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First Observation of the Doubly Charmed Baryon Decay $Ξ_{c c}^{+ +} \to Ξ_{c}^{+} π^{+}$

R. Aaij²⁷, B. Adeva⁴¹, M. Adinolfi⁴⁸, C. A. Aidala⁷³, Z. Ajaltouni⁵, S. Akar⁵⁹, P. Albicocco¹⁸, J. Albrecht¹⁰, F. Alessio⁴² et al. (LHCb Collaboration)

F. Alessio⁴², M. Alexander⁵³, A. Alfonso Albero⁴⁰, S. Ali²⁷, G. Alkhazov³³, P. Alvarez Cartelle⁵⁵, A. A. Alves, Jr⁴¹, S. Amato², S. Amerio²³, Y. Amhis⁷, L. An³, L. Anderlini¹⁷, G. Andreassi⁴³, M. Andreotti^16,a, J. E. Andrews⁶⁰, R. B. Appleby⁵⁶, F. Archilli²⁷, P. d’Argent¹², J. Arnau Romeu⁶, A. Artamonov³⁹, M. Artuso⁶¹, K. Arzymatov³⁷, E. Aslanides⁶, M. Atzeni⁴⁴, B. Audurier²², S. Bachmann¹², J. J. Back⁵⁰, S. Baker⁵⁵, V. Balagura^7,b, W. Baldini¹⁶, A. Baranov³⁷, R. J. Barlow⁵⁶, S. Barsuk⁷, W. Barter⁵⁶, F. Baryshnikov⁷⁰, V. Batozskaya³¹, B. Batsukh⁶¹, V. Battista⁴³, A. Bay⁴³, J. Beddow⁵³, F. Bedeschi²⁴, I. Bediaga¹, A. Beiter⁶¹, L. J. Bel²⁷, S. Belin²², N. Beliy⁶³, V. Bellee⁴³, N. Belloli^20,c, K. Belous³⁹, I. Belyaev^34,42, E. Ben-Haim⁸, G. Bencivenni¹⁸, S. Benson²⁷, S. Beranek⁹, A. Berezhnoy³⁵, R. Bernet⁴⁴, D. Berninghoff¹², E. Bertholet⁸, A. Bertolin²³, C. Betancourt⁴⁴, F. Betti^15,42, M. O. Bettler⁴⁹, M. van Beuzekom²⁷, Ia. Bezshyiko⁴⁴, S. Bhasin⁴⁸, J. Bhom²⁹, S. Bifani⁴⁷, P. Billoir⁸, A. Birnkraut¹⁰, A. Bizzeti^17,d, M. Bjørn⁵⁷, M. P. Blago⁴², T. Blake⁵⁰, F. Blanc⁴³, S. Blusk⁶¹, D. Bobulska⁵³, V. Bocci²⁶, O. Boente Garcia⁴¹, T. Boettcher⁵⁸, A. Bondar^38,e, N. Bondar³³, S. Borghi^56,42, M. Borisyak³⁷, M. Borsato⁴¹, F. Bossu⁷, M. Boubdir⁹, T. J. V. Bowcock⁵⁴, C. Bozzi^16,42, S. Braun¹², M. Brodski⁴², J. Brodzicka²⁹, A. Brossa Gonzalo⁵⁰, D. Brundu²², E. Buchanan⁴⁸, A. Buonaura⁴⁴, C. Burr⁵⁶, A. Bursche²², J. Buytaert⁴², W. Byczynski⁴², S. Cadeddu²², H. Cai⁶⁴, R. Calabrese^16,a, R. Calladine⁴⁷, M. Calvi^20,c, M. Calvo Gomez^40,f, A. Camboni^40,f, P. Campana¹⁸, D. H. Campora Perez⁴², L. Capriotti⁵⁶, A. Carbone^15,g, G. Carboni²⁵, R. Cardinale^19,h, A. Cardini²², P. Carniti^20,c, L. Carson⁵², K. Carvalho Akiba², G. Casse⁵⁴, L. Cassina²⁰, M. Cattaneo⁴², G. Cavallero^19,h, R. Cenci^24,i, D. Chamont⁷, M. G. Chapman⁴⁸, M. Charles⁸, Ph. Charpentier⁴², G. Chatzikonstantinidis⁴⁷, M. Chefdeville⁴, V. Chekalina³⁷, C. Chen³, S. Chen²², S.-G. Chitic⁴², V. Chobanova⁴¹, M. Chrzaszcz⁴², A. Chubykin³³, P. Ciambrone¹⁸, X. Cid Vidal⁴¹, G. Ciezarek⁴², P. E. L. Clarke⁵², M. Clemencic⁴², H. V. Cliff⁴⁹, J. Closier⁴², V. Coco⁴², J. A. B. Coelho⁷, J. Cogan⁶, E. Cogneras⁵, L. Cojocariu³², P. Collins⁴², T. Colombo⁴², A. Comerma-Montells¹², A. Contu²², G. Coombs⁴², S. Coquereau⁴⁰, G. Corti⁴², M. Corvo^16,a, C. M. Costa Sobral⁵⁰, B. Couturier⁴², G. A. Cowan⁵², D. C. Craik⁵⁸, A. Crocombe⁵⁰, M. Cruz Torres¹, R. Currie⁵², C. D’Ambrosio⁴², F. Da Cunha Marinho², C. L. Da Silva⁷⁴, E. Dall’Occo²⁷, J. Dalseno⁴⁸, A. Danilina³⁴, A. Davis³, O. De Aguiar Francisco⁴², K. De Bruyn⁴², S. De Capua⁵⁶, M. De Cian⁴³, J. M. De Miranda¹, L. De Paula², M. De Serio^14,j, P. De Simone¹⁸, C. T. Dean⁵³, D. Decamp⁴, L. Del Buono⁸, B. Delaney⁴⁹, H.-P. Dembinski¹¹, M. Demmer¹⁰, A. Dendek³⁰, D. Derkach³⁷, O. Deschamps⁵, F. Desse⁷, F. Dettori⁵⁴, B. Dey⁶⁵, A. Di Canto⁴², P. Di Nezza¹⁸, S. Didenko⁷⁰, H. Dijkstra⁴², F. Dordei⁴², M. Dorigo^42,k, A. Dosil Suárez⁴¹, L. Douglas⁵³, A. Dovbnya⁴⁵, K. Dreimanis⁵⁴, L. Dufour²⁷, G. Dujany⁸, P. Durante⁴², J. M. Durham⁷⁴, D. Dutta⁵⁶, R. Dzhelyadin³⁹, M. Dziewiecki¹², A. Dziurda²⁹, A. Dzyuba³³, S. Easo⁵¹, U. Egede⁵⁵, V. Egorychev³⁴, S. Eidelman^38,e, S. Eisenhardt⁵², U. Eitschberger¹⁰, R. Ekelhof¹⁰, L. Eklund⁵³, S. Ely⁶¹, A. Ene³², S. Escher⁹, S. Esen²⁷, T. Evans⁵⁹, A. Falabella¹⁵, N. Farley⁴⁷, S. Farry⁵⁴, D. Fazzini^20,42,c, L. Federici²⁵, P. Fernandez Declara⁴², A. Fernandez Prieto⁴¹, F. Ferrari¹⁵, L. Ferreira Lopes⁴³, F. Ferreira Rodrigues², M. Ferro-Luzzi⁴², S. Filippov³⁶, R. A. Fini¹⁴, M. Fiorini^16,a, M. Firlej³⁰, C. Fitzpatrick⁴³, T. Fiutowski³⁰, F. Fleuret^7,b, M. Fontana^22,42, F. Fontanelli^19,h, R. Forty⁴², V. Franco Lima⁵⁴, M. Frank⁴², C. Frei⁴², J. Fu^21,l, W. Funk⁴², C. Färber⁴², M. Féo Pereira Rivello Carvalho²⁷, E. Gabriel⁵², A. Gallas Torreira⁴¹, D. Galli^15,g, S. Gallorini²³, S. Gambetta⁵², Y. Gan³, M. Gandelman², P. Gandini²¹, Y. Gao³, L. M. Garcia Martin⁷², B. Garcia Plana⁴¹, J. García Pardiñas⁴⁴, J. Garra Tico⁴⁹, L. Garrido⁴⁰, D. Gascon⁴⁰, C. Gaspar⁴², L. Gavardi¹⁰, G. Gazzoni⁵, D. Gerick¹², E. Gersabeck⁵⁶, M. Gersabeck⁵⁶, T. Gershon⁵⁰, D. Gerstel⁶, Ph. Ghez⁴, S. Gianì⁴³, V. Gibson⁴⁹, O. G. Girard⁴³, L. Giubega³², K. Gizdov⁵², V. V. Gligorov⁸, D. Golubkov³⁴, A. Golutvin^55,70, A. Gomes^1,m, I. V. Gorelov³⁵, C. Gotti^20,c, E. Govorkova²⁷, J. P. Grabowski¹², R. Graciani Diaz⁴⁰, L. A. Granado Cardoso⁴², E. Graugés⁴⁰, E. Graverini⁴⁴, G. Graziani¹⁷, A. Grecu³², R. Greim²⁷, P. Griffith²², L. Grillo⁵⁶, L. Gruber⁴², B. R. Gruberg Cazon⁵⁷, O. Grünberg⁶⁷, C. Gu³, E. Gushchin³⁶, Yu. Guz^39,42, T. Gys⁴², C. Göbel⁶², T. Hadavizadeh⁵⁷, C. Hadjivasiliou⁵, G. Haefeli⁴³, C. Haen⁴², S. C. Haines⁴⁹, B. Hamilton⁶⁰, X. Han¹², T. H. Hancock⁵⁷, S. Hansmann-Menzemer¹², N. Harnew⁵⁷, S. T. Harnew⁴⁸, T. Harrison⁵⁴, C. Hasse⁴², M. Hatch⁴², J. He⁶³, M. Hecker⁵⁵, K. Heinicke¹⁰, A. Heister¹⁰, K. Hennessy⁵⁴, L. Henry⁷², E. van Herwijnen⁴², M. Heß⁶⁷, A. Hicheur², R. Hidalgo Charman⁵⁶, D. Hill⁵⁷, M. Hilton⁵⁶, P. H. Hopchev⁴³, W. Hu⁶⁵, W. Huang⁶³, Z. C. Huard⁵⁹, W. Hulsbergen²⁷, T. Humair⁵⁵, M. Hushchyn³⁷, D. Hutchcroft⁵⁴, D. Hynds²⁷, P. Ibis¹⁰, M. Idzik³⁰, P. Ilten⁴⁷, K. Ivshin³³, R. Jacobsson⁴², J. Jalocha⁵⁷, E. Jans²⁷, A. Jawahery⁶⁰, F. Jiang³, M. John⁵⁷, D. Johnson⁴², C. R. Jones⁴⁹, C. Joram⁴², B. Jost⁴², N. Jurik⁵⁷, S. Kandybei⁴⁵, M. Karacson⁴², J. M. Kariuki⁴⁸, S. Karodia⁵³, N. Kazeev³⁷, M. Kecke¹², F. Keizer⁴⁹, M. Kelsey⁶¹, M. Kenzie⁴⁹, T. Ketel²⁸, E. Khairullin³⁷, B. Khanji¹², C. Khurewathanakul⁴³, K. E. Kim⁶¹, T. Kirn⁹, S. Klaver¹⁸, K. Klimaszewski³¹, T. Klimkovich¹¹, S. Koliiev⁴⁶, M. Kolpin¹², R. Kopecna¹², P. Koppenburg²⁷, I. Kostiuk²⁷, S. Kotriakhova³³, M. Kozeiha⁵, L. Kravchuk³⁶, M. Kreps⁵⁰, F. Kress⁵⁵, P. Krokovny^38,e, W. Krupa³⁰, W. Krzemien³¹, W. Kucewicz^29,n, M. Kucharczyk²⁹, V. Kudryavtsev^38,e, A. K. Kuonen⁴³, T. Kvaratskheliya^34,42, D. Lacarrere⁴², G. Lafferty⁵⁶, A. Lai²², D. Lancierini⁴⁴, G. Lanfranchi¹⁸, C. Langenbruch⁹, T. Latham⁵⁰, C. Lazzeroni⁴⁷, R. Le Gac⁶, A. Leflat³⁵, J. Lefrançois⁷, R. Lefèvre⁵, F. Lemaitre⁴², O. Leroy⁶, T. Lesiak²⁹, B. Leverington¹², P.-R. Li⁶³, T. Li³, Z. Li⁶¹, X. Liang⁶¹, T. Likhomanenko⁶⁹, R. Lindner⁴², F. Lionetto⁴⁴, V. Lisovskyi⁷, X. Liu³, D. Loh⁵⁰, A. Loi²², I. Longstaff⁵³, J. H. Lopes², G. H. Lovell⁴⁹, D. Lucchesi^23,o, M. Lucio Martinez⁴¹, A. Lupato²³, E. Luppi^16,a, O. Lupton⁴², A. Lusiani²⁴, X. Lyu⁶³, F. Machefert⁷, F. Maciuc³², V. Macko⁴³, P. Mackowiak¹⁰, S. Maddrell-Mander⁴⁸, O. Maev^33,42, K. Maguire⁵⁶, D. Maisuzenko³³, M. W. Majewski³⁰, S. Malde⁵⁷, B. Malecki²⁹, A. Malinin⁶⁹, T. Maltsev^38,e, G. Manca^22,p, G. Mancinelli⁶, D. Marangotto^21,l, J. Maratas^5,q, J. F. Marchand⁴, U. Marconi¹⁵, C. Marin Benito⁷, M. Marinangeli⁴³, P. Marino⁴³, J. Marks¹², P. J. Marshall⁵⁴, G. Martellotti²⁶, M. Martin⁶, M. Martinelli⁴², D. Martinez Santos⁴¹, F. Martinez Vidal⁷², A. Massafferri¹, M. Materok⁹, R. Matev⁴², A. Mathad⁵⁰, Z. Mathe⁴², C. Matteuzzi²⁰, A. Mauri⁴⁴, E. Maurice^7,b, B. Maurin⁴³, A. Mazurov⁴⁷, M. McCann^55,42, A. McNab⁵⁶, R. McNulty¹³, J. V. Mead⁵⁴, B. Meadows⁵⁹, C. Meaux⁶, F. Meier¹⁰, N. Meinert⁶⁷, D. Melnychuk³¹, M. Merk²⁷, A. Merli^21,l, E. Michielin²³, D. A. Milanes⁶⁶, E. Millard⁵⁰, M.