# FYSS4556 Perturbative QCD (7 cr)

**Study level:**

**Grading scale:**

**Language:**

**Responsible organisation:**

**Curriculum periods:**

## Description

SU(3) gauge transformations, gauge fixing, and QCD Feynman rules

SU(N) algebra: derivation of color identities, calculation of color factors for scattering cross sections

Inclusive jet and hard hadron production in proton-proton collisions: kinematics and leading-order partonic cross sections, gluon polarization states and ghosts, parton distribution functions and fragmentation functions, collinear factorization

Deep inelastic scattering: electroweak-current cases in leading-order perturbation theory, QCD-improved parton model, computation of the next-to-leading order QCD corrections and definition of parton distribution functions, DGLAP scale evolution equations and their solutions

Drell-Yan dilepton process: kinematics, computation of the cross sections in leading and next-to-leading order perturbative QCD

Decay of a quarkonium state: calculation of a decay width using perturbative QCD in the non-relativistic limit of the decaying meson state

## Learning outcomes

After this course, the student will

understand the QCD dynamics in various types of particle collisions

be able to compute various types of perturbative QCD scattering cross sections and also decay widths for heavy mesons

understand the group theoretical SU(3) color algebra involved in QCD scatterings

understand the gluon polarization states and know how to correctly deal with them in scattering calculations

know the basics of collinear factorization

understand the definition of process-independent parton distribution functions in next-to-leading order perturbative QCD, and know how to apply these in scattering calculations

understand the basics of the scale evolution of the parton distribution functions

## Description of prerequisites

## Study materials

## Literature

- R.K. Ellis, W.J. Stirling and B.R. Webber, QCD and Collider Physics (Cambridge Univ. Press), ISBN 0-521-54589-7.
- George Sterman, An introduction to Quantum Field Theory (Cambridge), ISBN 0-521-311322.

## Completion methods

### Method 1

**Description:**

**Evaluation criteria:**

**Time of teaching:**

### Method 2

**Description:**

**Evaluation criteria:**

**Parts of the completion methods**

### Teaching (7 cr)

**Type:**

**Grading scale:**

**Evaluation criteria:**

**Language:**

**Study methods:**

Lectures, weekly exercises and exam.

#### Teaching

##### 1/11–3/17/2022 Lectures

##### 3/25–3/25/2022 Final exam

### Independent study (7 cr)

**Type:**

**Grading scale:**

**Evaluation criteria:**

**Language:**

**Study methods:**

Independent studying, exercises and exam.