Luminosity measurement with the LHCb RICH detectors in Run 3

Journal of Instrumentation IOP Publishing 20:08 (2025) P08001

Authors:

P Alvarez Cartelle, A Anelli, A Balboni, A Beck, F Betti, J Bex, F Borgato, R Calabrese, M Calvi, R Cardinale, G Cavallero, L Cojocariu, DC Craik, E Dall'Occo, C D'Ambrosio, V Duk, L Fantini, F Ferrari, M Fiorini, E Franzoso, C Frei, S Gambetta, S Ghizzo, Z Ghorbanimoghaddam, J Patoc

Abstract:

The LHCb Ring-Imaging Cherenkov detectors are built to provide charged hadron identification over a large range of momentum. The upgraded detectors are also capable of providing an independent measurement of the luminosity for the LHCb experiment during LHC Run 3. The modelling of the opto-electronics chain, the application of the powering strategy during operations, the calibration procedures and the proof of principle of a novel technique for luminosity determination are presented. In addition, the preliminary precision achieved during the 2023 data-taking year for real-time and offline luminosity measurements is reported.

Search for radiative leptonic decay D + → γe + ν e using deep learning * * This work is supported in part by National Key R&D Program of China (2020YFA0406400, 2023YFA1606000, 2020YFA0406300); National Natural Science Foundation of China (NSFC) (11635010, 11735014, 11935015, 11935016, 11935018, 12025502, 12035009, 12035013, 12061131003, 12192260, 12192261, 12192262, 12192263, 12192264, 12192265, 12221005, 12225509, 12235017, 12361141819); the Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program; the CAS Center for Excellence in Particle Physics (CCEPP); Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1832207); CAS (YSBR-101); 100 Talents Program of CAS; CAS Project for Young Scientists in Basic Research (YSBR-117); The Institute of Nuclear and Particle Physics (INPAC) and Shanghai Key Laboratory for Particle Physics and Cosmology; Agencia Nacional de Investigación y Desarrollo de Chile (ANID), Chile (ANID PIA/APOYO AFB230003); German Research Foundation DFG (FOR5327); Istituto Nazionale di Fisica Nucleare, Italy; Knut and Alice Wallenberg Foundation (2021.0174, 2021.0299); Ministry of Development of Turkey (DPT2006K-120470); National Research Foundation of Korea (NRF-2022R1A2C1092335); National Science and Technology fund of Mongolia; National Science Research and Innovation Fund (NSRF) via the Program Management Unit for Human Resources & Institutional Development, Research and Innovation of Thailand (B50G670107); Polish National Science Centre (2019/35/O/ST2/02907); Swedish Research Council (2019.04595); The Swedish Foundation for International Cooperation in Research and Higher Education (CH2018-7756); U. S. Department of Energy (DE-FG02-05ER41374)

Chinese Physics C IOP Publishing 49:8 (2025) 083001

Authors:

M Ablikim, MN Achasov, P Adlarson, XC Ai, R Aliberti, A Amoroso, Q An, Y Bai, O Bakina, Y Ban, H-R Bao, V Batozskaya, K Begzsuren, N Berger, M Berlowski, M Bertani, D Bettoni, F Bianchi, E Bianco, A Bortone, I Boyko, RA Briere, A Brueggemann, H Cai

Abstract:

Using 20.3 fb–1 of annihilation data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report on an improved search for the radiative leptonic decay . An upper limit on its partial branching fraction for photon energies MeV was determined to be at a 90% confidence level; this excludes most current theoretical predictions. A sophisticated deep learning approach, which includes thorough validation and is based on the Transformer architecture, was implemented to efficiently distinguish the signal from massive backgrounds.

