Dark Matter Annihilating into Sterile Neutrino Yi-Lei Tang Center for High Energy Physics, Peking University October 26, 2016 Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Dark Matter Annihilating into Sterile Neutrino
Yi-Lei Tang
Center for High Energy Physics, Peking University
October 26, 2016
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I This slide is based on JHEP 1603 (2016) 043, Yi-Lei Tang,Shou-Hua Zhu, and arXiv:1609.07841.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to Seesaw Mechanisms
I Right-handed neutrino N can result in the light neutrinos’masses through Type-I seesaw mechanisms.
I Majorana mass among right-handed neutrinos.
I
M =
[0 mD
mTD mN
](1)
I → mν = −m2D
mN.
I mD = yνvEW, usually y ∼ 1, and mN � 1 TeV.
I yν ∼ 10−7-10−5, mN < 1 TeV (Naive TeV Seesaw).
I For linear see-saw or inverse see-saw (pseudo-Dirac sterileneutrino), yν can be as large as 10−3.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Sterile Neutrino-Portal Dark Matter?
I Sterile Neutrino Dark Matter? (mDM � 1 GeV, “Warm DarkMatter”)
I What about the dark matter annihilate into sterile neutrinos?
I Two previous examples,
I 1) NMSSM+Right-handed Neutrino.
I DM+DM→ N + N usually does not dominate, but can beimportant sometimes.
I 2) MSSM+(B-L)Z ′, R. Allahverdi, et.al., 0907.1486, etc.,
I In this model, there are some parameter space thatDM+DM→ N + N can dominate.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Current fittings on the galactic center excess of the γ-ray
I DM → bb fits the galactic center excess (GCE) well.W+W−, ZZ , tt do not.
Χ2 p-val.
hh 28.2 0.17
WW 38.3 0.017
tt 43.5 0.0041
bb 24.2 0.34
ZZ 35.6 0.033
1 10 1000
2
4
6
8
10
12
14
EΓ @GeVD
EΓ
2dN
�dE
Γ@1
0-
7G
eV�H
cm2
ssr
LD
Figure : From arXiv:1411.2592, by Prateek Agrawal, Brian Batell,Patrick J. Fox, and Roni Harnik. Data from F. Calore, et.al.,1409.0042.
I The key is the position of the peak and the length of the tail!W /Z/t is too heavy for a lighter peak.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Current fittings on the galactic center excess of the γ-ray
I DM → bb fits the galactic center excess (GCE) well.W+W−, ZZ , tt do not.
Χ2 p-val.
hh 28.2 0.17
WW 38.3 0.017
tt 43.5 0.0041
bb 24.2 0.34
ZZ 35.6 0.033
1 10 1000
2
4
6
8
10
12
14
EΓ @GeVD
EΓ
2dN
�dE
Γ@1
0-
7G
eV�H
cm2
ssr
LD
Figure : From arXiv:1411.2592, by Prateek Agrawal, Brian Batell,Patrick J. Fox, and Roni Harnik. Data from F. Calore, et.al.,1409.0042.
I The key is the position of the peak and the length of the tail!W /Z/t is too heavy for a lighter peak.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Model Independent Analysis of the GCE Originating FromDM+DM→ N + N
I DM+DM→ N + N, RHN → off-shell W , Z , which mightmove the position of the peak downward.
I The best-fitted points are mN = 32.0 GeV, mχ = 44.2 GeV,with χ2 = 24.22 and the best-fitted〈σv〉 = 2.63× 10−26cm3/s for the y1 = y2 = 0, y3 6= 0 case,and mN = 27.0 GeV, mχ = 45.4 GeV, with χ2 = 23.81 andthe best-fitted 〈σv〉 = 3.37× 10−26cm3/s for the y3 = 0,y21 + y22 6= 0 case.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Model Independent Analysis of the GCE Originating FromDM+DM→ N + N
I DM+DM→ N + N, RHN → off-shell W , Z , which mightmove the position of the peak downward.
I The best-fitted points are mN = 32.0 GeV, mχ = 44.2 GeV,with χ2 = 24.22 and the best-fitted〈σv〉 = 2.63× 10−26cm3/s for the y1 = y2 = 0, y3 6= 0 case,and mN = 27.0 GeV, mχ = 45.4 GeV, with χ2 = 23.81 andthe best-fitted 〈σv〉 = 3.37× 10−26cm3/s for the y3 = 0,y21 + y22 6= 0 case.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Model Independent Analysis of the GCE Originating FromDM+DM→ N + N
100 101 102
Eγ/GeV
0
2
4
6
8
10
12
E2 γdNdE/[10
−7GeV
/(cm
2·s·sr
)]
NN, y1 =y2 =0, χ2 =24.2
NN, y3 =0, χ2 =23.8
ZZ, χ2 =39.7
WW, χ2 =41.8
hh, χ2 =30.6
bb, χ2 =24.6
Flux with errors
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Model Independent Analysis of the GCE Originating FromDM+DM→ N + N
mN/GeV10 20 30 40 50 60 70
mχ/GeV
10
20
30
40
50
60
70
mN/GeV10 20 30 40 50 60 70
mχ/GeV
10
20
30
40
50
60
70
Figure : 1,2,3-σ area fitting the GCE data
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Model Independent Analysis of the GCE Originating FromDM+DM→ N + N
mN/GeV10 20 30 40 50 60 70
mχ/GeV
10
20
30
40
50
60
70
0
5
10
15
20
25
30
35
mN/G eV10 20 30 40 50 60 70
mχ/GeV
10
20
30
40
50
60
70
0
10
20
30
40
50
Figure : Best-fitted 〈σv〉 for the γ-ray GCE
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Standard WIMP Calculation?
