R D ( ) Anomaly: A Model-Independent Collider Signature and Possible - PowerPoint PPT Presentation

R D ( ∗ ) Anomaly: A Model-Independent Collider Signature and Possible Hint for R -parity Violating Supersymmetry B HUPAL D EV Washington University in St. Louis W. Altmannshofer, BD and A. Soni, Phys. Rev. D 96 , 095010 (2017) [arXiv:1704.06659 [hep-ph]] and in preparation. SUSY 2017 TIFR, Mumbai December 12, 2017

R D ( ∗ ) Anomaly R D ∗ = B ( B → D ∗ τν ) R D = B ( B → D τν ) B ( B → D ℓν ) , ( where ℓ = e , µ ) . B ( B → D ∗ ℓν ) R(D*) BaBar, PRL109,101802(2012) 0.5 ∆ χ 2 = 1.0 contours Belle, PRD92,072014(2015) LHCb, PRL115,111803(2015) SM Predictions Belle, PRD94,072007(2016) 0.45 Belle, PRL118,211801(2017) R(D)=0.300(8) HPQCD (2015) LHCb, FPCP2017 R(D)=0.299(11) FNAL/MILC (2015) Average R(D*)=0.252(3) S. Fajfer et al. (2012) 0.4 0.35 σ 4 σ 0.3 2 0.25 SM HFLAV FPCP 2017 0.2 χ 2 P( ) = 71.6% 0.2 0.3 0.4 0.5 0.6 R(D) [Talk by Giacomo Caria]

Outline A model-independent way to test the anomaly using ATLAS and CMS A possible correlation of the anomaly with the Higgs naturalness R -parity violating Supersymmetry with light 3rd generation

Model-independent Collider Analysis ⟶ τ ⁺ In a nut-shell, the anomalous behavior is in the basic process: b → c τν . This necessarily implies by crossing symmetry an analogous anomaly in g + c → b τν . Leads to a model-independent collider probe: pp → b τν .

Model-independent Collider Analysis ⟶ τ ⁺ In a nut-shell, the anomalous behavior is in the basic process: b → c τν . This necessarily implies by crossing symmetry an analogous anomaly in g + c → b τν . Leads to a model-independent collider probe: pp → b τν .

Effective Operators The effective 4-fermion Lagrangian for b → c τν in the SM is given by −L eff = 4 G F V cb τγ µ P L ν τ ) + H . c . √ (¯ c γ µ P L b ) (¯ 2 Same Lagrangian gives rise to pp → b τν , but the rate is CKM-suppressed. Need not be the case in a generic NP scenario, which might be observable above the SM background at the LHC. Various dimension-6 four-fermion operators possible: [Freytsis, Ligeti, Ruderman (PRD ’15)] c γ µ P R , L b ) (¯ O V R , L = (¯ τγ µ P L ν ) O S R , L = (¯ cP R , L b ) (¯ τ P L ν ) . c σ µν P L b )(¯ O T = (¯ τσ µν P L ν ) .

Effective Operators The effective 4-fermion Lagrangian for b → c τν in the SM is given by −L eff = 4 G F V cb τγ µ P L ν τ ) + H . c . √ (¯ c γ µ P L b ) (¯ 2 Same Lagrangian gives rise to pp → b τν , but the rate is CKM-suppressed. Need not be the case in a generic NP scenario, which might be observable above the SM background at the LHC. Various dimension-6 four-fermion operators possible: [Freytsis, Ligeti, Ruderman (PRD ’15)] c γ µ P R , L b ) (¯ O V R , L = (¯ τγ µ P L ν ) O S R , L = (¯ cP R , L b ) (¯ τ P L ν ) . c σ µν P L b )(¯ O T = (¯ τσ µν P L ν ) .

SM Backgrounds The direct pp → b τν is suppressed by | V cb | 2 . In a realistic hadron collider environment, however, there are other potentially dangerous backgrounds. pp → jW → j τν ( j misidentified as b ) pp → W → τν , with an ISR gluon → b ¯ b and one b is lost pp → tj → b τν j and pp → tW → b τν jj , where the jet(s) are lost pp → b ¯ bj , where one b is misidentified as a τ and the light jet is lost (i.e. misidentified as MET). The mis-ID rates at the LHC typically are at the level of ∼ 1 % . With basic trigger cuts p j , b ,ℓ > 20 GeV, / E T > 20 GeV, | η j , b ,ℓ | < 2 . 5 and T ∆ R ℓ j ,ℓ b , jb > 0 . 4 , we find the dominant contribution comes from pp → Wj and pp → b ¯ bj . E T ) ∼ 50 pb at √ s = 13 TeV LHC. σ SM ( pp → b τν → b ℓ + /

SM Backgrounds The direct pp → b τν is suppressed by | V cb | 2 . In a realistic hadron collider environment, however, there are other potentially dangerous backgrounds. pp → jW → j τν ( j misidentified as b ) pp → W → τν , with an ISR gluon → b ¯ b and one b is lost pp → tj → b τν j and pp → tW → b τν jj , where the jet(s) are lost pp → b ¯ bj , where one b is misidentified as a τ and the light jet is lost (i.e. misidentified as MET). The mis-ID rates at the LHC typically are at the level of ∼ 1 % . With basic trigger cuts p j , b ,ℓ > 20 GeV, / E T > 20 GeV, | η j , b ,ℓ | < 2 . 5 and T ∆ R ℓ j ,ℓ b , jb > 0 . 4 , we find the dominant contribution comes from pp → Wj and pp → b ¯ bj . E T ) ∼ 50 pb at √ s = 13 TeV LHC. σ SM ( pp → b τν → b ℓ + /