Observation of the $${{{\varLambda } ^0_{b}} \!\rightarrow {{J \hspace{-1.66656pt}/\hspace{-1.111pt}\psi }} {{\varXi } ^-} {{K} ^+} }$$ and $${{{{\varXi } ^0_{b}} \!\rightarrow {{J \hspace{-1.66656pt}/\hspace{-1.111pt}\psi }} {{\varXi } ^-} {{\pi } ^+} }}$$ decays

The European Physical Journal C SpringerOpen 85:7 (2025) 812

Authors:

R Aaij, ASW Abdelmotteleb, C Abellan Beteta, F Abudinén, T Ackernley, AA Adefisoye, B Adeva, M Adinolfi, P Adlarson, C Agapopoulou, CA Aidala, Z Ajaltouni, S Akar, K Akiba, P Albicocco, J Albrecht, F Alessio, M Alexander, Z Aliouche, P Alvarez Cartelle, R Amalric, S Amato, JL Amey, Y Amhis, L An, L Anderlini, M Andersson, A Andreianov, P Andreola, M Andreotti, D Andreou, A Anelli, D Ao, F Archilli, M Argenton, S Arguedas Cuendis, A Artamonov, M Artuso, E Aslanides, R Ataíde Da Silva, M Atzeni, B Audurier, D Bacher, I Bachiller Perea, S Bachmann, M Bachmayer, JJ Back, P Baladron Rodriguez, V Balagura, A Balboni

Abstract:

The first observation of the Ξb0 → J/ψΞ− π+ decay and the most precise measurement of the branching fraction of the Λb0 → J/ψΞ− K+ decay are reported, using proton-proton collision data from the LHCb experiment collected in 2016–2018 at a centre of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1. Using the Λb0 → J/ψΛ and Ξb0 → J/ψΞ− decays as normalisation channels, the ratios of branching fractions are measured to be B(Λb0 → J/ψΞ− K+)/B(Λb0 → J/ψΛ) = (1.17 ± 0.14 ± 0.08) × 10−2, B(Ξb0 → J/ψΞ− π+)/B(Ξb0 → J/ψΞ−) = (11.9 ± 1.4 ± 0.6) × 10−2, where the first uncertainty is statistical and the second systematic

Search for the decay $B^0 \rightarrow ϕϕ$

(2025)

Authors:

LHCb collaboration, R Aaij, ASW Abdelmotteleb, C Abellan Beteta, F Abudinén, T Ackernley, AA Adefisoye, B Adeva, M Adinolfi, P Adlarson, C Agapopoulou, CA Aidala, Z Ajaltouni, S Akar, K Akiba, P Albicocco, J Albrecht, F Alessio, Z Aliouche, P Alvarez Cartelle, R Amalric, S Amato, JL Amey, Y Amhis, L An, L Anderlini, M Andersson, P Andreola, M Andreotti, S Andres Estrada, A Anelli, D Ao, F Archilli, Z Areg, M Argenton, S Arguedas Cuendis, A Artamonov, M Artuso, E Aslanides, R Ataíde Da Silva, M Atzeni, B Audurier, JA Authier, D Bacher, I Bachiller Perea, S Bachmann, M Bachmayer, JJ Back, P Baladron Rodriguez, V Balagura, A Balboni, W Baldini, L Balzani, H Bao, J Baptista de Souza Leite, C Barbero Pretel, M Barbetti, IR Barbosa, RJ Barlow, M Barnyakov, S Barsuk, W Barter, J Bartz, S Bashir, B Batsukh, PB Battista, A Bay, A Beck, M Becker, F Bedeschi, IB Bediaga, NA Behling, S Belin, K Belous, I Belov, I Belyaev, G Benane, G Bencivenni, E Ben-Haim, A Berezhnoy, R Bernet, S Bernet Andres, A Bertolin, C Betancourt, F Betti, J Bex, Ia Bezshyiko, O Bezshyyko, J Bhom, MS Bieker, NV Biesuz, P Billoir, A Biolchini, M Birch, FCR Bishop, A Bitadze, A Bizzeti, T Blake, F Blanc, JE Blank, S Blusk, V Bocharnikov, JA Boelhauve, O Boente Garcia, T Boettcher, A Bohare, A Boldyrev, CS Bolognani, R Bolzonella, RB Bonacci, N Bondar, A Bordelius, F Borgato, S Borghi, M Borsato, JT Borsuk, E Bottalico, SA Bouchiba, M Bovill, TJV Bowcock, A Boyer, C Bozzi, JD Brandenburg, A Brea Rodriguez, N Breer, J Brodzicka, A Brossa Gonzalo, J Brown, D Brundu, E Buchanan, L Buonincontri, M Burgos Marcos, AT Burke, C Burr, JS Butter, J Buytaert, W Byczynski, S Cadeddu, H Cai, Y Cai, A Caillet, R Calabrese, S Calderon Ramirez, L Calefice, S Cali, M Calvi, M Calvo Gomez, P Camargo Magalhaes, JI Cambon Bouzas, P Campana, DH Campora Perez, AF Campoverde Quezada, S Capelli, 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, S Cesare, AJ Chadwick, I Chahrour, H Chang, M Charles, Ph Charpentier, E Chatzianagnostou, R Cheaib, M Chefdeville, C Chen, J Chen, S Chen, Z Chen, 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, PEL Clarke, M Clemencic, HV 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, C Coronel, I Corredoira, A Correia, G Corti, J Cottee Meldrum, B Couturier, DC Craik, M Cruz Torres, E Curras Rivera, R Currie, CL Da Silva, S Dadabaev, L Dai, X Dai, E Dall'Occo, J Dalseno, C D'Ambrosio, J Daniel, P d'Argent, G Darze, A Davidson, JE 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, JM De Miranda, L De Paula, M De Serio, P De Simone, F De Vellis, JA de Vries, F Debernardis, D Decamp, S Dekkers, L Del Buono, B Delaney, H-P Dembinski, 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, AD Docheva, A Doheny, C Dong, AM Donohoe, F Dordei, AC dos Reis, AD Dowling, L Dreyfus, W Duan, P Duda, MW Dudek, L Dufour, V Duk, P Durante, MM Duras, JM Durham, OD Durmus, A Dziurda, A Dzyuba, S Easo, E Eckstein, U Egede, A Egorychev, V Egorychev, S Eisenhardt, E Ejopu, L Eklund, M Elashri, J Ellbracht, S Ely, A Ene, J Eschle, S Esen, T Evans, F Fabiano, S Faghih, LN Falcao, B Fang, R Fantechi, L Fantini, M Faria, K Farmer, D Fazzini, L Felkowski, M Feng, M Feo, A Fernandez Casani, M Fernandez Gomez, AD Fernez, F Ferrari, F Ferreira Rodrigues, M Ferrillo, M Ferro-Luzzi, S Filippov, RA Fini, M Fiorini, M Firlej, KL Fischer, DS Fitzgerald, C Fitzpatrick, T Fiutowski, F Fleuret, A Fomin, M Fontana, LF Foreman, R Forty, D Foulds-Holt, V Franco Lima, M Franco Sevilla, M Frank, E Franzoso, G Frau, C Frei, DA Friday, J Fu, Q Führing, T Fulghesu, G Galati, MD Galati, A Gallas Torreira, D Galli, S Gambetta, M Gandelman, P Gandini, B Ganie, H Gao, R Gao, TQ Gao, Y Gao, Y Gao, Y Gao, LM Garcia Martin, P Garcia Moreno, J García Pardiñas, P Gardner, KG Garg, L Garrido, C Gaspar, A Gavrikov, G Gazzoni, LL Gerken, E Gersabeck, M Gersabeck, T Gershon, S Ghizzo, Z Ghorbanimoghaddam, L Giambastiani, FI Giasemis, V Gibson, HK Giemza, AL Gilman, M Giovannetti, A Gioventù, L Girardey, MA Giza, FC Glaser, VV Gligorov, C Göbel, L Golinka-Bezshyyko, E Golobardes, D Golubkov, A Golutvin, S Gomez Fernandez, W Gomulka, I Gonà ales Vaz, F Goncalves Abrantes, M Goncerz, G Gong, JA Gooding, IV Gorelov, C Gotti, E Govorkova, JP Grabowski, LA Granado Cardoso, E Graugés, E Graverini, L Grazette, G Graziani, AT Grecu, LM Greeven, NA Grieser, L Grillo, S Gromov, C Gu, M Guarise, L Guerry, V Guliaeva, PA Günther, A-K Guseinov, E Gushchin, Y Guz, T Gys, K Habermann, T Hadavizadeh, C Hadjivasiliou, G Haefeli, C Haen, S Haken, G Hallett, PM Hamilton, J Hammerich, Q Han, X Han, S Hansmann-Menzemer, L Hao, N Harnew, TH Harris, M Hartmann, S Hashmi, J He, A Hedes, F Hemmer, C Henderson, R Henderson, RDL Henderson, AM Hennequin, K Hennessy, L Henry, J Herd, P Herrero Gascon, J Heuel, A Hicheur, G Hijano Mendizabal, J Horswill, R Hou, Y Hou, DC Houston, N Howarth, J Hu, W Hu, X Hu, W Hulsbergen, RJ Hunter, M Hushchyn, D Hutchcroft, M Idzik, D Ilin, P Ilten, A Iniukhin, A Ishteev, K Ivshin, H Jage, SJ Jaimes Elles, S Jakobsen, E Jans, BK Jashal, A Jawahery, C Jayaweera, V Jevtic, Z Jia, E Jiang, X Jiang, Y Jiang, YJ Jiang, E Jimenez Moya, N Jindal, M John, A John Rubesh Rajan, D Johnson, CR Jones, S Joshi, B Jost, J Juan Castella, N Jurik, I Juszczak, D Kaminaris, S Kandybei, M Kane, Y Kang, C Kar, M Karacson, A Kauniskangas, JW Kautz, MK Kazanecki, F Keizer, M Kenzie, T Ketel, B Khanji, A Kharisova, S Kholodenko, G Khreich, T Kirn, VS Kirsebom, O Kitouni, S Klaver, N Kleijne, K Klimaszewski, MR Kmiec, S Koliiev, L Kolk, A Konoplyannikov, P Kopciewicz, P Koppenburg, A Korchin, M Korolev, I Kostiuk, O Kot, S Kotriakhova, E Kowalczyk, A Kozachuk, P Kravchenko, L Kravchuk, M Kreps, P Krokovny, W Krupa, W Krzemien, O Kshyvanskyi, S Kubis, M Kucharczyk, V Kudryavtsev, E Kulikova, A Kupsc, V Kushnir, B Kutsenko, I Kyryllin, D Lacarrere, P Laguarta Gonzalez, A Lai, A Lampis, D Lancierini, C Landesa Gomez, JJ Lane, G Lanfranchi, C Langenbruch, J Langer, O Lantwin, T Latham, F Lazzari, C Lazzeroni, R Le Gac, H Lee, R Lefèvre, A Leflat, S Legotin, M Lehuraux, E Lemos Cid, O Leroy, T Lesiak, ED Lesser, B Leverington, A Li, C Li, C Li, H Li, J Li, K Li, L Li, M Li, P Li, P-R Li, Q Li, T Li, T Li, Y Li, Y Li, Y Li, Z Lian, Q Liang, X Liang, S Libralon, AL Lightbody, C Lin, T Lin, R Lindner, H Linton, R Litvinov, D Liu, FL Liu, G Liu, K Liu, S Liu, W Liu, Y Liu, Y Liu, YL Liu, G Loachamin Ordonez, A Lobo Salvia, A Loi, T Long, JH Lopes, A Lopez Huertas, C Lopez Iribarnegaray, S Là pez Soliño, Q Lu, C Lucarelli, D Lucchesi, M Lucio Martinez, Y Luo, A Lupato, E Luppi, K Lynch, X-R Lyu, GM Ma, S Maccolini, F Machefert, F Maciuc, B Mack, I Mackay, LM Mackey, LR Madhan Mohan, MJ Madurai, D Magdalinski, D Maisuzenko, JJ Malczewski, S Malde, L Malentacca, A Malinin, T Maltsev, G Manca, G Mancinelli, C Mancuso, R Manera Escalero, FM Manganella, D Manuzzi, D Marangotto, JF Marchand, R Marchevski, U Marconi, E Mariani, S Mariani, C Marin Benito, J Marks, AM 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, KR Mattioli, A Mauri, E Maurice, J Mauricio, P Mayencourt, J Mazorra de Cos, M Mazurek, M McCann, TH McGrath, NT McHugh, A McNab, R McNulty, B Meadows, G Meier, D Melnychuk, D Mendoza Granada, FM Meng, M Merk, A Merli, L Meyer Garcia, D Miao, H Miao, M Mikhasenko, DA Milanes, A Minotti, E Minucci, T Miralles, B Mitreska, DS Mitzel, A Modak, L Moeser, RD Moise, EF Molina Cardenas, T Mombächer, M Monk, S Monteil, A Morcillo Gomez, G Morello, MJ Morello, MP Morgenthaler, J Moron, W Morren, AB Morris, AG Morris, R Mountain, H Mu, ZM Mu, E Muhammad, F Muheim, M Mulder, K Müller, F Muñoz-Rojas, R Murta, V Mytrochenko, P Naik, T Nakada, R Nandakumar, T Nanut, I Nasteva, M Needham, E Nekrasova, N Neri, S Neubert, N Neufeld, P Neustroev, J Nicolini, D Nicotra, EM Niel, N Nikitin, Q Niu, P Nogarolli, P Nogga, C Normand, J Novoa Fernandez, G Nowak, C Nunez, HN Nur, A Oblakowska-Mucha, V Obraztsov, T Oeser, A Okhotnikov, O Okhrimenko, R Oldeman, F Oliva, E Olivart Pino, M Olocco, CJG Onderwater, RH O'Neil, JS Ordonez Soto, D Osthues, JM Otalora Goicochea, P Owen, A Oyanguren, O Ozcelik, F Paciolla, A Padee, KO Padeken, B Pagare, T Pajero, A Palano, M Palutan, C Pan, X Pan, S Panebianco, G Panshin, L Paolucci, A Papanestis, M Pappagallo, LL Pappalardo, C Pappenheimer, C Parkes, D Parmar, B Passalacqua, G Passaleva, D Passaro, A Pastore, M Patel, J Patoc, C Patrignani, A Paul, CJ 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, MJ Peters, K Petridis, A Petrolini, JP Pfaller, H Pham, L Pica, M Piccini, L Piccolo, B Pietrzyk, G Pietrzyk, RN Pilato, D Pinci, F Pisani, M Pizzichemi, VM Placinta, M Plo Casasus, T Poeschl, F Polci, M Poli Lener, A Poluektov, N Polukhina, I Polyakov, E Polycarpo, S Ponce, D Popov, S Poslavskii, K Prasanth, C Prouve, D Provenzano, V Pugatch, G Punzi, S Qasim, QQ Qian, W Qian, N Qin, S Qu, R Quagliani, B Quintana, RI Rabadan Trejo, JH Rademacker, M Rama, M Ramírez García, V Ramos De Oliveira, M Ramos Pernas, MS Rangel, F Ratnikov, G Raven, M Rebollo De Miguel, F Redi, J Reich, F Reiss, Z Ren, PK Resmi, M Ribalda Galvez, R Ribatti, G Ricart, D Riccardi, S Ricciardi, K Richardson, M Richardson-Slipper, K Rinnert, P Robbe, G Robertson, E Rodrigues, A Rodriguez Alvarez, E Rodriguez Fernandez, JA Rodriguez Lopez, E Rodriguez Rodriguez, J Roensch, A Rogachev, A Rogovskiy, DL Rolf, P Roloff, V Romanovskiy, A Romero Vidal, G Romolini, F Ronchetti, T Rong, M Rotondo, SR Roy, MS Rudolph, M Ruiz Diaz, RA Ruiz Fernandez, J Ruiz Vidal, JJ Saavedra-Arias, JJ Saborido Silva, SER Sacha Emile R., R Sadek, 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, M Saur, D Savrina, H Sazak, F Sborzacchi, A Scarabotto, S Schael, S Scherl, M Schiller, H Schindler, M Schmelling, B Schmidt, S Schmitt, H Schmitz, O Schneider, A Schopper, N Schulte, MH Schune, G Schwering, B Sciascia, A Sciuccati, I Segal, S Sellam, A Semennikov, T Senger, M Senghi Soares, A Sergi, N Serra, L Sestini, A Seuthe, B Sevilla Sanjuan, Y Shang, DM Shangase, M Shapkin, RS Sharma, I Shchemerov, L Shchutska, T Shears, L Shekhtman, Z Shen, S Sheng, V Shevchenko, B Shi, Q Shi, WS Shi, Y Shimizu, E Shmanin, R Shorkin, JD Shupperd, R Silva Coutinho, G Simi, S Simone, M Singha, N Skidmore, T Skwarnicki, MW Slater, E Smith, K Smith, M Smith, L Soares Lavra, MD Sokoloff, FJP Soler, A Solomin, A Solovev, NS Sommerfeld, R Song, Y Song, Y Song, YS Song, FL Souza De Almeida, B Souza De Paula, E Spadaro Norella, E Spedicato, JG Speer, P Spradlin, V Sriskaran, F Stagni, M Stahl, S Stahl, S Stanislaus, M Stefaniak, EN Stein, O Steinkamp, H Stevens, D Strekalina, Y Su, F Suljik, J Sun, J Sun, L Sun, D Sundfeld, W Sutcliffe, K Swientek, F Swystun, A Szabelski, T Szumlak, Y Tan, Y Tang, YT Tang, MD Tat, JA Teijeiro Jimenez, A Terentev, F Terzuoli, F Teubert, E Thomas, DJD Thompson, AR Thomson-Strong, H Tilquin, V Tisserand, S T'Jampens, M Tobin, TT Todorov, L Tomassetti, G Tonani, X Tong, T Tork, D Torres Machado, L Toscano, DY Tou, C Trippl, G Tuci, N Tuning, LH Uecker, A Ukleja, DJ Unverzagt, A Upadhyay, B Urbach, A Usachov, A Ustyuzhanin, U Uwer, V Vagnoni, V Valcarce Cadenas, G Valenti, N Valls Canudas, J van Eldik, H Van Hecke, E van Herwijnen, CB Van Hulse, R Van Laak, M van Veghel, G Vasquez, R Vazquez Gomez, P Vazquez Regueiro, C Và zquez Sierra, S Vecchi, JJ 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, FC Volle, D vom Bruch, N Voropaev, K Vos, C Vrahas, J Wagner, J Walsh, EJ Walton, G Wan, A Wang, B Wang, C Wang, G Wang, H Wang, J Wang, J Wang, J Wang, J Wang, M Wang, NW Wang, R Wang, X Wang, X Wang, XW Wang, Y Wang, Y Wang, YH Wang, Z Wang, Z Wang, Z Wang, JA Ward, M Waterlaat, NK Watson, D Websdale, Y Wei, J Wendel, BDC Westhenry, C White, M Whitehead, E Whiter, AR Wiederhold, D Wiedner, MA Wiegertjes, C Wild, G Wilkinson, MK Wilkinson, M Williams, MJ Williams, MRJ Williams, R Williams, S Williams, Z Williams, FF Wilson, M Winn, W Wislicki, M Witek, L Witola, T Wolf, E Wood, G Wormser, SA Wotton, H Wu, J Wu, X Wu, Y Wu, Z Wu, K Wyllie, S Xian, Z Xiang, Y Xie, TX Xing, A Xu, L Xu, L Xu, M Xu, Z Xu, Z Xu, Z Xu, K Yang, X Yang, Y Yang, Z Yang, V Yeroshenko, H Yeung, H Yin, X Yin, CY Yu, J Yu, X Yuan, Y Yuan, E Zaffaroni, M Zavertyaev, M Zdybal, F Zenesini, C Zeng, M Zeng, C Zhang, D Zhang, J Zhang, L Zhang, R Zhang, S Zhang, S Zhang, Y Zhang, YZ Zhang, Z Zhang, Y Zhao, A Zhelezov, SZ Zheng, XZ Zheng, Y Zheng, T Zhou, X Zhou, Y Zhou, V Zhovkovska, LZ Zhu, X Zhu, X Zhu, Y Zhu, V Zhukov, J Zhuo, Q Zou, D Zuliani, G Zunica

Measurement of the ψ (2S) to J /ψ cross-section ratio as a function of centrality in PbPb collisions at s NN = 5. 02 TeV

Journal of High Energy Physics Springer 2025:7 (2025) 235

Authors:

R Aaij, ASW Abdelmotteleb, C Abellan Beteta, F Abudinén, T Ackernley, AA Adefisoye, B Adeva, M Adinolfi, P Adlarson, C Agapopoulou, CA Aidala, Z Ajaltouni, S Akar, K Akiba, P Albicocco, J Albrecht, F Alessio, M Alexander, Z Aliouche, P Alvarez Cartelle, R Amalric, S Amato, JL Amey, Y Amhis, D Bacher

Abstract:

The ratio of prompt production cross-sections of ψ(2S) and J/ψ mesons in their dimuon final state is measured as a function of centrality, using data collected by the LHCb detector in PbPb collisions at sNN = 5.02 TeV, for the first time in the forward rapidity region. The measured ratio shows no dependence on the collision centrality, and is compared to the latest theory predictions and to the recent measurements in literature.