8GeV轻子/标量暗物质解析Fermi-LAT与CDMS异常

52 浏览量更新于2024-09-03 收藏 355KB PDF 举报

本文主要探讨了轻型铁离子/标量暗物质（<math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi> m_DM </mi></mrow><mrow><mi mathvariant="DM"></mi></mrow></msub><mo>≥^</mo><mn>8</mn></标准模型下的暗物质，其质量大约在8 GeV左右，这种轻暗物质能够解释由CDMS（ Cryogenic Dark Matter Search）实验和CoGeNT（Cryogenic Germanium Neutrino Observatory）观察到的信号，同时也能在Fermi-LAT（ Fermi Large Area Telescope）的伽马射线观测中发现潜在的异常现象。作者们在相对简洁的理论框架下，深入研究了暗物质的各种湮灭（annihilation）和散射（scattering）过程，着重讨论了这些过程对粒子物理学的理论限制。他们假设CDMS和CoGeNT的数据以及Fermi-LAT的观测结果可能源于相同的暗物质起源，并且这些现象可以通过一个共享的媒介进行解释。在这样的情况下，暗物质倾向于通过s通道（spin-symmetric channel）湮灭成τ/反τ轻子对，以避免因p波抑制（p-wave suppression）而导致的低效率。此外，暗物质还可能通过t通道（tensorial channel）与核发生散射，这是解释观测结果的关键过程。文章还关注了粒子物理学中的重要现象学约束，比如对暗物质粒子性质（如自旋、电荷等）的要求，以及对媒介粒子（如新希格斯玻色子）的质量和相互作用强度的估计。作者们通过细致的理论分析，力图在满足现有观测数据的同时，提出一种合理的暗物质模型，以便进一步指导实验和理论的发展。这篇发表于《物理快报B》的文章，为理解轻暗物质如何解释多种观测现象提供了新的视角，同时也揭示了粒子物理学家在寻找暗物质过程中面临的复杂性和可能性。对于那些对暗物质研究感兴趣的读者来说，这篇文章不仅包含了最新的研究成果，还为未来的研究方向指明了路径。

Physics Letters B 732 (2014) 373–379

Contents lists available at ScienceDirect

Physics Letters B

www.elsevier.com/locate/physletb

Light dark matter for Fermi-LAT and CDMS observations

Bumseok Kyae

,Jong-ChulPark

b,∗

Department of Physics, Pusan National University, Busan 609-735, Republic of Korea

Department of Physics, Sungkyunkwan University, Suwon 440-746, Republic of Korea

article info abstract

Article history:

Received 15 October 2013

Received in revised form 27 March 2014

Accepted 1 April 2014

Available online 4 April 2014

Editor: G.F. Giudice

Keywords:

Light dark matter

Fermi-LAT

Gamma-ray

CDMS

CoGeNT

Light fermionic/scalar dark matter (DM) (m

≈ 8 GeV) neutral under the standard model can be

responsible for the CDMS and CoGeNT signals, and the Fermi-LAT gamma-ray excesses. In order to

explain them in a relatively simple framework, we have explored various DM annihilation and scattering

processes, discussing important phenomenological constraints coming from particle physics. Assuming

that the two independent observations have a common DM origin and the processes arise through a

common mediator, DM should annihilate into tau/anti-tau lepton pairs through an s-channel, and scatter

with nuclei through a t-channel process. To avoid the p-wave suppression, a new Higgs-like scalar ﬁeld

with a mass of

O(1) TeV is necessary as a common mediator of both the processes. We propose a

supersymmetric model realizing the scenario.

(http://creativecommons.org/licenses/by/3.0/). Funded by SCOAP

1. Introduction

Dark matter (DM) is one of the most important building blocks

constituting the universe [1]. According to the recent precise ob-

servation from the Planck satellite experiment, it is believed that

DM occupies 27 percent of the present energy density of the uni-

verse [2]. In particular, weakly interacting massive particle (WIMP),

which is the most promising DM candidate, is essential for under-

standing the physics law at the electroweak (EW) scale as well as

the structure formation in the universe. Thus, various experiments

to explore DM are being carried out on the earth and also outside

the atmosphere.

