abstract

• The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.7 nb-1 and 320 pb-1, respectively. Hadronic collision data with one reconstructed Z boson candidate with the transverse momentum pT>30 GeV/c are analyzed. The Z boson constrains the initial energy and direction of the associated parton. In heavy ion events, azimuthal angular distributions of charged hadrons with respect to the direction of a Z boson are sensitive to modifications of the in-medium parton shower and medium response. compared to reference data from pp interactions, the results for central Pb-Pb collisions indicate a modification of the angular correlations. The measurements of the fragmentation functions and pT spectra of charged particles in Z boson events, which are sensitive to medium modifications of the parton shower longitudinal structure, are also reported. Significant modifications in central Pb-Pb events compared to the pp reference data are also found for these observables. © 2022 CERN.

authors

• CMS Collaboration
• Morelos Pineda Antonio

publication date

• 2022-01-01

funding provided via

• National Science Foundation, NSF; U.S. Department of Energy, USDOE; Hispanics in Philanthropy, HIP; Maryland Ornithological Society, MOS; Departamento Administrativo de Ciencia, Tecnología e Innovación (COLCIENCIAS); Secretaría de Educación Pública, SEP; Türkiye Atom Enerjisi Kurumu, TAEK; Louisiana Academy of Sciences, LAS; Missouri University of Science and Technology, MST; CERN; Thailand Center of Excellence in Physics; Cosmetic Surgery Foundation, CSF; Institute for the Promotion of Teaching Science and Technology, IPST; Science and Technology Facilities Council, STFC; Department of Science and Technology, Ministry of Science and Technology, India, डीएसटी; Ministry of Education - Singapore, MOE; Department of Atomic Energy, Government of India, DAE; Science Foundation Ireland, SFI; Helmholtz-Gemeinschaft, HGF; Deutsche Forschungsgemeinschaft, DFG; Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP; National Natural Science Foundation of China, NSFC; National Science Council, NSC; Fundação para a Ciência e a Tecnologia, FCT; Russian Foundation for Basic Research, РФФИ; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES; Academy of Finland, AKA; Bundesministerium für Bildung und Forschung, BMBF; Chinese Academy of Sciences, CAS; Austrian Science Fund, FWF; Fonds De La Recherche Scientifique - FNRS, FNRS; Russian Academy of Sciences, РАН; Fonds Wetenschappelijk Onderzoek, FWO; Consejo Nacional de Ciencia y Tecnología, CONACYT; Ministerio de Economía y Competitividad, MINECO; General Secretariat for Research and Technology, GSRT; Ministry of Business, Innovation and Employment, MBIE; Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq; Ministry of Science, ICT and Future Planning, MSIP; National Research Foundation of Korea, NRF; Joint Institute for Nuclear Research, JINR; Instituto Nazionale di Fisica Nucleare, INFN; National Science and Technology Development Agency, สวทช: Thailand; Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, FAPERGS; Secretaría de Educación Superior, Ciencia, Tecnología e Innovación, SENESCYT; Universiti Malaya, UM; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, FAPERJ; Ministry of Science and Technology, Taiwan, MOST; National Academy of Sciences of Ukraine, NASU; Centre National de la Recherche Scientifique, CNRS; Ministry of Education and Science, MES; Institute for Research in Fundamental Sciences, IPM; Benemérita Universidad Autónoma de Puebla, BUAP; Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA; Secretaría de Estado de Investigación, Desarrollo e Innovación, SEIDI; European Regional Development Fund, ERDF; State Atomic Energy Corporation ROSATOM, ROSATOM; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, CINVESTAV; