Electroweak Baryogenesis in the MSSM and Beyond C.E.M. Wagner EFI - PowerPoint PPT Presentation

Electroweak Baryogenesis in the MSSM and Beyond C.E.M. Wagner EFI & KICP , Univ. of Chicago HEP Division, Argonne National Lab. Fields, Sarkar ACFI Workshop , Amherst, September 18th, 2015

The Puzzle of the Matter-Antimatter asymmetry • Anti-matter is governed by the same interactions as matter. • Observable Universe is composed of matter. • Anti-matter is only seen in cosmic rays and particle physics accelerators • The rate observed in cosmic rays consistent with secondary emission of antiprotons n 4 P 10 ! " n P

Conditions for Baryogenesis Baryogenesis at the weak scale Baryogenesis at the weak scale ! Under natural assumptions, there are three conditions, enunciated by Sakharov, that need to be fulfilled for baryogenesis. The SM fulfills them : ! Baryon number violation: Anomalous Processes ! C and CP violation: Quark CKM mixing ! Non-equilibrium: Possible at the electroweak phase transition.

Baryon Number Violation at finite T Anomalous processes violate both baryon and lepton number, but n preserve B – L. Relevant for the explanation of the Universe baryon asymmetry. 2 " S ) = exp( S 2 # " ! inst B 0 inst ! % $ W At zero T baryon number violating processes highly suppressed n At finite T, only Boltzman suppression n T<T EW − 4 M W T>T EW Tet Klinkhamer and Manton ’85, Arnold and Mc Lerran ’88

Baryon Asymmetry Preservation If Baryon number generated at the electroweak phase transition, Kuzmin, Rubakov and Shaposhnikov, ’85—’87 Baryon number erased unless the baryon number violating processes are out of equilibrium in the broken phase. Therefore, to preserve the baryon asymmetry, a strongly first order phase transition is necessary:

Electroweak Phase Transition Higgs Potential Evolution in the case of a first order Phase Transition 6

Finite Temperature Higgs Potential in the SM D receives contributions at one-loop proportional to the sum of the couplings of all bosons and fermions squared, and is responsible for the phenomenon of symmetry restoration E receives contributions proportional to the sum of the cube of all light boson particle couplings Since in the SM the only bosons are the gauge bosons, and the quartic coupling is proportional to the square of the Higgs mass,

CP-Violation sources Another problem for the realization of the SM electroweak baryogenesis scenario: Absence of sufficiently strong CP-violating sources Even assuming preservation of baryon asymmetry, baryon number generation several order of magnitues lower than required 3   � 3 π α W T J ( m 2 t − m 2 c )( m 2 t − m 2 u )( m 2 c − m 2 u ) ( m 2 b − m 2 s )( m 2 s − m 2 d )( m 2 b − m 2 d ) ∆ max CP = 32 √ α s   M 6 2 (2 γ ) 9 W l � i ] = c 1 c 2 c 3 s 2 J ≡ ± Im [ K li K ∗ lj K l � j K ∗ 1 s 2 s 3 s δ , γ : Quark Damping rate Gavela, Hernandez, Orloff, Pene and Quimbay’94 12 8

Preservation of the Baryon Asymmetry EW Baryogenesis would be possible in the presence of new boson n degrees of freedom with strong couplings to the Higgs. Supersymmetry provides a natural framework for n this scenario. Huet, Nelson ’91; Giudice ’91, Espinosa, Quiros,Zwirner ’93. Relevant SUSY particle: Superpartner of the top n Each stop has six degrees of freedom (3 of color, two of charge) n and coupling of order one to the Higgs M. Carena, M. Quiros, C.W. ’96, ‘98 Since n Higgs masses up to 120 GeV may be accomodated

Comments Stop particles have explicit soft mass terms and acquire temperature dependent masses at high T The effective coupling is reduced due to the presence of mixing. For left-handed stops much heavier than the right handed ones ( m Q � m U ) ! U + 4 g 2 1 � A 2 9 T 2 + .. + h 2 t m 2 t 1 ' m 2 3 t φ 2 ˜ m 2 Q This is the object entering in the cubic term In order to strengthen the phase transision the mixing must be small and the right-handed stop mass parameter must be negative. One stop is lighter than the top ! But mixing and stop masses controls the Higgs mass !

Comments II • No mixing and a light stop imply that the heaviest stop must be far away from the LHC reach. • One loop effective potential leads to a weak first order phase transition for the observed Higgs masses. Two loop effects are important, and bring a dependence on the strong gauge coupling ⎡ �⎤ � � �� 2 � � Λ H � � � φ 2 T 2 A 2 A 2 ⎣ 51 t sin 2 β ⎦ log t t 16 g 2 − 3 h 2 t sin β 2 + 8 g 2 s h 2 V 2 ( φ , T ) 1 − 1 − ≃ m 2 m 2 32 π 2 φ Q Q • Negative stop masses also bring potential color breaking problems