I Standard WIMP calculation requires the annihilation productsto fall into thermal equilibrium rapidly with the thermal bath.
I
sHzdYχdz
= −〈σv〉χχ→N(D)N(D)s2(Y 2
χ − Y 2χeq) (2)
I For naive seesaw model, yν � 1, N might deviate from thethermal equilibrium with the thermal bath!
I For the pseudo-Dirac sterile neutrinos, yNDcan ∼ 0.01,
however, when T < mND, the effective decay/inverse-decay
rate drops rapidly.
I Secluded dark matter.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Standard WIMP Calculation?
I Standard WIMP calculation requires the annihilation productsto fall into thermal equilibrium rapidly with the thermal bath.
I
sHzdYχdz
= −〈σv〉χχ→N(D)N(D)s2(Y 2
χ − Y 2χeq) (2)
I For naive seesaw model, yν � 1, N might deviate from thethermal equilibrium with the thermal bath!
I For the pseudo-Dirac sterile neutrinos, yNDcan ∼ 0.01,
however, when T < mND, the effective decay/inverse-decay
rate drops rapidly.
I Secluded dark matter.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Standard WIMP Calculation?
I Standard WIMP calculation requires the annihilation productsto fall into thermal equilibrium rapidly with the thermal bath.
I
sHzdYχdz
= −〈σv〉χχ→N(D)N(D)s2(Y 2
χ − Y 2χeq) (2)
I For naive seesaw model, yν � 1, N might deviate from thethermal equilibrium with the thermal bath!
I For the pseudo-Dirac sterile neutrinos, yNDcan ∼ 0.01,
however, when T < mND, the effective decay/inverse-decay
rate drops rapidly.
I Secluded dark matter.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Standard WIMP Calculation?
I Standard WIMP calculation requires the annihilation productsto fall into thermal equilibrium rapidly with the thermal bath.
I
sHzdYχdz
= −〈σv〉χχ→N(D)N(D)s2(Y 2
χ − Y 2χeq) (2)
I For naive seesaw model, yν � 1, N might deviate from thethermal equilibrium with the thermal bath!
I For the pseudo-Dirac sterile neutrinos, yNDcan ∼ 0.01,
however, when T < mND, the effective decay/inverse-decay
rate drops rapidly.
I Secluded dark matter.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Standard WIMP Calculation?
I Standard WIMP calculation requires the annihilation productsto fall into thermal equilibrium rapidly with the thermal bath.
I
sHzdYχdz
= −〈σv〉χχ→N(D)N(D)s2(Y 2
χ − Y 2χeq) (2)
I For naive seesaw model, yν � 1, N might deviate from thethermal equilibrium with the thermal bath!
I For the pseudo-Dirac sterile neutrinos, yNDcan ∼ 0.01,
however, when T < mND, the effective decay/inverse-decay
rate drops rapidly.
I Secluded dark matter.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I New progress: the relic abundance of such kind of model.
I A model independent analysis cannot formulate a completeand reliable 〈σv〉(T ) at any temperature, so we rely on asimple model based on Miguel Escudero, et.al, 1607.02373.
I A majorana spinor χ and a real-scalar φ take the minusZ(2,DM) charge and mχ < mφ, so χ is the dark mattercandidate.
I χ+ χ→ N(D) + N(D) through the χN(D)φ-interaction.
I φ can interact with the Higgs boson through the φφH†Hterms.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I New progress: the relic abundance of such kind of model.
I A model independent analysis cannot formulate a completeand reliable 〈σv〉(T ) at any temperature, so we rely on asimple model based on Miguel Escudero, et.al, 1607.02373.
I A majorana spinor χ and a real-scalar φ take the minusZ(2,DM) charge and mχ < mφ, so χ is the dark mattercandidate.
I χ+ χ→ N(D) + N(D) through the χN(D)φ-interaction.
I φ can interact with the Higgs boson through the φφH†Hterms.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I New progress: the relic abundance of such kind of model.
I A model independent analysis cannot formulate a completeand reliable 〈σv〉(T ) at any temperature, so we rely on asimple model based on Miguel Escudero, et.al, 1607.02373.
