Multiparticle Dark Matter and implications for detection Purusottam - PowerPoint PPT Presentation

Multiparticle Dark Matter and implications for detection Purusottam Ghosh IIT Guwahati, India YSF, Moriond EW 2019, La Thuile, Italy based on JHEP 1902 (2019) 059, S. Bhattacharya, P.Ghosh and N.Sahu [arXiv: 1809.07474] Purusottam Ghosh IIT Guwahati March 21, 2019 1 / 10

����������������������������� Dark Matter 0 . 1133  ⌦ h 2  0 . 1189 ������������������������� Rotation Curve of Galaxies CMB data � ������������������������ � ������������������� • Properties of DM particles: • None of the SM be the suitable � ��������������������������������� candidate of Dark Matter. � EM charge neutral ������������������������������������������� � Weakly-interacting • What kind of elementary ����������������� � Still around today (stable) ����������������� particles can be Dark Matter ? ������������������������������������� � Massive (cold/non-relativistic) ⇒ We do not know. Weeakly Interacting Massive φ DM = Particle (WIMP) Fermion , A µ dark { ψ dark Boson , φ dark Scalar , ..... } (dark ≡ EM charge neutral) Purusottam Ghosh IIT Guwahati March 21, 2019 2 / 10

The Model • SM Extension: A scalar singlet ( S ) and three vectorlike fermions: two singlets ( χ 1 , χ 2 ) and a doublet, N = ( N 0 N − ) T . � ×Z 2 × Z ′ 2 Dark Fields SU (3) C × SU (2) L × U (1) Y � �� � � ( N 0 N = 1 2 -1 - + N − χ 1 1 1 0 - + 1 1 0 + - χ 2 S 1 1 0 - - ⊃ L V LF + L Scalar + L messenger . L L messenger = χ 2 ( iγ µ ∂ µ − m χ 2 ) χ 2 − Y 2 ( χ 1 χ 2 S + h.c ) . • χ 2 behave as a messenger between scalar and VF DM sector. Purusottam Ghosh IIT Guwahati March 21, 2019 3 / 10

Single component DM scenarions Scalar DM and Vectorlike fermionic DM • Scalar DM : A real singlet, S . Z 2 : S → − S . 1 1 L Scalar ∂ µ S∂ µ S − m 2 S S 2 = 2 2 1 λ S S 4 − 4! � v 2 � 1 H † H − S 2 − λ SH 2 2 ref: V. Silveira and A. Zee • Parameters: { m S , λ SH } Purusottam Ghosh IIT Guwahati March 21, 2019 4 / 10

Single component DM scenarions Scalar DM and Vectorlike fermionic DM • Scalar DM : A real singlet, S . • Fermionic DM : Admixture of vector-like fermionic singlet ( χ 1 ) Z 2 : S → − S . and a doublet ( N ) . ref: PRD93(2016)no.11, 1 1 115040 L Scalar ∂ µ S∂ µ S − m 2 S S 2 = 2 2 µ − ig ′ Y ′ σ a 1 L V LF = N [ iγ µ ( ∂ µ − ig W a λ S S 4 B µ ) − m N ] N − 2 2 4! + χ 1 ( iγ µ ∂ µ − m χ 1 ) χ 1 − ( Y 1 N � � v 2 � 1 Hχ 1 + h.c ) H † H − S 2 − λ SH 2 2 • { N 0 , χ 1 } → { N 1 , N 2 } (Physical States) The lightest ref: V. Silveira and A. Zee physical states N 1 ( m N 1 < m N 2 ) be a stable DM . • Parameters: { m S , λ SH } • Parameters: { m N 1 , ∆ m (= m N 2 ( m N ± ) − m N 1 ) , sin θ } Purusottam Ghosh IIT Guwahati March 21, 2019 4 / 10