-N. Minard⁴, L. Minzoni^16,a, D. S. Mitzel¹², A. Mogini⁸, J. Molina Rodriguez^1,r, T. Mombächer¹⁰, I. A. Monroy⁶⁶, S. Monteil⁵, M. Morandin²³, G. Morello¹⁸, M. J. Morello^24,s, O. Morgunova⁶⁹, J. Moron³⁰, A. B. Morris⁶, R. Mountain⁶¹, F. Muheim⁵², M. Mulder²⁷, C. H. Murphy⁵⁷, D. Murray⁵⁶, A. Mödden¹⁰, D. Müller⁴², J. Müller¹⁰, K. Müller⁴⁴, V. Müller¹⁰, P. Naik⁴⁸, T. Nakada⁴³, R. Nandakumar⁵¹, A. Nandi⁵⁷, T. Nanut⁴³, I. Nasteva², M. Needham⁵², N. Neri²¹, S. Neubert¹², N. Neufeld⁴², M. Neuner¹², T. D. Nguyen⁴³, C. Nguyen-Mau^43,t, S. Nieswand⁹, R. Niet¹⁰, N. Nikitin³⁵, A. Nogay⁶⁹, N. S. Nolte⁴², D. P. O’Hanlon¹⁵, A. Oblakowska-Mucha³⁰, V. Obraztsov³⁹, S. Ogilvy¹⁸, R. Oldeman^22,p, C. J. G. Onderwater⁶⁸, A. Ossowska²⁹, J. M. Otalora Goicochea², P. Owen⁴⁴, A. Oyanguren⁷², P. R. Pais⁴³, T. Pajero^24,s, A. Palano¹⁴, M. Palutan^18,42, G. Panshin⁷¹, A. Papanestis⁵¹, M. Pappagallo⁵², L. L. Pappalardo^16,a, W. Parker⁶⁰, C. Parkes⁵⁶, G. Passaleva^17,42, A. Pastore¹⁴, M. Patel⁵⁵, C. Patrignani^15,g, A. Pearce⁴², A. Pellegrino²⁷, G. Penso²⁶, M. Pepe Altarelli⁴², S. Perazzini⁴², D. Pereima³⁴, P. Perret⁵, L. Pescatore⁴³, K. Petridis⁴⁸, A. Petrolini^19,h, A. Petrov⁶⁹, S. Petrucci⁵², M. Petruzzo^21,l, B. Pietrzyk⁴, G. Pietrzyk⁴³, M. Pikies²⁹, M. Pili⁵⁷, D. Pinci²⁶, J. Pinzino⁴², F. Pisani⁴², A. Piucci¹², V. Placinta³², S. Playfer⁵², J. Plews⁴⁷, M. Plo Casasus⁴¹, F. Polci⁸, M. Poli Lener¹⁸, A. Poluektov⁵⁰, N. Polukhina^70,u, I. Polyakov⁶¹, E. Polycarpo², G. J. Pomery⁴⁸, S. Ponce⁴², A. Popov³⁹, D. Popov^47,11, S. Poslavskii³⁹, C. Potterat², E. Price⁴⁸, J. Prisciandaro⁴¹, C. Prouve⁴⁸, V. Pugatch⁴⁶, A. Puig Navarro⁴⁴, H. Pullen⁵⁷, G. Punzi^24,i, W. Qian⁶³, J. Qin⁶³, R. Quagliani⁸, B. Quintana⁵, B. Rachwal³⁰, J. H. Rademacker⁴⁸, M. Rama²⁴, M. Ramos Pernas⁴¹, M. S. Rangel², F. Ratnikov^37,v, G. Raven²⁸, M. Ravonel Salzgeber⁴², M. Reboud⁴, F. Redi⁴³, S. Reichert¹⁰, A. C. dos Reis¹, F. Reiss⁸, C. Remon Alepuz⁷², Z. Ren³, V. Renaudin⁷, S. Ricciardi⁵¹, S. Richards⁴⁸, K. Rinnert⁵⁴, P. Robbe⁷, A. Robert⁸, A. B. Rodrigues⁴³, E. Rodrigues⁵⁹, J. A. Rodriguez Lopez⁶⁶, M. Roehrken⁴², A. Rogozhnikov³⁷, S. Roiser⁴², A. Rollings⁵⁷, V. Romanovskiy³⁹, A. Romero Vidal⁴¹, M. Rotondo¹⁸, M. S. Rudolph⁶¹, T. Ruf⁴², J. Ruiz Vidal⁷², J. J. Saborido Silva⁴¹, N. Sagidova³³, B. Saitta^22,p, V. Salustino Guimaraes⁶², C. Sanchez Gras²⁷, C. Sanchez Mayordomo⁷², B. Sanmartin Sedes⁴¹, R. Santacesaria²⁶, C. Santamarina Rios⁴¹, M. Santimaria¹⁸, E. Santovetti^25,w, G. Sarpis⁵⁶, A. Sarti^18,x, C. Satriano^26,y, A. Satta²⁵, M. Saur⁶³, D. Savrina^34,35, S. Schael⁹, M. Schellenberg¹⁰, M. Schiller⁵³, H. Schindler⁴², M. Schmelling¹¹, T. Schmelzer¹⁰, B. Schmidt⁴², O. Schneider⁴³, A. Schopper⁴², H. F. Schreiner⁵⁹, M. Schubiger⁴³, M. H. Schune⁷, R. Schwemmer⁴², B. Sciascia¹⁸, A. Sciubba^26,x, A. Semennikov³⁴, E. S. Sepulveda⁸, A. Sergi^47,42, N. Serra⁴⁴, J. Serrano⁶, L. Sestini²³, A. Seuthe¹⁰, P. Seyfert⁴², M. Shapkin³⁹, Y. Shcheglov^33,†, T. Shears⁵⁴, L. Shekhtman^38,e, V. Shevchenko⁶⁹, E. Shmanin⁷⁰, B. G. Siddi¹⁶, R. Silva