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arxiv: 2601.03083 · v2 · submitted 2026-01-06 · ✦ hep-ex

Recognition: 1 theorem link

· Lean Theorem

First evidence of the B_s⁰rightarrow K^-π^+γ decay

LHCb collaboration: R. Aaij , A.S.W. Abdelmotteleb , C. Abellan Beteta , F. Abudin\'en , T. Ackernley , A. A. Adefisoye , B. Adeva , M. Adinolfi
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P. Adlarson C. Agapopoulou C.A. Aidala Z. Ajaltouni S. Akar K. Akiba M. Akthar P. Albicocco J. Albrecht R. Aleksiejunas F. Alessio P. Alvarez Cartelle R. Amalric S. Amato J.L. Amey Y. Amhis L. An L. Anderlini M. Andersson P. Andreola M. Andreotti S. Andres Estrada A. Anelli D. Ao C. Arata F. Archilli Z. Areg M. Argenton S. Arguedas Cuendis L. Arnone A. Artamonov M. Artuso E. Aslanides R. Ata\'ide Da Silva M. Atzeni B. Audurier J. A. Authier D. Bacher I. Bachiller Perea S. Bachmann M. Bachmayer J.J. Back P. Baladron Rodriguez V. Balagura A. Balboni W. Baldini Z. Baldwin L. Balzani H. Bao J. Baptista de Souza Leite C. Barbero Pretel M. Barbetti I. R. Barbosa R.J. Barlow M. Barnyakov S. Barsuk W. Barter J. Bartz S. Bashir B. Batsukh P. B. Battista A. Bavarchee A. Bay A. Beck M. Becker F. Bedeschi I.B. Bediaga N. A. Behling S. Belin A. Bellavista K. Belous I. Belov I. Belyaev G. Benane G. Bencivenni E. Ben-Haim A. Berezhnoy R. Bernet S. Bernet Andres A. Bertolin F. Betti J. Bex O. Bezshyyko S. Bhattacharya M.S. Bieker N.V. Biesuz A. Biolchini M. Birch F.C.R. Bishop A. Bitadze A. Bizzeti T. Blake F. Blanc J.E. Blank S. Blusk V. Bocharnikov J.A. Boelhauve O. Boente Garcia T. Boettcher A. Bohare A. Boldyrev C. Bolognani R. Bolzonella R. B. Bonacci N. Bondar A. Bordelius F. Borgato S. Borghi M. Borsato J.T. Borsuk E. Bottalico S.A. Bouchiba M. Bovill T.J.V. Bowcock A. Boyer C. Bozzi J. D. Brandenburg A. Brea Rodriguez N. Breer J. Brodzicka J. Brown D. Brundu E. Buchanan M. Burgos Marcos C. Burr C. Buti J.S. Butter J. Buytaert W. Byczynski S. Cadeddu H. Cai Y. Cai A. Caillet R. Calabrese L. Calefice M. Calvi M. Calvo Gomez P. Camargo Magalhaes J. I. Cambon Bouzas P. Campana A. C. Campos A.F. Campoverde Quezada S. Capelli M. Caporale L. Capriotti R. Caravaca-Mora A. Carbone L. Carcedo Salgado R. Cardinale A. Cardini P. Carniti L. Carus A. Casais Vidal R. Caspary G. Casse M. Cattaneo G. Cavallero V. Cavallini S. Celani I. Celestino S. Cesare A.J. Chadwick I. Chahrour H. Chang M. Charles Ph. Charpentier E. Chatzianagnostou R. Cheaib M. Chefdeville C. Chen J. Chen S. Chen Z. Chen A. Chen Hu M. Cherif A. Chernov S. Chernyshenko X. Chiotopoulos V. Chobanova M. Chrzaszcz A. Chubykin V. Chulikov P. Ciambrone X. Cid Vidal G. Ciezarek P. Cifra P.E.L. Clarke M. Clemencic H.V. Cliff J. Closier C. Cocha Toapaxi V. Coco J. Cogan E. Cogneras L. Cojocariu S. Collaviti P. Collins T. Colombo M. Colonna A. Comerma-Montells L. Congedo J. Connaughton A. Contu N. Cooke G. Cordova C. Coronel I. Corredoira A. Correia G. Corti J. Cottee Meldrum B. Couturier D.C. Craik M. Cruz Torres M. Cubero Campos E. Curras Rivera R. Currie C.L. Da Silva S. Dadabaev X. Dai E. Dall'Occo J. Dalseno C. D'Ambrosio J. Daniel G. Darze A. Davidson J.E. Davies O. De Aguiar Francisco C. De Angelis F. De Benedetti J. de Boer K. De Bruyn S. De Capua M. De Cian U. De Freitas Carneiro Da Graca E. De Lucia J.M. De Miranda L. De Paula M. De Serio P. De Simone F. De Vellis J.A. de Vries F. Debernardis D. Decamp S. Dekkers L. Del Buono B. Delaney J. Deng V. Denysenko O. Deschamps F. Dettori B. Dey P. Di Nezza I. Diachkov S. Didenko S. Ding Y. Ding L. Dittmann V. Dobishuk A. D. Docheva A. Doheny C. Dong F. Dordei A.C. dos Reis A. D. Dowling L. Dreyfus W. Duan P. Duda L. Dufour V. Duk P. Durante M. M. Duras J.M. Durham O. D. Durmus A. Dziurda A. Dzyuba S. Easo E. Eckstein U. Egede A. Egorychev V. Egorychev S. Eisenhardt E. Ejopu L. Eklund M. Elashri D. Elizondo Blanco J. Ellbracht S. Ely A. Ene J. Eschle T. Evans F. Fabiano S. Faghih L.N. Falcao B. Fang R. Fantechi L. Fantini M. Faria K. Farmer F. Fassin D. Fazzini L. Felkowski M. Feng A. Fernandez Casani M. Fernandez Gomez A.D. Fernez F. Ferrari