Observation of an exotic narrow doubly charmed tetraquark

C. Beteta,F. Gallego,T. Ackernley,B. Adeva,M. Adinolfi,H. Afsharnia,C. Agapopoulou,C. Aidala,Simone Aiola,Z. Ajaltouni,S. Akar,J. Albrecht,F. Alessio,M. Alexander,A. Albero,Z. Aliouche,G. Alkhazov,P. Cartelle,S. Amato,J. Amey,Y. Amhis,L. An,L. Anderlini,A. Andreianov,M. Andreotti,F. Archilli,A. Artamonov,M. Artuso,K. Arzymatov,E. Aslanides,M. Atzeni,B. Audurier,S. Bachmann,Marie Bachmayer,J. Back,P. Rodríguez,V. Balagura,W. Baldini,J. Leite,M. Barbetti,R. Barlow,S. Barsuk,W. Barter,M. Bartolini,F. Baryshnikov,J. Basels,S. Bashir,G. Bassi,B. Batsukh,A. Battig,A. Bay,A. Beck,M. Becker,F. Bedeschi,I. Bediaga,A. Beiter,V. Belavin,S. Belin,V. Bellée,K. Belous,I. Belov,I. Belyaev,G. Bencivenni,E. Ben-Haim,A. Berezhnoy,R. Bernet,D. Berninghoff,H. Bernstein,C. Bertella,A. Bertolin,C. Betancourt,F. Betti,Ia. Bezshyiko,S. Bhasin,J. Bhom,L. Bian,M. Bieker,S. Bifani,P. Billoir,M. Birch,F. Bishop,A. Bitadze,A. Bizzeti,M. Bjørn,M. Blago,T. Blake,F. Blanc,S. Blusk,D. Bobulska,J. Boelhauve,O. García,T. Boettcher,A. Boldyrev,A. Bondar,S. Borghi,M. Borisyak,M. Borsato,J. Borsuk,Sonia Bouchiba,T. Bowcock,A. Boyer,C. Bozzi,Matthew Bradley,S. Braun,A. Rodríguez,J. Brodzicka,A. Gonzalo,D. Brundu,A. Buonaura,L. Buonincontri,A. Burke,C. Burr,A. Bursche,A. Butkevich,J. Butter,J. Buytaert,W. Byczynski,S. Cadeddu,H. Cai,R. Calabrese,Lukas Calefice,L. Diaz,S. Cali,R. Calladine,M. Calvi,M. Gomez,P. Magalhaes,P. Campana,Alexis Quezada,S. Capelli,L. Capriotti,A. Carbone,G. Carboni,R. Cardinale,A. Cardini,T. Carli,P. Carniti,L. Carus,K. Akiba,A. Vidal,G. Casse,M. Cattaneo,G. Cavallero,S. Celani,J. Cerasoli,D. Červenkov,Abbie Chadwick,Matthew Chapman,M. Charles,Ph. Charpentier,G. Chatzikonstantinidis,C. Barajas,M. Chefdeville,Chen Chen,S. Chen,A. Chernov,V. Chobanova,S. Cholak,M. Chrzaszcz,A. Chubykin,V. Chulikov,P. Ciambrone,M. Cicala,X. Vidal,G. Ciezarek,P. Clarke,M. Clemencic,H. Cliff,J. Closier,John Cobbledick,V. Coco,J. Coelho,J. Cogan,E. Cogneras,L. Cojocariu,Paula Collins,T. Colombo,L. Congedo,A. Contu,N. Cooke,G. Coombs,I. Corredoira,G. Corti,C. Sobral,B. Couturier,D. Craik,J. Crkovská,M. Torres,R. Currie,C. Silva,S. Dadabaev,L. Dai,E. Dall’Occo,J. Dalseno,C. D’Ambrosio,A. Danilina,P. d’Argent,J. Davies,A. Davis,O. Francisco,K. Bruyn,S. Capua,M. Cian,J. Miranda,L. Paula,M. Serio,D. Simone,P. Simone,F. Vellis,J. Vries,C.