Coutinho⁴⁴, L. Silva de Oliveira², G. Simi^23,o, S. Simone^14,j, N. Skidmore¹², T. Skwarnicki⁶¹, J. G. Smeaton⁴⁹, E. Smith⁹, I. T. Smith⁵², M. Smith⁵⁵, M. Soares¹⁵, l. Soares Lavra¹, M. D. Sokoloff⁵⁹, F. J. P. Soler⁵³, B. Souza De Paula², B. Spaan¹⁰, P. Spradlin⁵³, F. Stagni⁴², M. Stahl¹², S. Stahl⁴², P. Stefko⁴³, S. Stefkova⁵⁵, O. Steinkamp⁴⁴, S. Stemmle¹², O. Stenyakin³⁹, M. Stepanova³³, H. Stevens¹⁰, A. Stocchi⁷, S. Stone⁶¹, B. Storaci⁴⁴, S. Stracka^24,i, M. E. Stramaglia⁴³, M. Straticiuc³², U. Straumann⁴⁴, S. Strokov⁷¹, J. Sun³, L. Sun⁶⁴, K. Swientek³⁰, V. Syropoulos²⁸, T. Szumlak³⁰, M. Szymanski⁶³, S. T’Jampens⁴, Z. Tang³, A. Tayduganov⁶, T. Tekampe¹⁰, G. Tellarini¹⁶, F. Teubert⁴², E. Thomas⁴², J. van Tilburg²⁷, M. J. Tilley⁵⁵, V. Tisserand⁵, M. Tobin³⁰, S. Tolk⁴², L. Tomassetti^16,a, D. Tonelli²⁴, D. Y. Tou⁸, R. Tourinho Jadallah Aoude¹, E. Tournefier⁴, M. Traill⁵³, M. T. Tran⁴³, A. Trisovic⁴⁹, A. Tsaregorodtsev⁶, G. Tuci²⁴, A. Tully⁴⁹, N. Tuning^27,42, A. Ukleja³¹, A. Usachov⁷, A. Ustyuzhanin³⁷, U. Uwer¹², A. Vagner⁷¹, V. Vagnoni¹⁵, A. Valassi⁴², S. Valat⁴², G. Valenti¹⁵, R. Vazquez Gomez⁴², P. Vazquez Regueiro⁴¹, S. Vecchi¹⁶, M. van Veghel²⁷, J. J. Velthuis⁴⁸, M. Veltri^17,z, G. Veneziano⁵⁷, A. Venkateswaran⁶¹, T. A. Verlage⁹, M. Vernet⁵, M. Veronesi²⁷, N. V. Veronika¹³, M. Vesterinen⁵⁷, J. V. Viana Barbosa⁴², D. Vieira⁶³, M. Vieites Diaz⁴¹, H. Viemann⁶⁷, X. Vilasis-Cardona^40,f, A. Vitkovskiy²⁷, M. Vitti⁴⁹, V. Volkov³⁵, A. Vollhardt⁴⁴, B. Voneki⁴², A. Vorobyev³³, V. Vorobyev^38,e, J. A. de Vries²⁷, C. Vázquez Sierra²⁷, R. Waldi⁶⁷, J. Walsh²⁴, J. Wang⁶¹, M. Wang³, Y. Wang⁶⁵, Z. Wang⁴⁴, D. R. Ward⁴⁹, H. M. Wark⁵⁴, N. K. Watson⁴⁷, D. Websdale⁵⁵, A. Weiden⁴⁴, C. Weisser⁵⁸, M. Whitehead⁹, J. Wicht⁵⁰, G. Wilkinson⁵⁷, M. Wilkinson⁶¹, I. Williams⁴⁹, M. R. J. Williams⁵⁶, M. Williams⁵⁸, T. Williams⁴⁷, F. F. Wilson^51,42, J. Wimberley⁶⁰, M. Winn⁷, J. Wishahi¹⁰, W. Wislicki³¹, M. Witek²⁹, G. Wormser⁷, S. A. Wotton⁴⁹, K. Wyllie⁴², D. Xiao⁶⁵, Y. Xie⁶⁵, A. Xu³, M. Xu⁶⁵, Q. Xu⁶³, Z. Xu³, Z. Xu⁴, Z. Yang³, Z. Yang⁶⁰, Y. Yao⁶¹, L. E. Yeomans⁵⁴, H. Yin⁶⁵, J. Yu^65,aa, X. Yuan⁶¹, O. Yushchenko³⁹, K. A. Zarebski⁴⁷, M. Zavertyaev^11,u, D. Zhang⁶⁵, L. Zhang³, W. C. Zhang^3,bb, Y. Zhang⁷, A. Zhelezov¹², Y. Zheng⁶³, X. Zhu³, V. Zhukov^9,35, J. B. Zonneveld⁵², and S. Zucchelli¹⁵ (LHCb Collaboration)