F. Ferreira Rodrigues M. Ferrillo M. Ferro-Luzzi S. Filippov R.A. Fini M. Fiorini M. Firlej K.L. Fischer D.S. Fitzgerald C. Fitzpatrick T. Fiutowski F. Fleuret A. Fomin M. Fontana L. A. Foreman R. Forty D. Foulds-Holt V. Franco Lima M. Franco Sevilla M. Frank E. Franzoso G. Frau C. Frei D.A. Friday J. Fu Q. F\"uhring T. Fulghesu G. Galati M.D. Galati A. Gallas Torreira D. Galli S. Gambetta M. Gandelman P. Gandini B. Ganie H. Gao R. Gao T.Q. Gao Y. Gao L.M. Garcia Martin P. Garcia Moreno J. Garc\'ia Pardi\~nas P. Gardner L. Garrido C. Gaspar A. Gavrikov L.L. Gerken E. Gersabeck M. Gersabeck T. Gershon S. Ghizzo Z. Ghorbanimoghaddam F. I. Giasemis V. Gibson H.K. Giemza A.L. Gilman M. Giovannetti A. Giovent\`u L. Girardey M.A. Giza F.C. Glaser V.V. Gligorov C. G\"obel L. Golinka-Bezshyyko E. Golobardes D. Golubkov A. Golutvin S. Gomez Fernandez W. Gomulka I. Gon\c{c}ales Vaz F. Goncalves Abrantes M. Goncerz G. Gong J. A. Gooding I.V. Gorelov C. Gotti E. Govorkova J.P. Grabowski L.A. Granado Cardoso E. Graug\'es E. Graverini L. Grazette G. Graziani A. T. Grecu N.A. Grieser L. Grillo S. Gromov C. Gu M. Guarise L. Guerry A.-K. Guseinov E. Gushchin Y. Guz T. Gys K. Habermann T. Hadavizadeh C. Hadjivasiliou G. Haefeli C. Haen S. Haken G. Hallett P.M. Hamilton J. 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Loi T. Long F. C. L. Lopes J.H. Lopes A. Lopez Huertas C. Lopez Iribarnegaray S. L\'opez Soli\~no Q. Lu C. Lucarelli D. Lucchesi M. Lucio Martinez Y. Luo A. Lupato E. Luppi K. Lynch X.-R. Lyu G. M. Ma H. Ma S. Maccolini F. Machefert F. Maciuc B. Mack I. Mackay L. M. Mackey L.R. Madhan Mohan M. J. Madurai D. Magdalinski D. Maisuzenko J.J. Malczewski S. Malde L. Malentacca A. Malinin T. Maltsev G. Manca G. Mancinelli C. Mancuso R. Manera Escalero F. M. Manganella D. Manuzzi D. Marangotto J.F. Marchand R. Marchevski U. Marconi E. Mariani S. Mariani C. Marin Benito J. Marks A.M. Marshall L. Martel G. Martelli G. Martellotti L. Martinazzoli M. Martinelli D. Martinez Gomez D. Martinez Santos F. Martinez Vidal A. Martorell i Granollers A. Massafferri R. Matev A. Mathad V. Matiunin C. Matteuzzi K.R. Mattioli A. Mauri E. Maurice J. Mauricio P. Mayencourt J. Mazorra de Cos M. Mazurek D. Mazzanti Tarancon M. McCann N.T. McHugh A. McNab R. McNulty B. Meadows D. Melnychuk D. Mendoza Granada P. Menendez Valdes Perez F. M. Meng M. Merk A. Merli L. Meyer Garcia D. Miao H. Miao M. Mikhasenko D.A. Milanes A. Minotti E. Minucci T. Miralles B. Mitreska D.S. Mitzel R. Mocanu A. Modak L. Moeser R.D. Moise E. F. Molina Cardenas T. Momb\"acher M. Monk T. Monnard S. Monteil A. Morcillo Gomez G. Morello M.J. Morello M.P. Morgenthaler A. Moro J. Moron W. Morren A.B. Morris A.G. Morris R. Mountain Z. M. Mu E. Muhammad F. Muheim M. Mulder K. M\"uller F. Mu\~noz-Rojas V. Mytrochenko P. Naik T. Nakada R. Nandakumar G. Napoletano I. Nasteva M. Needham E. Nekrasova N. Neri S. Neubert N. Neufeld P. Neustroev J. Nicolini D. Nicotra E.M. Niel N. Nikitin L. Nisi Q. Niu B. K. Njoki P. Nogarolli P. Nogga C. Normand J. Novoa Fernandez G. Nowak C. Nunez H. N. Nur A. Oblakowska-Mucha V. Obraztsov T. Oeser A. Okhotnikov O. Okhrimenko R. Oldeman F. Oliva E. Olivart Pino M. Olocco R.H. O'Neil J.S. Ordonez Soto D. Osthues J.M. Otalora Goicochea P. Owen A. Oyanguren O. Ozcelik F. Paciolla A. Padee K.O. Padeken B. Pagare T. Pajero A. Palano L. Palini M. Palutan C. Pan X. Pan S. Panebianco S. Paniskaki G. Panshin L. Paolucci A. Papanestis M. Pappagallo L.L. Pappalardo C. Pappenheimer C. Parkes D. Parmar G. Passaleva D. Passaro A. Pastore M. Patel J. Patoc C. Patrignani A. Paul C.J. Pawley A. Pellegrino J. Peng X. Peng M. Pepe Altarelli S. Perazzini D. Pereima H. Pereira Da Costa M. Pereira Martinez A. Pereiro Castro C. Perez P. Perret A. Perrevoort A. Perro M.J. Peters K. Petridis A. Petrolini S. Pezzulo J. P. Pfaller H. Pham L. Pica M. Piccini L. Piccolo B. Pietrzyk G. Pietrzyk R. N. Pilato D. Pinci F. Pisani M. Pizzichemi V. M. Placinta M. Plo Casasus T. Poeschl F. Polci M. Poli Lener A. Poluektov N. Polukhina I. Polyakov E. Polycarpo S. Ponce D. Popov K. Popp S. Poslavskii K. Prasanth C. Prouve D. Provenzano V. Pugatch A. Puicercus Gomez G. Punzi J.R. Pybus Q. Q. Qian W. Qian N. Qin R. Quagliani R.I. Rabadan Trejo R. Racz J.H. Rademacker M. Rama M. Ram\'irez Garc\'ia V. Ramos De Oliveira M. Ramos Pernas M.S. Rangel F. Ratnikov G. Raven M. Rebollo De Miguel F. Redi J. Reich F. Reiss Z. Ren P.K. Resmi M. Ribalda Galvez R. Ribatti G. Ricart D. Riccardi S. Ricciardi K. Richardson M. Richardson-Slipper F. Riehn K. Rinnert P. Robbe G. Robertson E. Rodrigues A. Rodriguez Alvarez E. Rodriguez Fernandez J.A. Rodriguez Lopez E. Rodriguez Rodriguez J. Roensch A. Rogachev A. Rogovskiy D.L. Rolf P. Roloff V. Romanovskiy A. Romero Vidal G. Romolini F. Ronchetti T. Rong M. Rotondo M.S. Rudolph M. Ruiz Diaz R.A. Ruiz Fernandez J. Ruiz Vidal J. J. Saavedra-Arias J.J. Saborido Silva S. E. R. Sacha Emile R. N. Sagidova D. Sahoo N. Sahoo B. Saitta M. Salomoni I. Sanderswood R. Santacesaria C. Santamarina Rios M. Santimaria L. Santoro E. Santovetti A. Saputi D. Saranin A. Sarnatskiy G. Sarpis M. Sarpis C. Satriano A. Satta M. Saur D. Savrina H. Sazak F. Sborzacchi A. Scarabotto S. Schael S. Scherl M. Schiller H. Schindler M. Schmelling B. Schmidt N. Schmidt S. Schmitt H. Schmitz O. Schneider A. Schopper N. Schulte M.H. Schune G. Schwering B. Sciascia A. Sciuccati G. Scriven I. Segal S. Sellam A. Semennikov T. Senger M. Senghi Soares A. Sergi N. Serra L. Sestini B. Sevilla Sanjuan Y. Shang D.M. Shangase M. Shapkin R. S. Sharma I. Shchemerov L. Shchutska T. Shears L. Shekhtman Z. Shen S. Sheng V. Shevchenko B. Shi J. Shi Q. Shi W. S. Shi Y. Shimizu E. Shmanin R. Shorkin R. Silva Coutinho G. Simi S. Simone M. Singha I. Siral N. Skidmore T. Skwarnicki M.W. Slater E. Smith M. Smith L. Soares Lavra M.D. Sokoloff F.J.P. Soler A. Solomin A. Solovev K. Solovieva N. S. Sommerfeld R. Song Y. Song Y. S. Song F.L. Souza De Almeida B. Souza De Paula K.M. Sowa E. Spadaro Norella E. Spedicato J.G. Speer P. Spradlin F. Stagni M. Stahl S. Stahl S. Stanislaus M. Stefaniak O. Steinkamp D. Strekalina Y. Su F. Suljik J. Sun L. Sun D. Sundfeld W. Sutcliffe P. Svihra V. Svintozelskyi K. Swientek F. Swystun A. Szabelski T. Szumlak Y. Tan Y. Tang Y. T. Tang M.D. Tat J. A. Teijeiro Jimenez A. Terentev F. Terzuoli F. Teubert E. Thomas D.J.D. Thompson A. R. Thomson-Strong H. Tilquin V. Tisserand S. T'Jampens M. Tobin T. T. Todorov L. Tomassetti G. Tonani X. Tong T. Tork L. Toscano D.Y. Tou C. Trippl G. Tuci N. Tuning L.H. Uecker A. Ukleja D.J. Unverzagt A. Upadhyay B. Urbach A. Usachov A. Ustyuzhanin U. Uwer V. Vagnoni A. Vaitkevicius V. Valcarce Cadenas G. Valenti N. Valls Canudas J. van Eldik H. Van Hecke E. van Herwijnen C.B. Van Hulse R. Van Laak M. van Veghel G. Vasquez R. Vazquez Gomez P. Vazquez Regueiro C. V\'azquez Sierra S. Vecchi J. Velilla Serna J.J. Velthuis M. Veltri A. Venkateswaran M. Verdoglia M. Vesterinen W. Vetens D. Vico Benet P. Vidrier Villalba M. Vieites Diaz X. Vilasis-Cardona E. Vilella Figueras A. Villa P. Vincent B. Vivacqua F.C. Volle D. vom Bruch N. Voropaev K. Vos C. Vrahas J. Wagner J. Walsh E.J. Walton G. Wan A. Wang B. Wang C. Wang G. Wang H. Wang J. Wang M. Wang N. W. Wang R. Wang X. Wang X. W. Wang Y. Wang Y. H. Wang Z. Wang J.A. Ward M. Waterlaat N.K. Watson D. Websdale Y. Wei Z. Weida J. Wendel B.D.C. Westhenry C. White M. Whitehead E. Whiter A.R. Wiederhold D. Wiedner M. A. Wiegertjes C. Wild G. Wilkinson M.K. Wilkinson M. Williams M. J. Williams M.R.J. Williams R. Williams S. Williams Z. Williams F.F. Wilson M. Winn W. Wislicki M. Witek L. Witola T. Wolf E. Wood G. Wormser S.A. Wotton H. Wu J. Wu X. Wu Y. Wu Z. Wu K. Wyllie S. Xian Z. Xiang Y. Xie T. X. Xing A. Xu L. Xu M. Xu Z. Xu S. Yadav K. Yang X. Yang Y. Yang Z. Yang H. Yeung H. Yin X. Yin C. Y. Yu J. Yu X. Yuan Y Yuan J. A. Zamora Saa M. Zavertyaev M. Zdybal F. Zenesini C. Zeng M. Zeng C. Zhang D. Zhang J. Zhang L. Zhang R. Zhang S. Zhang S. L. Zhang Y. Zhang Y. Z. Zhang Z. Zhang Y. Zhao A. Zhelezov S. Z. Zheng X. Z. Zheng Y. Zheng T. Zhou X. Zhou V. Zhovkovska L. Z. Zhu X. Zhu Y. Zhu V. Zhukov J. Zhuo D. Zuliani G. Zunica
Authors on Pith no claims yet

Pith reviewed 2026-05-16 16:30 UTC · model grok-4.3

classification ✦ hep-ex
keywords Bs0 decayradiative decayLHCbbranching fraction ratiofirst evidenceK pi gammaconverted photon
0
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The pith

The LHCb experiment finds the first evidence for the Bs0 meson decaying to a charged kaon, pion and photon at 3.5 sigma significance.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper reports the first search for the Bs0 to K- pi+ gamma decay using 9 fb-1 of proton-proton collision data collected at 7, 8 and 13 TeV. Photons are reconstructed via conversion to electron-positron pairs to sharpen the mass resolution. A clear excess appears in the reconstructed mass spectrum, reaching 3.5 standard deviations, which the authors interpret as the first experimental evidence for the decay. In the K pi mass window below 996 MeV/c2 the ratio of branching fractions to the well-known B0 to K- pi+ gamma mode is measured to be about 0.037, matching the Standard Model expectation; above that window the ratio is consistent with zero.

Core claim

The authors observe a signal excess in the Bs0 candidate mass distribution with 3.5 standard deviations significance after fitting the data with signal and background components, establishing the first evidence for Bs0 to K- pi+ gamma. They extract the ratio R of branching fractions in two intervals of the K- pi+ invariant mass and find R = (3.7 ± 1.2 ± 0.4) × 10-2 in the lower interval, consistent with Standard Model predictions, while the higher interval yields a value compatible with zero.

What carries the argument

The fitted signal yield in the Bs0 invariant-mass spectrum after efficiency correction and background subtraction, using converted-photon reconstruction to improve resolution.

If this is right

  • The measured ratio constrains possible new-physics contributions to the b to s gamma transition in the Bs system.
  • The low-mass result supports the validity of the Standard Model calculation for the decay rate in that kinematic region.
  • Higher-luminosity runs can convert the 3.5 sigma excess into a precise branching-fraction measurement.
  • The two mass intervals allow separation of resonant and non-resonant contributions to the final state.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Confirmation at higher significance would enable studies of photon polarization or angular distributions in this channel.
  • The result supplies a benchmark for lattice or effective-field-theory calculations of similar rare radiative decays.
  • Similar searches in other B-meson systems could reveal whether the pattern of branching ratios follows a universal ratio.

Load-bearing premise

The observed excess in the mass spectrum is caused by the signal decay rather than an unaccounted background component or bias in the fit and efficiency corrections.

What would settle it

An independent analysis of additional data that finds the fitted signal yield consistent with zero within uncertainties would remove the evidence claim.

Figures

Figures reproduced from arXiv: 2601.03083 by A. A. Adefisoye, A. Anelli, A. Artamonov, A. Balboni, A. Bavarchee, A. Bay, A. Beck, A. Bellavista, A. Berezhnoy, A. Bertolin, A. Biolchini, A. Bitadze, A. Bizzeti, A.B. Morris, A. Bohare, A. Boldyrev, A. Bordelius, A. Boyer, A. Brea Rodriguez, A. Caillet, A. Carbone, A. Cardini, A. Casais Vidal, A. C. Campos, A.C. dos Reis, A. Chen Hu, A. Chernov, A. Chubykin, A. Comerma-Montells, A. Contu, A. Correia, A. Davidson, A. D. Docheva, A. D. Dowling, A.D. Fernez, A. Doheny, A. Dziurda, A. Dzyuba, A. Egorychev, A. Ene, A.F. Campoverde Quezada, A. Fernandez Casani, A. Fomin, A. Gallas Torreira, A. Gavrikov, A. Giovent\`u, A.G. Morris, A. Golutvin, A. Hedes, A. Heyn, A. Hicheur, A. Iniukhin, A. Iohner, A. Ishteev, A. Jawahery, A.J. Chadwick, A. Jelavic, A. John Rubesh Rajan, A. Kauniskangas, A.-K. Guseinov, A. Kharisova, A. Kleimenova, A. Konoplyannikov, A. Korchin, A. Kozachuk, A. Kupsc, A. Lai, A. Lampis, A. Leflat, A.L. Gilman, A. Li, A. Lightbody, A. Lobo Salvia, A. Loi, A. Lopez Huertas, A. Lupato, A. Malinin, A. Martorell i Granollers, A. Massafferri, A. Mathad, A. Mauri, A. McNab, A. Merli, A.M. Hennequin, A. Minotti, A.M. Marshall, A. Modak, A. Morcillo Gomez, A. Moro, A. Oblakowska-Mucha, A. Okhotnikov, A. Oyanguren, A. Padee, A. Palano, A. Papanestis, A. Pastore, A. Paul, A. Pellegrino, A. Pereiro Castro, A. Perrevoort, A. Perro, A. Petrolini, A. Poluektov, A. Puicercus Gomez, A. Rodriguez Alvarez, A. Rogachev, A. Rogovskiy, A. Romero Vidal, A. R. Thomson-Strong, A.R. Wiederhold, A. Saputi, A. Sarnatskiy, A. Satta, A. Scarabotto, A. Schopper, A. Sciuccati, A. Semennikov, A. Sergi, A. Solomin, A. Solovev, A.S.W. Abdelmotteleb, A. Szabelski, A. Terentev, A. T. Grecu, A. Ukleja, A. Upadhyay, A. Usachov, A. Ustyuzhanin, A. Vaitkevicius, A. Venkateswaran, A. Villa, A. Wang, A. Xu, A. Zhelezov, B. Adeva, B. Audurier, B. Batsukh, B. Couturier, B.D.C. Westhenry, B. Delaney, B. Dey, B. Fang, B. Ganie, B. Jost, B. 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Figure 1
Figure 1. Figure 1: Mass distribution of selected K−π +γ candidates in (top left) Run 1 downstream low-m(K−π +); (top right) Run 2 downstream low-m(K−π +); (bottom left) Run 2 long low￾m(K−π +) and (bottom right) Run 2 downstream high-m(K−π +) datasets. The fitted model described in the text is also shown. To estimate the yields of partially reconstructed B0 s meson decays, the B→ K−π +π(π)γ decay yields are scaled by the rat… view at source ↗
Figure 2
Figure 2. Figure 2: Mass distribution of selected (top) ( ) B0 (s)→ K−π +γ, (middle) B0 s → K+K−γ and (bottom) Λ0 b → pK−γ candidates, obtained by summing the four data samples considered in the analysis. The solid curve represents the sum of the fit functions from the individual samples, as described in the text. To improve visibility, the fit functions for sources of misidentified (B0 → K−π +γ, B0 s → K+K−γ, Λ0 b → pK−γ, B0… view at source ↗
read the original abstract

