Observation of the Very Rare Σ⁺ → pμ⁺μ^- Decay

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Aaij, R, Abdelmotteleb, ASW, Beteta, C Abellan, Abudinen, F, Ackernley, T, Adefisoye, AA, Adeva, B, Adinolfi, M, Adlarson, P, Agapopoulou, C et al (show 1124 more authors) , Aidala, CA, Ajaltouni, Z, Akar, S, Akiba, K, Albicocco, P, Albrecht, J, Alessio, F, Aliouche, Z, Cartelle, P Alvarez, Amalric, R, Amato, S, Amey, JL, Amhis, Y, An, L, Anderlini, L, Andersson, M, Andreianov, A, Andreola, P, Andreotti, M, Andreou, D, Anelli, A, Ao, D, Archilli, F, Argenton, M, Cuendis, S Arguedas, Artamonov, A, Artuso, M, Aslanides, E, Da Silva, R Ataide, Atzeni, M, Audurier, B, Bacher, D, Perea, I Bachiller, Bachmann, S, Bachmayer, M, Back, JJ, Rodriguez, P Baladron, Balagura, V, Balboni, A, Baldini, W, Balzani, L, Bao, H, Leite, J Baptista de Souza, Pretel, C Barbero, Barbetti, M, Barbosa, IR, Barlow, RJ, Barnyakov, M, Barsuk, S, Barter, W, Bartz, J, Bashir, S, Batsukh, B, Battista, PB, Bay, A, Beck, A, Becker, M, Bedeschi, F, Bediaga, B, Behling, NA, Belin, S, Belous, K, Belov, I, Belyaev, I, Benane, G, Bencivenni, G, Ben-Haim, E, Berezhnoy, A, Bernet, R, Andres, S Bernet, Bertolin, A, Betancourt, C, Betti, F, Bex, J, Bezshyiko, Ia, Bezshyyko, O, Bhom, J, Bieker, MS, Biesuz, NV, Billoir, P, Biolchini, A, Birch, M, Bishop, FCR, Bitadze, A, Bizzeti, A, Blake, T, Blanc, F, Blank, JE, Blusk, S, Bocharnikov, V, Boelhauve, JA, Garcia, O Boente, Boettcher, T, Bohare, A, Boldyrev, A, Bolognani, CS, Bolzonella, R, Bonacci, RB, Bondar, N, Bordelius, A, Borgato, F, Borghi, S, Borsato, M, Borsuk, JT, Bottalico, E ORCID: 0000-0003-2238-8803, Bouchiba, SA, Bovill, M, Bowcock, TJV ORCID: 0000-0002-3505-6915, Boyer, A, Bozzi, C, Brandenburg, JD, Rodriguez, A Brea, Breer, N, Brodzicka, J, Gonzalo, A Brossa, Brown, J, Brundu, D, Buchanan, E, Buonincontri, L, Marcos, M Burgos, Burke, AT, Burr, C, Butter, JS, Buytaert, J, Byczynski, W, Cadeddu, S, Cai, H, Caillet, A, Calabrese, R, Ramirez, S Calderon, Calefice, L, Cali, S, Calvi, M, Gomez, M Calvo, Magalhaes, P Camargo, Bouzas, JI Cambon, Campana, P, Perez, DH Campora, Quezada, AF Campoverde, Capelli, S, Capriotti, L, Caravaca-Mora, R, Carbone, A, Salgado, L Carcedo, Cardinale, R, Cardini, A, Carniti, P, Carus, L, Vidal, A Casais, Caspary, R, Casse, G ORCID: 0000-0002-8516-237X, Cattaneo, M, Cavallero, G, Cavallini, V, Celani, S, Cesare, S, Chadwick, AJ, Chahrour, I, Chang, H, Charles, M, Charpentier, Ph, Chatzianagnostou, E, Chefdeville, M, Chen, C, Chen, S, Chen, Z, Chernov, A, Chernyshenko, S, Chiotopoulos, X, Chobanova, V, Chrzaszcz, M, Chubykin, A, Chulikov, V, Ciambrone, P, Vidal, X Cid, Ciezarek, G, Cifra, P, Clarke, PEL, Clemencic, M, Cliff, HV, Closier, J, Toapaxi, C Cocha, Coco, V, Cogan, J, Cogneras, E, Cojocariu, L, Collaviti, S, Collins, P, Colombo, T, Colonna, M, Comerma-Montells, A, Congedo, L, Contu, A, Cooke, N, Coronel, C, Corredoira, I, Correia, A, Corti, G, Meldrum, J Cottee, Couturier, B, Craik, DC, Torres, M Cruz, Rivera, E Curras, Currie, R, Da Silva, CL, Dadabaev, S, Dai, L, Dai, X, Dall'Occo, E, Dalseno, J, D'Ambrosio, C, Daniel, J, d'Argent, P, Darze, G, Davidson, A, Davies, JE, Francisco, O De Aguiar, De Angelis, C, De Benedetti, F, de Boer, J, De Bruyn, K, De Capua, S, De Cian, M, Da Graca, U De Freitas Carneiro, De Lucia, E, De Miranda, JM, De Paula, L, De Serio, M, De Simone, P, De Vellis, F, de Vries, JA, Debernardis, F, Decamp, D, Dekkers, S, Del Buono, L, Delaney, B, Dembinski, H-P, Deng, J, Denysenko, V, Deschamps, O, Dettori, F, Dey, B, Di Nezza, P, Diachkov, I, Didenko, S, Ding, S, Dittmann, L, Dobishuk, V, Docheva, AD, Dong, C, Donohoe, AM, Dordei, F, dos Reis, AC, Dowling, AD, Duan, W, Duda, P, Dudek, MW, Dufour, L, Duk, V, Durante, P, Duras, MM, Durham, JM, Durmus, OD, Dziurda, A, Dzyuba, A, Easo, S, Eckstein, E, Egede, U, Egorychev, A, Egorychev, V, Eisenhardt, S, Ejopu, E ORCID: 0000-0003-3711-7547, Eklund, L, Elashri, M, Ellbracht, J, Ely, S, Ene, A, Eschle, J, Esen, S, Evans, T, Fabiano, F, Faghih, S, Falcao, LN, Fang, B, Fantini, L, Faria, M, Farmer, K, Fazzini, D, Felkowski, L, Feng, M, Feo, M, Casani, A Fernandez, Gomez, M Fernandez, Fernez, AD, Ferrari, F, Rodrigues, F Ferreira, Ferrillo, M, Ferro-Luzzi, M, Filippov, S, Fini, RA, Fiorini, M, Firlej, M, Fischer, KL, Fitzgerald, DS, Fitzpatrick, C, Fiutowski, T, Fleuret, F, Fontana, M, Foreman, LF, Forty, R, Foulds-Holt, D, Lima, V Franco, Sevilla, M Franco, Frank, M, Franzoso, E, Frau, G, Frei, C, Friday, DA, Fu, J, Fuhring, Q, Fujii, Y, Fulghesu, T, Gabriel, E, Galati, G, Galati, MD, Torreira, A Gallas, Galli, D, Gambetta, S, Gandelman, M, Gandini, P, Ganie, B, Gao, H, Gao, R, Gao, TQ, Gao, Y, Martin, LM Garcia, Moreno, P Garcia, Pardinas, J Garcia, Gardner, P, Garg, KG, Garrido, L, Gaspar, C, Gavrikov, A, Gerken, LL, Gersabeck, E, Gersabeck, M, Gershon, T, Ghizzo, S, Ghorbanimoghaddam, Z, Giambastiani, L, Giasemis, FI, Gibson, V, Giemza, HK, Gilman, AL, Giovannetti, M, Gioventu, A, Girardey, L, Giugliano, C, Giza, MA, Glaser, FC, Gligorov, VV, Gobel, C, Golinka-Bezshyyko, L, Golobardes, E, Golubkov, D, Golutvin, A, Fernandez, S Gomez, Gomulka, W, Abrantes, F Goncalves, Goncerz, M, Gong, G, Gooding, JA, Gorelov, IV, Gotti, C, Govorkova, E, Grabowski, JP, Cardoso, LA Granado, Grauges, E, Graverini, E, Grazette, L, Graziani, G, Grecu, AT, Greeven, LM, Grieser, NA, Grillo, L, Gromov, S, Gu, C, Guarise, M, Guerry, L, Guliaeva, V, Gunther, PA, Guseinov, A-K, Gushchin, E, Guz, Y, Gys, T, Habermann, K, Hadavizadeh, T, Hadjivasiliou, C, Haefeli, G, Haen, C, Hallett, G, Hamilton, PM, Hammerich, J, Han, Q, Han, X, Hansmann-Menzemer, S, Hao, L, Harnew, N, Harris, TH, Hartmann, M, Hashmi, S, He, J, Hemmer, F, Henderson, C, Henderson, RDL, Hennequin, AM, Hennessy, K ORCID: 0000-0002-1529-8087, Henry, L, Herd, J, Gascon, P Herrero, Heuel, J, Hicheur, A, Mendizabal, G Hijano, Horswill, J, Hou, R, Hou, Y, Howarth, N, Hu, J, Hu, W, Hu, X, Hulsbergen, W, Hunter, RJ, Hushchyn, M, Hutchcroft, D ORCID: 0000-0002-4174-6509, Idzik, M, Ilin, D, Ilten, P, Inglessi, A, Iniukhin, A, Ishteev, A, Ivshin, K, Jage, H, Elles, SJ Jaimes, Jakobsen, S, Jans, E, Jashal, BK, Jawahery, A, Jevtic, V, Jiang, E, Jiang, X, Jiang, Y, Jiang, YJ, John, M, Rajan, A John Rubesh, Johnson, D, Jones, CR, Jones, TP, Joshi, S, Jost, B, Castella, J Juan, Jurik, N, Juszczak, I, Kaminaris, D, Kandybei, S, Kane, M, Kang, Y, Kar, C, Karacson, M, Karpenkov, D, Kauniskangas, A, Kautz, JW, Kazanecki, MK, Keizer, F, Kenzie, M, Ketel, T, Khanji, B, Kharisova, A, Kholodenko, S, Khreich, G, Kirn, T, Kirsebom, VS, Kitouni, O, Klaver, S, Kleijne, N, Klimaszewski, K, Kmiec, MR, Koliiev, S, Kolk, L, Konoplyannikov, A, Kopciewicz, P, Koppenburg, P, Korchin, A, Korolev, M, Kostiuk, I, Kot, O, Kotriakhova, S, Kozachuk, A, Kravchenko, P, Kravchuk, L, Kreps, M, Krokovny, P, Krupa, W, Krzemien, W, Kshyvanskyi, O, Kubis, S, Kucharczyk, M, Kudryavtsev, V, Kulikova, E, Kupsc, A, Kushnir, V, Kutsenko, B, Kyryllin, I, Lacarrere, D, Gonzalez, P Laguarta, Lai, A, Lampis, A, Lancierini, D, Gomez, C Landesa, Lane, JJ, Lanfranchi, G, Langenbruch, C, Langer, J, Lantwin, O, Latham, T, Lazzari, F, Lazzeroni, C, Le Gac, R, Lee, H, Lefevre, R, Leflat, A, Legotin, S, Lehuraux, M, Cid, E Lemos, Leroy, O, Lesiak, T, Lesser, ED, Leverington, B, Li, A, Li, C, Li, H, Li, J, Li, K, Li, L, Li, M, Li, P, Li, P-R, Li, Q, Li, S, Li, T, Li, Y, Lian, Z, Liang, X, Libralon, S, Lin, C, Lin, T, Lindner, R, Linton, H, Lisovskyi, V, Litvinov, R, Liu, D, Liu, FL, Liu, G, Liu, K, Liu, S, Liu, W, Liu, Y, Liu, YL, Ordonez, G Loachamin, Salvia, A Lobo, Loi, A, Long, T, Lopes, JH, Huertas, A Lopez, Solino, S Lopez, Lu, Q, Lucarelli, C, Lucchesi, D, Martinez, M Lucio, Luo, Y, Lupato, A, Luppi, E, Lynch, K, Lyu, X-R, Ma, GM, Maccolini, S, Machefert, F, Maciuc, F, Mack, B, Mackay, I, Mackey, LM, Mohan, LR Madhan, Madurai, MJ, Magdalinski, D, Maisuzenko, D, Malczewski, JJ, Malde, S, Malentacca, L, Malinin, A, Maltsev, T, Manca, G, Mancinelli, G, Mancuso, C, Escalero, R Manera, Manganella, FM, Manuzzi, D, Marangotto, D, Marchand, JF, Marchevski, R, Marconi, U, Mariani, E, Mariani, S, Benito, C Marin, Marks, J, Marshall, AM, Martel, L, Martelli, G, Martellotti, G, Martinazzoli, L, Martinelli, M, Gomez, D Martinez, Santos, D Martinez, Vidal, F Martinez, Martorell i Granollers, A, Massafferri, A, Matev, R, Mathad, A, Matiunin, V, Matteuzzi, C, Mattioli, KR, Mauri, A, Maurice, E, Mauricio, J, Mayencourt, P, de Cos, J Mazorra, Mazurek, M, McCann, M, McGrath, TH, McHugh, NT, McNab, A, McNulty, R, Meadows, B, Meier, G, Melnychuk, D, Meng, FM, Merk, M, Merli, A, Garcia, L Meyer, Miao, D, Miao, H, Mikhasenko, M, Milanes, DA, Minotti, A, Minucci, E, Miralles, T, Mitreska, B, Mitzel, DS, Modak, A, Moeser, L, Mohammed, RA, Moise, RD, Cardenas, EF Molina, Mombacher, T, Monk, M, Monteil, S, Gomez, A Morcillo, Morello, G, Morello, MJ, Morgenthaler, MP, Moron, J, Morren, W, Morris, AB, Morris, AG, Mountain, R, Mu, H, Mu, ZM, Muhammad, E, Muheim, F, Mulder, M, Mueller, K, Munoz-Rojas, F, Murta, R, Mytrochenko, V, Naik, P ORCID: 0000-0001-6977-2971, Nakada, T, Nandakumar, R, Nanut, T, Nasteva, I, Needham, M, Nekrasova, E, Neri, N, Neubert, S, Neufeld, N, Neustroev, P, Nicolini, J, Nicotra, D, Niel, EM, Nikitin, N, Niu, Q, Nogarolli, P, Nogga, P, Normand, C, Fernandez, J Novoa, Nowak, G, Nunez, C, Nur, HN, Oblakowska-Mucha, A, Obraztsov, V, Oeser, T, Okamura, S, Okhotnikov, A, Okhrimenko, O, Oldeman, R, Oliva, F, Olocco, M, Onderwater, CJG, O'Neil, RH, Osthues, D, Goicochea, JM Otalora, Owen, P, Oyanguren, A, Ozcelik, O, Paciolla, F, Padee, A, Padeken, KO, Pagare, B, Pajero, T, Palano, A, Palutan, M, Pan, X, Panebianco, S, Panshin, G, Paolucci, L, Papanestis, A, Pappagallo, M, Pappalardo, LL, Pappenheimer, C, Parkes, C, Parmar, D, Passalacqua, B, Passaleva, G, Passaro, D, Pastore, A, Patel, M, Patoc, J, Patrignani, C, Paul, A, Pawley, CJ, Pellegrino, A, Peng, J, Altarelli, M Pepe, Perazzini, S, Pereima, D, Da Costa, H Pereira, Castro, A Pereiro, Perret, P, Perrevoort, A, Perro, A, Peters, MJ, Petridis, K, Petrolini, A, Pfaller, JP, Pham, H, Pica, L, Piccini, M, Piccolo, L, Pietrzyk, B, Pietrzyk, G, Pilato, RN ORCID: 0000-0002-4325-7530, Pinci, D, Pisani, F, Pizzichemi, M, Placinta, V, Casasus, M Plo, Poeschl, T, Polci, F, Lener, M Poli, Poluektov, A, Polukhina, N, Polyakov, I, Polycarpo, E, Ponce, S, Popov, D, Poslavskii, S, Prasanth, K, Prouve, C, Provenzano, D, Pugatch, V, Punzi, G, Qasim, S, Qian, QQ, Qian, W, Qin, N, Qu, S, Quagliani, R, Trejo, RI Rabadan, Rademacker, JH, Rama, M, Garcia, M Ramirez, De Oliveira, V Ramos, Pernas, M Ramos, Rangel, MS, Ratnikov, F, Raven, G, De Miguel, M Rebollo, Redi, F, Reich, J, Reiss, F, Ren, Z, Resmi, PK, Galvez, M Ribalda, Ribatti, R, Ricart, G, Riccardi, D, Ricciardi, S, Richardson, K, Richardson-Slipper, M, Rinnert, K, Robbe, P, Robertson, G, Rodrigues, E, Alvarez, A Rodriguez, Fernandez, E Rodriguez, Lopez, JA Rodriguez, Rodriguez, E Rodriguez, Roensch, J, Rogachev, A, Rogovskiy, A, Rolf, DL, Roloff, P, Romanovskiy, V, Vidal, A Romero, Romolini, G, Ronchetti, F, Rong, T, Rotondo, M, Roy, SR, Rudolph, MS, Diaz, M Ruiz, Fernandez, RA Ruiz, Vidal, J Ruiz, Saavedra-Arias, JJ, Silva, JJ Saborido, Sadek, R, Sagidova, N, Sahoo, D, Sahoo, N, Saitta, B, Salomoni, M, Sanderswood, I, Santacesaria, R, Rios, C Santamarina, Santimaria, M, Santoro, L, Santovetti, E, Saputi, A, Saranin, D, Sarnatskiy, A, Sarpis, G, Sarpis, M, Satriano, C, Satta, A, Saur, M, Savrina, D, Sazak, H, Sborzacchi, F, Scarabotto, A, Schael, S, Scherl, S, Schiller, M, Schindler, H, Schmelling, M, Schmidt, B, Schmitt, S, Schmitz, H, Schneider, O, Schopper, A, Schulte, N, Schulte, S, Schune, MH, Schwering, G, Sciascia, B, Sciuccati, A, Segal, I, Sellam, S, Semennikov, A, Senger, T, Soares, M Senghi, Sergi, A, Serra, N, Sestini, L, Seuthe, A, Sanjuan, B Sevilla, Shang, Y, Shangase, DM, Shapkin, M, Sharma, RS, Shchemerov, I, Shchutska, L, Shears, T ORCID: 0000-0002-2653-1366, Shekhtman, L, Shen, Z, Sheng, S, Shevchenko, V, Shi, B, Shi, Q, Shimizu, Y, Shmanin, E, Shorkin, R, Shupperd, JD, Coutinho, R Silva, Simi, G, Simone, S, Singha, M, Skidmore, N, Skwarnicki, T, Slater, MW, Smith, E, Smith, K, Smith, M, Lavra, L Soares, Sokoloff, MD, Soler, FJP, Solomin, A, Solovev, A, Solovyev, I, Sommerfeld, NS, Song, R, Song, Y, Song, Y, Song, YS, De Almeida, FL Souza, De Paula, B Souza, Norella, E Spadaro, Spedicato, E, Speer, JG, Spiridenkov, E, Spradlin, P, Sriskaran, V, Stagni, F, Stahl, M, Stahl, S, Stanislaus, S, Stefaniak, M, Stein, EN, Steinkamp, O, Stenyakin, O, Stevens, H, Strekalina, D, Su, Y, Suljik, F, Sun, J, Sun, L, Sundfeld, D, Sutcliffe, W, Swientek, K, Swystun, F, Szabelski, A, Szumlak, T, Tan, Y, Tang, Y, Tang, YT, Tat, MD, Terentev, A, Terzuoli, F, Teubert, F, Thoma, U, Thomas, E, Thompson, DJD, Tilquin, H, Tisserand, V, T'Jampens, S, Tobin, M, Tomassetti, L, Tonani, G, Tong, X, Tork, T, Machado, D Torres, Toscano, L, Tou, DY, Trippl, C, Tuci, G, Tuning, N, Uecker, LH, Ukleja, A, Unverzagt, DJ, Upadhyay, A, Urbach, B, Usachov, A, Ustyuzhanin, A, Uwer, U, Vagnoni, V, Cadenas, V Valcarce, Valenti, G, Canudas, N Valls, van Eldik, J, Van Hecke, H, van Herwijnen, E, Van Hulse, CB, Van Laak, R, van Veghel, M, Vasquez, G, Gomez, R Vazquez, Regueiro, P Vazquez, Sierra, C Vazquez, Vecchi, S, Velthuis, JJ, Veltri, M, Venkateswaran, A, Verdoglia, M, Vesterinen, M, Benet, D Vico, Villalba, P Vidrier, Diaz, M Vieites, Vilasis-Cardona, X, Figueras, E Vilella, Villa, A, Vincent, P, Vivacqua, B, Volle, FC, vom Bruch, D, Voropaev, N, Vos, K, Vrahas, C, Wagner, J, Walsh, J, Walton, EJ, Wan, G, Wang, A, Wang, C, Wang, G, Wang, H, Wang, J, Wang, M, Wang, NW, Wang, R, Wang, X, Wang, XW, Wang, Y, Wang, YW, Wang, Z, Ward, JA, Waterlaat, M, Watson, NK, Websdale, D, Wei, Y, Wendel, J, Westhenry, BDC, White, C, Whitehead, M, Whiter, E, Wiederhold, AR, Wiedner, D, Wilkinson, G, Wilkinson, MK, Williams, M, Williams, MJ, Williams, MRJ, Williams, R, Williams, Z, Wilson, FF, Winn, M, Wislicki, W, Witek, M, Witola, L, Wormser, G, Wotton, SA, Wu, H, Wu, J, Wu, X, Wu, Y, Wu, Z, Wyllie, K, Xian, S, Xiang, Z, Xie, Y, Xing, TX, Xu, A, Xu, L, Xu, M, Xu, Z, Yang, K, Yang, X, Yang, Y, Yang, Z, Yeroshenko, V, Yeung, H, Yin, H, Yin, X, Yu, CY, Yu, J, Yuan, X, Yuan, Y, Zaffaroni, E, Zavertyaev, M, Zdybal, M, Zenesini, F, Zeng, C, Zeng, M, Zhang, C, Zhang, D, Zhang, J, Zhang, L, Zhang, R, Zhang, S, Zhang, Y, Zhang, YZ, Zhang, Z, Zhao, Y, Zhelezov, A, Zheng, SZ, Zheng, XZ, Zheng, Y, Zhou, T, Zhou, X, Zhou, Y, Zhovkovska, V, Zhu, LZ, Zhu, X, Zhu, Y, Zhukov, V, Zhuo, J, Zou, Q, Zuliani, D and Zunica, G (2025) Observation of the Very Rare Σ⁺ → pμ⁺μ^- Decay PHYSICAL REVIEW LETTERS, 135 (5). 051801-. ISSN 0031-9007, 1079-7114

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Abstract

The first observation of the ς+→pμ+μ- decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 5.4 fb-1, collected with the LHCb detector at a center-of-mass energy of 13 TeV. A yield of 237±16 ς+→pμ+μ- decays is obtained, where the uncertainty is statistical only. A branching fraction of (1.08±0.17)×10-8 is measured, where the uncertainty includes statistical and systematic sources. No evidence of resonant structures is found in the dimuon invariant-mass distribution. All results are compatible with standard model expectations. This represents the rarest decay of a baryon ever observed.

Item Type:	Article
Uncontrolled Keywords:	LHCb Collaboration
Divisions:	Faculty of Humanities & Social Sciences Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering Faculty of Science & Engineering > School of Physical Sciences Faculty of Science & Engineering > School of Physical Sciences > Physics Faculty of Humanities & Social Sciences > School of the Arts Faculty of Humanities & Social Sciences > School of the Arts > Architecture Faculty of Science & Engineering > School of Engineering > Civil and Environmental Engineering
Depositing User:	Symplectic Admin
Date Deposited:	13 Oct 2025 07:59
Last Modified:	23 May 2026 10:28
DOI:	10.1103/r3v2-kmmp
Open Access URL:	https://journals.aps.org/prl/pdf/10.1103/r3v2-kmmp
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3194812
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