由低能参数决定的轻子生成
Leptogenesis Determined By Low Energy Parameters
- Shanghai Jiao Tong University（上海交通大学）
- The University of Melbourne（墨尔本大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究在三种I型跷跷板模型中研究热轻子生成，发现正常排序且非零马约拉纳相位下，模型B和C能产生观测到的重子不对称性，并为未来无中微子双贝塔衰变实验提供明确目标。
AI中文摘要：
我们研究了三种可预测的I型跷跷板模型中的热轻子生成，在这些模型中，中微子狄拉克质量矩阵分别等于上型夸克、下型夸克或带电轻子的质量矩阵。在此框架下，跷跷板关系允许从低能中微子参数完全重建重右手中微子质量矩阵，这大大减少了参数自由度。我们进行了基于密度矩阵玻尔兹曼方程的系统数值扫描，以检验是否能获得观测到的宇宙重子不对称性。成功的轻子生成发生在光中微子质量具有非零马约拉纳相位的正常排序情况下。在这种情况下，在与下型夸克相关的模型B和与带电轻子相关的模型C中找到了可行解。两者都指向满足$|M_i-M_j|/M_i<10^{-3}$的紧致质量对重中微子，同时处于常规准简并共振区域之外。我们选择了四个代表性基准点来展示不对称性的演化以及不同旁观者效应处理的影响。进一步研究了所有能产生可接受重子不对称性$\eta_B = (6.12 \pm 0.20)\times 10^{-10}$的参数点的无中微子双贝塔衰变。某些情况下的预测有效马约拉纳质量可由具有亚10 meV灵敏度的下一代实验探测，如LEGEND-1000、nEXO、JUNO 50吨和CUPID-1T。因此，该框架为未来的搜索提供了明确的目标。
英文摘要：
We study thermal leptogenesis in three predictive type-I seesaw models in which the neutrino Dirac mass matrix is equal to the mass matrix of up-type quarks, or down-type quarks, or charged leptons. In this framework, the seesaw relation permits a full reconstruction of the heavy right-handed neutrino mass matrix from low-energy neutrino parameters, which greatly reduces the parameter freedom. A systematic numerical scan based on density matrix Boltzmann equations is performed to examine whether the observed baryon asymmetry of the Universe can be obtained. Successful leptogenesis occurs for normal ordering of light neutrino masses with nonzero Majorana phases. In this case, viable solutions are found in model B, associated with down-type quarks, and model C, associated with charged leptons. Both point to a close-mass pair of heavy neutrinos satisfying $|M_i-M_j|/M_i<10^{-3}$, while remaining outside the conventional quasi-degenerate resonant regime. Four representative benchmark points are selected to show the evolution of the asymmetry and the impact of different treatments of spectator effects. Neutrinoless double beta decay is further studied for all parameter points that can generate an acceptable baryon asymmetry $η_B = (6.12 \pm 0.20)\times 10^{-10}$. The predicted effective Majorana mass for certain cases can be probed by next generation experiments with sub-10 meV sensitivity, such as LEGEND-1000, nEXO, JUNO 50 tons, and CUPID-1T. This framework therefore provides clear targets for future searches.
