First measurement of the strange axial coupling constant using neutral-current quasielastic interactions of atmospheric neutrinos at KamLAND
First measurement of the strange axial coupling constant using neutral-current quasielastic interactions of atmospheric neutrinos at KamLAND
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DOI：
10.1103/physrevd.107.072006
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发表时间：
2022-11
影响因子：
5
通讯作者：
K. Abe;S. Asami;M. Eizuka;S. Futagi;A. Gando;Y. Gando;T. Gima;A. Goto;T. Hachiya;K. Hata;K. Ichimura;S. Ieki;H. Ikeda;K. Inoue;K. Ishidoshiro;Y. Kamei;N. Kawada;Y. Kishimoto;M. Koga;M. Kurasawa;T. Mitsui;H. Miyake;T. Nakahata;K. Nakamura;R. Nakamura;H. Ozaki;T. Sakai;I. Shimizu;J. Shirai;K. Shiraishi;A. Suzuki;Y. Suzuki;A. Takeuchi;K. Tamae;H. Watanabe;Y. Yoshida;Shuhei Obara;A. Ichikawa;S. Yoshida;S. Umehara;K. Fushimi;K. Kotera;Y. Urano;B. Berger;B. Fujikawa;J. Learned;J. Maricic;S. Axani;Z. Fu;J. Smolsky;L. Winslow;Y. Efremenko;H. Karwowski;D. Markoff;W. Tornow;J. Detwiler;S. Enomoto;M. Decowski;C. Grant;A. Li;H. Song;S. Dell’Oro;T. O’Donnell
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文献类型：
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作者：
K. Abe;S. Asami;M. Eizuka;S. Futagi;A. Gando;Y. Gando;T. Gima;A. Goto;T. Hachiya;K. Hata;K. Ichimura;S. Ieki;H. Ikeda;K. Inoue;K. Ishidoshiro;Y. Kamei;N. Kawada;Y. Kishimoto;M. Koga;M. Kurasawa;T. Mitsui;H. Miyake;T. Nakahata;K. Nakamura;R. Nakamura;H. Ozaki;T. Sakai;I. Shimizu;J. Shirai;K. Shiraishi;A. Suzuki;Y. Suzuki;A. Takeuchi;K. Tamae;H. Watanabe;Y. Yoshida;Shuhei Obara;A. Ichikawa;S. Yoshida;S. Umehara;K. Fushimi;K. Kotera;Y. Urano;B. Berger;B. Fujikawa;J. Learned;J. Maricic;S. Axani;Z. Fu;J. Smolsky;L. Winslow;Y. Efremenko;H. Karwowski;D. Markoff;W. Tornow;J. Detwiler;S. Enomoto;M. Decowski;C. Grant;A. Li;H. Song;S. Dell’Oro;T. O’Donnell
我们使用KamLAND的大气中微子数据报告了奇怪轴向耦合常数$g_A^s$的测量结果。这个常数是中性流准弹性相互作用（NCQE）的轴向形状因子的一个分量。g_A^s$的值显著地改变了质子和中子NCQE截面的比率。KamLAND适用于测量NCQE相互作用，因为它可以以低能量阈值检测核子反冲，并以高效率测量中子多重性。KamLAND数据，包括与NCQE相互作用相关的中子多重性的信息，使得有可能测量$g_A^s$与轴向质量$M_A$的抑制依赖性，这尚未确定。为了全面预测与中微子相互作用相关的中子发射，我们建立了通过$^{12}$C的核去激发的粒子发射模拟，这是现有中微子蒙特卡罗事件发生器中未考虑的过程。对每个中子多重数的能谱拟合给出了g_A^s =-0.14 ^{+0.25}-0.26}$，这是在没有M_A$约束的情况下用NCQE相互作用得到的最严格的极限。在本分析中考虑的两体电流贡献依赖于理论上有效的模型和电子散射实验，并需要通过直接测量和未来模型改进进行进一步验证。
We report a measurement of the strange axial coupling constant $g_A^s$ using atmospheric neutrino data at KamLAND. This constant is a component of the axial form factor of the neutral-current quasielastic (NCQE) interaction. The value of $g_A^s$ significantly changes the ratio of proton and neutron NCQE cross sections. KamLAND is suitable for measuring NCQE interactions as it can detect nucleon recoils with low-energy thresholds and measure neutron multiplicity with high efficiency. KamLAND data, including the information on neutron multiplicity associated with the NCQE interactions, makes it possible to measure $g_A^s$ with a suppressed dependence on the axial mass $M_A$, which has not yet been determined. For a comprehensive prediction of the neutron emission associated with neutrino interactions, we establish a simulation of particle emission via nuclear deexcitation of $^{12}$C, a process not considered in existing neutrino Monte Carlo event generators. Energy spectrum fitting for each neutron multiplicity gives $g_A^s =-0.14^{+0.25}_{-0.26}$, which is the most stringent limit obtained using NCQE interactions without $M_A$ constraints. The two-body current contribution considered in this analysis relies on a theoretically effective model and electron scattering experiments and requires future verification by direct measurements and future model improvement.