The International School for Advanced Studies (SISSA) was founded in 1978 and was the first institution in Italy to promote post-graduate courses leading to a Doctor Philosophiae (or PhD) degree. A centre of excellence among Italian and international universities, the school has around 65 teachers, 100 post docs and 245 PhD students, and is located in Trieste, in a campus of more than 10 hectares with wonderful views over the Gulf of Trieste.
SISSA hosts a very high-ranking, large and multidisciplinary scientific research output. The scientific papers produced by its researchers are published in high impact factor, well-known international journals, and in many cases in the world's most prestigious scientific journals such as Nature and Science. Over 900 students have so far started their careers in the field of mathematics, physics and neuroscience research at SISSA.
The following article is Open access
A new algorithm for identifying the flavour of B0s mesons at LHCb
R. Aaij39, C. Abellán Beteta41, B. Adeva38, M. Adinolfi47, A. Affolder53, Z. Ajaltouni5, S. Akar6, J. Albrecht10, F. Alessio39, M. Alexander52, S. Ali42, G. Alkhazov31, P. Alvarez Cartelle54, A.A. Alves Jr58, S. Amato2, S. Amerio23, Y. Amhis7, L. An3,40, L. Anderlini18, G. Andreassi40, M. Andreotti17,75, J.E. Andrews59, R.B. Appleby55, O. Aquines Gutierrez11, F. Archilli39, P. d'Argent12, A. Artamonov36, M. Artuso60, E. Aslanides6, G. Auriemma26,82, M. Baalouch5, S. Bachmann12, J.J. Back49, A. Badalov37, C. Baesso61, W. Baldini17,39, R.J. Barlow55, C. Barschel39, S. Barsuk7, W. Barter39, V. Batozskaya29, V. Battista40, A. Bay40, L. Beaucourt4, J. Beddow52, F. Bedeschi24, I. Bediaga1, L.J. Bel42, V. Bellee40, N. Belloli21,79, I. Belyaev32, E. Ben-Haim8, G. Bencivenni19, S. Benson39, J. Benton47, A. Berezhnoy33, R. Bernet41, A. Bertolin23, F. Betti15, M.-O. Bettler39, M. van Beuzekom42, S. Bifani46, P. Billoir8, T. Bird55, A. Birnkraut10, A. Bizzeti18,77, T. Blake49, F. Blanc40, J. Blouw11, S. Blusk60, V. Bocci26, A. Bondar35, N. Bondar31,39, W. Bonivento16, A. Borgheresi21,79, S. Borghi55, M. Borisyak66, M. Borsato38, T.J.V. Bowcock53, E. Bowen41, C. Bozzi17,39, S. Braun12, M. Britsch12, T. Britton60, J. Brodzicka55, N.H. Brook47, E. Buchanan47, C. Burr55, A. Bursche41, J. Buytaert39, S. Cadeddu16, R. Calabrese17,75, M. Calvi21,79, M. Calvo Gomez37,84, P. Campana19, D. Campora Perez39, L. Capriotti55, A. Carbone15,73, G. Carboni25,80, R. Cardinale20,78, A. Cardini16, P. Carniti21,79, L. Carson51, K. Carvalho Akiba2, G. Casse53, L. Cassina21,79, L. Castillo Garcia40, M. Cattaneo39, Ch. Cauet10, G. Cavallero20, R. Cenci24,88, M. Charles8, Ph. Charpentier39, G. Chatzikonstantinidis46, M. Chefdeville4, S. Chen55, S.-F. Cheung56, N. Chiapolini41, M. Chrzaszcz27,41, X. Cid Vidal39, G. Ciezarek42, P.E.L. Clarke51, M. Clemencic39, H.V. Cliff48, J. Closier39, V. Coco39, J. Cogan6, E. Cogneras5, V. Cogoni16,74, L. Cojocariu30, G. Collazuol23,86, P. Collins39, A. Comerma-Montells12, A. Contu39, A. Cook47, M. Coombes47, S. Coquereau8, G. Corti39, M. Corvo17,75, B. Couturier39, G.A. Cowan51, D.C. Craik51, A. Crocombe49, M. Cruz Torres61, S. Cunliffe54, R. Currie54, C. D'Ambrosio39, E. Dall'Occo42, J. Dalseno47, P.N.Y. David42, A. Davis58, O. De Aguiar Francisco2, K. De Bruyn6, S. De Capua55, M. De Cian12, J.M. De Miranda1, L. De Paula2, P. De Simone19, C.