-T. Dean,F. Debernardis,V. Dedu,L. Buono,B. Delaney,H.-P. Dembinski,A. Dendek,V. Denysenko,D. Derkach,O. Deschamps,F. Desse,F. Dettori,B. Dey,A. Cicco,P. Nezza,S. Didenko,L. Maronas,H. Dijkstra,Vasyl Dobishuk,C. Dong,A. Donohoe,F. Dordei,A. Reis,L. Douglas,A. Dovbnya,A. Downes,M. Dudek,L. Dufour,V. Duk,P. Durante,J. Durham,D. Dutta,A. Dziurda,A. Dzyuba,S. Easo,U. Egede,V. Egorychev,S. Eidelman,S. Eisenhardt,S. Ek-In,L. Eklund,S. Ely,A. Ene,E. Epple,S. Escher,Jonas Eschle,S. Esen,T. Evans,A. Falabella,J. Fan,Y. Fan,B. Fang,S. Farry,D. Fazzini,M. Féo,A. Prieto,A. Fernez,F. Ferrari,L. Lopes,F. Rodrigues,S. Sole,M. Ferrillo,M. Ferro-Luzzi,S. Filippov,R. Fini,M. Fiorini,M. Firlej,K. Fischer,D. Fitzgerald,C. Fitzpatrick,T. Fiutowski,A. Fkiaras,F. Fleuret,M. Fontana,F. Fontanelli,R. Forty,Daniel Foulds-Holt,V. Lima,M. Sevilla,M. Frank,E. Franzoso,Giulia Frau,C. Frei,D. Friday,J. Fu,E. Gabriel,G. Galati,A. Torreira,D. Galli,S. Gambetta,Y. Gan,M. Gandelman,P. Gandini,Y. Gao,M. Garau,L. Martin,P. Moreno,J. Pardiñas,F. Rosales,L. Garrido,C. Gaspar,R. Geertsema,D. Gerick,L. Gerken,E. Gersabeck,M. Gersabeck,T. Gershon,D. Gerstel,Luca Giambastiani,V. Gibson,H. Giemza,A. Gilman,M. Giovannetti,A. Gioventù,P. Gironell,L. Giubega,C. Giugliano,K. Gizdov,E. Gkougkousis,V. Gligorov,C. Göbel,E. Golobardes,D. Golubkov,A. Golutvin,A. Gomes,S. Fernandez,F. Abrantes,M. Goncerz,G. Gong,P. Gorbounov,I. Gorelov,C. Gotti,E. Govorkova,J. Grabowski,T. Grammatico,L. Cardoso,E. Graugés,E. Graverini,G. Graziani,A. Grecu,L. Greeven,Nathan Grieser,L. Grillo,S. Gromov,B. Cazon,C. Gu,M. Guarise,M. Guittiere,P. Günther,E. Gushchin,Andreas Güth,Y. Guz,T. Gys,T. Hadavizadeh,G. Haefeli,C. Haen,J. Haimberger,T. Halewood-leagas,P. Hamilton,J. Hammerich,Q. Han,X. Han,T. Hancock,E. Hansen,S. Hansmann-Menzemer,N. Harnew,T. Harrison,C. Hasse,M. Hatch,J. He,M. Hecker,K. Heijhoff,K. Heinicke,Arthur Hennequin,K. Hennessy,L. Henry,J. Heuel,A. Hicheur,D. Hill,M. Hilton,S. Hollitt,R. Hou,Y. Hou,Jifeng Hu,W. Hu,X. Hu,W. Huang,X. Huang,W. Hulsbergen,R. Hunter,M. Hushchyn,D. Hutchcroft,D. Hynds,P. Ibis,M. Idzik,D. Ilin,P. Ilten,A. Inglessi,Artur Ishteev,К. Ившин,R. Jacobsson,H. Jage,S. Jakobsen,E. Jans,B. Jashal,A. Jawahery,Vukan