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Delving into the –ino sector of the MSSM Jan Kalinowski

Delving into the –ino sector of the MSSM Jan Kalinowski. Outline. Introduction MSSM charginos and neutralinos tree level: basic properties, parameter determination, CP violation CP in chargino production at one loop Towards reconstructing the fundamental theory

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Delving into the –ino sector of the MSSM Jan Kalinowski

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  1. Delving into the –inosector of the MSSMJan Kalinowski

  2. Outline • Introduction • MSSM charginos and neutralinos • tree level: basic properties, parameter determination, • CP violation • CP in chargino production at one loop • Towards reconstructing thefundamental theory • the SPA Convention and Project Delving into the -inos of the MSSM

  3. Exact SUSY • SUSY implies relations between masses and couplings: • gauge coupling = Yukawa coupling crucial for hierarchy problem • scalars and fermions from the same multiplet have equal masses Exact SUSY => no new parameters SUSY must be broken or From Strings to LHC Top-down: Derive SUSY breaking from high-scale physics Delving into the -inos of the MSSM

  4. Bottom-up: From LHC (and ILC) to Strings Unconstrained MSSM No particular SUSY breaking mechanism assumed L. Girardello, M. Grisaru ’82 Most general case: 105 new parameter – masses, mixing angles, CP phases Good phenomenological description if universal breaking terms Experimental determination of SUSY parameters => patterns of SUSY breaking Delving into the -inos of the MSSM

  5. MSSM charginos and neutralinos Mass matrices neutralinos charginos At tree level: charginos neutralinos CP phases Expected to be among the lightest sparticles A good starting point towards SUSY parameter determination Delving into the -inos of the MSSM

  6. Charginos Chargino mass matrix diagonalized by two unitary matrices Delving into the -inos of the MSSM

  7. Neutralinos Neutralino mass matrix diagonalized by a unitary matrix Can be solved analytically Unitarity constraints – two types of unitarity quadrangles Two rows: CKMZ ’01 Two columns Unlike in CKM or MNS, the orientation of all quadrangles is physical CP is conserved if all quadrangles collaps to lines parallel to either Re or Im axis Delving into the -inos of the MSSM

  8. Unitarity quadrangles D M Choi, JK, Moortgat-Pick, Zerwas All phases determined by two phases of M1 and mu parameters – many consistency checks Delving into the -inos of the MSSM

  9. Chargino production in e+e- • linear in • CP phases enter only (12)/(21) • sneutrino only in LR amplitude • breaks L-R symmetry after Fierz-ing For diagonal pairs (11)/(22) For non-diagonal pairs (12)/(21) Choi ea Delving into the -inos of the MSSM

  10. Chargino production in e+e- With polarized beams , summing chargino polarizations Polarized beams not sufficient to probe CP from cross-section measurements alone • Only Q4 changes sign under CP • determines the normal component of the polarization vector of produced chargino • vanishes if produced charginos are of equal mass Delving into the -inos of the MSSM

  11. Determining masses and mixings [fb] Masses: from threshold or in continuum If mass splitting small, exploit U.Martyn C.Hensel Mixing angles: from polarized cross sections Choi ea. If only light chargino measured, reconstruction possible with help from neutralinos Delving into the -inos of the MSSM

  12. Derive SUSY parameterss Choi ea., Kneur & Moultaka • Two-fold ambiguity in resolved from • chargino spin • or CP-asymmetries in production+decay, e.g. Bartl ea., hep-ph/0608065 Delving into the -inos of the MSSM

  13. Neutralino production after Fierz-ing selectron exchanges For polarized beams and summing neutralino polarizations Majorana nature => new term non-vanishing only if CP violated and neutralinos of different mass where e.g. Transverse beam polarization useful to probe CP in non-diagonal neutralino pairs Delving into the -inos of the MSSM

  14. Neutralino masses, couplings Martyn Masses from threshold or in continuum Couplings: gauge=Yukawa Choi ea If only the lightest accessible, exploit Ambrosanio, Mele Possible with high luminosity + polarization O.Kittel, LCWS’07 Delving into the -inos of the MSSM

  15. LHC/ILC interplay Gjelsten, Miller, Osland hep-ph/0507232 Desch, JK, Moortgat-Pick, Nojiri, Polesello, hep-ph/0312069 • false solutions may occur • ILC would help to eliminate them • heavy gauginos in cascade decays • ILC would help to identify edges • of beyond-ILC states Delving into the -inos of the MSSM

  16. Neutralinos as tools Berggren If a double cascade occurs, the intermediate state can be fully reconstructed e.g. • Assuming neutralino masses known to some extent • two LSP 4-momenta => 8 unknowns • 4 mass relations + E,p conservation => 8 constraints • LSP momenta can be reconstructed 4-momentum of the intermediate particle (here slepton) can be measured! So if you are used to think that a sparticle is just an edge or an end-point, change your mind – it can be a peak! Delving into the -inos of the MSSM

