Vector boson production in hadronic collisions

TL;DR

The paper develops a comprehensive perturbative QCD framework for vector-boson production and decay in hadronic collisions, combining $q_T$ resummation in the Collins-Soper-Sterman formalism with fixed-order $O(\alpha_S)$ calculations and a non-perturbative Gaussian-type form factor $F^{NP}$ via a $b_*$ prescription. It provides explicit expressions for the resummed and finite components, including the Sudakov form factor, modified PDFs, and coefficient functions, while ensuring the $q_T$-integrated cross section is correct. Through detailed studies of $F^{NP}$, $b_{ m lim}$, and low–high $q_T$ matching, the work applies the framework to Tevatron $W$ and $Z$ production, discusses implications for $W$ mass measurements, and highlights the need for higher-statistics data and decay-inclusive treatments to achieve precise predictions. The findings underscore the importance of non-perturbative effects and decay kinematics in accurately modeling vector-boson observables at hadron colliders.

Abstract

We consider the production of $γ^*, W$ and $Z$ vector bosons in hadron-hadron collisions in perturbative QCD. We present results from a new numerical program which gives a full description of the production of the vector bosons and of their decay products. At small $\qt$ the calculation includes resummation of large logarithms and non-perturbative effects. The resummation is matched with the full $O(α_S)$ calculation. In addition, the program correctly reproduces the known $O(α_S)$ cross section when integrated over $\qt$. Besides presenting results for $W$ and $Z$ production at the Tevatron, we also review constraints on the non-perturbative functions using fixed target data on lepton pair production, and make several observations on this topic.

Figures (17)

• Figure 1: Scales $\mu(b)$ and $\lambda(b)$ compared to $b_0/b$ for $Q=5,100~{\;\rm GeV}$.
• Figure 2: The Sudakov form factor for $Q=5,10$ and $100~{\;\rm GeV}$.
• Figure 3: $S\ d\sigma^2 /d\sqrt{\tau}dy$ distribution from E288 compared to theory multiplied by $K=0.83$.
• Figure 4: $E\ d\sigma^3 /d^3p$ distribution from E288 compared to theory with $K=0.75$ (full line) and $K=0.83$ (dashed line).
• Figure 5: $S\ d\sigma^2 /d\sqrt{\tau}dy$ distribution from E605 compared to theory multiplied by $K=0.88$.