Recently, DM direct detection experiments such as CoGeNT [3],

CDMS-Ge [4] and

CDMS-Si [5] have reported the observations of

some WIMP-candidate events at (2–3)

σ conﬁdence level. They are

claimed to be interpreted as DM signals with a relatively light

mass of m

≈ 7–10 GeV and a spin-independent (SI) elastic scat-

tering cross section per nucleon of

≈ 10

−41

–10

−40

.The

best ﬁt point for these three measurements is around m

≈

8 GeV and σ

≈ 3 ×10

−41

. DAMA/LIBRA [6] and CRESST-II [7]

results also support similar parameter regions. However, all such

signals are not exactly compatible with the constraints from

XENON10 [8] and XENON100 [9]. Recently, the authors of Ref. [10]

have pointed out that XENON10’s constraint should be weakened,

Corresponding author.

E-mail addresses: bky

ae@pusan.ac.kr (B. Kyae), log1079@gmail.com (J.-C. Park).

and the XENON10 Collaboration has corrected the old result in

the erratum to Ref. [8]. In addition, the author of Ref. [11] has

studied various uncertainties and assumptions, which could af-

fect XENON100’s constraint on light DM. Very recently, CoGeNT

released the updated data, conﬁrming their previous light DM sig-

nals [12]. Under such a tension among the observations, we will

particularly focus on the positive results of CDMS and CoGeNT in

this paper.

If DM annihilates into the standard model (SM) chiral fermions,

it should also emit gamma-rays. Fermi Large Area Telescope

(Fermi-LAT) [17] is a satellite based experiment measuring cos-

mic gamma-rays. The recent analyses [18] based on the data

from Fermi-LAT show peaks at energies around 1–10 GeV in the

gamma-ray spectrum coming from around the galactic center. It

could be interpreted as an evidence of DM annihilation into the

leptons l

l with m

≈ 7–12 GeV or the bottom quarks bb with

≈ 25–45 GeV. In this case, the required annihilation cross

section is

σ v ∼ 10

−26

/s.

Right after completion of this work, LUX [13] reported more stringent limit,

constraining all the positive signal regions. In light of LUX, light DM possibilities

have been examined in various ways in Refs. [14–16].

The current limits on the annihilation of light DM into leptons coming from the

cosmic microwave background (CMB) are

σ v

≈ 0.5–1 ×10

−26

/s, σ v

μμ

≈

1–2 × 10

−26

/s, and σ v

τ τ

≈ 2–3 × 10

−26

/s [19].Thus,thecaseofDM

annihilations into e

−

, μ

−

, τ

−

with the same ratio is slightly constrained

by the CMB bound. However, if DM mainly annihilates only into

−

,theCMB

constraint could be easily avoidable.

http://dx.doi.org/10.1016/j.physletb.2014.04.003

0370-2693/

SCOAP

下载后可阅读完整内容，剩余6页未读，立即下载

weixin_38687928

粉丝: 2
资源: 950

8GeV轻子/标量暗物质解析Fermi-LAT与CDMS异常

伽马射线爆发的峰值能量相关

根据AMS-02，DAMPE和Fermi-LAT数据，具有标量暗物质的II型跷跷板机制

Fermi-LAT:Fermi-LAT数据缩减的有用工具

Fermi-LAT GeV过量的暗物质解释界线

重新审视AMS-02和Fermi-LAT的简化暗物质模型

AMS-02与Fermi-LAT观测下的暗物质简化模型解析

具有全局U（1）X对称性和Fermi-LAT 130 GeVγ射线过量的隐藏扇区暗物质

费米-LAT GeV过量：暗物质解释的界限与实验检验

sc-fermi-开源

Fermi-in-the-air:selfFERMIlet

最新资源