lhc limits on the higgs-portal wimps
TRANSCRIPT
Yoshitaro Takaesu U. of Tokyo
LHC limits on the Higgs-‐portal WIMPs
arXiv: 1407.6882 in collabora5on with M. Endo (U.Tokyo)
Portal models to Hidden Sector
2
Consider another world where par5cles are SM singlets (Hidden Sector).
The par5cles interact to our SM world through Gravity.
Also, they may interact through…
DM ?
HL�
FYµ�Xµ�
1fS
Fµ�F̃µ�S
|H|2S2
Neutrino Portal
Vector Portal
Axion Portal
Higgs Portal
Sterile neutrino
Dark Photon
Axino-‐like par5cle
Higgs invisible decay
SM Hidden G
In this talk, we discuss the Higgs-‐portal possibility.
Constraints on Higgs-‐portal models
3
• Relic abundance • Direct detec5on • Collider search
�
�
� �
�
�
Tight constraints on Higgs-‐portal “DM”. S5ll important to know to what extent LHC can explore the heavier Higgs-‐portal models.
Heavy Higgs-‐portal WIMP search
[Simone, Giudice, Strumia: 1402.6287]
Need not to be the DM
Collider search for Heavy Higgs-‐portal WIMP
4
Higgs-‐portal models to be studied
5
Scalar
Vector
AnI-‐sym. Tensor
S, Vµ, Bµ� are SM singlets.
parity is assumed for and to ensure their stability.
m2B = M2
B + 4cBv2m2V = M2
V + 2cV v2m2S = M2
S + 2cSv2
LV = �14V µ�Vµ� +
12M2
V V µVµ + cV |H|2V µVµ � �V (V µVµ)2
LB =14��Bµ���Bµ� �
12�µBµ���B
�� � 14M2
BBµ�Bµ� � cB |H|2Bµ�Bµ�
� �BBµ�B��B��B�µ
LS =12�µS�µS � 1
2M2
SS2 � cS |H|2S2 � �SS4
Z2 S Vµ
a^er EWSB
Fermionic hidden par5cle is not considered for simplicity.
(SM singlet is stable without imposing parity by hand) Bµ�
[A. Djouadi et al.1205.3169, S.Kanemura et al.1005.5651 ]
[O.Cata, A. Ibarra: 1404.0432]
Z2
Cross secIon of WIMP-‐pair producIon
6
We can express the WIMP pair produc5on cross sec5on as
This is the basic formulae for our analysis.
�
��s̃
�S(�
s̃,mS ; cS) =c2S
8�
v2
�s̃
�1� 4m2
S
s̃
�V (�
s̃,mV ; cV ) =c2V
32�
v2
�s̃
s̃2
m4V
�1� 4m2
V
s̃+
12m4V
s̃2
� �1� 4m2
V
s̃
�B(�
s̃,mB ; cB) =c2B
4�
v2
�s̃
s̃2
m4B
�1� 4m2
B
s̃+
6m4B
s̃2
� �1� 4m2
B
s̃
Experimental searches
7
• VBF Higgs invisible decay • Mono-‐jet • Mono-‐Z
Higgs producIon Cross SecIons
Gluon-‐fusion
VBF
WH
ZH
Searches for Higgs invisible decay at the LHC
9
�
�
Vector Boson Fusion (VBF)
BR_inv < 0.65 [CMS: 8TeV 19.5 j^-‐1: 1404.1344]
��
Z associated producIon (ZH)
BR_inv < 0.75 [ATLAS: 8TeV 20.3 j^-‐1: 1402.3244]
BR_inv < 0.81 [CMS: 8TeV 19.5 j^-‐1: 1404.1344]
• Good S/B (Z-‐mass constraint, 2-‐lepton +missing) • Cross sec5on is small (Useful at high luminosity)
• 2nd largest Higgs produc5on process • Good S/B (large rapidity gap of 2 energe5c forwarding jets)
Mono-‐X searches
10
Mono-‐X searches (X +missing pT) are also sensi5ve to Higgs-‐portal models.