Multi-Component DM model • Non observations of direct search put strong constarints on single component DM parameter space. • ∆ m = m N ± − m N 1 � 12 GeV, Vector like fermionic DM can not observe at LHC due to dominate SM background. • In presence of an interacting two component framework, the situation alters. • Yukawa Interaction: Y 2 χ 1 χ 2 S Type-I : m χ 2 > m N 1 + m S : Stable DM components: 1 . Vector like Fermion , N 1 , 2 . Real Scalar Singlet , S . Ω DM h 2 = Ω N 1 h 2 +Ω S h 2 ∆ m = m N 2 − m N 1 ≈ m N ± − m N 1 (sin Purusottam Ghosh IIT Guwahati March 21, 2019 5 / 10

Relic and Direct search outcome DM-DM Conversion • Large ∆ m = m N ± − m N 1 > 12 GeV is allowed in this two component model which is otherway absent in single component VLF DM scenario. Purusottam Ghosh IIT Guwahati March 21, 2019 6 / 10

Collider Signature of VLF DM at LHC , √ s = 14 TeV Signal :: p p → N + N − , (N − → ℓ − ν ℓ N 1 ) , (N + → ℓ + ν ℓ N 1 ) ℓ = e , µ • Large ∆ m allows MET distribution peaking at high value. • This helps in elliminations of SM background. Purusottam Ghosh IIT Guwahati March 21, 2019 7 / 10

Summary DM-DM interaction plays a crucial role and yields lagrer region of allowed parameter space of heavier DM component. Presence of scalar DM, large ∆ m = m N ± − m N 1 region (upto 500 GeV) of VLF becomes allowed from relic and direct search bound which is otherway absent in single component VLF DM scenario. The signal of VLF DM can be observed at LHC at high Luminosity in presence of second lighter DM component. Purusottam Ghosh IIT Guwahati March 21, 2019 8 / 10

Backup � � � � � dY Ni µ √ g ∗ Y Ni Y Nj − Y EQ Ni Y EQ = − 0 . 264 M P l � σv NiNj → SM � Nj dx x 2 j Y EQ Ni Y EQ � � Nj Y 2 + � σv NiNj → SS � Y Ni Y Nj − Θ( m Ni + m Nj − 2 m S ) S 2 Y EQ S 2 � � Y EQ � Y 2 S −� σv SS → NiNj � S − Y Ni Y Nj Θ(2 m S − m Ni − m Nj ) Y EQ Ni Y EQ Nj �� � Y Ni Y N ± − Y EQ Ni Y EQ + � σv NiN ±→ SM � , N ± � � 2 � dY S √ g ∗ µ 2 − Y EQ = − 0 . 264 M P l � σv SS → SM � Y S S x 2 dx Y EQ Ni Y EQ � � � � Nj Y 2 + − � σv NiNj → SS � Y Ni Y Nj − Θ( m Ni + m Nj − 2 m S ) S 2 Y EQ i,j S � Y EQ 2 � � Y 2 S + � σv SS → NiNj � S − Y Ni Y Nj Θ(2 m S − m Ni − m Nj ) , Y EQ Ni Y EQ Nj (1) Purusottam Ghosh IIT Guwahati March 21, 2019 9 / 10

Backup N 1 N 1 N 1 N 1 S S Z h h n n n n n n Feynman diagrams of spin independent (SI) direct detection of fermion DM (left) and scalar DM (right). � Ω N 1 h 2 � � Ω S h 2 � σ SI σ SI σ SI σ SI eff ( N 1 ) = N 1 , eff ( S ) = S . Ω T h 2 Ω T h 2 � � � � � � n t � v � ρ c n t � v � ρ c n t � v � ρ c Ω T σ SI Ω 1 σ DD Ω 2 σ DD R = = + , T 1 2 m φ m φ 1 m φ 2 � � m φ 1 n t � v � ρ c [Ω 1 σ DD Ω 2 σ DD = + ] 1 2 m φ 1 m φ 2 � m φ 1 � Ω 1 Ω 2 σ SI σ DD σ DD ∴ = + . (2) T 1 2 Ω T Ω T m φ 2 Purusottam Ghosh IIT Guwahati March 21, 2019 10 / 10