Imperial College London

ProfessorPaulDauncey

Faculty of Natural SciencesDepartment of Physics

Professor of Particle Physics
 
 
 
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Contact

 

+44 (0)20 7594 7803p.dauncey Website

 
 
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Assistant

 

Ms Paula Brown +44 (0)20 7594 7823

 
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Location

 

506Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Sirunyan:2020:10.1103/PhysRevLett.124.162002,
author = {Sirunyan, AM and Tumasyan, A and Adam, W and Ambrogi, F and Bergauer, T and Dragicevic, M and Eroe, J and Del, Valle AE and Flechl, M and Fruehwirth, R and Jeitler, M and Krammer, N and Kraetschmer, I and Liko, D and Madlener, T and Mikulec, I and Rad, N and Schieck, J and Schoefbeck, R and Spanring, M and Waltenberger, W and Wulz, C-E and Zarucki, M and Drugakov, V and Mossolov, V and Gonzalez, JS and Darwish, MR and De, Wolf EA and Di, Croce D and Janssen, X and Kello, T and Lelek, A and Pieters, M and Sfar, HR and Van, Haevermaet H and Van, Mechelen P and Van, Putte S and Van, Remortel N and Blekman, F and Bols, ES and Chhibra, SS and D'Hondt, J and De, Clercq J and Lontkovskyi, D and Lowette, S and Marchesini, I and Moortgat, S and Python, Q and Tavernier, S and Van, Doninck W and Van, Mulders P and Beghin, D and Bilin, B and Clerbaux, B and De, Lentdecker G and Delannoy, H and Dorney, B and Favart, L and Grebenyuk, A and Kalsi, AK and Moureaux, L and Popov, A and Postiau, N and St},
doi = {10.1103/PhysRevLett.124.162002},
journal = {Physical Review Letters},
title = {Constraints on the χc1 versus χc2 polarizations in proton-proton collisions at √s=8 TeV},
url = {http://dx.doi.org/10.1103/PhysRevLett.124.162002},
volume = {124},
year = {2020}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - The polarizations of promptly produced χc1 and χc2 mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χc states are reconstructed via their radiative decays χc→J/ψγ, with the photons being measured through conversions to e+e−, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χc2 to χc1 yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ→μ+μ− decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum.
AU - Sirunyan,AM
AU - Tumasyan,A
AU - Adam,W
AU - Ambrogi,F
AU - Bergauer,T
AU - Dragicevic,M
AU - Eroe,J
AU - Del,Valle AE
AU - Flechl,M
AU - Fruehwirth,R
AU - Jeitler,M
AU - Krammer,N
AU - Kraetschmer,I
AU - Liko,D
AU - Madlener,T
AU - Mikulec,I
AU - Rad,N
AU - Schieck,J
AU - Schoefbeck,R
AU - Spanring,M
AU - Waltenberger,W
AU - Wulz,C-E
AU - Zarucki,M
AU - Drugakov,V
AU - Mossolov,V
AU - Gonzalez,JS
AU - Darwish,MR
AU - De,Wolf EA
AU - Di,Croce D
AU - Janssen,X
AU - Kello,T
AU - Lelek,A
AU - Pieters,M
AU - Sfar,HR
AU - Van,Haevermaet H
AU - Van,Mechelen P
AU - Van,Putte S
AU - Van,Remortel N
AU - Blekman,F
AU - Bols,ES
AU - Chhibra,SS
AU - D'Hondt,J
AU - De,Clercq J
AU - Lontkovskyi,D
AU - Lowette,S
AU - Marchesini,I
AU - Moortgat,S
AU - Python,Q
AU - Tavernier,S
AU - Van,Doninck W
AU - Van,Mulders P
AU - Beghin,D
AU - Bilin,B
AU - Clerbaux,B
AU - De,Lentdecker G
AU - Delannoy,H
AU - Dorney,B
AU - Favart,L
AU - Grebenyuk,A
AU - Kalsi,AK
AU - Moureaux,L
AU - Popov,A
AU - Postiau,N
AU - Starling,E
AU - Thomas,L
AU - Vander,Velde C
AU - Vanlaer,P
AU - Vannerom,D
AU - Cornelis,T
AU - Dobur,D
AU - Khvastunov,I
AU - Niedziela,M
AU - Roskas,C
AU - Skovpen,K
AU - Tytgat,M
AU - Verbeke,W
AU - Vermassen,B
AU - Vit,M
AU - Bruno,G
AU - Caputo,C
AU - David,P
AU - Delaere,C
AU - Delcourt,M
AU - Giammanco,A
AU - Lemaitre,V
AU - Prisciandaro,J
AU - Saggio,A
AU - Vischia,P
AU - Zobec,J
AU - Alves,GA
AU - Correia,Silva G
AU - Hensel,C
AU - Moraes,A
AU - Belchior,Batista Das Chagas E
AU - Carvalho,W
AU - Chinellato,J
AU - Coelho,E
AU - Da,Costa EM
AU - Da,Silveira GG
AU - De,Jesus Damiao D
AU - De,Oliveira Martins C
AU - Fonseca,De Souza S
AU - Malbouisson,H
AU - Martins,J
AU - Matos,Figueiredo D
AU - Medina,Jaime M
AU - Melo,De Almeida M
AU - Mora,Herrera C
AU - Mundim,L
AU - Nogima,H
AU - Prado,Da Silva WL
AU - Rebello,Teles P
AU - Sanchez,Rosas LJ
AU - Santoro,A
AU - Sznajder,A
AU - Thiel,M
AU - Tonelli,Manganote EJ
AU - Torres,Da Silva De Araujo F
AU - Vilela,Pereira A
AU - Bernardes,CA
AU - Calligaris,L
AU - Fernandez,Perez Tomei TR
AU - Gregores,EM
AU - Lemos,DS
AU - Mercadante,PG
AU - Novaes,SF
AU - Padula,S
AU - Aleksandrov,A
AU - Antchev,G
AU - Hadjiiska,R
AU - Iaydjiev,P
AU - Misheva,M
AU - Rodozov,M
AU - Shopova,M
AU - Sultanov,G
AU - Bonchev,M
AU - Dimitrov,A
AU - Ivanov,T
AU - Litov,L
AU - Pavlov,B
AU - Petkov,P
AU - Petrov,A
AU - Fang,W
AU - Gao,X
AU - Yuan,L
AU - Ahmad,M
AU - Hu,Z
AU - Wang,Y
AU - Chen,GM
AU - Chen,HS
AU - Chen,M
AU - Jiang,CH
AU - Leggat,D
AU - Liao,H
AU - Liu,Z
AU - Spiezia,A
AU - Tao,J
AU - Yazgan,E
AU - Zhang,H
AU - Zhang,S
AU - Zhao,J
AU - Agapitos,A
AU - Ban,Y
AU - Chen,G
AU - Levin,A
AU - Li,J
DO - 10.1103/PhysRevLett.124.162002
PY - 2020///
SN - 0031-9007
TI - Constraints on the χc1 versus χc2 polarizations in proton-proton collisions at √s=8 TeV
T2 - Physical Review Letters
UR - http://dx.doi.org/10.1103/PhysRevLett.124.162002
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000528518000007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR - http://hdl.handle.net/10044/1/79035
VL - 124
ER -