Right-handed Stop Potential A negative stop mass can induce color breaking minima � U + γ U T 2 � U 2 − TE U U 3 + λ U m 2 2 U 4 , V 0 ( U ) + V 1 ( U, T ) = − � where � � t R ( T ) Π � ≃ 4 g 2 9 + h 2 λ U ≃ g 2 1 + sin 2 β (1 − � s t s A 2 t /m 2 γ U Q ) ; ≡ T 2 6 3 � √ � �� 3/2 2 g 2 2 s E U 1 + √ ≃ 6 π 3 3 ⎧ ⎫ � 5 � t sin 3 β (1 − � ⎨ Q ) 3 / 2 ⎬ + h 3 A 2 t /m 2 g 3 s + 3 + 1 ⎭ . √ ⎩ 12 π 3 π 3 � 100 � �� � Λ U � � V 2 ( U, T ) = U 2 T 2 A 2 t sin 2 β t 9 g 4 s − 2 h 2 1 − log m 2 16 π 2 U Q Wagner, Carena, Quiros’96 &’98 Contribution of longitudinal gluons ignored

The upper bound on the Higgs comes from the impossibility of obtaining larger Higgs masses for the chosen parameters Carena, Quiros, C.W.’98 But phase transition can still be strong, if one includes the metastable regions. For larger values of mQ, however, large logarithmic contributions must be resummed.

Final Results (Meta)stability of Color Breaking Minima assumed Point A B C D E F G | A t /m Q | 0.5 0 0 0 0.3 0.4 0.7 tan β 15 15 2.0 1.5 1.0 1.0 1.0 6 TeV m Q ≤ 50 TeV m Q ≤ 10 120 120 D 115 115 C E 110 110 [GeV] [GeV] B 105 F 105 100 100 m ˜ m ˜ t t 95 95 90 90 G A 114 117 120 123 126 129 132 114 117 120 123 126 129 132 [GeV] [GeV] m h m h M. Carena, G. Nardini, M. Quiros, C.W.’13

LHC Higgs Physics Combining all channels the LHC experiments found a best fit to the Higgs production rate consistent with that one of a SM Higgs of mass close to 125 GeV resolving&all&the&loops.& Within2current2precision22 Higgs2couplings2scale2with22 parAcle2masses2 & As these measurements become more precise, they constrain possible

Higgs Physics Constraints Chung, Long, Wang’12 Light Stop Contribution to Higgs Loop Processes • In a normalization in which the stops contribute a factor 4 to the amplitude, the stops contribute like m 2 ˜ t t � m 2 t 1 + m 2 t 2 � X 2 � δ A . γγ ,gg / ˜ ˜ t m 2 t 1 m 2 ˜ ˜ t 2 • For the diphoton rate, the SM contribution to the amplitude would be approximately (-15) and governed by W contributions. • In the limit of light stops we are considering, one can see the appearance of the light stop coupling we discuss before. • This contribution grows for light stops and small mixing, and can cause important enhancement of the gluon fusion process rate. • The diphoton decay branching ratio will be affected in a negative way.

Higgs Signatures put a strong constraint on this scenario A. Menon and D. Morrisey’09 SM , M = 1000 TeV, tan β = 5 SM , M = 1000 TeV, tan β = 15 Γ gg / Γ gg Γ gg / Γ gg 160 4 160 4 150 150 3.5 3.5 140 140 m t 1 (GeV) m t 1 (GeV) 3 3 130 130 120 120 2.5 2.5 110 110 2 2 100 100 90 1.5 90 1.5 110 115 120 125 130 135 110 115 120 125 130 135 m h 0 (GeV) m h 0 (GeV) Diphoton Production σ BR / σ BR SM , M = 1000 TeV, tan β = 5 σ BR / σ BR SM , M = 1000 TeV, tan β = 15 160 1.6 160 1.6 150 150 1.55 1.55 140 140 1.5 1.5 m t 1 (GeV) m t 1 (GeV) 130 130 1.45 1.45 120 120 1.4 1.4 110 110 1.35 1.35 100 100 90 1.3 90 1.3 110 115 120 125 130 135 110 115 120 125 130 135 m h 0 (GeV) m h 0 (GeV) Similar results, by Cohen, Morrissey and Pierce’12 showed Higgs physics testability of this model at the LHC Moreover, other authors found these results to be inconsistent with LHC data [Curtin, Jaiswal, Meade ’12; Katz + Perelstein ’14]

Alternative : Increase Higgs Invisible Width M. Carena, G. Nardini, M.Quiros, C.W., JHEP 1302 (2013) 001 BR Point G ( σ × BR) Point G M 2 =200 GeV µ =200 GeV M 2 =200 GeV µ =200 GeV 4 WW qq,ll,VV (ggF) 1.4 bb qq,ll,VV (VBF) gg γγ (ggF) 0 χ 0 1.2 χ 100 GeV 3 γγ (VBF) 1 1 + m χ mass χ 1 1 ( σ × BR) SM 0 mass χ σ × BR 2 0.8 2 0.6 BR 0.4 1 0.2 0 0 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 [GeV] [GeV] m χ 0 m χ 0 1 1 LHC Data put strong constraints on this possibility. Only a narrow band, of neutralino masses close to threshold would be allowed in this case The invisible width would be of order 50 percent and then, again, could be tested. Weak Boson Fusion processes would be suppressed. This model is in agony.

No Evidence of VBF Suppression SM2BRs2assumed22 SM2producAon2σ2assumed2 SM2pCvalue2 SM2pCvalue2 60%2 25%2 Global2μ & • Signal&strengths&in&different&channels&are&consistent&with&1&