¹Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil
²Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
³Center for High Energy Physics, Tsinghua University, Beijing, China
⁴Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IN2P3-LAPP, Annecy, France
⁵Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France
⁶Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France
⁷LAL, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France
⁸LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France
⁹I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany
¹⁰Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany
¹¹Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany
¹²Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
¹³School of Physics, University College Dublin, Dublin, Ireland
¹⁴INFN Sezione di Bari, Bari, Italy
¹⁵INFN Sezione di Bologna, Bologna, Italy
¹⁶INFN Sezione di Ferrara, Ferrara, Italy
¹⁷INFN Sezione di Firenze, Firenze, Italy
¹⁸INFN Laboratori Nazionali di Frascati, Frascati, Italy
¹⁹INFN Sezione di Genova, Genova, Italy
²⁰INFN Sezione di Milano-Bicocca, Milano, Italy
²¹INFN Sezione di Milano, Milano, Italy
²²INFN Sezione di Cagliari, Monserrato, Italy
²³INFN Sezione di Padova, Padova, Italy
²⁴INFN Sezione di Pisa, Pisa, Italy
²⁵INFN Sezione di Roma Tor Vergata, Roma, Italy
²⁶INFN Sezione di Roma La Sapienza, Roma, Italy
²⁷Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands
²⁸Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, Netherlands
²⁹Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
³⁰AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland
³¹National Center for Nuclear Research (NCBJ), Warsaw, Poland
³²Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
³³Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia
³⁴Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
³⁵Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia
³⁶Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia
³⁷Yandex School of Data Analysis, Moscow, Russia
³⁸Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia
³⁹Institute for High Energy Physics (IHEP), Protvino, Russia
⁴⁰ICCUB, Universitat de Barcelona, Barcelona, Spain
⁴¹Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
⁴²European Organization for Nuclear Research (CERN), Geneva, Switzerland
⁴³Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
⁴⁴Physik-Institut, Universität Zürich, Zürich, Switzerland
⁴⁵NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine
⁴⁶Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine
⁴⁷University of Birmingham, Birmingham, United Kingdom
⁴⁸H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom
⁴⁹Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
⁵⁰Department of Physics, University of Warwick, Coventry, United Kingdom
⁵¹STFC Rutherford Appleton Laboratory, Didcot, United Kingdom
⁵²School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom
⁵³School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
⁵⁴Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom
⁵⁵Imperial College London, London, United Kingdom
⁵⁶School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
⁵⁷Department of Physics, University of Oxford, Oxford, United Kingdom
⁵⁸Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
⁵⁹University of Cincinnati, Cincinnati, Ohio, USA
⁶⁰University of Maryland, College Park, Maryland, USA
⁶¹Syracuse University, Syracuse, New York, USA
⁶²Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil [associated with Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil]
⁶³University of Chinese Academy of Sciences, Beijing, China (associated with Center for High Energy Physics, Tsinghua University, Beijing, China)
⁶⁴School of Physics and Technology, Wuhan University, Wuhan, China (associated with Center for High Energy Physics, Tsinghua University, Beijing, China)
⁶⁵Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China (associated with Center for High Energy Physics, Tsinghua University, Beijing, China)
⁶⁶Departamento de Fisica, Universidad Nacional de Colombia, Bogota, Colombia (associated with LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France)
⁶⁷Institut für Physik, Universität Rostock, Rostock, Germany (associated with Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany)
⁶⁸Van Swinderen Institute, University of Groningen, Groningen, Netherlands (associated with Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands)
⁶⁹National Research Centre Kurchatov Institute, Moscow, Russia [associated with Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia]
⁷⁰National University of Science and Technology “MISIS”, Moscow, Russia [associated with Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia]
⁷¹National Research Tomsk Polytechnic University, Tomsk, Russia [associated with Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia]
⁷²Instituto de Fisica Corpuscular, Centro Mixto Universidad de Valencia - CSIC, Valencia, Spain (associated with ICCUB, Universitat de Barcelona, Barcelona, Spain)
⁷³University of Michigan, Ann Arbor, Michigan, USA (associated with Syracuse University, Syracuse, New York, USA)
⁷⁴Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, USA (associated with Syracuse University, Syracuse, New York, USA)

