Measurement of the forward $W$ boson cross-section in $pp$ collisions at $\sqrt{s} = 7 {\rm \, TeV}$
R. Aaij
,
Y. Amhis
(1)
,
S. Barsuk
(1)
,
M. Borsato
(1)
,
O. Kochebina
(1)
,
J. Lefrançois
(1)
,
F. Machefert
(1)
,
A. Martin Sanchez
(1)
,
Marie Nicol
(1)
,
P. Robbe
(1)
,
M.-H. Schune
(1)
,
M. Teklishyn
(1)
,
A. Vallier
(1)
,
B. Viaud
(1)
,
Ziad Zj Ajaltouni
(2)
,
M. Baalouch
(2)
,
E. Cogneras
(2)
,
O. Deschamps
(2)
,
I. El Rifai
(2)
,
M. Grabalosa Gándara
(2)
,
Pierre Henrard
(2)
,
M. Hoballah
(2)
,
R. Lefèvre
(2)
,
J. Maratas
(2)
,
S. Monteil
(2)
,
V. Niess
(2)
,
Pascal Perret
(2)
,
Diego Alejandro Roa Romero
(2)
,
S. Akar
(3)
,
E. Aslanides
(3)
,
J. Cogan
(3)
,
W. Kanso
(3)
,
R. Legac
(3)
,
O. Leroy
(3)
,
G. Mancinelli
(3)
,
A. Mordà
(3, 4)
,
M. Perrin-Terrin
(3)
,
J. Serrano
(3)
,
A. Tsaregorodtsev
(3)
,
L. Beaucourt
(5)
,
M. Chefdeville
(5)
,
D. Decamp
(5)
,
N. Déléage
(5)
,
Ph. Ghez
(5)
,
J.-P. Lees
(5)
,
J.F. Marchand
(5)
,
M.-N. Minard
(5)
,
B. Pietrzyk
(5)
,
W. Qian
(5)
,
S. t'Jampens
(5)
,
V. Tisserand
(5)
,
E. Tournefier
(5)
R. Aaij
- Function : Author
Ziad Zj Ajaltouni
- Function : Author
- PersonId : 903794
E. Cogneras
- Function : Author
- PersonId : 743220
- IdHAL : eric-cogneras
- ORCID : 0000-0002-8933-9427
O. Deschamps
- Function : Author
- PersonId : 12089
- IdHAL : olivier-deschamps
- ORCID : 0000-0002-7047-6042
- IdRef : 161447368
Pierre Henrard
- Function : Author
- PersonId : 829303
M. Hoballah
- Function : Author
- PersonId : 1174785
- IdHAL : mostafa-adam-hoballah-hobart
Pascal Perret
- Function : Author
- PersonId : 739797
- IdHAL : pascal-perret
- ORCID : 0000-0002-5732-4343
Diego Alejandro Roa Romero
- Function : Author
- PersonId : 769524
- IdRef : 172096839
J. Cogan
- Function : Author
- PersonId : 750510
- IdHAL : julien-cogan
- ORCID : 0000-0001-7194-7566
- IdRef : 078779014
O. Leroy
- Function : Author
- PersonId : 171866
- IdHAL : olivier-leroy
- ORCID : 0000-0002-2589-240X
- IdRef : 169871835
M. Perrin-Terrin
- Function : Author
- PersonId : 741779
- IdHAL : perrin-terrin
- ORCID : 0000-0002-3568-1956
- IdRef : 179269666
J. Serrano
- Function : Author
- PersonId : 175327
- IdHAL : justine-serrano
- ORCID : 0000-0003-2489-7812
- IdRef : 127525521
M. Chefdeville
- Function : Author
- PersonId : 741874
- IdHAL : maximilien-chefdeville
- ORCID : 0000-0002-6553-6493
S. t'Jampens
- Function : Author
- PersonId : 736045
- IdHAL : stephane-tjampens
- ORCID : 0000-0003-4249-6641
Abstract
A measurement of the inclusive $W \to \mu\nu$ production cross-section using data from $pp$ collisions at a centre-of-mass energy of $\sqrt{s} = 7 {\rm \, TeV}$ is presented. The analysis is based on an integrated luminosity of about $1.0 {\rm \, fb}^{-1}$ recorded with the LHCb detector. Results are reported for muons with a transverse momentum greater than $20 {\rm \, Ge\kern -0.1em V\!/}c$ and pseudorapidity between 2.0 and 4.5. The $W^{+}$ and $W^{-}$ production cross-sections are measured to be $$\sigma_{W^{+} \to \mu^{+}\nu} = 861.0 \pm 2.0 \pm 11.2 \pm 14.7 {\rm \, pb},$$ $$\sigma_{W^{-} \to \mu^{-}\overline{\nu}} = 675.8 \pm 1.9 \pm 8.8 \pm 11.6 {\rm \, pb},$$ where the first uncertainty is statistical, the second is systematic and the third is due to the luminosity determination. Cross-section ratios and differential distributions as functions of the muon pseudorapidity are also presented. The ratio of $W^{+}$ to $W^{-}$ cross-sections in the same fiducial kinematic region is determined to be $$\frac{\sigma_{W^{+} \to \mu^{+}\nu}}{\sigma_{W^{-} \to \mu^{-}\overline{\nu}}} = 1.274 \pm 0.005 \pm 0.009,$$ where the uncertainties are statistical and systematic, respectively. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.