I A majorana spinor χ and a real-scalar φ take the minusZ(2,DM) charge and mχ < mφ, so χ is the dark mattercandidate.
I χ+ χ→ N(D) + N(D) through the χN(D)φ-interaction.
I φ can interact with the Higgs boson through the φφH†Hterms.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I New progress: the relic abundance of such kind of model.
I A model independent analysis cannot formulate a completeand reliable 〈σv〉(T ) at any temperature, so we rely on asimple model based on Miguel Escudero, et.al, 1607.02373.
I A majorana spinor χ and a real-scalar φ take the minusZ(2,DM) charge and mχ < mφ, so χ is the dark mattercandidate.
I χ+ χ→ N(D) + N(D) through the χN(D)φ-interaction.
I φ can interact with the Higgs boson through the φφH†Hterms.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I New progress: the relic abundance of such kind of model.
I A model independent analysis cannot formulate a completeand reliable 〈σv〉(T ) at any temperature, so we rely on asimple model based on Miguel Escudero, et.al, 1607.02373.
I A majorana spinor χ and a real-scalar φ take the minusZ(2,DM) charge and mχ < mφ, so χ is the dark mattercandidate.
I χ+ χ→ N(D) + N(D) through the χN(D)φ-interaction.
I φ can interact with the Higgs boson through the φφH†Hterms.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I When the temperature T � mφ,χ,N(D), everything become in
thermal equilibrium with the thermal bath through theHiggs↔ φ portal processes.
I As the temperature T drops and φ decouples, N(D) and χtogether decouple from the thermal bath while they are inthermal-equilibrium within themselves.
I Finally, N(D) and χ decouple with each other and N(D) decaysup before the BBN.
I The contribution from the W /Z/γT in the thermal bath wasestimated according to the method introduced inPhys.Rev.Lett. 117 (2016) no.9, 091801.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I When the temperature T � mφ,χ,N(D), everything become in
thermal equilibrium with the thermal bath through theHiggs↔ φ portal processes.
I As the temperature T drops and φ decouples, N(D) and χtogether decouple from the thermal bath while they are inthermal-equilibrium within themselves.
I Finally, N(D) and χ decouple with each other and N(D) decaysup before the BBN.
I The contribution from the W /Z/γT in the thermal bath wasestimated according to the method introduced inPhys.Rev.Lett. 117 (2016) no.9, 091801.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I When the temperature T � mφ,χ,N(D), everything become in
thermal equilibrium with the thermal bath through theHiggs↔ φ portal processes.
I As the temperature T drops and φ decouples, N(D) and χtogether decouple from the thermal bath while they are inthermal-equilibrium within themselves.
I Finally, N(D) and χ decouple with each other and N(D) decaysup before the BBN.
I The contribution from the W /Z/γT in the thermal bath wasestimated according to the method introduced inPhys.Rev.Lett. 117 (2016) no.9, 091801.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Introduction to a Simple Sterile-Neutrino Portal Model.
I When the temperature T � mφ,χ,N(D), everything become in
thermal equilibrium with the thermal bath through theHiggs↔ φ portal processes.
I As the temperature T drops and φ decouples, N(D) and χtogether decouple from the thermal bath while they are inthermal-equilibrium within themselves.
I Finally, N(D) and χ decouple with each other and N(D) decaysup before the BBN.
I The contribution from the W /Z/γT in the thermal bath wasestimated according to the method introduced inPhys.Rev.Lett. 117 (2016) no.9, 091801.
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Results
I Calculate in a completed Boltzmann equation,
10 20 30 40 50 60 70 80z
101
103
105
107
109
1011
1013
1015
1017
1019
1021
1023
Y/Y
eqmχ =52 GeV, majorana neutrino and mN =24 GeV.
Yχ
Yχeq
YNYNeq
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Results
I In order for a correct relic abundance, the interactions of theχχ→ N(D)N(D) should be stronger than the usual standardWIMP calculations!
I
15 20 25 30 35 40 45 50mN/GeV
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
y χ
mχ =52 GeV, majorana neutrino
yN =10−7
yN =10−6
yN =10−5
yN =10−4
yN =10−3
yN =10−2
Old Boltzmann
15 20 25 30 35 40 45 50mN/GeV
0.30
0.35
0.40
0.45
0.50
0.55
0.60
0.65
0.70
0.75
y χ
mχ =52 GeV, pseudo-dirac neutrino.
yN =10−7
yN =10−6
yN =10−5
yN =10−4
yN =10−3
yN =10−2
Old Boltzmann
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Future Plan
I Future plan: to build a completesupersymmetric/nonsupersymmetric model that dark matter→ RHN. Explaining neutrino mass spectrum and mixingpatterns, leptogenesis, etc....
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Thank You!
Thank You!
Yi-Lei Tang Dark Matter Annihilating into Sterile Neutrino
Related Documents
