Laboratory Searches for Dark Matter Signatures with Electron Beams at JLab
Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ •...
Transcript of Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ •...
![Page 1: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/1.jpg)
Dark Radiationwith Super heavy DM
Seongchan Park Yonsei University & KIAS
LDW 2016July 11-15 2016,
IBS, Korea
New ScientistFEATURES 17 June 2015
![Page 2: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/2.jpg)
Unitarity bound for WIMP
Partial wave analysis:
[Griest, Kamionkowski, PRL 1990]
2
J
(cf) used to be 340 TeV in 1990s
![Page 3: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/3.jpg)
The Window for WIMP is closing out fast…
1401.6085
SUSY KK DM
For KK EWDM: Flacke, Kong, Kang, SCP 1607.xxxx
![Page 4: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/4.jpg)
The Window for WIMP is closing out fast…
1401.6085
LHC
SUSY KK DM
For KK EWDM: Flacke, Kong, Kang, SCP 1607.xxxx
![Page 5: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/5.jpg)
Beyond WIMP?
• One potentially interesting domain for DM is >100 TeV beyond the unitarity bound.
• The superheavy dark matter is sometimes called as “WIMPZILLA: Monster particle from the dawn of time” (after an editor of “New Scientist”)
![Page 6: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/6.jpg)
Superheavy DM
M =(100 TeV, Minf/2), this talk
unitarity production
stable or super-long lived
WIMP??
![Page 7: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/7.jpg)
Production of superheavy DM
![Page 8: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/8.jpg)
Production of superheavy DM
• Still can be non-thermally produced e.g. by inflaton decay and fits the DM abundance
![Page 9: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/9.jpg)
Production of superheavy DM
• Still can be non-thermally produced e.g. by inflaton decay and fits the DM abundance
• An interesting window well above 200 TeV (could be ~MGUT) pops out of the calculation by Chung, Kolb, Riotto (1998), Hui, Stewart (1998) with T~109 GeV or higher reheating temperature.
![Page 10: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/10.jpg)
WZ abundance from inflaton decay
[Mazumdar et.al. 1311.5297]
7
Inflaton
WZ
![Page 11: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/11.jpg)
WZ production from preheatingpreheating via damped oscillation of Inflaton
[Chung, Kolb, Riotto PRL1998]
WZ
![Page 12: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/12.jpg)
How to detect WZ?
• High energy cosmic ray from WZ decay [Rott, Kohri, SCP, PRD(2015)]
• Dark radiation: this talk [J.C.Park, SCP, PLB(2014), 2015]
![Page 13: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/13.jpg)
Stability of a heavy state
![Page 14: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/14.jpg)
Stability of a heavy state
• A heavy state easily decays unless forbidden:
![Page 15: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/15.jpg)
Stability of a heavy state
• A heavy state easily decays unless forbidden:
• 1/Γ~Δt~1/ΔE ~1/M
![Page 16: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/16.jpg)
Dark gauge symmetry for WZ
![Page 17: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/17.jpg)
Dark gauge symmetry for WZ• Think of the reason why electron is stable
![Page 18: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/18.jpg)
Dark gauge symmetry for WZ• Think of the reason why electron is stable
• U(1)em : Electron never decays since it is the lightest charged particle of U(1)em an exact symmetry of nature.
![Page 19: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/19.jpg)
Dark gauge symmetry for WZ• Think of the reason why electron is stable
• U(1)em : Electron never decays since it is the lightest charged particle of U(1)em an exact symmetry of nature.
• Why don’t we think of a new gauge symmetry, e.g. U(1), for DM stability?
![Page 20: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/20.jpg)
Dark gauge symmetry for WZ• Think of the reason why electron is stable
• U(1)em : Electron never decays since it is the lightest charged particle of U(1)em an exact symmetry of nature.
• Why don’t we think of a new gauge symmetry, e.g. U(1), for DM stability?
• There are lot of U(1)’s expected in string theory or GUT SO(10), E6, E8 etc and one of them may protect WZ!
![Page 21: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/21.jpg)
Dark gauge symmetry for WZ• Think of the reason why electron is stable
• U(1)em : Electron never decays since it is the lightest charged particle of U(1)em an exact symmetry of nature.
• Why don’t we think of a new gauge symmetry, e.g. U(1), for DM stability?
• There are lot of U(1)’s expected in string theory or GUT SO(10), E6, E8 etc and one of them may protect WZ!
• The new gauge boson associated with U(1)WZ is very light or even massless: this may provide observational consequences such as Dark Radiation
![Page 22: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/22.jpg)
Is Dark Radiation dead?
Planck collaboration, [arXiv:1502.01589]
![Page 23: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/23.jpg)
H0 vs Neff
Planck collaboration, [arXiv:1502.01589]
~ positively correlated
More DR
faster expansion
sigma 8 tension?
See Neelima Sehgal ’s talk
![Page 24: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/24.jpg)
Tension in Hubble Constant
Adam G. Riess et. al. [arXiv:1604.01424]
![Page 25: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/25.jpg)
Tension in Hubble Constant
High z(~indirect)
Adam G. Riess et. al. [arXiv:1604.01424]
![Page 26: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/26.jpg)
Tension in Hubble Constant
Low z(~Direct)
High z(~indirect)
Adam G. Riess et. al. [arXiv:1604.01424]
![Page 27: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/27.jpg)
H0 vs Neff
new
Adam G. Riess et. al. [arXiv:1604.01424]
faster expansion
More DR "Our best estimate of
H0 = 73.24 ± 1.74 km/s/Mpc and one plausible
explanation could involve an additional source of dark radiation in the early Universe in
the range of ∆Neff ≈ 0.4−1."
![Page 28: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/28.jpg)
Tension reconciled w/ Ghost?
Eleonora Di Valentino, Alessandro Melchiorri, and Joseph Silk [arXiv:1606.00634]
with New result
12 parameters fit to the cosmological data
A Ghost??
![Page 29: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/29.jpg)
The lesson
![Page 30: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/30.jpg)
The lesson
• Dark Radiation is NOT excluded.
![Page 31: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/31.jpg)
The lesson
• Dark Radiation is NOT excluded.
• Even we may say that DR is needed to reconcile with the data from low-z Hubble expansion.
![Page 32: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/32.jpg)
DR with WZ
• “DR= Dark gauge boson” associated with “Dark gauge symmetry
• Dark gauge symmetry is responsible for stability of superheavy dark matter >100 TeV
![Page 33: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/33.jpg)
Local symmetry vs
Global symmetry
![Page 34: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/34.jpg)
Local symmetry vs
Global symmetry
A global symmetry does not work in the presence of gravity, especially in the vicinity of black hole. All the stable particles (strings and branes) should be associated with gauge symmetries.
T. Banks and N. Seiberg, Phys. Rev. D 83, 084019 (2011)
![Page 35: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/35.jpg)
Dark radiation observation
![Page 36: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/36.jpg)
Dark radiation observation• A new gauge boson associated with the new U(1) does
not directly interact with the SM particles
![Page 37: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/37.jpg)
Dark radiation observation• A new gauge boson associated with the new U(1) does
not directly interact with the SM particles
• thus should be regarded as ‘Dark Radiation’.
![Page 38: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/38.jpg)
Dark radiation observation• A new gauge boson associated with the new U(1) does
not directly interact with the SM particles
• thus should be regarded as ‘Dark Radiation’.
• There have been several observations which set the bound on Dark radiation : CMB, BBN in particular
![Page 39: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/39.jpg)
Dark radiation observation• A new gauge boson associated with the new U(1) does
not directly interact with the SM particles
• thus should be regarded as ‘Dark Radiation’.
• There have been several observations which set the bound on Dark radiation : CMB, BBN in particular
![Page 40: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/40.jpg)
DR from WZ
![Page 41: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/41.jpg)
DR from WZ
• To have any sizable contribution DR is actually from a late time decay of a new (lighter) particle at BBN or CMB epoch.
![Page 42: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/42.jpg)
DR from WZ
• To have any sizable contribution DR is actually from a late time decay of a new (lighter) particle at BBN or CMB epoch.
★tBBN~O(0.1-1000) sec,
![Page 43: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/43.jpg)
DR from WZ
• To have any sizable contribution DR is actually from a late time decay of a new (lighter) particle at BBN or CMB epoch.
★tBBN~O(0.1-1000) sec,
★tCMB~3.8X105 yr=1.2X1013 sec
![Page 44: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/44.jpg)
DR from WZ
• To have any sizable contribution DR is actually from a late time decay of a new (lighter) particle at BBN or CMB epoch.
★tBBN~O(0.1-1000) sec,
★tCMB~3.8X105 yr=1.2X1013 sec
• WIMZILLA :U(1) charged fermion, which never decays but contributes the late time decay of a light particle
![Page 45: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/45.jpg)
A minimal modelstable, Dirac DM
long lived ~BBN,CMBDR
•The most general anomaly free, renormalizable Lagrangian of this type
J-C. Park, SCP (2014 & 2015)
![Page 46: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/46.jpg)
![Page 47: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/47.jpg)
•Why not Scalar WZ? .. not good unless ‘Higgs portal’ interaction is forbidden, which introduces additional constraints from other experiments
![Page 48: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/48.jpg)
•Why not Scalar WZ? .. not good unless ‘Higgs portal’ interaction is forbidden, which introduces additional constraints from other experiments
• U(1) mixing may be neglected if there is no bi-charged particle in the spectrum, which is the case for us
![Page 49: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/49.jpg)
(taken the asymptotic value for Veltman-Passario 1-loop function)
Late time decay via WZ loop
hidden sector particle
dark radiation
dark radiation
![Page 50: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/50.jpg)
Dark Radiation
(well known since Mangano et. al. 2005)
(our estimation /w 3.91, 107.75 at present and decoupling time)
primordial
late time decay
![Page 51: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/51.jpg)
The ball park range for DR from WZ
J-C. Park, SCP (2014 & 2015)
![Page 52: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/52.jpg)
Discussion
![Page 53: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/53.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
![Page 54: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/54.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
• WZ >100 TeV can be a good dark matter candidate and have observational consequences
![Page 55: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/55.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
• WZ >100 TeV can be a good dark matter candidate and have observational consequences
• An extra gauge symmetry may be responsible for the stability of Superheavy Dark Matter. Associated gauge boson may play the role of Dark Radiation.
![Page 56: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/56.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
• WZ >100 TeV can be a good dark matter candidate and have observational consequences
• An extra gauge symmetry may be responsible for the stability of Superheavy Dark Matter. Associated gauge boson may play the role of Dark Radiation.
• We suggest a minimal model including WZ (>100 TeV, Dirac), Φ (~GeV, decays late through WZ loop) and Dark Radiation.
![Page 57: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/57.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
• WZ >100 TeV can be a good dark matter candidate and have observational consequences
• An extra gauge symmetry may be responsible for the stability of Superheavy Dark Matter. Associated gauge boson may play the role of Dark Radiation.
• We suggest a minimal model including WZ (>100 TeV, Dirac), Φ (~GeV, decays late through WZ loop) and Dark Radiation.
• NOTE) Φ can also be seen in the invisible decay of the Higgs if the new scalar particle is light enough through the Higgs portal interaction
![Page 58: Dark Radiation with Super heavy DM - Institute for Basic ... · Dark gauge symmetry for WZ • Think of the reason why electron is stable • U(1)em : Electron never decays since](https://reader033.fdocuments.us/reader033/viewer/2022052105/604049eabd061e5a6945c528/html5/thumbnails/58.jpg)
Discussion• Let’s not forget that there is possibility that we are digging into totally wrong place!
• WZ >100 TeV can be a good dark matter candidate and have observational consequences
• An extra gauge symmetry may be responsible for the stability of Superheavy Dark Matter. Associated gauge boson may play the role of Dark Radiation.
• We suggest a minimal model including WZ (>100 TeV, Dirac), Φ (~GeV, decays late through WZ loop) and Dark Radiation.
• NOTE) Φ can also be seen in the invisible decay of the Higgs if the new scalar particle is light enough through the Higgs portal interaction
• Obviously there are more.