Abstract
K+K- pairs may be produced in photonuclear collisions, either from the decays of photoproduced φ(1020) mesons or directly as nonresonant K+K- pairs. Measurements of K+K- photoproduction probe the couplings between the φ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of K+K- pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct K+K- production. There is significant K+K- production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range 1.1<MKK<1.4 GeV/c2 above the φ(1020) resonance, for rapidity |yKK|<0.8 and pT,KK<0.1 GeV/c, the measured coherent photoproduction cross section is dσ/dy=3.37±0.61(stat)±0.15(syst) mb. The center-of-mass energy per nucleon of the photon-nucleus (Pb) system WγPb,n ranges from 33 to 188 GeV, far higher than previous measurements on heavy-nucleus targets. The cross section is larger than expected for φ(1020) photoproduction alone. The mass spectrum is fit to a cocktail consisting of φ(1020) decays, direct K+K- photoproduction, and interference between the two. The confidence regions for the amplitude and relative phase angle for direct K+K- photoproduction are presented.
| Original language | English |
|---|---|
| Article number | 222303 |
| Number of pages | 13 |
| Journal | Physical Review Letters |
| Volume | 132 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - 31 May 2024 |
Bibliographical note
Publisher Copyright:© 2024 CERN, for the ALICE Collaboration. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"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. Open access publication funded by CERN.
Funding
The ALICE Collaboration thanks all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex. The ALICE Collaboration gratefully acknowledges the resources and support provided by all Grid centers and the Worldwide LHC Computing Grid (WLCG) Collaboration. The ALICE Collaboration acknowledges the following funding agencies for their support in building and running the ALICE detector: A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science andWorld Federation of Scientists (WFS), Armenia; Austrian Academy of Sciences, Austrian Science Fund (FWF) [grant DOI: 10. 55776/M2467-N36], and Nationalstiftung fur Forschung, Technologie und Entwicklung, Austria; Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Financiadora de Estudos e Projetos (Finep), Fundacao de Amparo `a Pesquisa do Estado de Sao Paulo (FAPESP), and Universidade Federal do Rio Grande do Sul (UFRGS), Brazil; Bulgarian Ministry of Education and Science, within the National Roadmap for Research Infrastructures 2020-2027 (object CERN), Bulgaria; Ministry of Education of China (MOEC), Ministry of Science and Technology of China (MSTC), and National Natural Science Foundation of China (NSFC), China; Ministry of Science and Education and Croatian Science Foundation, Croatia; Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Cubaenergia, Cuba; Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic; The Danish Council for Independent Research | Natural Sciences, the VILLUM FONDEN, and Danish National Research Foundation (DNRF), Denmark; Helsinki Institute of Physics (HIP), Finland; Commissariat `a l'Energie Atomique (CEA) and Institut National de Physique Nucl ' eaire et de Physique des Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS), France; Bundesministerium fur Bildung und Forschung (BMBF) and GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Germany; General Secretariat for Research and Technology, Ministry of Education, Research and Religions, Greece; National Research, Development and Innovation Office, Hungary; Department of Atomic Energy Government of India (DAE), Department of Science and Technology, Government of India (DST), University Grants Commission, Government of India (UGC), and Council of Scientific and Industrial Research (CSIR), India; National Research and Innovation Agency-BRIN, Indonesia; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and Japan Society for the Promotion of Science (JSPS) KAKENHI, Japan; Consejo Nacional de Ciencia (CONACYT) y Tecnologia, through Fondo de Cooperacion Internacional en Ciencia y Tecnologia (FONCICYT) and Direccion General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands; The Research Council of Norway, Norway; Commission on Science and Technology for Sustainable Development in the South (COMSATS), Pakistan; Pontificia Universidad Catolica del Peru, Peru; Ministry of Education and Science, National Science Centre, and WUT ID-UB, Poland; Korea Institute of Science and Technology Information and National Research Foundation of Korea (NRF), Republic of Korea; Ministry of Education and Scientific Research, Institute of Atomic Physics, Ministry of Research and Innovation, and Institute of Atomic Physics and Universitatea Nationala de Stiinta si Tehnologie Politehnica Bucuresti, Romania; Ministry of Education, Science, Research and Sport of the Slovak Republic, Slovakia; National Research Foundation of South Africa, South Africa; Swedish Research Council (VR) and Knut and Alice Wallenberg Foundation (KAW), Sweden; European Organization for Nuclear Research, Switzerland; Suranaree University of Technology (SUT), National Science and Technology Development Agency (NSTDA), and National Science, Research and Innovation Fund (NSRF via PMU-B B05F650021), Thailand; Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), Turkey; National Academy of S ciences of Ukraine, Ukraine; Science and Technology Facilities Council (STFC), United Kingdom; National Science Foundation (NSF) and U.S. Department of Energy, Office of Nuclear Physics (DOE NP), USA. In addition, individual groups or members have received support from: Czech Science Foundation (Grant No. 23-07499S), Czech Republic; European Research Council, Strong 2020Horizon 2020 (Grants No. 950692 and No. 824093), European Union; ICSC-Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing, European Union-NextGenerationEU; and Academy of Finland (Center of Excellence in Quark Matter) (Grants No. 346327 and No. 346328), Finland.
