High precision single-differential $$W^\pm $$ -boson production cross-sections as a function of electron or muon transverse momentum $$p_\textrm{T}$$ or their pseudorapity $$\eta $$ , as well as double-differential cross-sections as functions of these variables, are measured in proton–proton collisions at centre-of-mass energies $$\sqrt{s}=5.02$$ TeV and 13 TeV. The $\textit{W}$-boson charge asymmetry as a function of lepton $$\eta $$ is also measured. The data, collected in dedicated runs at reduced instantaneous luminosity with the ATLAS detector at the Large Hadron Collider, correspond to integrated luminosities of 255 pb $$^{-1}$$ at 5.02 TeV and 338 pb $$^{-1}$$ at 13 TeV. The measurements are in agreement with Standard-Model predictions calculated at next-to-next-to-leading-order in the strong coupling constant $$\alpha _s$$ including transverse-momentum resummation at next-to-next-to-leading logarithmic accuracy using several parton distribution functions. The impact of the measured differential cross-sections as a function of lepton $$\eta $$ on the determination of these functions is studied using a profiling technique.

France

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N. Abicht

S. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Y. Abulaiti

Italy

United Kingdom

B. Acharya

A. Ackermann

C. Bourdarios

Poland

L. Adamczyk

S. Addepalli

M. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A. Affolder

Y. Afik

Spain

M. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

Azerbaijan

F. Ahmadov

S. Ahuja

China

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

B. Aitbenchikh

M. Akbiyik

Sweden

T. Åkesson

A. Akimov

Japan

D. Akiyama

N. Akolkar

S. Aktas

G. Alberghi

Canada

J. Albert

P. Albicocco

G. Albouy

S. Alderweireldt

Z. Alegria

Switzerland

M. Aleksa

I. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

Saudi Arabia

H. Ali

S. Ali

S. Alibocus

South Africa

M. Aliev

G. Alimonti

W. Alkakhi

C. Allaire

B. Allbrooke

J. Allen

P. Allport

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

Z. Alsolami

A. Alvarez Fernandez

M. Alves Cardoso

M. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

A. Ambler

C. Amelung

M. Amerl

C. Ames

D. Amidei

B. Amini

K. Amirie

A. Amirkhanov

Portugal

S. Amor Dos Santos

K. Amos

D. Amperiadou

S. An

V. Ananiev

C. Anastopoulos

T. Andeen

J. Anders

A. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

Measurement of $$W^{\pm }$$ -boson differential cross-sections in proton–proton collisions with low pile-up data at $$\sqrt{s} = 5.02$$ TeV and $$13\,\hbox {TeV}$$ with the ATLAS detector

We compute a complete set of the two-loop Feynman integrals that are required for the next-to-next-to-leading order QCD corrections to on-shell top-pair production in association with a $\textit{W}$ boson at hadron colliders in the leading colour approximation. These Feynman integrals also contribute to Higgs or $\textit{Z}$-boson production in association with a top pair. We employ the method of differential equations (DEs), facilitated by the use of finite field methods to handle the algebraic complexity stemming from the seven-scale kinematics. The presence of the top quark in the virtual propagators, in addition to the mass of the external $\textit{W}$ boson, gives rise to nested square roots and three elliptic curves. We obtain DEs that depend at most quadratically on the dimensional regulator $\textit{ϵ}$ for sectors where these analytic structures appear, and are $\textit{ϵ}$-factorised otherwise. We express the DEs in terms of a minimal set of differential one-forms, separating the logarithmic ones. We solve the DEs numerically in the physical kinematic region, with the method of generalised power series expansions.

Matteo Becchetti

Dhimiter Canko

Vsevolod Chestnov

Tiziano Peraro

Mattia Pozzoli

Simone Zoia

Two-loop Feynman integrals for leading colour $$ t\overline{t}W $$ production at hadron colliders

Measurements of the production yields of charm baryons ( <math altimg='si103.svg'><msubsup><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>c</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup></math>) and charm mesons ( <math altimg='si3.svg'><msubsup><mrow><mi mathvariant='normal'>D</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup></math>) in proton-lead collisions at a nucleon-nucleon center-of-mass energy of 8.16&#8239;TeV are presented. The data were collected in 2016 with the CMS experiment and correspond to an integrated luminosity of 186 <math altimg='si4.svg'><mspace width='0.2em' /><msup><mrow><mtext>nb</mtext></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>&#8722;</mo><mn>1</mn></mrow></msup></math>. The <math altimg='si103.svg'><msubsup><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>c</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup></math> baryon is reconstructed from the decay channel <math altimg='si5.svg'><msubsup><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>c</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup><mo stretchy='false'>&#8594;</mo><msubsup><mrow><mi mathvariant='normal'>K</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>S</mi></mrow><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup><mi mathvariant='normal'>p</mi><msubsup><mrow /><mrow /><mrow /></msubsup></math>, while the <math altimg='si3.svg'><msubsup><mrow><mi mathvariant='normal'>D</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup></math> meson is reconstructed via <math altimg='si43.svg'><msubsup><mrow><mi mathvariant='normal'>D</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup><mo stretchy='false'>&#8594;</mo><msubsup><mrow><mi mathvariant='normal'>K</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mo linebreak='badbreak' linebreakstyle='after'>&#8722;</mo></mrow></msubsup><msubsup><mrow><mi mathvariant='normal'>&#960;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup></math>. The <math altimg='si103.svg'><msubsup><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>c</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup></math> baryon and <math altimg='si3.svg'><msubsup><mrow><mi mathvariant='normal'>D</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup></math> meson yields are extracted in several charged-particle multiplicity classes. No strong multiplicity dependence of the <math altimg='si103.svg'><msubsup><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>c</mi></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msubsup></math>-to- <math altimg='si3.svg'><msubsup><mrow><mi mathvariant='normal'>D</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow /><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup></math> yield ratio is observed, unlike the observed strange baryon to strange meson yield ratio of <math altimg='si7.svg'><mi mathvariant='normal'>&#923;</mi><mo stretchy='false'>/</mo><mover accent='true'><mrow><mi mathvariant='normal'>&#923;</mi></mrow><mo>&#8254;</mo></mover></math> to <math altimg='si8.svg'><msubsup><mrow><mi mathvariant='normal'>K</mi></mrow><mrow /><mrow /></msubsup><msubsup><mrow /><mrow><mi mathvariant='normal'>S</mi></mrow><mrow><mn mathvariant='normal'>0</mn></mrow></msubsup></math>, which shows a strong multiplicity dependence. This observation indicates different mechanisms for the multiplicity evolution of hadronization processes for charm and strange quarks and provides new constraints to the understanding of heavy flavor production and collectivity in small collision systems.

Armenia

A. Hayrapetyan

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

S. Templ

W. Waltenberger

C.E. Wulz

Belgium

M.R. Darwish

T. Janssen

P. Van Mechelen

E.S. Bols

J. D'Hondt

S. Dansana

A. De Moor

M. Delcourt

H. El Faham

S. Lowette

I. Makarenko

D. Müller

A.R. Sahasransu

S. Tavernier

M. Tytgat

S. Van Putte

D. Vannerom

B. Clerbaux

G. De Lentdecker

L. Favart

D. Hohov

J. Jaramillo

A. Khalilzadeh

K. Lee

M. Mahdavikhorrami

A. Malara

S. Paredes

L. Pétré

N. Postiau

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

Y. Hong

J. Knolle

L. Lambrecht

G. Mestdach

C. Rendón

A. Samalan

Multiplicity dependence of charm baryon and charm meson production in pPb collisions at <math altimg='si1.svg'><msqrt><mrow><msub><mrow><mi>s</mi></mrow><mrow><msub><mrow /><mrow><mi mathvariant='normal'>NN</mi></mrow></msub></mrow></msub></mrow></msqrt><mo linebreak='goodbreak' linebreakstyle='after'>=</mo><mn>8.16</mn><mspace width='0.2em' /><mtext>TeV</mtext></math>