Jevtic,F. Jiang,M. John,D. Johnson,C. Jones,T. Jones,B. Jost,N. Jurik,S. Kadavath,S. Kandybei,Y. Kang,M. Karacson,M. Karpov,F. Keizer,D. Keller,M. Kenzie,T. Ketel,B. Khanji,A. Kharisova,S. Kholodenko,T. Kirn,V. Kirsebom,O. Kitouni,S. Klaver,N. Kleijne,K. Klimaszewski,M. Kmiec,S. Koliiev,A. Kondybayeva,A. Konoplyannikov,P. Kopciewicz,R. Kopecna,P. Koppenburg,M. Korolev,I. Kostiuk,O. Kot,S. Kotriakhova,P. Kravchenko,L. Kravchuk,R. Krawczyk,M. Kreps,F. Kress,S. Kretzschmar,P. Krokovny,W. Krupa,W. Krzemień,M. Kucharczyk,V. Kudryavtsev,H. Kuindersma,G. Kunde,T. Kvaratskheliya,D. Lacarrere,G. Lafferty,A. Lai,A. Lampis,D. Lancierini,J. Lane,R. Lane,G. Lanfranchi,C. Langenbruch,J. Langer,O. Lantwin,T. Latham,F. Lazzari,R. Gac,S. Lee,R. Lefèvre,A. Leflat,S. Legotin,O. Leroy,T. Lesiak,B. Leverington,H. Li,S. Li,Z. Li,X. Liang,T. Lin,R. Lindner,V. Lisovskyi,R. Litvinov,Lei Zhu,H. Liu,Q. Liu,Shuaiyi Liu,A. Salvia,A. Loi,J. Castro,I. Longstaff,J. Lopes,S. Solino,G. Lovell,Yi Lu,C. Lucarelli,D. Lucchesi,S. Luchuk,M. Martinez,V. Lukashenko,Y. Luo,A. Lupato,E. Luppi,O. Lupton,A. Lusiani,X. Lyu,L. Ma,R. Ma,S. Maccolini,F. Machefert,F. Maciuc,V. Macko,P. Mackowiak,Samuel Maddrell-Mander,O. Madejczyk,L. Mohan,O. Maev,A. Maevskiy,D. Maisuzenko,M. Majewski,J. Malczewski,S. Malde,B. Małecki,A. Malinin,T. Maltsev,H. Malygina,G. Manca,G. Mancinelli,Daniele Manuzzi,D. Marangotto,J. Maratas,J. Marchand,U. Marconi,S. Mariani,C. Benito,M. Marinangeli,J. Marks,A. Marshall,Phillip Marshall,G. Martelli,G. Martellotti,L. Martinazzoli,M. Martinelli,D. Santos,F. Vidal,A. Massafferri,M. Materok,R. Matev,A. Mathad,V. Matiunin,C. Matteuzzi,K. Mattioli,A. Mauri,E. Maurice,J. Mauricio,M. Mazurek,M. McCann,L. Mcconnell,T. Mcgrath,N. Mchugh,A. McNab,R. McNulty,J. Mead,B. Meadows,G. Meier,N. Meinert,D. Melnychuk,S. Meloni,M. Merk,A. Merli,L. Garcia,M. Mikhasenko,D. Milanés,E. Millard,M. Milovanovic,M.-N. Minard,A. Minotti,L. Minzoni,S. Mitchell,Biljana Mitreska,D. Mitzel,A. Mödden,Rizwaan Mohammed,R. Moise,S. Mokhnenko,T. Mombächer,I. Monroy,S. Monteil,D. Moran,G. Morello,M. Morello,J. Moroń,A. Morris,R. Mountain,H. Mu,F. Muheim,M. Mulder,D. Müller,K. Müller,C. Murphy,D. Murray,P. Muzzetto,P. Naik,T. Nakada,R. Nandakumar,M. Needham,I. Nasteva,I. Neri,N. Néri,S. Neubert,N. Neufeld,R. Newcombe,E. Niel,S. Nieswand,N. Nikitin,Niklas Nolte,C. Normand,C. Nunez,A. Obłąkowska-Mucha,V. Obraztsov,Τ. Oeser,D.P. O'Hanlon,S. 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