  17. Heavy sfermion case • obtain sneutrino mass • distinguish models • (e.g. focus point SUSY fromsplit SUSY) => AFB Decay lepton FB asymmetry Desch, JK, Moortgat-Pick, Rolbiecki, Stirling sfermions ~ 2 TeV, only stop1 ~1.1 TeV FB asymmetry very sensitive to sneutrino mass , Z Even a partial spectrum can tell a lot… Delving into the -inos of the MSSM

  18. Majorana and CP of neutralinos • if => P-wave • if => S-wave CPC:if (13) and (23) in S-wave (12) must be in P-wave otherwise CP violated JK Can be probed in many ways 1. Production at threshold If CP conserved, in non-relat. limit ( intrinsic CP ) Delving into the -inos of the MSSM

  19. Majorana and CP of neutralinos Production: Decay: Compare production of (12) with decay of 2->1 CPC:if production in S-wave decay must be in P-wave otherwise CP violated S.Y.Choi 2. neutralino decay spectrum near the end-point for production for decay Delving into the -inos of the MSSM

  20. Majorana and CP of neutralinos • Kinematics fully reconstructable • Neutralino coming from selectron fully polarized • left-handed in • right-handed in One can have a sample of fully polarized neutralinos and analyze their decay in the rest frame! • lepton angular distribution w.r.t. neutralino spin: slopes equal irresp. CP • CP-odd asymmetry Choi, Chung, Kim, JK, Rolbiecki 3. neutralino production and decay Consider the process + c.c. Aguilar-Saavedra Delving into the -inos of the MSSM

  21. CP in chargino production no CP violation in Delving into the -inos of the MSSM

  22. For non-diagonal pairs Possibility to construct the CP asymmetry without polarization measurements Osland, Vereshagin ‘07 Full one-loop calculations: Rolbiecki & JK, PRD76, 115006 (2007) Delving into the -inos of the MSSM

  23. Loop corrections Delving into the -inos of the MSSM

  24. Source of CP asymmetry Delving into the -inos of the MSSM

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  31. Summary • Supersymmetry as a way to stabilize the hierarchy • Charginos and neutralinos can be among light sparticles • Perfect starting point for SUSY parameter determination • LHC –gross feature can be seen • ILC – ideal place, in particular for studying CP violation • Time to think seriously „From LHC/ILC to Strings” Delving into the -inos of the MSSM

  32. From LHC/ILC to Strings We would like to know the relation of the visible sector to the fundamental theory: • what is the origin of SUSY breaking ? • what is the role of neutrinos ? • is it related to the theory of early universe ? • how to embed gravity ? etc., etc. Probably we won’t have a direct experimental access to these questions But SUSY is a predictive framework ! We can analyse precision data and state how well within some specific SUSY/GUT model the relation of observable to fundamental physics can be established • Supersymmetry particles will be discovered at the LHC • Future ILC will provide additional precision data on masses and couplings Will everybody be happy? You may ask: who cares about precision ?? Delving into the -inos of the MSSM

  33. Remember Tycho Brache ? from W. Kilian Delving into the -inos of the MSSM

  34. Practical questions • What precision can be achieved on parameters of the MSSM Lagrangian ? • Lagrangian parameters not directly measurable • some parameters are not directly related to one particular observable, e.g., tanb, m • fitting procedure, .... • Can we reconsruct the fundamental theory at high scale ? • unification of couplings, soft masses etc.??? • which SUSY breaking mechanism ?? Project • How precisely can we predict masses, cross sections, branching ratos, couplings etc. ? • many relations between sparticle masses already at tree-level, much worse at loop-level • no obvious choice of renormalizaton scheme Spiritus movens: Peter Zerwas Delving into the -inos of the MSSM

  35. The Project mi The SPA Project is exactly this: • Define a framework and tools for precision SUSY analyses • Establish a common language • Set up a testbed model and its ‘epicycles’ • Find the strong and weak points validating them with simulated data . - improve where necessary and use this to establish the connection to a - the fundamental theory Status of today: issues have been ordered, written up and published for tomorrow: plenty of work to do! Delving into the -inos of the MSSM

  36. The Document More than one ‘astronomer’ involved http://spa.desy.de/spa Delving into the -inos of the MSSM

  37. The project • a well defined framework for SUSY analyses • all necessary theoretical and computational tools • a well defined testground SPS1a’ • a platform for future extensions/developments • SPA: a joint interregional theoretical and experimental effort • It provides: • Report • Many things to work on both experimental and theoretical side Eur.Phys.J.C46:43-60,2006 [arXiv:hep-ph/05113444]. http://spa.desy.de/spa • LHC+ILC – telescope to GUT/Pl physics Delving into the -inos of the MSSM

  38. Summary • Supersymmetry as a way to stabilize the hierarchy • Charginos and neutralinos can be among light sparticles • Perfect starting point for SUSY parameter determination • LHC –gross feature can be seen • ILC – ideal place, in particular for studying CP violation • Time to think seriously „From LHC/ILC to Strings” • SPA Project - a platform for future developments Delving into the -inos of the MSSM

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