Mono-‐jet
• Large Cross sec5on • Main mono-‐X mode so far • S/B is not good • Gluon-‐fusion Higgs produc5on
Mono-‐Z
• Same topology as ZH for Higgs-‐portal model
Mono-‐lepton Mono-‐photon Mono-‐top Mono-‐Higgs etc …
Analysis Details
11
• VBF Higgs invisible decay • Mono-‐jet • Mono-‐Z
* ZH, mono-‐lepton results (profile-‐based) will not be used since they rely on the on-‐shell Higgs produc5on topology.
VBF analysis (CMS , 1404.1344)
12
We calculate under the following cuts (w/ MCFM-‐6.8):
Compare to the upper bound on the signal events.
N lims = 210� 0.65 � 137
95% CL upper bound
�H(pp� jj H;mH)
19.5 fb�1
pp� H� jj � �� jj
�
�
c2�(m�) <
N lims
���(m�, c� = 1)L
���(m�, c�)L < N lims
Mono-‐jet analysis
13
pp� H�j � ��jWe would like to evaluate the cross sec5on at least NLO QCD order. However, NLO cross sec5ons are only known in limit. mt ��
We approximate the NLO cross sec5on as
LO K-‐factor K-‐factor
[R.V.Handler et al. 1206.0157]
[L.Altenkamp et al. 1211.5015]
�
�
Mono-‐jet analysis (CMS-‐PAS-‐EXO-‐12-‐048 )
14
pp� H�j � ��j
We calculate under the following cuts (w/ MCFM-‐6.8): �NLOH (pp� jH;mH)
pTH > 450 GeV (for �LO(mt))
pTH > mH/2 (for K factor)
pTj1 > 110 GeV, |�j1 | < 2.4
• Taming the infinite top mass effects • Avoiding large region log(mH/pTH)
giving the most stringent limit
19.5 fb�1
(* 2nd jet with pT > 30 GeV (from NLO real emission) is not vetoed, due to technical reason. )
Mono-‐Z analysis (ATLAS , 1404.0051)
15
We calculate under the following cuts (w/ HAWK-‐2.0): �H(pp� ZH;mH)
20.3 fb�1
pµT > 20 GeV, |�µ| < 2.5
peT > 20 GeV, |�e| < 2.47
76 GeV < mll < 106 GeV|�ll| < 2.5
�pT > 150 GeV giving the most stringent limit
��
8 TeV LHC constraints
16
�S(�
s̃,mS ; cS) =c2S
8�
v2
�s̃
�1� 4m2
S
s̃
�V (�
s̃,mV ; cV ) =c2V
32�
v2
�s̃
s̃2
m4V
�1� 4m2
V
s̃+
12m4V
s̃2
� �1� 4m2
V
s̃
�B(�
s̃,mB ; cB) =c2B
4�
v2
�s̃
s̃2
m4B
�1� 4m2
B
s̃+
6m4B
s̃2
� �1� 4m2
B
s̃
Limits for the Heavy Higgs-‐portal WIMPs
17
Tensor Vector
Scalar
Data : BG VBF 390 : 332(58) Mono-‐jet 1772 : 1931(131) Mono-‐Z 45 : 52(18)
14 TeV LHC prospects
18
How to perform (rough) projecIon
19
We need to know and to es5mate the 14 TeV constraints on .
N limsig
���c�
c2�(m�) <
N limsig
���(m�, c� = 1)L
is roughly es5mated with the following assump5ons: N limsig
95% CL (simple Gaussian)
Rela5ve does not improve
Rela5ve reduces as . 1/�
NBG
NBG increases due to PDF (luminosity ra5o) and integrated luminosity L
��� is es5mated by theore5cal calcula5ons with experimental cuts.
