双光子过量与左右模型及规范统一的关联研究

28 浏览量更新于2024-09-05 收藏 487KB PDF 举报

"双光子过量对左右模型和量表统一的影响" 本文探讨了750 GeV不变质量的双光子过量现象在左-右对称模型（Left-Right Symmetric Model, LRSM）中的解释。左-右对称模型是一种扩展标准模型的理论框架，其中包含额外的标量单重态和类似矢量的费米子。这些新粒子的存在不仅能够解释实验观测到的双光子异常，还可能对LRSM的费米子质量结构和混合产生显著的理论影响。双光子过量是高能物理实验中的一种重要信号，通常与未知的新粒子或过程有关。在这个上下文中，作者提出了一种最小化的模型，该模型假设存在额外的标量粒子和类似矢量的费米子，它们能够与现有的标准模型粒子相互作用，从而产生750 GeV的双光子事件。这种解释提供了一个研究新物理现象的窗口，有助于我们理解宇宙的基本力和粒子性质。将LRSM扩展到包括这些类似矢量的费米子，会带来新的现象学挑战和机会。这些新费米子可能会导致费米子的质量矩阵发生改变，从而影响粒子的混合和振荡。这可能会影响中微子振荡等现象的解释，以及弱电对称性的破缺方式。此外，这些粒子的存在还可能对弱电对称性恢复的能标产生影响，即可能影响到规范耦合的统一。文章进一步讨论了这些类似载体的费米子在再生物理（如中微子衰变）和暗物质领域的潜在影响。暗物质是宇宙中的一大谜团，其性质和起源至今未解。新引入的类似矢量的费米子可能作为暗物质的候选者，或者与暗物质相互作用，这将丰富我们对宇宙暗物质成分的理解。文章中还提到了一个包含潜在暗物质候选者的双三重标量的引入，这使得在能量尺度达到10^17.7 GeV时，规范耦合有可能实现统一。这是大统一理论（Grand Unified Theory, GUT）的一个关键预测，即在极高能下，强、弱和电磁三种基本力可以统一为一个单一的力。这篇研究工作深入分析了750 GeV双光子过量现象对左-右对称模型的含义，以及它如何影响粒子的质量、混合、暗物质和规范统一等多个关键问题。这样的研究对于推进我们对宇宙基本法则的理解至关重要，并为未来的高能物理实验提供了理论指导。

Physics Letters B 757 (2016) 223–230

Contents lists available at ScienceDirect

Physics Letters B

www.elsevier.com/locate/physletb

Implications of the diphoton excess on left–right models and gauge

uniﬁcation

Frank F. Deppisch

, Chandan Hati

b,c

, Sudhanwa Patra

d,∗

, Prativa Pritimita

, Utpal Sarkar

Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom

Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, India

Indian Institute of Technology Gandhinagar, Chandkheda, Ahmedabad 382 424, India

Center of Excellence in Theoretical and Mathematical Sciences, Siksha ‘O’ Anusandhan University, Bhubaneswar-751030, India

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

Article history:

Received

19 January 2016

Received

in revised form 10 March 2016

Accepted

30 March 2016

Available

online 4 April 2016

Editor:

M. Cveti

The recent diphoton excess signal at an invariant mass of 750 GeV can be interpreted in the framework

of left–right symmetric models with additional scalar singlets and vector-like fermions. We propose a

minimal scenario for such a purpose. Extending the LRSM framework to include these new vector-like

fermionic ﬁelds, on the other hand, results in interesting phenomenological implications for the LRSM

fermion masses and mixing. Furthermore, existence of such vector-like fermions can also have interesting

implications for baryogenesis and the dark matter sector. The introduction of a real bi-triplet scalar which

contains a potential DM candidate will allow the gauge couplings to unify at ≈10

17.7

GeV.

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

1. Introduction

The CMS and ATLAS Collaborations have recently reported a

roughly 3σ excess in the diphoton channel at an invariant mass

of about 750 GeV in the ﬁrst 3fb

−1

of collected data from Run 2

of the LHC at 13 TeV [1,2]. The Landau–Yang theorem forbids the

possibility of a massive spin one resonance decaying to γγ. The

leading interpretations of the excess within the context of new

physics scenarios therefore consist of postulating a fundamental

spin zero or spin two particle with mass of about 750 GeV. How-

ever

no enhancements have been seen in the dijet, t

t, diboson or

dilepton channels posing a clear challenge to the possible inter-

pretations

of this excess. The absence of a peaked γγ angular

distribution in the observed events towards the beam direction

disfavours [3] the spin two hypothesis and the spin zero resonance

interpretation seems more favourable from a theoretical point of

view.

large number of interpretations of the diphoton signal in

terms of physics beyond the Standard Model have been proposed

in the literature [4–136]. One of the possibilities that has been

largely explored in the literature is a scalar or pseudo-scalar res-

Corresponding author.

E-mail

addresses: f.deppisch@ucl.ac.uk (F.F. Deppisch), chandan@prl.res.in

(C. Hati),

sudha.astro@gmail.com (S. Patra), pratibha.pritimita@gmail.com

(P. Pritimita),

utpal@prl.res.in (U. Sarkar).

onance produced through gluon–gluon fusion and decaying to γγ

via loop diagrams with circulating fermions or bosons. Anew res-

onance

coupling with the Standard Model (SM) t quark or W

can give rise to such loop diagrams, however, they will be highly

suppressed at the large γγ invariant masses and the dominant

decay channel would have to be t

t or W

−

. Hence the obser-

vation

of the γγ resonance at 750 GeV (much greater than the

electroweak symmetry breaking scale) hints towards the existence

of vector-like fermions around that mass scale. Given that both the

ATLAS and CMS Collaborations have suggested signal events con-

sistent

with each other at a tempting 3σ statistical signiﬁcance

level, hinting towards a new physics scenario, it is important to

explore the possible model framework that can naturally accom-

modate

such vector-like fermions.

From a theoretical stand point, aframework that can explain

the diphoton excess while being consistent with other searches for

new physics is particularly intriguing. To this end, one must men-

tion

the results reported by the CMS Collaboration in the ﬁrst run

of LHC for the right-handed gauge boson W

search at

√

s =8TeV

and

19.7fb

−1

of integrated luminosity [137]. A2.8σ local excess

was reported in the eej j channel in the energy range 1.8TeV<

ee jj

< 2.2TeV, hinting at a right handed gauge counterpart of the

SM SU(2)

broken around the TeV scale. The Left–Right Symmet-

ric

Model (LRSM) framework with g

= g

can explain such signal

with the possibility of being embedded into a ultraviolet complete

higher gauge group [138–141]. It is thus an interesting exercise to

http://dx.doi.org/10.1016/j.physletb.2016.03.081

0370-2693/

SCOAP

下载后可阅读完整内容，剩余7页未读，立即下载

weixin_38651661

粉丝: 6
资源: 960

双光子过量与左右模型及规范统一的关联研究

四环中微子模型受750 GeV的双光子过量启发

750 GeV双光子过量的复合模型

双光子过量的有效解释

双光子吸收现象的定义以及双光子吸收现象对脉冲压缩的影响

matlab双光子成像

python求解双光子Dicke模型量子电池能量随时间的演化

给出了双光子和三光子吸收的非线性偏振表达式

给出双光子吸收和三光子吸收的非线性偏振表达式

用matlab模拟折射率失配对双光子三维信息存储中信息点的影响

一维光子晶体,双稳态,传输矩阵,matlab

最新资源