Colliders and Neutrinos

The following sections are included:

• Preface

• Contents

We begin with a discussion of a model with a flat extra dimension which addresses the flavor hierarchy of the Standard Model (SM) using profiles for the SM fermions in the extra dimension. We then show how flavor violation and contributions to the electroweak precision tests can be suppressed [even with O(TeV) mass scale for the new particles] in this framework by suitable modifications to the basic model. Finally, we briefly discuss a model with a warped extra dimension in which all the SM fields propagate and we sketch how this model "mimics" the earlier model in a flat extra dimension. In this process, we outline a "complete" model addressing the Planck-weak as well as the flavor hierarchy problems of the SM.

The International Linear Collider (ILC) is the next large scale project in accelerator particle physics. Colliding electrons with positrons at energies from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy needed to complement the LHC data and extend the sensitivity to new phenomena at the high energy frontier and answer some of the fundamental questions in particle physics and in its relation to Cosmology. This paper reviews some highlights of the ILC physics program and of the major challenges for the accelerator and detector design.

Neutrino astronomy is on the verge of discovering new sources, and this will lead to important advances in astrophysics, cosmology, particle physics, and nuclear physics. This paper is meant for non-experts, so that they might understand the basic issues in this field.

The origin of the asymmetry between matter and anti-matter of the Universe has been one of the great challenges in particle physics and cosmology. Leptogenesis as a mechanism for generating the cosmological baryon asymmetry of the Universe has gained significant interests ever since the advent of the evidence of non-zero neutrino masses. In these lectures presented at TASI 2006, I review various realizations of leptogenesis and allude to recent developments in this subject.

The following sections are included:

• Neutrinos As We Knew Them
  • Neutrinos in the Standard Model
  • Neutrino Interactions
  • Sources of Neutrinos
  • Typical Neutrino Detectors

• Neutrinos As We Know Them Now
  • Neutrino Oscillations
    • The Basic Formalism
    • Matter Effects
    • Designing an Oscillation Experiment
    • Experimental Evidence for Oscillations
  • Direct Measurements of Neutrino Mass

• Neutrinos We Would Like to Meet
  • Neutrinos and the New Paradigm
    • How Neutrinos Might Get Their Mass
    • Majorana vs. Dirac?
    • CP Violation in the Neutrino Sector
  • Neutrinos and the Unexpected
    • The LSND Anomaly
    • The NuTeV Anomaly
  • Neutrinos and the Cosmos
    • Neutrinos as Dark Matter
    • Ultra High Energy Neutrinos

• Conclusions

• Acknowledgments

• References

This is the written version of an introductory self-contained course on string model-building and string phenomenology given at the 2006 TASI summer school. No prior knowledge of string theory is assumed. The goal is to provide a practical, "how-to" manual on string theory, string model-building, and string phenomenology with a minimum of mathematics. These notes cover the construction of bosonic strings, super-strings, and heterotic strings prior to compactification. These notes also develop the ten-dimensional free-fermionic construction. A final lecture discusses general features of heterotic string models, Type I (open) string models, and recent trends of string phenomenology. and general features of low-energy string phenomenology.

Neutrino oscillation experiments have yielded valuable information on the nature of neutrino masses and mixings and have provided the first glimpse of new physics beyond the standard model. Even though we are far from a complete understanding of the new physics implied by them, some tell-tale hints are emerging which have narrowed the direction of the new physics and have provided some insight into the flavor problem. In these lectures, I provide a panoramic overview of the current thinkings in neutrino model building.

These lectures on Higgs boson collider searches were presented at TASI 2006. I first review the Standard Model searches: what LEP did, prospects for Tevatron searches, the program planned for LHC, and some of the possibilities at a future ILC. I then cover in-depth what comes after a candidate discovery at LHC: the various measurements one has to make to determine exactly what the Higgs sector is. Finally, I discuss the MSSM extension to the Higgs sector.

A brief pedagogical overview of the phenomenology of Z' gauge bosons is presented. Such particles can arise in various electroweak extensions of the Standard Model (SM). We provide a quick survey of a number of Z' models, review the current constraints on the possible properties of a Z' and explore in detail how the LHC may discover and help elucidate the nature of these new particles. We provide an overview of the Z' studies that have been performed by both ATLAS and CMS. The role of the ILC in determining Z' properties is also discussed.

The following sections are included:

• Introduction - fundamentals of ββ decay

• Mechanism of the 0νββ decay

• Overview of the experimental status of search for ββ decay

• Nuclear matrix elements

• Neutrino magnetic moment and the distinction between Dirac and Majorana neutrinos

• Summary

• Acknowlegment

• References

These lectures give a general introduction to supersymmetry, emphasizing its application to models of elementary particle physics at the 100 GeV energy scale. I discuss the following topics: the construction of supersymmetric Lagrangians with scalars, fermions, and gauge bosons, the structure and mass spectrum of the Minimal Supersymmetric Standard Model (MSSM), the measurement of the parameters of the MSSM at high-energy colliders, and the solutions that the MSSM gives to the problems of electroweak symmetry breaking and dark matter.