leptophilic dark matter & the magnetic moment of the muon
DESCRIPTION
Leptophilic Dark Matter & The Magnetic Moment of the Muon . May 6 2014. with Zackaria Chacko & Prateek Agrawal h ep-ph:1402.7369. Dark Matter. Characteristics still unknown. Leptophilic Bounds. Tree level scattering through renormalizable couplings with leptons only. Fewer photons. - PowerPoint PPT PresentationTRANSCRIPT
Leptophilic Dark Matter &The Magnetic Moment of the Muon
with Zackaria Chacko& Prateek Agrawalhep-ph:1402.7369
May 6 2014
Dark Matter
Characteristics still unknown
Leptophilic Bounds
• Tree level scattering through renormalizable couplings with leptons only
Hadron ColliderElectrons are light
Fewer photons
LeptophilicDM
• Charged mediator carries flavor
Anomalous Magnetic Momentof the Muon
• Or,
•
• (Exp)(Thy)
𝑎𝜇 : A Probe of New Physics• agrees with experiment to
• New Physics contribution if only lepton mass breaks chirality
• is times more sensitive to new physics than • Naively sets a scale for physics that removes
the anomaly, ~150 GeV
ExperimentBrookhaven Fermilab J-PARC
E821 E989E34
Experiments expect to reduce uncertainty by a factor of 4
Charged Mediators• Categorize by spin of the DM
– Use the notation
– As well as and• Example: Spin 0 DM
Neutral Mediators
• Spin 0:
• Spin 1:
Comparison Bounds
• LEP– Monophoton
• Fermionic DM only– Compositeness
• Neutral Mediators Only
• Direct Detection– LUX– Effective Operator
Analysis
Scalar DM Results
• 2 σ blue band
Only for Complex Scalar
• For λ~1 the scale is ~100 GeV• Expect LEP bounds to disfavor entire band
• Purple:600 Gev• Green: 400 GeV• Black: 250 GeV
Scalar DM with Neutral Mediator
Only for Complex Scalar
• For λ~1 the scale is ~100 GeV in unexcluded region
Fermionic DM• Charged Vector Mediator
• Neutral Vector Mediator
Dirac
MajoranaDirac Only
• For λ~1 scale is ~ 100 GeV
Conclusions
• Leptophilic DM has potential to solve the anomaly
• Charged mediator models that preserve chiral symmetry require mediator masses less than a few hundred GeV for ~1 couplings
• A few windows aside, these models are tightly constrained by experiment
• Viable Leptophilic Wimps may require chiral symmetry breaking interactions
Extras
Direct Detection Bounds
• Use LUX bounds and effective operators
LEP Bounds• Assume universal
coupling to leptons• P. J. Fox, R. Harnik, J. Kopp,Y. Tsai,
Phys. Rev. D 84, 014028 (2011)
• Only Fermionic DM for monophoton (so far)
• Compositeness bounds for neutral mediators
Indirect Detection• Y. Bai and J. Berger hep-ph/1402.6696
Relic Abundance• Y. Bai and J. Berger hep-ph/1402.6696
g-2 Theory QED
4-loop calculation & 5-loop estimationWeak
2-loopHadronic Vacuum polarization
Kind of. (Optical Theorem) Dominates error
Hadronic Light by Light Error Runner up
X
Direct Detection• DM couples to atomic electrons• Momentum transfer from DM is tiny
– –
• J. Kopp, V. Niro, T. Schwetz, and J. Zupan, Phys. Rev. D 80, 083502 (2009)
Direct Detection Operators
• Real Scalar: None• Complex Scalar:• Majorana Fermion:None• Dirac Fermion:
• Real Vector: None
LEP Compositeness
• Only neutral mediator models bounded