LHC Run-2下的矢量媒介对 Flavor-Changing Interactions的约束：新信号与3-3-1模型的关联

67 浏览量更新于2024-09-03 收藏 532KB PDF 举报

本文主要探讨了在LHC Run-2（大型强子对撞机第二阶段）13 TeV运行期间，针对中性介子系统（如K0-K'0、D0-D'0和B0-B'0）的风味变化（Flavor Changing Neutral Currents, FCNC）与可能存在但受限的矢量媒介（vector mediators）之间的相互作用。背景是LHC在罕见B衰变中的观测结果引发了一种理论兴趣，即是否存在某种新物理信号，这些信号与双链共振的搜索相一致。研究者特别关注了3-3-1模型，这是一个扩展的标准模型，其中费米子和标量粒子在弱SU(3)规范群的基态中具有不同的排列。在这一模型中，双链共振的质量限制导致了风味变化相互作用受到严格的约束。作者分析了LHC Run-2的 dilepton 数据，这些数据对可能的新物理信号进行了严格的限制，尤其是当考虑CKM矩阵（ Cabibbo-Kobayashi-Maskawa matrix）对角化过程中的特殊纹理参数化时。文章指出，如果在风味变化的相互作用中观察到新信号，那很可能是3-3-1模型之外的物理现象。这是因为现有的数据几乎没有空间容纳3-3-1模型所预测的此类信号。换句话说，对矢量媒介在LHC Run-2下的FCNC行为的进一步实验观察，对于验证或排除3-3-1模型的解释至关重要。总结来说，这篇论文通过比较LHC Run-2的数据与3-3-1模型的预测，探讨了在矢量媒介的背景下，如何通过检验风味变化的相互作用来寻找可能的新物理迹象，并评估了这种模型对现有实验限制的响应。这不仅对于理解基本粒子物理学中的标准模型扩展有重要意义，还对未来实验设计和理论发展提供了有价值的方向。

Physics Letters B 763 (2016) 269–274

Contents lists available at ScienceDirect

Physics Letters B

www.elsevier.com/locate/physletb

Constraining ﬂavor changing interactions from LHC Run-2 dilepton

bounds with vector mediators

Farinaldo S. Queiroz

a,∗

, Clarissa Siqueira

, José W.F. Valle

Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany

Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970, João Pessoa, PB, Brazil

AHEP Group, Instituto de Física Corpuscular, C.S.I.C., Universitat de Valencia Ediﬁcio de Institutos de Paterna, C/Catedratico José Beltran, 2, E-46980 Paterna,

Valencia, Spain

a r t i c l e i n f o a b s t r a c t

Article history:

Received

2 September 2016

Received

in revised form 17 October 2016

Accepted

24 October 2016

Available

online 27 October 2016

Editor:

A. Ringwald

Within the context of vector mediators, is a new signal observed in ﬂavor changing interactions,

particularly in the neutral mesons systems K

−

, D

−

and B

−

, consistent with dilepton

resonance searches at the LHC? In the attempt to address this very simple question, we discuss the

complementarity between ﬂavor changing neutral current (FCNC) and dilepton resonance searches at

the LHC run 2 at 13 TeV with 3.2fb

−1

of integrated luminosity, in the context of vector mediators at

tree level. Vector mediators, are often studied in the ﬂavor changing framework, specially in the light of

the recent LHCb anomaly observed at the rare B decay. However, the existence of stringent dilepton

bound severely constrains ﬂavor changing interactions, due to restrictive limits on the Z



mass. We

discuss this interplay explicitly in the well motivated framework of a 3-3-1 scheme, where fermions

and scalars are arranged in the fundamental representation of the weak SU(3) gauge group. Due to the

paucity of relevant parameters, we conclude that dilepton data leave little room for a possible new

physics signal stemming from these systems, unless a very peculiar texture parametrization is used in

the diagonalization of the CKM matrix. In other words, if a signal is observed in such ﬂavor changing

interactions, it unlikely comes from a 3-3-1 model.

(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP

1. Introduction

The Standard Model (SM) has passed all precision tests thus

far, and it is the best description of nature. Although, we need

physics beyond the standard model so as to account for neutrino

masses and dark matter. Many models that address these puzzles

are plagued by ﬂavor changing neutral current (FCNC) processes,

which are, however, absent in the SM at tree-level, thanks to the

GIM mechanism

[4]. Therefore, precise measurement of ﬂavor

transition processes, such as those from neutral meson oscillations,

−

, D

−

and B

−

, which are forbidden in the SM

at tree level, provide an excellent laboratory to test new physics

models, due to lack of standard model background. Conversely, ﬂa-

vor

changing charged currents, are overwhelmed by numerous W

boson processes.

Corresponding author.

E-mail

address: queiroz@mpi-hd.mpg.de (F.S. Queiroz).

The concept of minimal ﬂavor violation has guided us at how to suppress new

physics interactions [1–3].

That said, ﬂavor changing neutral currents are often examined

in the context of neutral vector gauge boson, Z



. A multitude of

Abelian and non-Abelian models predict the existence of extra

neutral gauge bosons. Generally speaking they provide a straight-

forward

cross-correlation among observables, such as FCNC and



at the LHC. Simpliﬁed models have become powerful tools

in this endeavor, since they capture the main features of UV-

complete

models [5–8]. However, at the end of the day one needs

a full theory to draw conclusive statements. In this attempt, we

will address the complementarity between ﬂavor changing neu-

tral

currents and dilepton resonance searches at the LHC, which

refers to those with charged lepton pairs in the ﬁnal state [9],

in the context of electroweak extensions of the SM, based on the

SU(3)

⊗ SU(3)

⊗ U (1)

gauge group, shortly referred as 3-3-1

models.

3-3-1

models are self-consistent if there exists only three gen-

erations

due to the combined effect of triangle gauge anoma-

lies

cancellations and QCD asymptotic freedom [10–14]. Moreover,

the model furnishes a suitable environment for neutrino masses

through see-saw mechanisms [15–28], dark matter [29–45], ex-

planation

of the strong CP problem in the quark sector [46,47],

http://dx.doi.org/10.1016/j.physletb.2016.10.057

0370-2693/

SCOAP

下载后可阅读完整内容，剩余5页未读，立即下载

weixin_38724349

粉丝: 5
资源: 916

LHC Run-2下的矢量媒介对 Flavor-Changing Interactions的约束：新信号与3-3-1模型的关联

根据当前LHC Run-2数据，天然SUSY中的前排

根据目前的LHC run-2和LUX数据，从广义最小超重力中获得自然超对称状态

LHC Run-I约束在相同符号狄布森衰变情形下双电荷希格斯玻色子的质量

LHC的spin-2介体简化了暗物质模型

关于LHC夸克-胶子等离子体的全息描述的存在

复合2HDM中LHC Run II的矢量共振

在LHC Run II中探查非标准中微子相互作用

LHC Run-2与LUX数据下CMSSM的现状分析

LHC Run-I：双电荷希格斯玻色子质量限制与狄布森衰变

LHC Run-1下的T-奇异性小希格斯模型：单个顶伴在Higgs到双光子通道中的研究

最新资源