Electroweak axion in light of GRB221009A Weikang Lin1 2and Tsutomu T. Yanagida2 3 1South-Western Institute For Astronomy Research

2025-05-03 0 0 502.41KB 3 页 10玖币

侵权投诉

Electroweak axion in light of GRB221009A

Weikang Lin1, 2, ∗and Tsutomu T. Yanagida2, 3, †

1South-Western Institute For Astronomy Research,

Yunnan University, Kunming 650500, Yunnan, P. R. China

2Tsung-Dao Lee Institute (TDLI) & School of Physics and Astronomy, Shanghai Jiao Tong University,

Shengrong Road 520, 201210 Shanghai, P. R. China

3Kavli IPMU (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583, Japan

Very high energy (VHE) photons may have a higher survival rate than that expected in standard-

model physics, as suggested by the recently reported Gamma Ray Burst GRB221009A. While a

photon-axion like particle (ALP) oscillation can boost the survival rate of the VHE photons, current

works have not been based on concrete particle models, leaving the identity of the corresponding

ALP unclear. Here, we show that the required ALP scenario is consistent with the electroweak

axion with an anomaly free Z10 Froggatt-Nielsen symmetry.

Recently, an unexpectedly bright and long-duration

Gamma Ray Burst (GRB), GRB221009A, has been de-

tected at redshift z= 0.15 (corresponding to a comoving

distance of ∼600 Mpc) [1]. LHAASO reported more

than 5000 VHE photons with energies up to ∼18 TeV

associated with this event [2]. Later, Carpet-2 reported

a 251 TeV photon-like air shower [3].

The detection of VHE photons at such a distance is

diﬃcult to explain with conventional physical processes.

In particular, due to the interaction with the extragalac-

tic background light (EBL) via an electron-positron pair

production, VHE photons have a large optical depth and

their survival rate is extremely low [4].

While the GRB221009A anomaly of VHE photons still

needs close examinations, it is soon pointed out in [5,6]

that the survival rate can be signiﬁcantly increased by a

photon-ALP oscillation. The VHE photons may convert

back and forth to ALPs in the presence of a magnetic

ﬁeld in the host galaxy, the intergalactic medium and

the Milky Way. During the ALP phase, they evade the

interaction with EBL, and hence the optical depth is re-

duced. With the benchmark ALP mass mA= 10−10 eV

and photon-ALP coupling constant gAγγ = 0.5×10−11

GeV−1, the survival rate for photons with E>

∼1013

eV is signiﬁcantly boosted [5]. This benchmark value

of gAγγ = 0.5×10−11 is consistent with the constraints

from both the star cooling eﬀects (see [7] and references

wherein) and laboratory experiments [8]. The benchmark

ALP mass is within the region of ALP mass (mA>10−12

eV) that allows such a high gAγγ [7].

However, the suggested ALP mass is far smaller than

that of the QCD axion given gaγ ≃10−11 GeV−1. In

this short paper, we point out that the suggested param-

eter space is consistent with the electroweak (EW) axion

whose mass is generated by the electroweak instantons

[9,10].

The EW axion is a hypothetical pseudo-Nambu-

Goldstone boson ﬁeld that couples to the SU(2) EW

∗linweikang-academia@outlook.com

†tsutomu.tyanagida@sjtu.edu.cn

gauge ﬁelds with the following interaction,

L ⊃ g2

32π2

µν f

Wiµν ,(1)

where Wi

µν (with i= 1,2,3) is the weak SU(2) gauge

ﬁeld tensor and f

Wiµν is its dual tensor 1. The EW ax-

ion was originally proposed to explain why the age of

the universe appeared to be shorter than that of some

old stars [9]. The potential generated by the EW instan-

ton eﬀect is comparable to the magnitude of dark energy

density observed [9,10].2The version considered in [10]

is a supersymmetric model and the EW instanton eﬀect

generates the axion potential, which reads

VA=Λ4

21−cos(A/FA),(2)

with

Λ4

A≃2e−2π

α2(MP l )c ϵ10m3

3/2MP l

≃cϵ

1/1710m3/2

1 TeV 3(1.4×10−3eV)4,(3)

where cis a dimensionless constant of O(1), ϵ≃1/17

is the suppression factor due to the Froggatt-Nielsen

U(1)F N ﬂavor symmetry, m3/2is the gravitino mass and

FAis the decay constant.3The axion potential Eq. (2)

gives us the EW axion mass mAaround the potential

minimum as

mA=Λ2

√2FA≃ϵ

1/1710m3/2

1 TeV 3

2MP l

FA×6×10−34 eV ,

(4)

1We consider that the Planck scale MP l ≃2.4×1018 GeV is the

cut-oﬀ scale of the theory as explained in [11].

2It is also shown to be able to explain the recently observed cosmic

birefringence [11,12].

3This result does not change even if some SU (2) charged particles

exist at the intermediate energy scale owing to the SUSY miracle

[10].

arXiv:2210.08841v3 [hep-ph] 16 Oct 2023

文档加载中……请稍候！
如果长时间未打开，您也可以点击刷新试试。

下载文档到电脑，查找使用更方便

10 玖币 0人已下载

立即下载

摘要：

ElectroweakaxioninlightofGRB221009AWeikangLin1,2,∗andTsutomuT.Yanagida2,3,†1South-WesternInstituteForAstronomyResearch,YunnanUniversity,Kunming650500,Yunnan,P.R.China2Tsung-DaoLeeInstitute(TDLI)&SchoolofPhysicsandAstronomy,ShanghaiJiaoTongUniversity,ShengrongRoad520,201210Shanghai,P.R.China3KavliIPM...

展开>> 收起<<

Electroweak axion in light of GRB221009A Weikang Lin1 2and Tsutomu T. Yanagida2 3 1South-Western Institute For Astronomy Research.pdf

共3页,预览1页

还剩页未读，继续阅读

声明：本站为文档C2C交易模式，即用户上传的文档直接被用户下载，本站只是中间服务平台，本站所有文档下载所得的收益归上传人(含作者)所有。玖贝云文库仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私，请立即通知玖贝云文库，我们立即给予删除！

Electroweak axion in light of GRB221009A Weikang Lin1 2and Tsutomu T. Yanagida2 3 1South-Western Institute For Astronomy Research

相关推荐

开通VIP享超值会员特权

作者详情

相关内容

热门标签

举报选择: