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This talk focuses on the electroweak phase transition in the early universe and its connection to scalar dark matter. It discusses the theoretical issues and experimental signatures of these phenomena, as well as their implications for particle physics and cosmology.
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Electroweak Phase Transition, Scalar Dark Matter, & the LHC M.J. Ramsey-Musolf Wisconsin-Madison NPAC Theoretical Nuclear, Particle, Astrophysics & Cosmology http://www.physics.wisc.edu/groups/particle-theory/ TNT Colloquium, November 2012
Recent Work • M. Gonderinger, Y. Li, H. Patel, & MRM, arXiv:1202.1316 • M. Buckley & MRM JHEP 1109 (2011) 094 • H. Patel & MRM, JHEP 1107 (2011) 029 • C. Wainwright, S. Profumo, MRM Phys Rev. D84 (2011) 023521 • M. Gonderinger, H. Lim, & MRM, Phys. Rev. D86 (2012) 043511 • W. Chao, M. Gonderinger, & MRM, arXiv:1210.0491 Earlier Work • D. O’Connell, MRM, & M.B. Wise, PR D75 (2007) 037701 • S. Profumo, MRM, & G. Shaugnessy, JHEP 0708 (2007) 010 • V. Barger, P. Langacker, M. McCaskey, MRM, & G. Shaugnessy, PR D77 (2008) 035005, D79 (2009) 015018 • P. Fileviez-Perez, H. Patel, MRM & K. Wang, PR D79 (2009) 055024
Outline Intro & Motivation EWPT & General Features Three minimal extensions of the Standard Model scalar sector ( How will we know it’s a scalar ? ) ( Theoretical issues )
Scalar Fields in Cosmology What role do scalar fields play (if any) in the physics of the early universe ?
Standard Model Hidden Sector (DM) Dark Matter Portals
Scalar fields are theoretically problematic m2 ~ 2 Scalar Fields in Particle Physics Scalar fields are a simple Has a fundamental scalar finally been discovered ? If so, is it telling us anything about ?
Remarkable agreement with EWPO Tension: EWPO + Direct Searches EWPO: data favor a “light” SM-like Higgs scalar What is the BSM Energy Scale ?
Remarkable agreement with EWPO Agreement w/ SM at ~ 10-3 level:ONP = c / 2 Barbieri & Strumia ‘99 ~ 10 TeV generically What is the BSM Energy Scale ?
Scalar fields are theoretically problematic m2 ~ 2 Scalar Fields in Particle Physics Scalar fields are a simple Must BSM ~ TeV to maintain a weak scale scalar ? EWPO: for new interactions coupling to gauge bosons or fermions, BSM >> TeV
Scalar fields are theoretically problematic m2 ~ 2 Scalar Fields in Particle Physics Scalar fields are a simple Must BSM ~ TeV to maintain a weak scale scalar ? Perhaps new weak scale physics couples only to scalar sector: “Higgs portal”
Problem Theory Exp’t Scalar Fields in Cosmology • Inflation • Dark Energy • Dark Matter • Phase transitions
EW Symmetry Breaking: Higgs ? QCD: q+g! n,p… Astro: stars, galaxies,.. New Scalars ? Standard Model Universe QCD: n+p! nuclei Scalar Fields & Cosmic History
EW Symmetry Breaking: Higgs ? QCD: q+g! n,p… Astro: stars, galaxies,.. New Scalars ? Standard Model Universe • Flatness • Isotropy • Homogeneity Scalar Field: Inflaton Reheat “Slow roll” QCD: n+p! nuclei Scalar Fields & Inflation
CDM • Supernovae • BAO Cosmological constant ? > 0 Scalar Field: Quintessence ? Scalar Fields & Dark Energy ?
Baryogenesis: When? CPV? SUSY? Neutrinos? Non-equilibrium dynamics or CPT violation? • BBN ( t ~ 100 s ) • CMB ( t ~ 105 y ) Scalar Fields & the Origin of Matter ?
Baryogenesis: When? CPV? SUSY? Neutrinos? Non-equilibrium dynamics or CPT violation? Electroweak Phase Transition ? New Scalars • BBN ( t ~ 100 s ) • CMB ( t ~ 105 y ) Scalar Fields & the Origin of Matter ?
Baryogenesis: When? CPV? SUSY? Neutrinos? Non-equilibrium dynamics or CPT violation? Electroweak Phase Transition ? New Scalars • Rotation curves • Lensing • Bullet clusters Darkogenesis: When? SUSY? Neutrinos? Axions ? YB related ? Scalar Fields & the Origin of Matter ? ?
Baryogenesis: When? CPV? SUSY? Neutrinos? Non-equilibrium dynamics or CPT violation? Electroweak Phase Transition ? New Scalars: CDM ? • Rotation curves • Lensing • Bullet clusters Darkogenesis: When? SUSY? Neutrinos? Axions ? YB related ? Scalar Fields & the Origin of Matter ? ?
? ? ? ? Scalar Fields in Cosmology Problem Theory Exp’t • Inflation • Dark Energy • Dark Matter • Phase transitions
Problem Theory Exp’t • Inflation • Dark Energy • Dark Matter • Phase transitions ? ? ? ? Scalar Fields in Cosmology Could experimental discovery of a fundamental scalar point to early universe scalar field dynamics?
Scalar Fields in Cosmology Problem Theory Exp’t • Inflation • Dark Energy • Dark Matter • Phase transitions ? ? ? ? Focus of this talk, but perhaps part of larger role of scalar fields in early universe
Questions for this Talk: • Was there a cosmic phase transition at T ~ 100 GeV ? • Did it have the characteristics needed for successful electroweak baryogenesis and/or production of gravity waves? • Are its dynamics coupled to dark matter ? • What are the experimental signatures ? • How robust is the underlying theory ?
* Tree level L = (D y D- V() Quantum corrections V() ) VEFF(,T) • T=0 : Coleman-Weinberg (RG improved) • T>0 : Finite-T effective potential * Many applications: Effective action Effective Potential
1st order 2nd order Increasingmh New scalars EW Phase Transition: New Scalars
1st order 2nd order Increasingmh Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars New scalars
1st order 2nd order Increasingmh Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars
1st order 2nd order Increasingmh Bubble nucleation EWSB Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars
1st order 2nd order Increasingmh Bubble nucleation Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars YB : CPV & EW sphalerons EWSB
1st order 2nd order Increasingmh Bubble nucleation Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars YB : diffuses into interiors EWSB
1st order 2nd order Quench EW sph Increasingmh Preserve YBinitial Bubble nucleation Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars YB : diffuses into interiors EWSB
1st order 2nd order Increasingmh Preserve YBinitial Bubble nucleation Baryogenesis Gravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT Quench EW sph New scalars YB : diffuses into interiors EWSB TC , Esph, Stunnel F()
1st order 2nd order Detonation & turbulence Increasingmh Bubble nucleation EWSB BaryogenesisGravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT New scalars
1st order 2nd order Increasingmh Bubble nucleation BaryogenesisGravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT Detonation & turbulence New scalars EWSB GW Spectra: Q & tEW F()
1st order 2nd order Increasingmh Bubble nucleation BaryogenesisGravity Waves Scalar DM LHC Searches EW Phase Transition: New Scalars “Strong” 1st order EWPT Detonation & turbulence nMSSM New scalars EWSB Q tEW GW Spectra: Q & tEW F()
1st order 2nd order Increasingmh Bubble nucleation BaryogenesisGravity WavesScalar DM ? LHC Searches ? EW Phase Transition: New Scalars “Strong” 1st order EWPT YB preservation, detonation & turbulence New scalars EWSB TC , Esph, Stunnel Q & tEW F()
LHC Observation LHC Exclusion LEP, Tevatron, & ATLAS Exclusion Non-SM Higgs(es) ? SM Higgs properties ? SM Higgs? • SM “background” well below new CPV expectations • New expts: 102 to 103 more sensitive • CPV needed for BAU? Precision Tests
Thermal DM: WIMP Direct detection: Spin-indep DM-nucleus scattering A SM A SM Dark Matter: & SI
Extension DOF EWPT DM 1 1 2 ? 3 III. Simplest Scalar Extensions Real singlet Real singlet Complex Singlet Real Triplet May be low-energy remnants of UV complete theory & illustrative of generic features
Extension DOF EWPT DM 1 1 2 ? 3 Higgs Portal: Simple Scalar Extensions Real singlet Real singlet Complex Singlet Real Triplet May be low-energy remnants of UV complete theory & illustrative of generic features
Stable S (dark matter?) • Tree-level Z2 symmetry: a1=b3=0 to prevent s-h mixing and one-loop s hh • x0 =0 to prevent h-s mixing Mass matrix H-S Mixing H1 !H2H2 EWPT: a1,2 = 0 & <S> = 0 DM: a1 = 0 & <S> = 0 / / Signal Reduction Factor Independent Parameters: v0, x0, l0, a1, a2, b3, b4 xSM EWPT: Production Decay The Simplest Extension Model Simplest extension of the SM scalar sector: add one real scalar S (SM singlet) O’Connel, R-M, Wise; Profumo, R-M, Shaugnessy; Barger, Langacker, McCaskey, R-M Shaugnessy; He, Li, Li, Tandean, Tsai; Petraki & Kusenko; Gonderinger, Li, Patel, R-M; Cline, Laporte, Yamashita; Ham, Jeong, Oh; Espinosa, Quiros; Konstandin & Ashoorioon…
Stable S (dark matter?) • Tree-level Z2 symmetry: a1=b3=0 to prevent s-h mixing and one-loop s hh • x0 =0 to prevent h-s mixing Mass matrix H-S Mixing H1 !H2H2 Raise barrier Lower TC : a2 < 0 Signal Reduction Factor Independent Parameters: v0, x0, l0, a1, a2, b3, b4 xSM EWPT: Production Decay The Simplest Extension Model EWPT Scenario
Finite Temperature Potential Multiple fields & new interactions: novel patters of symmetry breaking, lower TC , greater super-cooling, “stronger 1st order EWPT”
Stable S (dark matter?) • Tree-level Z2 symmetry: a1=b3=0 to prevent s-h mixing and one-loop s hh • x0 =0 to prevent h-s mixing Mass matrix H-S Mixing H1 !H2H2 Signal Reduction Factor Mixing Independent Parameters: v0, x0, l0, a1, a2, b3, b4 Modified BRs Two mixed (singlet-doublet) states w/ reduced SM branching ratios xSM EWPT: Production Decay The Simplest Extension Model Low energy phenomenology Raise barrier Lower TC
Mixed States h1 = cosh + sins h2 = -sinh + coss
LHC exotic final states: 4b-jets, gg + 2 b-jets… Light: all models Black: LEP allowed LHC: reduced BR(h SM) Scan: EWPT-viable model parameters m2 > 2 m1 m1 > 2 m2 Signal Reduction Factor Production Decay EWPT & LHC Phenomenology Signatures Profumo, R-M, Shaugnessy