SM Backgrounds The direct pp → b τν is suppressed by | V cb | 2 . In a realistic hadron collider environment, however, there are other potentially dangerous backgrounds. pp → jW → j τν ( j misidentified as b ) pp → W → τν , with an ISR gluon → b ¯ b and one b is lost pp → tj → b τν j and pp → tW → b τν jj , where the jet(s) are lost pp → b ¯ bj , where one b is misidentified as a τ and the light jet is lost (i.e. misidentified as MET). The mis-ID rates at the LHC typically are at the level of ∼ 1 % . With basic trigger cuts p j , b ,ℓ > 20 GeV, / E T > 20 GeV, | η j , b ,ℓ | < 2 . 5 and T ∆ R ℓ j ,ℓ b , jb > 0 . 4 , we find the dominant contribution comes from pp → Wj and pp → b ¯ bj . E T ) ∼ 50 pb at √ s = 13 TeV LHC. σ SM ( pp → b τν → b ℓ + /

Signal Rate We consider the dimension-6 NP operators O V R , L and O S R , L . For a typical choice g NP / Λ 2 = ( 1 TeV ) − 2 , the signal cross section for pp → b τν → b ℓ + / E T of σ V ≃ 1 . 1 pb (vector case) and σ S ≃ 1 . 8 pb (scalar case), both at √ s = 13 TeV LHC. Can directly probe mediator masses up to around 2.4 (2.6) TeV at 3 σ CL in the vector (scalar) operator case with O ( 1 ) couplings at √ s = 13 TeV LHC with L = 300 fb − 1 . The signal-to-background ratio can be significantly improved by using specialized selection cuts, e.g. p b T > 100 GeV, M b ℓ > 100 GeV and / E T > 100 GeV.

Signal Rate We consider the dimension-6 NP operators O V R , L and O S R , L . For a typical choice g NP / Λ 2 = ( 1 TeV ) − 2 , the signal cross section for pp → b τν → b ℓ + / E T of σ V ≃ 1 . 1 pb (vector case) and σ S ≃ 1 . 8 pb (scalar case), both at √ s = 13 TeV LHC. Can directly probe mediator masses up to around 2.4 (2.6) TeV at 3 σ CL in the vector (scalar) operator case with O ( 1 ) couplings at √ s = 13 TeV LHC with L = 300 fb − 1 . The signal-to-background ratio can be significantly improved by using specialized selection cuts, e.g. p b T > 100 GeV, M b ℓ > 100 GeV and / E T > 100 GeV.

Kinematic Distributions SM Vector Scalar SM Vector Scalar 10000 10000 Normalized Evenets Normalized Evenets 8000 8000 6000 6000 4000 4000 2000 2000 0 0 0 200 400 600 800 1000 0 200 400 600 800 1000 l ( GeV ) b ( GeV ) p T p T SM Vector Scalar SM Vector Scalar 10000 10000 Normalized Evenets Normalized Evenets 8000 8000 6000 6000 4000 4000 2000 2000 0 0 0 500 1000 1500 2000 0 200 400 600 800 1000 M bl ( GeV ) MET ( GeV )

Cut Efficiency Cut Efficiency Observable value SM Signal Signal (GeV) background (Vector case) (Scalar case) 100 0.01 0.52 0.56 p ℓ 50 0.10 0.78 0.82 T 30 0.44 0.92 0.94 100 0.13 0.99 0.33 p b 50 0.47 1.00 0.62 T 30 0.75 1.00 0.84 100 0.18 0.96 0.76 M b ℓ 50 0.63 0.99 0.94 30 0.88 1.00 0.98 100 0.01 0.54 0.70 / E T 50 0.09 0.70 0.86 30 0.29 0.79 0.92

Possible Hint for Natural SUSY with RPV Anomaly involved 3rd generation of the SM. Speculation: May be related to Higgs naturalness? An obvious UV-complete candidate: Natural SUSY with light 3rd generation. [Brust, Katz, Lawrence, Sundrum (JHEP ’12); Papucci, Ruderman, Weiler (JHEP ’12)] Coupling unification still preserved, even with RPV. 60 50 SM 40 RPV 3 1 ê Α i 30 MSSM 20 10 10 4 10 7 10 10 10 13 10 16 10 19 Μ @ GeV D

Explaining the R D ( ∗ ) Anomaly Consider a minimal RPV SUSY setup with the λ ′ -couplings. � ν iL ¯ d kR d jL + ˜ d jL ¯ d kR ν iL + ˜ L = λ ′ d ∗ ν c ˜ kR ¯ iL d jL ijk � e iL ¯ u jL ¯ d kR e iL − ˜ d ∗ e c − ˜ d kR u jL − ˜ kR ¯ + H . c . iL u jL Leads to the effective 4-fermion interactions: [Deshpande, He (EPJC ’17)] � λ ′ ijk λ ′∗ mnk ν mL γ µ ν iL ¯ L eff ⊃ ¯ d nL γ µ d jL 2 m 2 ˜ d kR � � V † e mL γ µ e iL (¯ + ¯ u L V CKM ) n γ µ CKM u L j � � � − ν mL γ µ e iL ¯ V † d nL γ µ j + h.c. CKM u L λ ′ ijk λ ′∗ mjn e mL γ µ e iL ¯ − ¯ d kR γ µ d nR , 2 m 2 ˜ u jL Contributes to R D ( ∗ ) at tree-level: b → � b ν → c τν .