Leptoquarks and Compositeness Scales from a Contact Interaction Analysis of Deep Inelastic $e^\pm \, p$ Scattering at HERA

TL;DR

This paper uses deep inelastic scattering data from HERA to search for signs of new physics like leptoquarks and compositeness, setting limits due to no observed deviations from the Standard Model.

Contribution

It provides the first contact interaction analysis of HERA data to constrain leptoquark parameters and quark compositeness scales.

Findings

No significant deviation from the Standard Model observed.

Limits set on leptoquark couplings and masses.

Constraints on quark compositeness scales and quark radius.

Abstract

A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic $e^\pm p \rightarrow e^\pm \, hadrons$ scattering. The data are collected with the H1 detector at HERA and correspond to integrated luminosities of $0.909 \ {\rm pb}^{-1}$ and $2.947 \ {\rm pb}^{-1}$ for electron and positron beams, respectively. The differential cross sections $d\sigma / dQ^2$ are measured in the $Q^2$ range bet\-ween $160 \ \GeV^2$ and $20,000 \ \GeV^2$. The absence of any significant deviation from the Standard Model prediction is used to constrain the couplings and masses of new leptoquarks and to set limits on electron--quark compositeness scales and on the radius of light quarks.