Impact of fully coherent energy loss on heavy meson production in pA collisions

François Arleo,Stéphane Peigné,Greg Jackson

doi:10.1007/jhep01(2022)164

Abstract

Hadron production in proton-nucleus (pA) collisions was previously shown to be suppressed by medium-induced fully coherent energy loss (FCEL). We show that the quenching of D and B mesons in pPb collisions at the LHC due solely to FCEL is, at least, on par with other nuclear effects such as gluon shadowing or saturation. This is consistent with previous findings for both quarkonium and light hadron production in pA collisions, emphasising that FCEL effects need to be included for a reliable understanding of hadron production measurements in pA collisions.

Highlights

Another important nuclear effect, fully coherent energy loss (FCEL) in cold nuclear matter, is expected in hadron and jet production in pA collisions, for which the underlying partonic process consists in forward scattering of an incoming high-energy parton to an outgoing colour charge [20, 21] or colourful system of partons [22]
Since FCEL arises from first principles and is comparable in magnitude with nPDF effects, we argue that it should be taken into account in nPDF global fit analyses using the pA data on D/B meson production
The results show that FCEL is a sizable effect, accounting for about half of the D-meson nuclear suppression observed at forward rapidity, in a wide p⊥-range

Summary

Introduction

Fully coherent energy loss (FCEL) in cold nuclear matter, is expected in hadron and jet production in pA collisions, for which the underlying partonic process consists in forward scattering (when viewed in the target nucleus rest frame) of an incoming high-energy parton to an outgoing colour charge [20, 21] or colourful system of partons [22]. A second aim is to demonstrate that the FCEL effect on open heavy-flavour production is quantitatively sizable (as is the case for quarkonium [31,32,33] and light hadron production [36, 37]), and turns out to explain about half of the heavy-flavour nuclear suppression observed at the LHC at forward rapidities (2 < y < 4) and for p⊥ 5 GeV. Since FCEL arises from first principles and is comparable in magnitude with nPDF effects, we argue that it should be taken into account in nPDF global fit analyses using the pA data on D/B meson production (as well as on quarkonium and light hadron production). Our results suggest that such analyses are not exempt from FCEL

Objectives

Results

Conclusion