jan kalinowski

SUSY 3

Jan Kalinowski

J. Kalinowski Supersymmetry, part 3 2

Outline

Linear Collider: why?

Precision SUSY measurements at the ILC

masses, couplings, mixing angles, CP phases,

Towards reconstructing the fundamental theory

the SPA Convention and Project

Summary


After discovering SUSY at LHC

Many burning questions will arise:

• is it really SUSY? (measurement of quantum numbers)

• how is it realized? (MSSM, NMSSM, …)

• how is it broken?

ILC will be indispensable to answer these questions!

Make full use of the flexibilityof the machine:

- tunable energy

- polarized beams

- possibly e-e- and collisions

500200 1000 3000

Sobloher


An intense R&D process since 1992Huge world-wide effort to be ready for construction in 2009/10(Global Design Effort GDE)

ICFA parameter document:The baseline: - e+e- LC running from MZ to 500 GeV, tunable energy - e- /e+ polarization - at least 500 fb-1 in the first 4 years

Upgrade: to ~ 1 TeV 500 fb-1 /year

Options :- GigaZ (high luminosity running at MZ)- , e, e-e- collisions

Choice of options depending on LHC+ILC physics results

The International Linear Collider


0. Top quark at threshold• measure its mass, verify its couplings

The ILC physics case

(LHC/ILC study group, `Weiglein et al.)

LHC + LC data analysed together synergy!

1. Higgs• ‘light’ (consistent with precision EW)

verify the Higgs mechanism is at work in all elements• ‘heavy’ (inconsistent with precision EW)

find out why prec. EW data are inconsistent2. 1.+ new states (SUSY, ED, extra Z’, little H,...)

• measurements of new states: masses, couplings• infer properties of states above kinematic limit

3. No Higgs, no new states• find out why precision EW data are inconsistent• look for threshold effects of strong/delayed EWSB


Masses

Two methods to obtain absolute sparticle masses:

In the continuum At the kinematic threshold

Martyn

smuons:


Masses

If a double cascade occurs, the intermediate state can be fully reconstructed

e.g.

Assuming neutrino 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!

Berggren


Couplings and mixings

EW gauge and Yukawa couplings

can be probed in e.g.

Freitas et al


Charginos + neutralinos

Including masses and polarized cross sections for light neutralinos:

Now ask your LHC friends to look for => crucial test of the model

Desch, JK, Moortgat-Pick, Nojiri, Polesello

Feeding info on m( ) back to ILC=> improved accuracy


Neutralino couplings

also the equality of EW gauge and Yukawa couplings can be tested with polarized beams

In these analyses sleptons assumed to be seen at ILC and measured. What if all sfermons heavy, like in focus-point or split SUSY?

Choi, JK, Moortgat-Pick, Zerwas


Expectations at LHC:• decay dominates, but huge background from top production• other squarks accessible, but low statistics, BG, .. => m=50 GeV• large gluino production, dilepton edge clearly seen, measure

Heavy sfermion case

Focus-point inspired case

sfermions ~ 2 TeV only stop1 ~1.1 TeV

Expectations at ILC 500 GeV• large production, measure its mass precisely• very small cross section for neutralinos• masss from decay + LHC

Desch, JK, Moortgat-Pick, Rolbiecki, Stirling


Heavy sfermion case

FB asymmetry very sensitive to sneutrino mass

, Z

Desch, JK, Moortgat-Pick, Rolbiecki, Stirling

• obtain sneutrino mass• distinguish models (e.g. focus point SUSY from split SUSY)AFB

Decay lepton FB asymmetry

=>

Even a partial spectrum can tell a lot…


Majorana and CP of neutralinos

Can be probed in • neutralino pair production at threshold• neutralino decay spectrum near the end-point • neutralino production decay

after Fierz-ing selectron exchanges

+

Production:

Decay:

( intrinsic CP )

If CP conserved, in non-relat. limit

for productionfor decay


Majorana and CP of neutralinos

CPC: if (12) and (13) in S-wave (23) must be in P-waveotherwise CP violated

• if => P-wave• if => S-wave

1. Production at threshold

JK

2. Compare production of (12) with decay of 2->1

S.Y.Choi

CPC: if production in S-wave decay must be in P-waveotherwise CP violated


e and options

Create HE photon beam by Compton back-scattering laser light on electrons

Ginzburg, Kotkin, Serbo, Telnov

Photons retain ~90% of electron beam energy almost 100% conversion – no loss of luminosity


e example

important SM background from

can be considerably suppressed by taking right-handed electron beam

Illian, Monig ’05

signal

E (GeV)

N

Assume that LSP mass=100 GeV and already measured => higher reach in selectron mass


examples

1. very useful for Higgs boson studies - higher kinematic reach - investigate CP using polarized beams

2. Measure tan(for moderate to large values)

- important parameter - notoriuosly difficult to determine

Choi, JK, Lee, Muhlleitner, Spira, Zerwas


Cosmology connection: benchmarks

How well <v> can be predicted from LHC/ILC depends on model for NP American LCC + Snowmass05 benchmark points

Peskin, LCWS06


LCC2

Squarks and sleptons heavy, relevant param. M1, M2, tan

J. Alexander et al.

LHC alone allows multiple solutions

Need to know gaugino-higgsino mixing anglecan be measured at ILC ILC

resolves

measured at LHC


LCC2: cross-checks, predictions

• rate of from DM annihilation in the galactic center, or using measured rate determine the DM density

• neutralino-proton cross section for direct DM search experiments, or using measured cross section determine the flux of DM

With the LSP properties determined, calculate


The LHC will start testing cosmology.

other LCC points

In some cases the LC will be invaluable.


Towards reconstructing SUSY:

Supersymmetry particles will be discovered at the LHC

Future ILC will provide additional precision data on masses and couplings

Will everybody be happy?

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 establishedYou may ask: who cares about precision ??


Remember Tycho Brache ?

from W. Kilian


Practical questions

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

Goals of the SPA Project

Lagrangian parameters not directly measurable

some parameters are not directly related to one particular observable, e.g., tan, fitting procedure, ....

What precision can be achieved on parameters of the MSSM Lagrangian ?

unification of couplings, soft masses etc.??? which SUSY breaking mechanism ??

Can we reconsruct the fundamental theory at high scale ?


http://spa.desy.de/spa

The SPA project is a joint study of theorists and experimentalists working on LHC and Linear Collider phenomenology. The study focuses on the supersymmetric extension of the Standard Model. The main targets are

•High-precision determination of the supersymmetry Lagrange parameters at the electroweak scale •Extrapolation to a high scale to reconstruct the fundamental parameters and the mechanism for supersymmetry breaking

The SPA convention and the SPA Project are described in the SPA reportSPA report, ,

Eur.Phys.J.C46:43-60,2006 [arXiv:hep-ph/05113444].

Spiritus movens: Peter Zerwas


The Document

More than one ‘astronomer’ involved

Please join in !!!!


Summa summarum

Supersymmetry has been motivated as a way to stabilize the

hierarchy

At present: no sign, but not excluded either

If true, exciting times at near-future colliders

Precision measurements will be necessary to reconstruct the

theory

Once seen and studied, it may provide a telescope to physics

at GUT/Planck/string scales

jan kalinowski

Documents

e e lc

reconstructed e

e polarization

mass relations e

tunable energy e

ilc masses

precision ew data

new states susy