Direct Detection Signals from Absorption of Fermionic Dark Matter - PowerPoint PPT Presentation

Direct Detection Signals from Absorption of Fermionic Dark Matter Searching for new physics - Leaving no stone unturned! University of Utah, August 5 2019 Gilly Elor University of Washington, Seattle Based on: Jeff Dror, GE, Robert McGehee [ 1905.12635 ] submitted to PRL Jeff Dror, GE, Robert McGehee [ 1908.xxxxx ] nuclear targets Jeff Dror, GE, Robert McGehee, Tien-Tien Yu [ 19xx.xxxxx ] electron targets

Dark Matter exists.

Searching for Dark Matter DM SM DM SM Dark Matter - Standard Model Interaction

Searching for Dark Matter Indirect Detection (today) DM SM DM SM Production at Colliders

Searching for Dark Matter Indirect Detection (today) DM SM n o i t c e t e D t c e r i D DM SM Today’s Talk Production at Colliders

Weakly Interacting Massive Particles χ χ Vanilla WIMP: χ χ χ • Interacts via weak force Λ M W • m χ ⇠ 10 GeV - 10 TeV • Stable T T N N x recoil energy: Direct Detection Searches: • Elastic Scattering: DM imparts kinetic energy on nuclei E R ⇠ µ 2 v 2 • Measure nuclear recoil M N • Order keV experimental thresholds

We Have Not Found WIMPs Ever smaller cross sections excluded while approaching the neutrino floor Snowmass Report 2013

Light Dark Matter Light (sub-GeV) dark matter (LDM) below experimental nuclear recoil thresholds E R ∼ µ 2 v 2 /M T Snowmass Report 2013

Need Lower Thresholds Lots of work has been done! χ χ Vanilla WIMP: χ χ χ • Interacts via weak force • Λ Λ m χ ⇠ 10 GeV - 10 TeV • Stable T T e − e − x recoil energy: Elastic scattering off electrons E R ∼ µ 2 v 2 /M T (Model space is actually highly constrained [1709.07882]) Moving away from Vanilla WIMP: Lack of discoveries motivates us to move away from the simplest scenarios.

Giving up Stability? Vanilla WIMP: • Interacts via weak force • m χ ⇠ 10 GeV - 10 TeV • Stable ??

Giving up Stability? Vanilla WIMP: • Interacts via weak force • m χ ⇠ 10 GeV - 10 TeV • Stable ?? Leaving no stone unturned!

Giving up Stability? Vanilla WIMP: • Interacts via weak force • m χ ⇠ 10 GeV - 10 TeV • Stable ?? Signals from Absorption of fermionic Dark Matter

Absorption of Fermionic Dark Matter • Distinctive new signals! Target can absorb fermionic DM rest mass • Can repurpose existing DM ⇠ m χ + 1 E NR 2 m χ v 2 direct detection and neutrino χ experiments. • No neutrino floor e ± ν χ χ Λ Λ 0 N, e − N, e − N N Charged Current Neutral Current

Fermion Absorption Operators ν χ Neutral Current: ⇤⇥ ¯ O NC = 1 ⇥ ⇤ χ Γ i ν ψ Γ j ψ ¯ ψ = p , n , e Λ , Λ 2 Γ i ⌘ { 1 , γ 5 , γ µ , γ µ γ 5 , σ µ ν } N, e − N, e − Ex. UV Model*: Z’ mediator, lepton no. charged DM and Dirac neutrinos e ± Charged Current: χ O CC = 1 ⇥ ⇤⇥ ⇤ χ Γ i e ¯ n Γ j p ¯ Λ Λ 2 Ex. UV Model*: L-R model vector mediator, lepton no. charged DM and Dirac neutrinos 0 N N *For model building details see: “ Absorption of Fermionic Dark Matter by Nuclear Targets ” [1908.xxxxx]

Dark Matter Decays

Dark Matter Decays • Certain problematic operators leading to fast decays can be suppressed e.g. χσ µ ν ν F µ ν ¯ • Decays are model dependent: build UV models which suppressed additional decay contributions. • Minimum contribution to decay is independent of UV model, but scales as powers of DM mass.

Dark Matter Decays • Certain problematic operators leading to fast decays can be suppressed e.g. χσ µ ν ν F µ ν ¯ • Decays are model dependent: build UV models which suppressed additional decay contributions. • Minimum contribution to decay is independent of UV model, but scales as powers of DM mass.

Dark Matter Decays • Certain problematic operators leading to fast decays can be suppressed e.g. χσ µ ν ν F µ ν ¯ • Decays are model dependent: build UV models which suppressed additional decay contributions. • Minimum contribution to decay is independent of UV model, but scales as powers of DM mass. c 1 Æ c 2 e + e - + FSR e ´ , χ p, n 10 26 γ , Z 10 25 t @ sec D 10 24 HEAO - 1 e ` , INTEGRAL 10 23 COMPTEL ν EGRET 10 22 FERMI „ 1 10 10 2 10 3 10 4 < m χ < 100 MeV m 1 @ MeV D [1309.4091]

Dark Matter Decays • Certain problematic operators leading to fast decays can be suppressed e.g. χσ µ ν ν F µ ν ¯ • Decays are model dependent: build UV models which suppressed additional decay contributions. • Minimum contribution to decay is independent of UV model, but scales as powers of DM mass. c 1 Æ c 2 e + e - + FSR e ´ , χ p, n 10 26 γ , Z 10 25 t @ sec D 10 24 HEAO - 1 e ` , INTEGRAL 10 23 COMPTEL ν EGRET 10 22 FERMI „ 1 10 10 2 10 3 10 4 < m χ < 100 MeV m 1 @ MeV D [1309.4091] • Speaking of Elephants: Little hope to detect sterile neutrinos τ N → νγ / Λ 2 / 1 /s 2 θ

New Signals!

Neutral Current Signals: Nuclear Targets JD, GE, RM [ 1905.12635 ] , [ 1908.xxxxx ] ν χ Λ N, N,

Neutral Current Signals: Nuclear Targets JD, GE, RM [ 1905.12635 ] , [ 1908.xxxxx ] • Operators: ν χ ⇤⇥ ¯ O NC = 1 ⇥ ⇤ ¯ nuc = p , n � Γ i ⌫ nuc Γ j nuc , Λ 2 Λ N, N,

Neutral Current Signals: Nuclear Targets JD, GE, RM [ 1905.12635 ] , [ 1908.xxxxx ] • Operators: ν χ ⇤⇥ ¯ O NC = 1 ⇥ ⇤ ¯ nuc = p , n � Γ i ⌫ nuc Γ j nuc , Λ 2 Λ • Kinematics: m 2 E ν ∼ m χ and E T ∼ χ 2 M N m χ << M N N, N, Dark matter rest mass is absorbed (kinetic energy negligible)

Neutral Current Signals: Nuclear Targets JD, GE, RM [ 1905.12635 ] , [ 1908.xxxxx ] • Operators: ν χ ⇤⇥ ¯ O NC = 1 ⇥ ⇤ ¯ nuc = p , n � Γ i ⌫ nuc Γ j nuc , Λ 2 Λ • Kinematics: m 2 E ν ∼ m χ and E T ∼ χ 2 M N m χ << M N N, N, Dark matter rest mass is absorbed (kinetic energy negligible) • Signal: • All events in one bin E R − m 2 ✓ ◆ dR • Isotope peaks χ ∝ δ 2 M N dE R • No neutrino floor • Sensitive to sub GeV DM masses E R ⇠ µ 2 v 2 Distinct from elastic scattering which recall is DM velocity dependent M N

Absorption vs Elastic Scattering Signals crystals s CaWO 4 ∼ m 2 ∼ m 2 χ v 2 vs E abs E elastic χ R R 2 M N M N aWO s CaW O 4 is � NC = m 2 4 ⇡ Λ 4 � � χ / ature of correlated, pe

Absorption vs Elastic Scattering Signals crystals s CaWO 4 aWO s CaW O 4 is � NC = m 2 4 ⇡ Λ 4 � � χ / ature of correlated, pe

Neutral Current Projections R = ⇢ χ X N j A 2 j F 2 j Θ ( E 0 R,j � E th ) . is � NC = m 2 4 ⇡ Λ 4 � � χ / � NC m χ ature of correlated, pe j 52 kg-days No . Events < 10 1905.12635 Robert McGehee

Neutral Current Projections R = ⇢ χ X N j A 2 j F 2 j Θ ( E 0 R,j � E th ) . is � NC = m 2 4 ⇡ Λ 4 � � χ / � NC m χ ature of correlated, pe j Λ < 1 TeV Mono-Jet searches [1807.03817] 52 kg-days No . Events < 10 1905.12635 Robert McGehee

Neutral Current Projections R = ⇢ χ X N j A 2 j F 2 j Θ ( E 0 R,j � E th ) . is � NC = m 2 4 ⇡ Λ 4 � � χ / � NC m χ ature of correlated, pe j Λ < 1 TeV 52 kg-days No . Events < 10 Isotopes nuclear recoil energy rises above experimental threshold E 0 R,j = m 2 χ / (2 M N j ) > E th 1905.12635 Robert McGehee

Neutral Current Projections Γ χ ! ν e + e � Decays? e.g Λ < 1 TeV 1905.12635 Robert McGehee

Neutral Current Projections Γ χ ! ν e + e � Decays? e.g Indirect Detection Λ < 1 TeV constraints [1309.4091] e � � Z 0 � ✏ e + ⌫ χ → ν e + e − ∝ m 5 Γ NC χ Λ 4 1905.12635 Robert McGehee

Neutral Current Projections Decays? e.g Γ χ ! ν e + e � Indirect Detection Λ < 1 TeV constraints [1309.4091] e � � Z 0 � ✏ e + ⌫ χ → ν e + e − ∝ m 5 Γ NC χ Λ 4 “Fine Tune “ away with a UV Kinetic Mixing 1905.12635 Robert McGehee

Neutral Current Projections Repurposing Existing Experiments No . Events < 10 σ NC . 10 m χ Ave. Isotope mass Fiducial Mass ⇥ Run Time ρ χ

Neutral Current Hypothetical Experiments Lighter targets and lower threshold to probe sub-MeV Dark Matter by collective m Since E R / 1 /M , this regime.

Neutral Current Hypothetical Experiments Lighter targets and lower threshold to probe sub-MeV Dark Matter by collective m Since E R / 1 /M , this regime. Decays? Indirect detection constraints: � e Z 0 � � ✏ ⌫ Γ χ → νγγγ / m power χ No/little need for Fine Tuning.

Charged Current Signals ⇥ ⇤ ⇥ ⇤ e ± χ • Operators: 1 Λ ⇥ ⇤ ⇥ n Γ µ p ⇤ ¯ ¯ χ Γ µ e Λ 2 0 N N

Charged Current Signals ⇥ ⇤ ⇥ ⇤ e ± χ • Operators: 1 Λ ⇥ ⇤ ⇥ n Γ µ p ⇤ ¯ ¯ χ Γ µ e Λ 2 0 N N • Kinematics: Massive DM induces (otherwise stable) “Beta” transitions if: m χ > m β ⌥ th ≡ M ( ⇤ ) A,Z ± 1 + m e − M A,Z ,