Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at sNN=5.02TeV

CMS Collaboration

doi:10.1016/j.physletb.2019.134826

Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at s_NN=5.02TeV

CMS Collaboration

Department of Physics Engineering

Research output: Contribution to journal › Article › peer-review

202 Citations (Scopus)

Abstract

Evidence for the light-by-light scattering process, γγ→γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390μb⁻¹ recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy E_T ^γ>2GeV, pseudorapidity |η^γ|<2.4, diphoton invariant mass m^γγ>5GeV, diphoton transverse momentum p_T ^γγ<1GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0±0.9(theo) events for the signal and 4.0±1.2(stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, σ_fid(γγ→γγ)=120±46(stat)±28(syst)±12(theo)nb, is consistent with the standard model prediction. The m^γγ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the (Figure presented.) process, in the mass range (Figure presented.).

Original language	English
Article number	134826
Journal	Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume	797
DOIs	https://doi.org/10.1016/j.physletb.2019.134826
Publication status	Published - 10 Oct 2019

Bibliographical note

Publisher Copyright:
© 2019 The Author(s)

Funding

Individuals have received support from the Marie-Curie programme and the European Research Council and Horizon 2020 Grant, contract No. 675440 (European Union); the Leventis Foundation ; the Alfred P. Sloan Foundation ; the Alexander von Humboldt Foundation ; the Belgian Federal Science Policy Office ; the Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S. - FNRS and FWO (Belgium) under the “Excellence of Science - EOS” - be.h project n. 30820817 ; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lendület (“Momentum”) Programme and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences , the New National Excellence Program ÚNKP , the NKFIA research grants 123842 , 123959 , 124845 , 124850 and 125105 (Hungary); the Council of Science and Industrial Research , India; the HOMING PLUS programme of the Foundation for Polish Science , cofinanced from European Union , Regional Development Fund, the Mobility Plus programme of the Ministry of Science and Higher Education , the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund ; the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu , grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias ; the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF ; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Welch Foundation , contract C-1845 ; and the Weston Havens Foundation (USA). We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centres and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq , CAPES , FAPERJ , FAPERGS , and FAPESP (Brazil); MES (Bulgaria); CERN ; CAS , MOST , and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador); MoER , ERC IUT , and ERDF (Estonia); Academy of Finland , MEC , and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF , DFG , and HGF (Germany); GSRT (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP , CINVESTAV , CONACYT , LNS , SEP , and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON , ROSATOM , RAS , RFBR , and NRC KI (Russia); MESTD (Serbia); SEIDI , CPAN , PCTI , and FEDER (Spain); MoSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter , IPST , STAR , and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA).