| Funders | Funder number |
|---|---|
| A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS), Armenia | |
| Austrian Science Fund (FWF), Austria | M 2467-N36 |
| Nationalstiftung fur Forschung, Technologie und Entwicklung, Austria | |
| Ministry of Communications and High Technologies, National Nuclear Research Center, Azerbaijan | |
| Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil | |
| Financiadora de Estudos e Projetos (Finep), Brazil | |
| Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil | |
| Universidade Federal do Rio Grande do Sul (UFRGS), Brazil | |
| Bulgarian Ministry of Education and Science, within the National Roadmap for Research Infrastructures 2020-2027 (object CERN), Bulgaria | |
| Ministry of Science & Technology of China (MSTC), China | |
| National Natural Science Foundation of China (NSFC), China | |
| Croatian Science Foundation, Croatia | |
| Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Cubaenergia, Cuba | |
| Ministry of Education, Youth and Sports of the Czech Republic, Czech Republic | |
| Danish Council for Independent Research | Natural Sciences, Denmark | |
| VILLUM FONDEN, Denmark | |
| Danish National Research Foundation (DNRF), Denmark | |
| Helsinki Institute of Physics (HIP), Finland | |
| Commissariat a l'Energie Atomique (CEA), France | |
| Centre National de la Recherche Scientifique (CNRS), France | |
| Bundesministerium fur Bildung und Forschung (BMBF), Germany | |
| GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Germany | |
| Council of Scientific and Industrial Research (CSIR), India | |
| Istituto Nazionale di Fisica Nucleare (INFN), Italy | |
| Japan Society for the Promotion of Science (JSPS) KAKENHI, Japan | |
| Consejo Nacional de Ciencia (CONACYT) y Tecnologia, through Fondo de Cooperacion Internacional en Ciencia y Tecnologia (FONCICYT), Mexico | |
| Direccion General de Asuntos del Personal Academico (DGAPA), Mexico | |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands | |
| Research Council of Norway, Norway | |
| Commission on Science and Technology for Sustainable Development in the South (COMSATS), Pakistan | |
| Pontificia Universidad Catolica del Peru, Peru | |
| Ministry of Education and Science, Poland | |
| National Science Centre, Poland | |
| WUT ID-UB, Poland | |
| Korea Institute of Science and Technology Information, Republic of Korea | |
| National Research Foundation of Korea (NRF), Republic of Korea | |
| Austrian Academy of Sciences, Austria | |
| Ministry of Education and Scientific Research, Romania | |
| Institute of Atomic Physics, Romania | |
| Ministry of Research and Innovation, Romania | |
| University Politehnica of Bucharest, Romania | |
| Ministry of Education, Science, Research and Sport of the Slovak Republic, Slovakia | |
| National Research Foundation of South Africa, South Africa | |
| Swedish Research Council (VR), Sweden | |
| Knut & Alice Wallenberg Foundation (KAW), Sweden | |
| European Organization for Nuclear Research, Switzerland | |
| Suranaree University of Technology (SUT), Thailand | |
| National Science and Technology Development Agency (NSTDA), Thailand | |
| Thailand Science Research and Innovation (TSRI) , Thailand | |
| National Science, Research and Innovation Fund (NSRF), Thailand | |
| Turkish Energy, Nuclear and Mineral Research Agency (TENMAK), Turkey | |
| National Academy of Sciences of Ukraine, Ukraine | |
| Science and Technology Facilities Council (STFC), United Kingdom | |
| National Science Foundation of the United States of America (NSF) , United States of America | |
| United States Department of Energy, Office of Nuclear Physics (DOE NP), United States of America | |
| Marie Skodowska Curie, European Union | |
| Strong 2020 - Horizon 2020, European Union | |
| European Research Council , European Union | 824093, 896850, 950692 |
| Academy of Finland (Center of Excellence in Quark Matter), Finland | 346327, 346328 |
| Ministry of Education of China (MOEC) , China | |
| Ministry of Science and Education, Croatia | |
| Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), France | |
| General Secretariat for Research and Technology, Ministry of Education, Research and Religions, Greece | |
| National Research, Development and Innovation Office, Hungary | |
| Department of Atomic Energy Government of India (DAE) | |
| Department of Science and Technology, Government of India (DST) | |
| University Grants Commission, Government of India (UGC) | |
| National Research and Innovation Agency - BRIN, Indonesia | |
| Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan |