Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from C12 and Al27
Measurement of the beam-normal single-spin asymmetry for elastic electron scattering from C12 and Al27
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DOI：
10.1103/physrevc.104.014606
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发表时间：
2021-03
影响因子：
3.1
通讯作者：
QWeak Collaboration D. Androic;D. Armstrong;A. Asaturyan;K. Bartlett;R. Beminiwattha;J. Benesch;F. Benmokhtar;J. Birchall;R. Carlini;M. Christy;J. Cornejo;S. Dusa;M. Dalton;C. Davis;W. Deconinck;J. Dowd;J. Dunne;D. Dutta;W. Duvall;M. Elassar;W. Falk;J. Finn;T. Forest;C. Gal;D. Gaskell;M. Gericke;V. Gray;F. Guo;J. Hoskins;D. Jones;M. Kargiantoulakis;P. King;E. Korkmaz;S. Kowalski;J. Leacock;J. Leckey;A. Lee;J. Lee;L. Lee;S. Macewan;D. Mack;J. Magee;R. Mahurin;J. Mammei;J. Martin;M. McHugh;D. Meekins;K. Mesick;R. Michaels;A. Mkrtchyan;H. Mkrtchyan;A. Narayan;L. Ndukum;Nuruzzaman;V. Nelyubin;W. Oers;V. Owen;S. Page;J. Pan;K. Paschke;S. Phillips;M. Pitt;R. Radloff;J. Rajotte;W. Ramsay;J. Roche;B. Sawatzky;T. Ševa;M. Shabestari;R. Silwal;N. Simicevic;G. Smith;P. Solvignon;D. Spayde;A. Subedi;R. Subedi;V. Tadevosyan;W. Tobias;B. Waidyawansa;P. Wang;S. Wells;S. Wood;P. Zang;S. Zhamkochyan
中科院分区：
文献类型：
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作者：
QWeak Collaboration D. Androic;D. Armstrong;A. Asaturyan;K. Bartlett;R. Beminiwattha;J. Benesch;F. Benmokhtar;J. Birchall;R. Carlini;M. Christy;J. Cornejo;S. Dusa;M. Dalton;C. Davis;W. Deconinck;J. Dowd;J. Dunne;D. Dutta;W. Duvall;M. Elassar;W. Falk;J. Finn;T. Forest;C. Gal;D. Gaskell;M. Gericke;V. Gray;F. Guo;J. Hoskins;D. Jones;M. Kargiantoulakis;P. King;E. Korkmaz;S. Kowalski;J. Leacock;J. Leckey;A. Lee;J. Lee;L. Lee;S. Macewan;D. Mack;J. Magee;R. Mahurin;J. Mammei;J. Martin;M. McHugh;D. Meekins;K. Mesick;R. Michaels;A. Mkrtchyan;H. Mkrtchyan;A. Narayan;L. Ndukum;Nuruzzaman;V. Nelyubin;W. Oers;V. Owen;S. Page;J. Pan;K. Paschke;S. Phillips;M. Pitt;R. Radloff;J. Rajotte;W. Ramsay;J. Roche;B. Sawatzky;T. Ševa;M. Shabestari;R. Silwal;N. Simicevic;G. Smith;P. Solvignon;D. Spayde;A. Subedi;R. Subedi;V. Tadevosyan;W. Tobias;B. Waidyawansa;P. Wang;S. Wells;S. Wood;P. Zang;S. Zhamkochyan
本文报道了宇称守恒电子束法向单自旋弹性散射不对称性B_n在$^{12}$C和$^{27}$Al上的测量结果。这些测量增加了一个额外的运动学点，以一系列先前的测量$B_n$上的$^{12}$C，并提供了第一次测量$^{27}$Al。实验利用的Qweak装置在杰斐逊实验室的束能量为1.158 GeV。两个目标的平均实验室散射角为7.7度，两个目标的平均Q^2为0.02437 GeV^2 $（Q=0.1561 GeV）。对于$^{12}$C，不对称性为$B_n$ = -10.68 $\pm $0.90 stat）$\pm $0.57（syst）ppm;对于$^{27}$Al，不对称性为$B_n$ = -12.16 $\pm $0.58（stat）$\pm $0.62（syst）ppm。结果与理论预测一致，并与现有数据进行了比较。当按Z/A标度时，从$^{1}$H到$^{27}$Al的所有远向角（θ < 10度）数据的Q依赖性可以用相同的斜率来描述，直到$Q \约0.35$ GeV。在同一Q范围内，来自其他实验的大角度数据与大约两倍陡峭的斜率一致。
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q-dependence of all the far-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep.