R-parity违反：解析b→sℓℓ异常的wino贡献与多约束过程

59 浏览量更新于2024-07-16 收藏 997KB PDF 举报

本文主要探讨了在超对称模型中，通过引入R奇偶性(R-parity)违反的λ'LQDc形式的相互作用，来解释在b→sℓℓ（即 beauty to strange lepton-lepton）转换过程中观测到的异常现象。作者Kevin Earland Thomas Gérögire和他们的团队对这个模型的参数空间进行了深入研究，特别关注的是那些之前未被充分探讨的winos（winos在这里可能指的是超对称粒子中的Wino）参与的图景，这些图贡献了显著的效应。在低能理论中，为了产生合适的有效算符，他们发现模型参数被引导进入一个以环路贡献为主的区域。这一研究涵盖了广泛的潜在限制过程，包括τ→μμμ（tau到muon三联体衰变）、B_s - B_s-bar（奇异粒子的混合）的过程、B→K^(*)ν_ν（ Beauty介子到轻子反轻子的衰变）、Z玻色子衰变为带电轻子的过程，以及直接针对这类新物理现象的LHC（Large Hadron Collider，大型强子对撞机）实验搜索。尽管这些新图示和大λ'值（lambda-prime）的结合提供了解释异常的可能性，但这也带来了一个挑战：较大的λ'值可能导致相对较低的Landau极点问题，即理论的有效性在能量升高时可能迅速失去稳定性。因此，作者的研究不仅关注了理论解释，还涉及到实际可检验的物理现象和实验约束。这项工作对R-parity违反的超对称模型进行了细致的分析，并试图在解释b→sℓℓ异常的同时，平衡理论的自然性和实验的可行性。这一研究结果对于理解超对称粒子模型、测试标准模型之外的新物理现象以及进一步探索高能物理的边界具有重要意义。

JHEP08(2018)201

u ν

(a)

−

˜u

L ˜ν

(b)

(c)

˜ν

d d

˜u

(d)

Figure 2. Box diagrams studied in this work. Figure 2(a) shows an example W loop diagram,

ﬁgure 2(b) shows an example wino loop diagram, and ﬁgures 2(c) and 2(d) show the four-λ

loop

diagrams.

a W boson and a right-handed down squark, ﬁgure 2(a). This diagram is just one of

many diagrams involving these two types of particles (if we ignore internal indices then

there are four other diagrams, three with a W boson and one with a Goldstone boson).

Collectively, we refer to these diagrams as the W loop diagrams. Second, consider the

diagram involving a wino and a down quark, ﬁgure 2(b). This diagram is just one of

many diagrams involving these two types of particles (if we ignore internal indices then

there are three other diagrams). Collectively, we refer to these diagrams as the wino loop

diagrams. Finally, consider the diagrams involving four λ

couplings, ﬁgures 2(c) and 2(d).

Collectively, we refer to these diagrams as the four-λ

loop diagrams.

Each of these diagrams contribute to C

. Indeed, the W loop diagrams and the four-

loop diagrams have previously been considered in the literature in the context of the

b → sµµ anomalies. For example, ref. [34] studied a leptoquark model where equivalent

diagrams to the W loop and the four-λ

loop with two right-handed down squarks were

considered. Additionally, ref. [48] studied an RPV supersymmetry model where the W

loop and both four-λ

loop diagrams were considered. To the best of our knowledge, the

wino loop diagrams have not been considered in the context of these anomalies. We now

proceed by writing down the contributions of each of these diagrams to C

. Although the

results for the W loop diagrams and the four-λ

loop diagrams can be found in the given

references, we present them here for completeness.

– 5 –

剩余28页未读，继续阅读

weixin_38711008

粉丝: 8
资源: 939

R-parity违反：解析b→sℓℓ异常的wino贡献与多约束过程

中微子在违反R奇偶性的R-奇偶校验中解释b→sℓ+ ℓ−数据

B→D（∗）τν¯和b→sμ+μ-异常的R奇偶违规相互作用的后果

r语言如何判断一个数的奇偶

c语言输入两个正整数a和b(1<a<b<1000)，输出二者之间所有数的奇偶归一猜想的验证过程。

R语言输入一个整数判断奇偶

编写单片机程序，将从串行口接收的16字节数据输入片内RAM的20H~2FH单元。要求波特率为2400b/s，作奇偶校验，波特率加倍，设单片机的晶振为11.0592MHZ。

用c51 实现带奇偶校验的串行通信

dosbox G[S]: S→CDA|-CDA|A A→0|2|4|6|8 B→1|2|3|4|5|6|7|8|9|0 C→1|2|3|4|5|6|7|8|9 D→DB|B|ε 上面的文法表示全部的偶数吗

logisim奇偶校验实验

最新资源