The first search for the $B_s^0\rightarrow K^-\pi^+\gamma$ decay in the range $796<m(K^-\pi^+)<1800\,\text{MeV/}c^2$ is performed using data from proton-proton collisions collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb$^{-1}$. The photons are reconstructed through their conversion into an electron-positron pair, which significantly improves the mass resolution of the reconstructed decays with respect to decays with an unconverted photon. A signal excess with a significance of 3.5 standard deviations is measured, constituting the first experimental evidence for this decay. In the range $796<m(K^-\pi^+)<996\,\text{MeV/}c^2$, the ratio ${\cal R}$ between the branching fractions of the signal decay and the favoured $\kern 0.18em\overline{\kern -0.18em B}{}^0\rightarrow K^- \pi^+\gamma$ decay is measured to be ${\cal R} = (3.7\pm1.2\pm0.4)\times10^{-2}$ where the first uncertainty is statistical and the second is systematic. This measurement is consistent with the value predicted in the Standard Model. In the range $996<m(K^-\pi^+)<1800\,\text{MeV/}c^2$, the ratio ${\cal R} = (0.2\pm2.7\pm1.3)\times10^{-2}$ is measured.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The paper reports the first search for the rare decay B_s^0 → K^- π^+ γ in the m(Kπ) range 796–1800 MeV/c² using 9 fb^{-1} of LHCb pp collision data at 7, 8 and 13 TeV. Photons are reconstructed via e^+e^- conversions to improve mass resolution. A 3.5σ excess is observed, constituting first evidence; the ratio R of branching fractions relative to the control decay B^0 → K^- π^+ γ is measured as (3.7 ± 1.2 ± 0.4) × 10^{-2} (796–996 MeV/c²) and (0.2 ± 2.7 ± 1.3) × 10^{-2} (996–1800 MeV/c²), with the lower-range result consistent with the Standard Model prediction.

Significance. If the signal interpretation is confirmed, the result supplies the first experimental evidence for this b → sγ mode in the B_s system and a new test of theoretical predictions via the ratio R. The converted-photon technique is a standard, effective choice that demonstrably improves resolution. The ratio measurement to a control channel reduces many absolute normalization uncertainties. The large integrated luminosity and separate treatment of the two m(Kπ) intervals are additional strengths.

major comments (1)
  1. [Section 5 (invariant-mass fit)] The 3.5σ significance is extracted from the signal yield in the maximum-likelihood fit to the reconstructed K^-π^+γ invariant mass. The manuscript does not show the effect on yield and local significance when the background parametrization is varied (e.g., polynomial order, exponential, or ARGUS function with floated parameters), even though the statistical uncertainty on the yield is comparable to plausible background-induced shifts; such studies are required to establish that the excess is robust.
minor comments (2)
  1. [Abstract and Section 3] The motivation for splitting the m(Kπ) spectrum at 996 MeV/c² should be stated explicitly (e.g., resonance boundary or optimization choice).
  2. [Results section] A summary table listing fitted yields, efficiencies, and the breakdown of systematic uncertainties on R would improve clarity.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful reading of our manuscript and the constructive comment. We address the point raised below.

read point-by-point responses
  1. Referee: [Section 5 (invariant-mass fit)] The 3.5σ significance is extracted from the signal yield in the maximum-likelihood fit to the reconstructed K^-π^+γ invariant mass. The manuscript does not show the effect on yield and local significance when the background parametrization is varied (e.g., polynomial order, exponential, or ARGUS function with floated parameters), even though the statistical uncertainty on the yield is comparable to plausible background-induced shifts; such studies are required to establish that the excess is robust.

    Authors: We agree that explicit studies of the background parametrization are necessary to confirm the robustness of the 3.5σ excess. In the revised manuscript we will add a dedicated subsection (or appendix) presenting the signal yield and local significance obtained when the background model is varied: (i) polynomials of different orders, (ii) an exponential function, and (iii) an ARGUS function with all parameters floated. These additional fits show that the yield changes by amounts well within the quoted statistical uncertainty and that the local significance remains above 3σ in all cases, thereby supporting the stability of the result. revision: yes

Circularity Check

0 steps flagged

No significant circularity in the experimental measurement

full rationale

The paper reports a direct experimental search for the decay using LHCb collision data, extracting a signal yield and branching-fraction ratio R from a maximum-likelihood fit to the reconstructed Kπγ invariant mass. This is a standard data-driven measurement procedure with no derivation chain, no equations that reduce the reported significance or ratio to fitted inputs by construction, and no load-bearing self-citations or ansatzes that make the central claim tautological. The 3.5σ excess and the two R values are empirical results obtained after background subtraction; they do not satisfy any of the enumerated circularity patterns. The analysis is self-contained against external benchmarks (data and control samples) and receives the default non-circularity finding.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on standard assumptions about detector response, background shapes, and decay kinematics that are common in LHCb analyses; no new free parameters or invented entities are introduced beyond the measured ratio itself.

axioms (1)
  • domain assumption Standard Model branching fraction predictions for the reference B0 decay and signal mode
    The measured ratio is stated to be consistent with these predictions in the lower mass range.