Funders	Funder number
CPAN
EU-ESF
Excellence of Science	30820817
MSES
MoER
PCTI
Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu	MDM-2015-0509
STAR
National Science Foundation
U.S. Department of Energy
Alfred P. Sloan Foundation
Welch Foundation	C-1845
Hispanics in Philanthropy
Maryland Ornithological Society
Alexander von Humboldt-Stiftung
Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS)
Qatar National Research Fund
Ministry of Education and Science
Direktion für Entwicklung und Zusammenarbeit
Secretaría de Educación Pública
Türkiye Atom Enerjisi Kurumu
Horizon 2020 Framework Programme
Weston Havens Foundation
Louisiana Academy of Sciences
CERN
Thailand Center of Excellence in Physics
Cosmetic Surgery Foundation
Institute for the Promotion of Teaching Science and Technology
Ministerstwo Obrony Narodowej
Science and Technology Facilities Council
European Commission
European Research Council
Department of Science and Technology, Ministry of Science and Technology, India
Council of Scientific and Industrial Research, India
Ministry of Education - Singapore
Department of Atomic Energy, Government of India
Taighde Éireann - Research Ireland
Helmholtz-Gemeinschaft
Deutsche Forschungsgemeinschaft
Fundação de Amparo à Pesquisa do Estado de São Paulo
National Natural Science Foundation of China
Research Promotion Foundation
Ministerstvo Školství, Mládeže a Tělovýchovy
National Science Council
Fundacja na rzecz Nauki Polskiej
Fundação para a Ciência e a Tecnologia
Russian Foundation for Basic Research
Eesti Teadusagentuur
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Academy of Finland
Bundesministerium für Bildung und Forschung
Chinese Academy of Sciences
Austrian Science Fund
Fonds De La Recherche Scientifique - FNRS
Russian Academy of Sciences
Belgian Federal Science Policy Office
Chulalongkorn University
Federación Española de Enfermedades Raras
Fonds Wetenschappelijk Onderzoek
Agentschap voor Innovatie door Wetenschap en Technologie
Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture
Consejo Nacional de Ciencia y Tecnología
Ministerio de Educación, Cultura y Deporte
General Secretariat for Research and Technology
Ministry of Business, Innovation and Employment
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Ministry of Science, ICT and Future Planning
National Research Foundation of Korea
Joint Institute for Nuclear Research
Magyar Tudományos Akadémia
Instituto Nazionale di Fisica Nucleare
A.G. Leventis Foundation
National Science and Technology Development Agency	Thailand
Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul
Narodowe Centrum Nauki	2014/15/B/ST2/03998, 2012/07/E/ST2/01406, 2015/19/B/ST2/02861, 2014/14/M/ST2/00428, 2014/13/B/ST2/02543
Secretaría de Educación Superior, Ciencia, Tecnología e Innovación
Universiti Malaya
Türkiye Bilimsel ve Teknolojik Araştirma Kurumu
Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja
Ministerstwo Edukacji i Nauki
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
Ministry of Science and Technology, Taiwan
National Academy of Sciences of Ukraine
Centre National de la Recherche Scientifique
Universidad Autónoma de San Luis Potosí
Ministry of Education and Science
Institute for Research in Fundamental Sciences
Benemérita Universidad Autónoma de Puebla
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
Secretaría de Estado de Investigación, Desarrollo e Innovación
Horizon 2020	675440
European Regional Development Fund
State Atomic Energy Corporation ROSATOM
Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional
Pakistan Atomic Energy Commission
State Fund for Fundamental Research of Ukraine
Ministry of Science,Technology and Research
Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie
Institut National de Physique Nucléaire et de Physique des Particules
Nemzeti Kutatási, Fejlesztési és Innovaciós Alap	124845, 123842, 125105, 124850, 123959
National Research Center "Kurchatov Institute"
Laboratorio Nacional de Supercómputo del Sureste de Mexico

Keywords

CMS
Light-by-light
PbPb
Photoproduction
UPC

Access to Document

10.1016/j.physletb.2019.134826

Cite this

@article{c07ed25befec4cfda42cb94ec42c06fb,

title = "Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at sNN=5.02TeV",

abstract = "Evidence for the light-by-light scattering process, γγ→γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390μb−1 recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy ET γ>2GeV, pseudorapidity |ηγ|<2.4, diphoton invariant mass mγγ>5GeV, diphoton transverse momentum pT γγ<1GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0±0.9(theo) events for the signal and 4.0±1.2(stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, σfid(γγ→γγ)=120±46(stat)±28(syst)±12(theo)nb, is consistent with the standard model prediction. The mγγ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the (Figure presented.) process, in the mass range (Figure presented.).",

keywords = "CMS, Light-by-light, PbPb, Photoproduction, UPC",

author = "{CMS Collaboration} and Sirunyan, {A. M.} and A. Tumasyan and W. Adam and F. Ambrogi and E. Asilar and T. Bergauer and J. Brandstetter and M. Dragicevic and J. Er{\"o} and {Escalante Del Valle}, A. and M. Flechl and R. Fr{\"u}hwirth and Ghete, {V. M.} and J. Hrubec and M. Jeitler and N. Krammer and I. Kr{\"a}tschmer and D. Liko and T. Madlener and I. Mikulec and N. Rad and H. Rohringer and J. Schieck and R. Sch{\"o}fbeck and M. Spanring and D. Spitzbart and A. Taurok and W. Waltenberger and J. Wittmann and Wulz, {C. E.} and M. Zarucki and V. Chekhovsky and V. Mossolov and {Suarez Gonzalez}, J. and {De Wolf}, {E. A.} and {Di Croce}, D. and X. Janssen and J. Lauwers and M. Pieters and {Van Haevermaet}, H. and {Van Mechelen}, P. and {Van Remortel}, N. and {Abu Zeid}, S. and F. Blekman and J. D'Hondt and {De Bruyn}, I. and {De Clercq}, J. and K. Deroover and G. Flouris and A. Cakir",

