pQCD and Hadron Collider Phenomenology 2005 Summer School pQCD and Hadron Collider Phenomenology C.-P. Yuan Michigan State University Tsinghua University, Beijing, China July 2005 (Revised from the lecture notes by Wu-Ki Tung)

Quantum Chromodynamics

Why does QCD play such a crucial role in High Energy Phenomenology? The parton picture language provides the foundation on which all modern particle theories are formulated, and all experimental results are interpreted. The validity of the parton picture is based empirically on an overwhelming amount of experimental evidence collected in the last 30-40 years, and theoretically on the Factorization Theorems of PQCD.

Key concepts: Ultra-violet divergences, bare Green fns, renormalization, RGE, anomalous dimensions, renormalized G.Fs , … etc.

Analogies and correspondences (see later) Analogies and correspondences (see later)

extracted by global analysis Lepton-hadron Sc. universal , Theory Input extracted by global analysis

Hadron Collider Physics partons, gauge bosons, new particles leptons, hadrons hadrons SM and New physics frag. functions (universal) parton Distributions hadronization models: MC programs jet algorithms

Example: Charm Production in DIS Experiments Flavor excitation Overlap/subtraction Flavor creation 4-flv (M ¹ 0) calculation (ACOT): ~ as ln(Q/M) Near Threshold: approx. 3-flv HQ calc. LO-FC (~ as) + O(as2) HE limit: approaches conventional ZM 4-flv LO (FE) + NLO (~ as) In the intermediate region, all three terms are needed to provide an accurate description of the physics.

Important HQ initiated Processes: Top and Higgs Single Top Production: W W t b t b g Higgs Production:

Apply it to Top Quark Phenomenology at Hadron Colliders Tevatron and LHC Beyond the Leading Order in QCD