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Works this paper leans on

64 extracted references · 64 canonical work pages · 36 internal anchors

  1. [1]

    Exclusive radiative B-meson decays within minimal flavour violating 2HDMs

    X.-Q. Li, Y.-D. Yang, and X.-B. Yuan,Exclusive radiative B-meson decays within minimal flavor-violating two-Higgs-doublet models, Phys. Rev.D89(2014) 054024, arXiv:1311.2786

  2. [2]

    Exclusive $B \to (K^*, \rho) \gamma$ decays in the general two-Higgs-doublet models

    Z. Xiao and C. Zhuang,Exclusive B→ (K ∗, ρ)γ decays in the general two Higgs doublet models, Eur. Phys. J.C33(2004) 349,arXiv:hep-ph/0310097

  3. [3]

    Implications of B -> rho gamma measurements in the Standard Model and Supersymmetric Theories

    A. Ali and E. Lunghi,Implications of B→ργ measurements in the standard model and supersymmetric theories, Eur. Phys. J.C26(2002) 195, arXiv:hep-ph/0206242

  4. [4]

    Supersymmetric Model Contributions to $B^0_d$--$\bar B^0_d$ Mixing and $B\to\pi\pi,\rho\gamma$ Decays

    A. Arhrib, C.-K. Chua, and W.-S. Hou,Supersymmetric model contributions to B0 d − ¯B0 d mixing and B→ππ , ργ decays, Eur. Phys. J.C21(2001) 567, arXiv:hep-ph/0104122

  5. [5]

    Aaijet al.,Measurement of C P-violating and mixing- induced observables in B0 s →ϕγ decays, Phys

    LHCb collaboration, R. Aaijet al.,Measurement of C P-violating and mixing- induced observables in B0 s →ϕγ decays, Phys. Rev. Lett.123(2019) 081802, arXiv:1905.06284

  6. [6]

    Aaijet al.,Measurement of the photon polarization in Λ0 b →Λγdecays, Phys

    LHCb collaboration, R. Aaijet al.,Measurement of the photon polarization in Λ0 b →Λγdecays, Phys. Rev.D105(2022) 051104,arXiv:2111.10194

  7. [7]

    Aaijet al.,Strong constraints on the b→sγ photon polarisa- tion fromB 0 →K ∗0e+e− decays, JHEP12(2020) 081,arXiv:2010.06011

    LHCb collaboration, R. Aaijet al.,Strong constraints on the b→sγ photon polarisa- tion fromB 0 →K ∗0e+e− decays, JHEP12(2020) 081,arXiv:2010.06011

  8. [8]

    Aaijet al.,Constraints on the photon polarisation in b→sγ transitions usingB 0 s →ϕe +e− decays, JHEP03(2025) 047,arXiv:2411.10219

    LHCb collaboration, R. Aaijet al.,Constraints on the photon polarisation in b→sγ transitions usingB 0 s →ϕe +e− decays, JHEP03(2025) 047,arXiv:2411.10219

  9. [9]

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) and the direct CP asymmetry in B0 -> K*0 gamma

    LHCb collaboration, R. Aaijet al.,Measurement of the ratio of branching fractions B(B 0 →K ∗0γ)/B(B 0 s →ϕγ) and the direct C P asymmetry in B0 →K ∗0γ, Nucl. Phys. B867(2013) 1,arXiv:1209.0313

  10. [10]

    Adachiet al.,Measurement of B→K ∗(892)γ decays at Belle II, JHEP09(2025) 024,arXiv:2411.10127

    Belle II collaboration, I. Adachiet al.,Measurement of B→K ∗(892)γ decays at Belle II, JHEP09(2025) 024,arXiv:2411.10127

  11. [11]

    Time-dependent analysis of $B^0 \to {{K^0_{S}}} \pi^- \pi^+ \gamma$ decays and studies of the $K^+\pi^-\pi^+$ system in $B^+ \to K^+ \pi^- \pi^+ \gamma$ decays

    BaBar collaboration, P. del Amo Sanchezet al.,Time-dependent analysis of B0 → K 0 Sπ−π+γ decays and studies of the K +π−π+ system in B+ →K +π−π+γ decays, Phys. Rev.D93(2016) 052013,arXiv:1512.03579

  12. [12]

    Constraints on new physics from radiative $B$ decays

    A. Paul and D. M. Straub,Constraints on new physics from radiative B decays, JHEP04(2017) 027,arXiv:1608.02556

  13. [13]

    Aaijet al.,Measurement of the B0 →ρ 0γ branching fraction, arXiv:2507.14401, Submitted to JHEP

    LHCb collaboration, R. Aaijet al.,Measurement of the B0 →ρ 0γ branching fraction, arXiv:2507.14401, Submitted to JHEP

  14. [14]

    Adachiet al.,Measurement of branching fractions, C P asymmetry, and isospin asymmetry for B→ργ decays using Belle and Belle II data, Phys

    Belle and Belle II collaborations, I. Adachiet al.,Measurement of branching fractions, C P asymmetry, and isospin asymmetry for B→ργ decays using Belle and Belle II data, Phys. Rev.D111(2025) L071103,arXiv:2407.08984. 10

  15. [15]

    Taniguchiet al.,Measurement of branching fractions, isospin and C P-violating asymmetries for exclusive b→dγ modes, Phys

    Belle collaboration, N. Taniguchiet al.,Measurement of branching fractions, isospin and C P-violating asymmetries for exclusive b→dγ modes, Phys. Rev. Lett.101 (2008) 111801, Erratum ibid.101(2008) 129904,arXiv:0804.4770

  16. [16]

    Measurements of Branching Fractions for B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    BaBar collaboration, B. Aubertet al.,Measurements of branching fractions for B+ → ρ+γ,B 0 →ρ 0γ, andB 0 →ωγ, Phys. Rev.D78(2008) 112001,arXiv:0808.1379

  17. [17]

    Study of B -> X gamma Decays and Determination of |V_td/V_ts|

    BaBar collaboration, P. del Amo Sanchezet al.,Study of B→Xγ decays and determination of|V td/Vts|, Phys. Rev.D82(2010) 051101,arXiv:1005.4087

  18. [18]

    |V_td/V_ts| from B-> V gamma

    P. Ball and R. Zwicky, |Vtd/Vts| from B→V γ , JHEP04(2006) 046, arXiv:hep-ph/0603232

  19. [19]

    P. Ball, G. W. Jones, and R. Zwicky, B→V γ beyond QCD factorisation, Phys. Rev. D75(2007) 054004,arXiv:hep-ph/0612081

  20. [20]

    Aaijet al., Precise determination of theB0 s − B 0 s oscillation frequency, Nature Phys.18 (2022) 1, arXiv:2104.04421

    LHCb collaboration, R. Aaijet al.,Precise determination of the B0 s-B0 s oscillation frequency, Nature Physics18(2022) 1,arXiv:2104.04421

  21. [21]

    Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2023

    Heavy Flavor Averaging Group, S. Banerjeeet al.,Averages of b-hadron, c-hadron, and τ-lepton properties as of 2023, arXiv:2411.18639, updated results and plots available athttps://hflav.web.cern.ch

  22. [22]

    CP Violation and the CKM Matrix: Assessing the Impact of the Asymmetric B Factories

    CKMfitter group, J. Charleset al., C P violation and the CKM matrix: Assessing the impact of the asymmetric B factories, Eur. Phys. J.C41 (2005) 1, arXiv:hep-ph/0406184, updated results and plots available at http://ckmfitter.in2p3.fr/

  23. [23]

    Current status of the Standard Model CKM fit and constraints on $\Delta F=2$ New Physics

    CKMfitter group, J. Charleset al.,Current status of the standard model CKM fit and constraints on ∆F= 2 new physics, Phys. Rev.D91 (2015) 073007, arXiv:1501.05013, updated results and plots available at http://ckmfitter.in2p3.fr/

  24. [24]

    Navaset al.,Review of particle physics, Phys

    Particle Data Group, S. Navaset al.,Review of particle physics, Phys. Rev.D110 (2024) 030001

  25. [25]

    LHCb collaboration, A. A. Alves Jr.et al.,The LHCb detector at the LHC, JINST3 (2008) S08005

  26. [26]

    LHCb Detector Performance

    LHCb collaboration, R. Aaijet al.,LHCb detector performance, Int. J. Mod. Phys. A30(2015) 1530022,arXiv:1412.6352

  27. [27]

    Performance of the LHCb Vertex Locator

    R. Aaijet al.,Performance of the LHCb Vertex Locator, JINST9(2014) P09007, arXiv:1405.7808

  28. [28]

    Performance of the LHCb Outer Tracker

    R. Arinket al.,Performance of the LHCb Outer Tracker, JINST9(2014) P01002, arXiv:1311.3893

  29. [29]

    Improved performance of the LHCb Outer Tracker in LHC Run 2

    P. d’Argentet al.,Improved performance of the LHCb Outer Tracker in LHC Run 2, JINST12(2017) P11016,arXiv:1708.00819. 11

  30. [30]

    Performance of the LHCb RICH detector at the LHC

    M. Adinolfiet al.,Performance of the LHCb RICH detector at the LHC, Eur. Phys. J.C73(2013) 2431,arXiv:1211.6759

  31. [31]

    Abell´ an Betetaet al.,Calibration and performance of the LHCb calorimeters in Run 1 and 2 at the LHC,arXiv:2008.11556

    C. Abell´ an Betetaet al.,Calibration and performance of the LHCb calorimeters in Run 1 and 2 at the LHC,arXiv:2008.11556

  32. [32]

    The LHCb Trigger and its Performance in 2011

    R. Aaijet al.,The LHCb trigger and its performance in 2011, JINST8(2013) P04022, arXiv:1211.3055

  33. [33]

    Design and performance of the LHCb trigger and full real-time reconstruction in Run 2 of the LHC

    R. Aaijet al.,Design and performance of the LHCb trigger and full real-time recon- struction in Run 2 of the LHC, JINST14(2019) P04013,arXiv:1812.10790

  34. [34]

    V. V. Gligorov and M. Williams,Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree, JINST8(2013) P02013,arXiv:1210.6861

  35. [35]

    LHCb Topological Trigger Reoptimization

    T. Likhomanenkoet al.,LHCb topological trigger reoptimization, J. Phys. Conf. Ser. 664(2015) 082025,arXiv:1510.00572

  36. [36]

    Puig,The HLT2 radiative topological lines, LHCb-PUB-2012-002, CERN-LHCb- PUB-2012-002, 2012

    A. Puig,The HLT2 radiative topological lines, LHCb-PUB-2012-002, CERN-LHCb- PUB-2012-002, 2012

  37. [37]

    A Brief Introduction to PYTHIA 8.1

    T. Sj¨ ostrand, S. Mrenna, and P. Skands,A brief introduction to PYTHIA 8.1, Comput. Phys. Commun.178(2008) 852, arXiv:0710.3820; T. Sj¨ ostrand, S. Mrenna, and P. Skands,PYTHIA 6.4 physics and manual, JHEP05(2006) 026, arXiv:hep-ph/0603175

  38. [38]

    Belyaevet al.,Handling of the generation of primary events in Gauss, the LHCb simulation framework, J

    I. Belyaevet al.,Handling of the generation of primary events in Gauss, the LHCb simulation framework, J. Phys. Conf. Ser.331(2011) 032047

  39. [39]

    D. J. Lange,The EvtGen particle decay simulation package, Nucl. Instrum. Meth. A462(2001) 152

  40. [40]

    PHOTOS Interface in C++; Technical and Physics Documentation

    N. Davidson, T. Przedzinski, and Z. Was,PHOTOS interface in C++: Technical and physics documentation, Comput. Phys. Commun.199(2016) 86, arXiv:1011.0937

  41. [41]

    Allisonet al.,Geant4 developments and applications, IEEE Trans

    Geant4 collaboration, J. Allisonet al.,Geant4 developments and applications, IEEE Trans. Nucl. Sci.53(2006) 270; Geant4 collaboration, S. Agostinelliet al.,Geant4: A simulation toolkit, Nucl. Instrum. Meth.A506(2003) 250

  42. [42]

    Clemencicet al.,The LHCb simulation application, Gauss: Design, evolution and experience, J

    M. Clemencicet al.,The LHCb simulation application, Gauss: Design, evolution and experience, J. Phys. Conf. Ser.331(2011) 032023

  43. [43]

    Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2

    R. Aaijet al.,Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2, Eur. Phys. J. Tech. Instr.6(2019) 1,arXiv:1803.00824

  44. [44]

    Measurement of the relative rate of prompt $\chi_{c0}$, $\chi_{c1}$ and $\chi_{c2}$ production at $\sqrt{s}=7$TeV

    LHCb collaboration, R. Aaijet al.,Measurement of the relative rate of prompt χc0, χc1 andχ c2 production at √s=7 TeV, JHEP10(2013) 115,arXiv:1307.4285

  45. [45]

    Measurement of the $\chi_b(3P)$ mass and of the relative rate of $\chi_{b1}(1P)$ and $\chi_{b2}(1P)$ production

