Doubly-charged scalars at high-energy and high-precision experiments - PowerPoint PPT Presentation

Doubly-charged scalars at high-energy and high-precision experiments B HUPAL D EV Washington University in St. Louis with M. J. Ramsey-Musolf (UMass) and Y. Zhang (WashU), arXiv:1805.0xxxx PHENO 2018 University of Pittsburgh May 8, 2018

Outline Introduction: Energy versus Precision Frontier Example: LHC versus MOLLER A case study: Doubly charged scalar Conclusion

Two Frontiers: Energy versus Precision [Le Dall, Pospelov, Ritz (PRD ’15)]

Two Frontiers: Energy versus Precision Complementary and intertwined. Need input from both to probe new physics.

Two Frontiers: Energy versus Precision detector systems hybrid toroid upstream liquid toroid hydrogen 28 m target electron beam Example: LHC versus MOLLER

MOLLER Experiment M easurement O f a L epton L epton E lectroweak R eaction detector systems hybrid toroid upstream liquid toroid hydrogen 2 8 target m electron beam Scattering of longitudinally polarized electrons off unpolarized electrons. Upgraded 11 GeV electron beam in Hall A at JLab.

Parity-Violating Asymmetry A PV = σ R − σ L σ R + σ L p 1 p 1 � p 1 e - e - e - e - e - e - e - p 1 � Z Z � � p 2 � e - e - e - e - e - e - e - � p 2 p 2 p 2 2 y ( 1 − y ) G F A SM 1 + y 4 + ( 1 − y ) 4 Q e PV = mE √ W � 2 πα � � � � For the MOLLER design, A SM PV ≈ 33 ppb (including 1-loop effect). Goal: δ A PV = 0 . 7 ppb. [J. Benesch et al. [MOLLER Collaboration], arXiv:1411.4088 [nucl-ex]] Achieve a 2.4% precision in the measurement of Q e W .

Sensitive to New Physics e − e − e − e − Λ 1 � = � √ ≃ 7 . 5 TeV | g 2 RR − g 2 LL | 2 G F | ∆ Q e W |

Case Study: Doubly Charged Scalar e − e − H −− f ee f ee e − e − | ( f L ) ee | 2 e L γ µ e L )(¯ M PV ∼ ) 2 (¯ e L γ µ e L ) + ( L ↔ R ) . 2 ( M ±± L M H ±± MOLLER Sensitivity : L , R | ( f L , R ) ee | � 5 . 3 TeV .

Case Study: Doubly Charged Scalar 10 MOLLER prospect 1 δ A PV [ ppb ] | ( | f ( f | ( L f L ) ) L 0.1 ee ee ) | ee | = | = = 0 0 . 1 0 . 1 1 10 - 2 10 - 3 10 4 100 1000 ±± [ GeV ] M H L [BD, Ramsey-Musolf, Zhang ’18]

Why Doubly Charged Scalar? Neutrino Mass via Type-II Seesaw L Y = − ( f L ) ij ψ T L , i C i σ 2 ∆ L ψ L , j + H . c . √ m ν U T . m ν = 2 f L v ∆ = U � [Schechter, Valle (PRD ’80); Mohapatra, Senjanovi´ c (PRD ’81); Lazarides, Shafi, Wetterich (NPB ’81)] Fixes the elements of f L (up to an overall scale)

LFV Constraints � � 2 Experimental limit M H L Bound × Process Constraint on on BR 100 GeV | ( f † < 4 . 2 × 10 − 13 < 2 . 4 × 10 − 6 µ → e γ L f L ) e µ | < 1 . 0 × 10 − 12 < 2 . 3 × 10 − 7 µ → 3 e | ( f L ) µ e || ( f L ) ee | | ( f † < 3 . 3 × 10 − 8 < 1 . 6 × 10 − 3 τ → e γ L f L ) e τ | | ( f † < 4 . 4 × 10 − 8 < 1 . 9 × 10 − 3 τ → µγ L f L ) µτ | τ → e + e − e − < 2 . 7 × 10 − 8 < 9 . 2 × 10 − 5 | ( f L ) τ e || ( f L ) ee | τ → µ + µ − e − < 2 . 7 × 10 − 8 < 6 . 5 × 10 − 5 | ( f L ) τµ || ( f L ) µ e | τ → e + µ − µ − < 1 . 7 × 10 − 8 < 7 . 3 × 10 − 5 | ( f L ) τ e || ( f L ) µµ | τ → e + e − µ − < 1 . 8 × 10 − 8 < 5 . 3 × 10 − 5 | ( f L ) τ e || ( f L ) µ e | τ → µ + e − e − < 1 . 5 × 10 − 8 < 6 . 9 × 10 − 5 | ( f L ) τµ || ( f L ) ee | τ → µ + µ − µ − < 2 . 1 × 10 − 8 < 8 . 1 × 10 − 5 | ( f L ) τµ || ( f L ) µµ | [BD, Rodejohann, Vila (NPB ’17)]

MOLLER versus LFV 10 M O L L E R p r o 1 s p e c t |( f L ) ee | excluded by μ → eee 0.1 excluded by μ → e γ 10 - 2 NH, M H L ±± = 1 TeV 10 - 3 10 - 2 0.1 1 10 v Δ [ eV ] [BD, Ramsey-Musolf, Zhang ’18]

MOLLER versus LFV 10 M O L L E R p r o s p e 1 c t |( f L ) ee | e x c l e u x d c e l 0.1 d u d b e y d b μ y → μ e → γ e e e 10 - 2 IH, M H L ±± = 1 TeV 10 - 2 0.1 1 10 v Δ [ eV ] [BD, Ramsey-Musolf, Zhang ’18]

Parity-Violating Left-Right Model L Y ⊃ − ( f R ) ij ψ T R , i C i σ 2 ∆ R ψ R , j + H . c .. Could have f R � = f L at low scale. [Chang, Mohapatra, Parida (PRL ’84)] f R is not related to the neutrino oscillation data. LFV constraints do not restrict ( f R ) ee anymore. Other relevant constraints: Neutrinoless double beta decay Bhabha scattering at LEP: e + e − → e + e − . Drell-Yan process at LHC: pp → γ ∗ / Z ∗ → H ++ H −− . Future prospects at ILC/CLIC: e + e − → e ± e ± H ∓∓ and e ± γ → e ∓ H ±± . R R [BD, Mohapatra, Zhang ’18]

Parity-Violating Left-Right Model 10 perturbative limit ee → ee [ IH ] MOLLER 1 0 νββ [ NH ] |( f R ) ee | 0.1 dilepton limits CLIC ILC 10 - 2 parity - violating case 10 - 3 0.5 1 5 10 ±± [ TeV ] M H R [BD, Ramsey-Musolf, Zhang ’18]

Conclusion Complementarity between the high-energy and high-precision experiments. We considered a case study of doubly-charged scalars. Can be probed at the MOLLER experiment up to ∼ 20 TeV. For the parity-violating left-right scenario, goes well beyond the current constraints, as well as the future collider sensitivities.