# Search for contact interactions and large extra dimensions in the dilepton mass spectra from proton-proton collisions at $\sqrt{s} =$ 13 TeV

## TL;DR

This study searches for signs of contact interactions and large extra dimensions in dilepton mass spectra from 13 TeV proton-proton collisions, setting new limits on related energy scales with no observed deviations from the standard model.

## Contribution

It provides the first 13 TeV dilepton results for large extra dimensions and improves existing limits on contact interaction and extra dimension models.

## Key findings

- No significant deviation from the standard model observed.
- Limits set on compositeness scale $\\Lambda$ from 20 to 32 TeV.
- Excludes ultraviolet cutoff parameter $\Lambda_\mathrm{T}$ below 6.9 TeV, improved to 7.7 TeV with combination.

## Abstract

A search for nonresonant excesses in the invariant mass spectra of electron and muon pairs is presented. The analysis is based on data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the CMS experiment in 2016, corresponding to a total integrated luminosity of 36 fb$^{-1}$. No significant deviation from the standard model is observed. Limits are set at 95% confidence level on energy scales for two general classes of nonresonant models. For a class of fermion contact interaction models, lower limits ranging from 20 to 32 TeV are set on the characteristic compositeness scale $\Lambda$. For the Arkani-Hamed, Dimopoulos, and Dvali model of large extra dimensions, the first results in the dilepton final state at 13 TeV are reported, and values of the ultraviolet cutoff parameter $\Lambda_\mathrm{T}$ below 6.9 TeV are excluded. A combination with recent CMS diphoton results improves this exclusion to $\Lambda_\mathrm{T}$ below 7.7 TeV, providing the most sensitive limits to date in nonhadronic final states.