note = "Publisher Copyright: {\textcopyright} 2019 The Author(s)",

year = "2019",

month = oct,

day = "10",

doi = "10.1016/j.physletb.2019.134826",

language = "English",

volume = "797",

journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",

issn = "0370-2693",

publisher = "Elsevier B.V.",

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TY - JOUR

T1 - Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at sNN=5.02TeV

AU - CMS Collaboration

AU - Sirunyan, A. M.

AU - Tumasyan, A.

AU - Adam, W.

AU - Ambrogi, F.

AU - Asilar, E.

AU - Bergauer, T.

AU - Brandstetter, J.

AU - Dragicevic, M.

AU - Erö, J.

AU - Escalante Del Valle, A.

AU - Flechl, M.

AU - Frühwirth, R.

AU - Ghete, V. M.

AU - Hrubec, J.

AU - Jeitler, M.

AU - Krammer, N.

AU - Krätschmer, I.

AU - Liko, D.

AU - Madlener, T.

AU - Mikulec, I.

AU - Rad, N.

AU - Rohringer, H.

AU - Schieck, J.

AU - Schöfbeck, R.

AU - Spanring, M.

AU - Spitzbart, D.

AU - Taurok, A.

AU - Waltenberger, W.

AU - Wittmann, J.

AU - Wulz, C. E.

AU - Zarucki, M.

AU - Chekhovsky, V.

AU - Mossolov, V.

AU - Suarez Gonzalez, J.

AU - De Wolf, E. A.

AU - Di Croce, D.

AU - Janssen, X.

AU - Lauwers, J.

AU - Pieters, M.

AU - Van Haevermaet, H.

AU - Van Mechelen, P.

AU - Van Remortel, N.

AU - Abu Zeid, S.

AU - Blekman, F.

AU - D'Hondt, J.

AU - De Bruyn, I.

AU - De Clercq, J.

AU - Deroover, K.

AU - Flouris, G.

AU - Cakir, A.

PY - 2019/10/10

Y1 - 2019/10/10

N2 - Evidence for the light-by-light scattering process, γγ→γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390μb−1 recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy ET γ>2GeV, pseudorapidity |ηγ|<2.4, diphoton invariant mass mγγ>5GeV, diphoton transverse momentum pT γγ<1GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0±0.9(theo) events for the signal and 4.0±1.2(stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, σfid(γγ→γγ)=120±46(stat)±28(syst)±12(theo)nb, is consistent with the standard model prediction. The mγγ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the (Figure presented.) process, in the mass range (Figure presented.).

AB - Evidence for the light-by-light scattering process, γγ→γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390μb−1 recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy ET γ>2GeV, pseudorapidity |ηγ|<2.4, diphoton invariant mass mγγ>5GeV, diphoton transverse momentum pT γγ<1GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0±0.9(theo) events for the signal and 4.0±1.2(stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, σfid(γγ→γγ)=120±46(stat)±28(syst)±12(theo)nb, is consistent with the standard model prediction. The mγγ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the (Figure presented.) process, in the mass range (Figure presented.).

KW - CMS

KW - Light-by-light

KW - PbPb

KW - Photoproduction

KW - UPC

UR - http://www.scopus.com/inward/record.url?scp=85070721104&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2019.134826

DO - 10.1016/j.physletb.2019.134826

M3 - Article

AN - SCOPUS:85070721104

SN - 0370-2693

VL - 797

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

M1 - 134826

ER -