�sys
�stat�
�stat
NBG
�
14TeV
=
�N8TeV
BG�N14TeV
BG
��stat
NBG
�
8TeV
N limsig � 2�tot
�tot =�
�2sys + �2
stat
��sys
NBG
�
14TeV
=�
�sys
NBG
�
8TeV
Mono-‐jet channel: 14 TeV LHC
20
1
10
100
1000
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DMpTcut = 400 GeV
600 GeV800 GeV
1
10
100
1000
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DM Vector DMpTcut = 400 GeV
600 GeV800 GeV
1
10
100
1000
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DM Vector DM
Scalar DMpTcut = 400 GeV
pp� H�j � ��j Cross Sec5ons at 14 TeV
Cx < 1 (100 1/j)
Cx < 0.2 (100 1/j)
N lims (�pT > 400) � 2000 (L = 100 fb�1)
Mono-‐jet SensiIvity
21
0
1
2
3
4
5
6
7
8
Tensor Vector Scalar
Mono-‐J 8TeV
14TeV 400 (100)
400 (3,000)
600 (100)
600 (3,000)
VBF 8TeV
14TeV (100)
ZH 8TeV
14TeV (300)
14TeV (3,000)
clim �
m� = 70GeV�pcut
T (L)
* Rough Es5mate
Tensor
Mono-‐Z channel: 14 TeV LHC
22
0.01
0.1
1
10
100
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DMpTcut = 150 GeV
250 GeV350 GeV450 GeV
0.01
0.1
1
10
100
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DM Vector DMpTcut = 150 GeV
250 GeV350 GeV450 GeV
0.01
0.1
1
10
100
65 80 100 120 140 160 180 200 220 240
Cros
s Sec
tion
/ c2 χ [
fb]
mχ [GeV]
Tensor DM Vector DM
Scalar DMpTcut = 150 GeV
250 GeV350 GeV450 GeV
Cross Sec5ons at 14 TeV
(L = 100 fb�1)N lims (�pT > 450) � 5
pp� ZH� � Z��
VBF channels
23
[5] ATLAS, 1402.3244 [6] CMS, 1404.1344 [16] D.Gosh et al., 1211.7015 [17] ATL-‐PHYS-‐PUB-‐2013-‐014 [18] Snowmass, 1309.7925
95% Upper bounds on the Higgs inv. decay ra5o at mH = 125 GeV
The VBF bound will be improved by a factor of 4 at mH = 125 GeV.
���
The Upper bound on improves a factor of 2. c�
��� =� �
4m2�
ds̃
2��H(s̃)��(s̃)
2�
s̃
(s̃�m2H)2 + �2
Hm2H
The ZH bound will be improved by a factor of 2 ~ 4 (300 1/j) and 4 ~ 12 (3,000 1/j).
The Upper bound on will be improved by a factor of 1.5 ~ 2 (300 1/j) and 2 ~ 3.5 (3,000 1/j).
c�
If this level of improvement holds for any mH, the Upper bound on improves a factor of 4.
Profile-‐based Cut-‐based
0
2
4
6
8
10
12
Tensor Vector Scalar
Mono-‐J 8TeV
14TeV 400 (100)
400 (300)
600 (100)
600 (300)
Mono-‐Z 8TeV
14TeV 450 (100)
450 (300)
VBF 8TeV
14TeV (100)
SensiIvity Summary (Mono-‐j, VBF, Mono-‐Z)
24
clim �
m� = 70GeV
MJ MZ VBF MJ MZ VBF MJ MZ VBF
* Rough Es5mate
Tensor
MJ MZ VBF
Summary
25
LHC constraints on the Heavy Higgs-‐portal WIMP have been Studied.
8 TeV LHC results can access the Higgs-‐portal couplings below 1 for the vector and tensor case. Scalar coupling limit is very weak.
14 TeV LHC can reach at O(0.1) couplings for vector and tensor case. The scalar coupling below O(1) will be remained unexplored.
VBF channel already shows good performance in 8 TeV LHC, replacing the mono-‐jet channel. ZH, Mono-‐Z channel will also be a important channel in 14 TeV LHC.