-T. Dean52, D. Decamp4, M. Deckenhoff10, L. Del Buono8, N. Déléage4, M. Demmer10, D. Derkach66, O. Deschamps5, F. Dettori39, B. Dey22, A. Di Canto39, F. Di Ruscio25, H. Dijkstra39, S. Donleavy53, F. Dordei39, M. Dorigo40, A. Dosil Suárez38, A. Dovbnya44, K. Dreimanis53, L. Dufour42, G. Dujany55, K. Dungs39, P. Durante39, R. Dzhelyadin36, A. Dziurda27, A. Dzyuba31, S. Easo39,50, U. Egede54, V. Egorychev32, S. Eidelman35, S. Eisenhardt51, U. Eitschberger10, R. Ekelhof10, L. Eklund52, I. El Rifai5, Ch. Elsasser41, S. Ely60, S. Esen12, H.M. Evans48, T. Evans56, A. Falabella15, C. Färber39, N. Farley46, S. Farry53, R. Fay53, D. Fazzini21,79, D. Ferguson51, V. Fernandez Albor38, F. Ferrari15, F. Ferreira Rodrigues1, M. Ferro-Luzzi39, S. Filippov34, M. Fiore17,39,75, M. Fiorini17,75, M. Firlej28, C. Fitzpatrick40, T. Fiutowski28, F. Fleuret7,70, K. Fohl39, P. Fol54, M. Fontana16, F. Fontanelli20,78, D. C. Forshaw60, R. Forty39, M. Frank39, C. Frei39, M. Frosini18, J. Fu22, E. Furfaro25,80, A. Gallas Torreira38, D. Galli15,73, S. Gallorini23, S. Gambetta51, M. Gandelman2, P. Gandini56, Y. Gao3, J. García Pardiñas38, J. Garra Tico48, L. Garrido37, D. Gascon37, C. Gaspar39, L. Gavardi10, G. Gazzoni5, D. Gerick12, E. Gersabeck12, M. Gersabeck55, T. Gershon49, Ph. Ghez4, S. Gianì40, V. Gibson48, O.G. Girard40, L. Giubega30, V.V. Gligorov39, C. Göbel61, D. Golubkov32, A. Golutvin39,54, A. Gomes1,69, C. Gotti21,79, M. Grabalosa Gándara5, R. Graciani Diaz37, L.A. Granado Cardoso39, E. Graugés37, E. Graverini41, G. Graziani18, A. Grecu30, P. Griffith46, L. Grillo12, O. Grünberg64, B. Gui60, E. Gushchin34, Yu. Guz36,39, T. Gys39, T. Hadavizadeh56, C. Hadjivasiliou60, G. Haefeli40, C. Haen39, S.C. Haines48, S. Hall54, B. Hamilton59, X. Han12, S. Hansmann-Menzemer12, N. Harnew56, S.T. Harnew47, J. Harrison55, J. He39, T. Head40, V. Heijne42, A. Heister9, K. Hennessy53, P. Henrard5, L. Henry8, J.A. Hernando Morata38, E. van Herwijnen39, M. Heß64, A. Hicheur2, D. Hill56, M. Hoballah5, C. Hombach55, W. Hulsbergen42, T. Humair54, M. Hushchyn66, N. Hussain56, D. Hutchcroft53, D. Hynds52, M. Idzik28, P. Ilten57, R. Jacobsson39, A. Jaeger12, J. Jalocha56, E. Jans42, A. Jawahery59, M. John56, D. Johnson39, C.R. Jones48, C. Joram39, B. Jost39, N. Jurik60, S. Kandybei44, W. Kanso6, M. Karacson39, T.M. Karbach39, S. Karodia52, M. Kecke12, M. Kelsey60, I.R. Kenyon46, M. Kenzie39, T. Ketel43, E. Khairullin66, B. Khanji21,39,79, C. Khurewathanakul40, T. Kirn9, S. Klaver55, K. Klimaszewski29, O. Kochebina7, M. Kolpin12, I. Komarov40, R.F. Koopman43, P. Koppenburg39,42, M. Kozeiha5, L. Kravchuk34, K. Kreplin12, M. Kreps49, G. Krocker12, P. Krokovny35, F. Kruse10, W. Krzemien29, W. Kucewicz27,83, M. Kucharczyk27, V. Kudryavtsev35, A. K. Kuonen40, K. Kurek29, T. Kvaratskheliya32, D. Lacarrere39, G. Lafferty39,55, A. Lai16, D. Lambert51, G. Lanfranchi19, C. Langenbruch49, B. Langhans39, T. Latham49, C. Lazzeroni46, R. Le Gac6, J. van Leerdam42, J.-P. Lees4, R. Lefèvre5, A. Leflat33,39, J. Lefrançois7, E. Lemos Cid38, O. Leroy6, T. Lesiak27, B. Leverington12, Y. Li7, T. Likhomanenko65,66, M. Liles53, R. Lindner39, C. Linn39, F. Lionetto41, B. Liu16, X. Liu3, D. Loh49, I. Longstaff52, J.H. Lopes2, D. Lucchesi23,86, M. Lucio Martinez38, H. Luo51, A. Lupato23, E. Luppi17,75, O. Lupton56, N. Lusardi22, A. Lusiani24, F. Machefert7, F. Maciuc30, O. Maev31, K. Maguire55, S. Malde56, A. Malinin65, G. Manca7, G. Mancinelli6, P. Manning60, A. Mapelli39, J. Maratas5, J.F. Marchand4, U. Marconi15, C. Marin Benito37, P. Marino24,39,88, J. Marks12, G. Martellotti26, M. Martin6, M. Martinelli40, D. Martinez Santos38, F. Martinez Vidal67, D. Martins Tostes2, L.M. Massacrier7, A. Massafferri1, R. Matev39, A. Mathad49, Z. Mathe39, C. Matteuzzi21, A. Mauri41, B. Maurin40, A. Mazurov46, M. McCann54, J. McCarthy46, A. McNab55, R. McNulty13, B. Meadows58, F. Meier10, M. Meissner12, D. Melnychuk29, M. Merk42, A Merli22,89, E Michielin23, D.A. Milanes63, M.-N. Minard4, D.S. Mitzel12, J. Molina Rodriguez61, I.A. Monroy63, S. Monteil5, M. Morandin23, P. Morawski28, A. Mordà6, M.J. Morello24,88, J. Moron28, A.B. Morris51, R. Mountain60, F. Muheim51, D. Müller55, J. Müller10, K. Müller41, V. Müller10, M. Mussini15, B. Muster40, P. Naik47, T. Nakada40, R. Nandakumar50, A. Nandi56, I. Nasteva2, M. Needham51, N. Neri22, S. Neubert12, N. Neufeld39, M. Neuner12, A.D. Nguyen40, C. Nguyen-Mau40,85, V. Niess5, S. Nieswand9, R. Niet10, N. Nikitin33, T. Nikodem12, A. Novoselov36, D.P. O'Hanlon49, A. Oblakowska-Mucha28, V. Obraztsov36, S. Ogilvy52, O. Okhrimenko45, R. Oldeman16,48,74, C.J.G. Onderwater68, B. Osorio Rodrigues1, J.M. Otalora Goicochea2, A. Otto39, P. Owen54, A. Oyanguren67, A. Palano14,72, F. Palombo22,89, M. Palutan19, J. Panman39, A. Papanestis50, M. Pappagallo52, L.L. Pappalardo17,75, C. Pappenheimer58, W. Parker59, C. Parkes55, G. Passaleva18, G.D. Patel53, M. Patel54, C. Patrignani20,78, A. Pearce50,55, A. Pellegrino42, G. Penso26,81, M. Pepe Altarelli39, S. Perazzini15,73, P. Perret5, L. Pescatore46, K. Petridis47, A. Petrolini20,78, M. Petruzzo22, E. Picatoste Olloqui37, B. Pietrzyk4, M. Pikies27, D. Pinci26, A. Pistone20, A. Piucci12, S. Playfer51, M. Plo Casasus38, T. Poikela39, F. Polci8, A. Poluektov35,49, I. Polyakov32, E. Polycarpo2, A. Popov36, D. Popov11,39, B. Popovici30, C. Potterat2, E. Price47, J.D. Price53, J. Prisciandaro38, A. Pritchard53, C. Prouve47, V. Pugatch45, A. Puig Navarro40, G. Punzi24,87, W. Qian56, R. Quagliani7,47, B. Rachwal27, J.H. Rademacker47, M. Rama24, M. Ramos Pernas38, M.S. Rangel2, I. Raniuk44, G. Raven43, F. Redi54, S. Reichert55, A.C. dos Reis1, V. Renaudin7, S. Ricciardi50, S. Richards47, M. Rihl39, K. Rinnert39,53, V. Rives Molina37, P. Robbe7,39, A.B. Rodrigues1, E. Rodrigues55, J.A. Rodriguez Lopez63, P. Rodriguez Perez55, A. Rogozhnikov66, S. Roiser39, V. Romanovsky36, A. Romero Vidal38, J. W. Ronayne13, M. Rotondo23, T. Ruf39, P. Ruiz Valls67, J.J. Saborido Silva38, N. Sagidova31, B. Saitta16,74, V. Salustino Guimaraes2, C. Sanchez Mayordomo67, B. Sanmartin Sedes38, R. Santacesaria26, C. Santamarina Rios38, M. Santimaria19, E. Santovetti25,80, A. Sarti19,81, C. Satriano26,82, A. Satta25, D.M. Saunders47, D. Savrina32,33, S. Schael9, M. Schiller39, H. Schindler39, M. Schlupp10, M. Schmelling11, T. Schmelzer10, B. Schmidt39, O. Schneider40, A. Schopper39, M. Schubiger40, M.-H. Schune7, R. Schwemmer39, B. Sciascia19, A. Sciubba26,81, A. Semennikov32, N. Serra41, J. Serrano6, L. Sestini23, P. Seyfert21, M. Shapkin36, I. Shapoval17,44,75, Y. Shcheglov31, T. Shears53, L. Shekhtman35, V. Shevchenko65, A. Shires10, B.G. Siddi17, R. Silva Coutinho41, L. Silva de Oliveira2, G. Simi23,87, M. Sirendi48, N. Skidmore47, T. Skwarnicki60, E. Smith54, I.T. Smith51, J. Smith48, M. Smith55, H. Snoek42, M.D. Sokoloff39,58, F.J.P. Soler52, F. Soomro40, D. Souza47, B. Souza De Paula2, B. Spaan10, P. Spradlin52, S. Sridharan39, F. Stagni39, M. Stahl12, S. Stahl39, S. Stefkova54, O. Steinkamp41, O. Stenyakin36, S. Stevenson56, S. Stoica30, S. Stone60, B. Storaci41, S. Stracka24,88, M. Straticiuc30, U. Straumann41, L. Sun58, W. Sutcliffe54, K. Swientek28, S. Swientek10, V. Syropoulos43, M. Szczekowski29, T. Szumlak28, S. T'Jampens4, A. Tayduganov6, T. Tekampe10, G. Tellarini17,75, F. Teubert39, C. Thomas56, E. Thomas39, J. van Tilburg42, V. Tisserand4, M. Tobin40, J. Todd58, S. Tolk43, L. Tomassetti17,75, D. Tonelli39, S. Topp-Joergensen56, E. Tournefier4, S. Tourneur40, K. Trabelsi40, M. Traill52, M.T. Tran40, M. Tresch41, A. Trisovic39, A. Tsaregorodtsev6, P. Tsopelas42, N. Tuning39,42, A. Ukleja29, A. Ustyuzhanin65,66, U. Uwer12, C. Vacca16,39,74, V. Vagnoni15, G. Valenti15, A. Vallier7, R. Vazquez Gomez19, P. Vazquez Regueiro38, C. Vázquez Sierra38, S. Vecchi17, M. van Veghel42, J.J. Velthuis47, M. Veltri18,76, G. Veneziano40, M. Vesterinen12, B. Viaud7, D. Vieira2, M. Vieites Diaz38, X. Vilasis-Cardona37,84, V. Volkov33, A. Vollhardt41, D. Voong47, A. Vorobyev31, V. Vorobyev35, C. Voß64, J.A. de Vries42, R. Waldi64, C. Wallace49, R. Wallace13, J. Walsh24, J. Wang60, D.R. Ward48, N.K. Watson46, D. Websdale54, A. Weiden41, M. Whitehead39, J. Wicht49, G. Wilkinson39,56, M. Wilkinson60, M. Williams39, M.P. Williams46, M. Williams57, T. Williams46, F.F. Wilson50, J. Wimberley59, J. Wishahi10, W. Wislicki29, M. Witek27, G. Wormser7, S.A. Wotton48, K. Wraight52, S. Wright48, K. Wyllie39, Y. Xie62, Z. Xu40, Z. Yang3, J. Yu62, X. Yuan35, O. Yushchenko36, M. Zangoli15, M. Zavertyaev11,71, L. Zhang3, Y. Zhang3, A. Zhelezov12, A. Zhokhov32, L. Zhong3, V. Zhukov9 and S. Zucchelli15
A new algorithm for the determination of the initial flavour of B0s mesons is presented. The algorithm is based on two neural networks and exploits the b hadron production mechanism at a hadron collider. The first network is trained to select charged kaons produced in association with the B0s meson. The second network combines the kaon charges to assign the B0s flavour and estimates the probability of a wrong assignment. The algorithm is calibrated using data corresponding to an integrated luminosity of 3 fb−1 collected by the LHCb experiment in proton-proton collisions at 7 and 8 TeV centre-of-mass energies. The calibration is performed in two ways: by resolving the B0s–0s flavour oscillations in B0s → D−sπ+ decays, and by analysing flavour-specific B*s2(5840)0 → B+K− decays. The tagging power measured in B0s → D−sπ+ decays is found to be (1.80 ± 0.19 (stat) ± 0.18 (syst))%, which is an improvement of about 50% compared to a similar algorithm previously used in the LHCb experiment.
published under the terms of the Creative Commons Attribution 3.0 Licenseby IOP Publishing Ltd and Sissa Medialab srl. Any further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation and DOI.