkert and D. S. Carman and A. Celentano and S. Chandavar and G. Charles and L. Colaneri and P. L. Cole and M. Contalbrigo and A. D'Angelo and N. Dashyan and R. De Vita and E. De Sanctis and A. Deur and C. Djalali and G. E. Dodge and R. Dupre and H. Egiyan and A. El Alaoui and L. El Fassi and P. Eugenio and G. Fedotov and S. Fegan and A. Filippi and J. A. Fleming and A. Fradi and G. P. Gilfoyle and K. L. Giovanetti and F. X. Girod and J. T. Goetz and W. Gohn and E. Golovatch and R. W. Gothe and K. A. Griffioen and M. Guidal and L. Guo and K. Hafidi and H. Hakobyan and N. Harrison and M. Hattawy and K. Hicks and M. Holtrop and S. M. Hughes and C. E. Hyde and Y. Ilieva and D. G. Ireland and B. S. Ishkhanov and D. Jenkins and H. Jiang and K. Joo and S. Joosten and M. Khandaker and W. Kim and A. Klein and F. J. Klein and S. Koirala and V. Kubarovsky and S. E. Kuhn and H. Y. Lu and I . J . D. MacGregor and N. Markov and M. Mayer and B. McKinnon and M. D. Mestayer and C. A. Meyer and M. Mirazita and V. Mokeev and R. A. Montgomery and C. I. Moody and H. Moutarde and A Movsisyan and C. Munoz Camacho and P. Nadel-Turonski and S. Niccolai and G. Niculescu and M. Osipenko and A. I. Ostrovidov and K. Park and E. Pasyuk and S. Pisano and O. Pogorelko and S. Procureur and Y. Prok and D. Protopopescu and A. J. R. Puckett and M. Ripani and A. Rizzo and G. Rosner and P. Rossi and F. Sabatié and D. Schott and R. A. Schumacher and Y. G. Sharabian and A. Simonyan and I. Skorodumina and E. S. Smith and G. D. Smith and D. I. Sober and N. Sparveris and S. Stepanyan and S. Strauch and V. Sytnik and M. Taiuti and Ye Tian and A. Trivedi and M. Ungaro and H. Voskanyan and E. Voutier and N. K. Walford and D. P. Watts and X. Wei and M. H. Wood and N. Zachariou and L. Zana and J. Zhang and Z. W. Zhao and I. Zonta and The CLAS Collaboration},
journal= {arXiv preprint arXiv:1411.6908},
year = {2015}
}
备注
6 pages, 4 figures, submitted to PRL