How strange is pion electroproduction
How strange is pion electroproduction
复制标题
介子电产生有多奇怪
DOI：
10.1016/j.physletb.2015.11.038
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发表时间：
2015
影响因子：
4.4
通讯作者：
Xilin Zhang
中科院分区：
文献类型：
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作者：
M. Gorchtein;H. Spiesberger;Xilin Zhang
在具有么正性的分波分析框架下，考虑了核子奇异性存在下宇称破坏电子散射（PVES）中的π介子产生。利用在弹性PVES中得到的奇异形状因子的实验界，我们研究了宇称破坏不对称性对奇异核子形状因子的敏感性。对于正向运动学和电子能量超过1 GeV，我们观察到，这种灵敏度可以达到约20%的阈值区域。由于宇称违反不对称性高达数十ppm，这项研究表明，PVES中的阈值π介子生产可以作为一种有前途的方法来更好地约束奇异贡献。利用这个中性流π介子产生模型，我们修正了色散γ Z盒修正对质子弱电荷的估计.在Qweak实验的运动学中，我们的新预测是Re□ γ Z V（E= 1.165 GeV）=（5.58±1.41）× 10− 3，比之前的不确定度估计±2.0× 10− 3有了改进。我们对即将到来的梅萨/P2实验的运动学的新预测是：Re□ γ Z V（E= 0.155 GeV）=（1.1±0.2）× 10− 3。
We consider pion production in parity-violating electron scattering (PVES) in the presence of nucleon strangeness in the framework of partial wave analysis with unitarity. Using the experimental bounds on the strange form factors obtained in elastic PVES, we study the sensitivity of the parity-violating asymmetry to strange nucleon form factors. For forward kinematics and electron energies above 1 GeV, we observe that this sensitivity may reach about 20% in the threshold region. With parity-violating asymmetries being as large as tens ppm, this study suggests that threshold pion production in PVES can be used as a promising way to better constrain strangeness contributions. Using this model for the neutral current pion production, we update the estimate for the dispersive γZ-box correction to the weak charge of the proton. In the kinematics of the Qweak experiment, our new prediction reads Re□ γ Z V (E= 1.165 GeV)=(5.58±1.41)× 10− 3, an improvement over the previous uncertainty estimate of±2.0× 10− 3. Our new prediction in the kinematics of the upcoming MESA/P2 experiment reads Re□ γ Z V (E= 0.155 GeV)=(1.1±0.2)× 10− 3.