Higgs

1
Higgs Precision Electroweak Group Summary
Berger et al., hep-ph/0205342 (published)
Higgs ? jets (no specific flavor), dominantly,
e.g.,

• into pair light bottom squarks.
  R-parityviolating decays in to jets
• light CP-odd scalars

LHC flails around, loses normal discovery
modes, sees odd excesses, SUSY cascades through
Higgs to jets LC still viable to sort out!
LHC loses all gt 3s
Rick Van Kooten, Indiana University, LC Workship,
Cornell, 16 July 2003
2
Baur, Plehn, Rainwater for trilinear Higgs
self-coupling, compare
LHC to LC
Mh lt 140150 GeV, HH ? bbbb (bbtt)
Mh lt 140150 GeV, HH ? WWWW
Higgs mass 150 200 GeV, LHC with 300 fb1
can rule out l 0 _at_ 95 C.L.
In this heavier mass range, extrapolating other
analyses, LHC can be better at constraining l
(but needs checking)
LC l to 20, decent to 150 GeV
LC better lighter, LHC better heavier,
complementary
3
Barklow to better on Br precisions by going to
higher energy and larger cross
section for WW fusion? (c.f. Battaglia et al.)
Kilian see plenary talk, Sunday
Little Higgs? ?? BIG PHYSICS!!

• Tailor-made for the LC!
• light Higgs doublet(s), heavy Higgs multiplets,
  sort it out!
• absolute Brs, total width, self-coupling
• new heavy vector bosons, W, Z
• precision measurements, virtual effects
• heavy vector-like top quark
• tt pair measurements

4
Precision Electroweak Summary

• Graham Wilson

5
E-166 Experiment
Achim Weidemann
45 collaborators
E-166 is a demonstration of undulator-based
polarized positron production for linear colliders

• E-166 uses the 50 GeV SLAC beam in conjunction
  with 1 m-long, helical undulator to make
  polarized photons in the FFTB.
• These photons are converted in a 0.5 rad. len.
  thick target into polarized positrons (and
  electrons).
• The polarization of the positrons and photons
  will be measured.

6
Polarimeter Overview

4 x 109 ? ? 4 x 107 ?
1 x 1010 e- ? 4 x 109 ?
4 x 109 ? ? 2 x 107 e
2 x 107 e ? 4 x 105 e
4 x 105 e ? 1 x 103 ?
7
(N_n discrepancy and NuTeV)
Preprint to appear soon
8
(No Transcript)
9
Neutrino-electron scattering experiment is
another possibility