# LXX International conference "NUCLEUS – 2020. Nuclear physics and elementary particle physics. Nuclear physics technologies"

Oct 11 – 17, 2020
Online
Europe/Moscow timezone

## First observation of diffraction in proton-lead collisions with the CMS detector

Oct 17, 2020, 11:45 AM
25m
Online

#### Online

Oral report Section 4. Relativistic nuclear physics, elementary particle physics and high-energy physics.

### Speaker

Dmitry Sosnov (NRC Kurchatov Institute PNPI (RU))

### Description

We present the first measurements of diffraction in $\sqrt{s_{NN}}=8.16$ TeV proton-lead collisions with CMS. The very large angular coverage of CMS is used to tag rapidity gaps on both the proton-going and lead-going sides and to identify both pomeron-lead and pomeron-proton topologies. Since the previous highest energy measurement of these processes was at $\sqrt{s_{NN}}=30$ GeV, the current data provides essentially unique information. The rapidity gap distributions are sensitive to the gluon distribution within nuclei but also provide important information for modeling cosmic ray collisions. The results are compared to predictions from the EPOS, QGSJET and HIJING event generators.

### Primary author

Dmitry Sosnov (NRC Kurchatov Institute PNPI (RU))