论文标题
稀有Lepton-number-violating $ w $衰减在LHC中违反CP
CP Violation in Rare Lepton-Number-Violating $W$ Decays at the LHC
论文作者
论文摘要
一些瘦素发生的模型涉及一对重成级的重中微子$ n_ {1,2} $，其质量可能很小，$ o（{\ rm gev}）$。这样的中微子可以为稀有的Lepton-number-Violating（LNV）衰减$ W^\ pm \ to \ ell_1^\ pm \ ell_2^\ pm（q'{\ bar q}）^\ mp $。如果$ n_1 $和$ n_2 $都有贡献，则可以在$ w^ - $的LNV衰减与其CP偶联衰减之间存在CP抗差差。在本文中，我们研究了LHC处的CP不对称$ a _ {\ rm cp} $的前景。我们假设重度中微子混合参数$ | b _ {\ ell n} |^2 = 10^{ - 5} $，这是由当前的实验约束允许的，并考虑$ 5〜 {\ rm gev} \ le m_n \ le m_n \ le mm_n \ le 80〜 {\ rm gev} $。我们考虑了三个版本的LHC-HL-LHC，He-LHC，FCC-HH-，并表明CP不对称的小值可以在$3σ$中，范围为$ 1 \％\％\％\％\％\％\ lyseSim a _ {\ rm Cp} \ rm cp} \ sieldsim 15 \％$ $。
Some models of leptogenesis involve a quasi-degenerate pair of heavy neutrinos $N_{1,2}$ whose masses can be small, $O({\rm GeV})$. Such neutrinos can contribute to the rare lepton-number-violating (LNV) decay $W^\pm \to \ell_1^\pm \ell_2^\pm (q'{\bar q})^\mp$. If both $N_1$ and $N_2$ contribute, there can be a CP-violating rate difference between the LNV decay of a $W^-$ and its CP-conjugate decay. In this paper, we examine the prospects for measuring such a CP asymmetry $A_{\rm CP}$ at the LHC. We assume a value for the heavy-light neutrino mixing parameter $|B_{\ell N}|^2 = 10^{-5}$, which is allowed by the present experimental constraints, and consider $5~{\rm GeV} \le M_N \le 80~{\rm GeV}$. We consider three versions of the LHC -- HL-LHC, HE-LHC, FCC-hh -- and show that small values of the CP asymmetry can be measured at $3σ$, in the range $1\% \lesssim A_{\rm CP} \lesssim 15\%$.