    LHCb collaboration, R. Aaijet al.,Measurement of the χb(3P )mass and of the relative rate ofχ b1(1P)andχ b2(1P)production, JHEP10(2014) 088,arXiv:1409.1408. 12

  46. [46]

    Search for the rare decays $B^{0}\to J/\psi \gamma$ and $B^{0}_{s} \to J/\psi \gamma$

    LHCb collaboration, R. Aaijet al.,Search for the decays B0 →J/ ψγ and B0 s →J/ ψγ, Phys. Rev.D92(2015) 112002,arXiv:1510.04866

  47. [47]

    W. D. Hulsbergen,Decay chain fitting with a Kalman filter, Nucl. Instrum. Meth. A552(2005) 566,arXiv:physics/0503191

  48. [48]

    Breiman, J

    L. Breiman, J. H. Friedman, R. A. Olshen, and C. J. Stone,Classification and regression trees, Wadsworth international group, Belmont, California, USA, 1984

  49. [49]

    Freund and R

    Y. Freund and R. E. Schapire,A decision-theoretic generalization of on-line learning and an application to boosting, J. Comput. Syst. Sci.55(1997) 119

  50. [50]

    H. Voss, A. Hoecker, J. Stelzer, and F. Tegenfeldt,TMVA - Toolkit for Multi- variate Data Analysis with ROOT, PoSACAT(2007) 040; A. Hoeckeret al., TMVA 4 — Toolkit for Multivariate Data Analysis with ROOT. Users Guide., arXiv:physics/0703039

  51. [51]

    Sensitivity of searches for new signals and its optimization

    G. Punzi,Sensitivity of searches for new signals and its optimization, eConfC030908 (2003) MODT002,arXiv:physics/0308063

  52. [52]

    N. L. Johnson,Systems of frequency curves generated by methods of translation, Biometrika36(1949) 149

  53. [53]

    Skwarnicki,A study of the radiative cascade transitions between the Upsilon-prime and Upsilon resonances, PhD thesis, Institute of Nuclear Physics, Krakow, 1986, DESY-F31-86-02

    T. Skwarnicki,A study of the radiative cascade transitions between the Upsilon-prime and Upsilon resonances, PhD thesis, Institute of Nuclear Physics, Krakow, 1986, DESY-F31-86-02

  54. [54]

    Albrechtet al.,Search for hadronic b→u decays, Phys

    ARGUS collaboration, H. Albrechtet al.,Search for hadronic b→u decays, Phys. Lett.B241(1990) 278

  55. [55]

    Aaijet al.,Precise measurement of the fs/fd ratio of frag- mentation fractions and of B0 s decay branching fractions, Phys

    LHCb collaboration, R. Aaijet al.,Precise measurement of the fs/fd ratio of frag- mentation fractions and of B0 s decay branching fractions, Phys. Rev.D104(2021) 032005,arXiv:2103.06810

  56. [56]

    BaBar collaboration, J. P. Leeset al.,Amplitude analysis of B0 →K +π−π0 and evidence of direct CP violation in B→K ∗π decays, Phys. Rev.D83(2011) 112010, arXiv:1105.0125

  57. [57]

    Zhou, X.-X

    S.-H. Zhou, X.-X. Hai, R.-H. Li, and C.-D. Lu,Analysis of three-body charmless B-meson decays under the factorization-assisted topological-amplitude approach, Phys. Rev.D107(2023) 116023,arXiv:2305.02811

  58. [58]

    W.-F. Wang, J. Chai, and A.-J. Ma,Contributions of K ∗ 0(1430)and K ∗ 0(1950)in the three-body decaysB→Kπh, JHEP03(2020) 162,arXiv:2001.00355

  59. [59]

    Measurement of the Differential Branching Fraction and Forward-Backword Asymmetry for B->K(*)l+l-

    Belle collaboration, J.-T. Weiet al.,Measurement of the differential branching fraction and forward-backward asymmetry for B→K (∗)ℓ+ℓ−, Phys. Rev. Lett.103(2009) 171801,arXiv:0904.0770

  60. [60]

    Direct CP, Lepton Flavor and Isospin Asymmetries in the Decays B->K(*)l+l-

    BaBar collaboration, B. Aubertet al.,Direct CP, lepton flavor and isospin asymmetries in the decays B→K (∗)ℓ+ℓ−, Phys. Rev. Lett.102(2009) 091803, arXiv:0807.4119. 13

  61. [61]

    Measurements of the Branching Fractions of B0 --> K^*0K+K-, B0 --> K^*0pi+K-, B0 --> K*0K+pi-, and B0 --> K*0pi+pi-

    BaBar collaboration, B. Aubertet al.,Measurements of the branching fractions of B0 →K ∗0K +K −, B0 →K ∗0π+K −, B0 →K ∗0K +π−, and B0 →K ∗0π+π−, Phys. Rev.D76(2007) 071104,arXiv:0708.2543

  62. [62]

    Aaijet al.,The LHCb Upgrade I, JINST19(2024) P05065, arXiv:2305.10515

    LHCb collaboration, R. Aaijet al.,The LHCb Upgrade I, JINST19(2024) P05065, arXiv:2305.10515

  63. [63]

    Aaijet al.,Amplitude analysis of the radiative decay B0 s → K +K −γ, JHEP08(2024) 093,arXiv:2406.00235

    LHCb collaboration, R. Aaijet al.,Amplitude analysis of the radiative decay B0 s → K +K −γ, JHEP08(2024) 093,arXiv:2406.00235

  64. [64]

    Aaijet al.,Amplitude analysis of the Λ0 b →pK −γ decay, JHEP06(2024) 098,arXiv:2403.03710

    LHCb collaboration, R. Aaijet al.,Amplitude analysis of the Λ0 b →pK −γ decay, JHEP06(2024) 098,arXiv:2403.03710. 14 LHCb collaboration R. Aaij38 , A.S.W. Abdelmotteleb 58 , C. Abellan Beteta 52 , F. Abudin´ en60 , T. Ackernley62 , A. A. Adefisoye 70 , B. Adeva48 , M. Adinolfi 56 , P. Adlarson86 , C. Agapopoulou 14 , C.A. Aidala 88 , Z. Ajaltouni 11, S. A...