^*Full author list given at the end of the article.
^†Deceased.
^aAlso at Università di Ferrara, Ferrara, Italy.
^bAlso at Laboratoire Leprince-Ringuet, Palaiseau, France.
^cAlso at Università di Milano Bicocca, Milano, Italy.
^dAlso at Università di Modena e Reggio Emilia, Modena, Italy.
^eAlso at Novosibirsk State University, Novosibirsk, Russia.
^fAlso at LIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain.
^gAlso at Università di Bologna, Bologna, Italy.
^hAlso at Università di Genova, Genova, Italy.
ⁱAlso at Università di Pisa, Pisa, Italy.
^jAlso at Università di Bari, Bari, Italy.
^kAlso at Sezione INFN di Trieste, Trieste, Italy.
^lAlso at Università degli Studi di Milano, Milano, Italy.
^mAlso at Universidade Federal do Triângulo Mineiro (UFTM), Uberaba-MG, Brazil.
ⁿAlso at AGH - University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Kraków, Poland.
^oAlso at Università di Padova, Padova, Italy.
^pAlso at Università di Cagliari, Cagliari, Italy.
^qAlso at MSU - Iligan Institute of Technology (MSU-IIT), Iligan, Philippines.
^rAlso at Escuela Agrícola Panamericana, San Antonio de Oriente, Honduras.
^sAlso at Scuola Normale Superiore, Pisa, Italy.
^tAlso at Hanoi University of Science, Hanoi, Vietnam.
^uAlso at P.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia.
^vAlso at National Research University Higher School of Economics, Moscow, Russia.
^wAlso at Università di Roma Tor Vergata, Roma, Italy.
^xAlso at Università di Roma La Sapienza, Roma, Italy.
^yAlso at Università della Basilicata, Potenza, Italy.
^zAlso at Università di Urbino, Urbino, Italy.
^aaAlso at Physics and Micro Electronic College, Hunan University, Changsha City, China.
^bbAlso at School of Physics and Information Technology, Shaanxi Normal University (SNNU), Xi’an, China.

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Phys. Rev. Lett. 121, 162002 – Published 17 October, 2018

DOI: https://doi.org/10.1103/PhysRevLett.121.162002

Abstract

The doubly charmed baryon decay $Ξ_{c c}^{+ +} \to Ξ_{c}^{+} π^{+}$ is observed for the first time, with a statistical significance of $5.9 σ$ , confirming a recent observation of the baryon in the $Λ_{c}^{+} K^{-} π^{+} π^{+}$ final state. The data sample used corresponds to an integrated luminosity of $1.7 {fb}^{- 1}$ , collected by the LHCb experiment in $p p$ collisions at a center-of-mass energy of 13 TeV. The $Ξ_{c c}^{+ +}$ mass is measured to be $3620.6 \pm 1.5 (stat) \pm 0.4 (syst) \pm 0.3 (Ξ_{c}^{+}) MeV / c^{2}$ and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be $[B (Ξ_{c c}^{+ +} \to Ξ_{c}^{+} π^{+}) \times B (Ξ_{c}^{+} \to p K^{-} π^{+})] / [B (Ξ_{c c}^{+ +} \to Λ_{c}^{+} K^{-} π^{+} π^{+}) \times B (Λ_{c}^{+} \to p K^{-} π^{+})] = 0.035 \pm 0.009 (stat) \pm 0.003 (syst)$ .

Physics Subject Headings (PhySH)

Charmed baryons

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References (33)

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Phys. Rev. Lett. 121, 162002– Published 17 October, 2018

Vol. 121, Iss. 16 — 19 October 2018

Received 9 July 2018
Revised 1 August 2018

DOI: https://doi.org/10.1103/PhysRevLett.121.162002

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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First Observation of the Doubly Charmed Baryon Decay $Ξ_{c c}^{+ +} \to Ξ_{c}^{+} π^{+}$

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First Observation of the Doubly Charmed Baryon Decay Ξcc++→Ξc+π+

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First Observation of the Doubly Charmed Baryon Decay $Ξ_{c c}^{+ +} \to Ξ_{c}^{+} π^{+}$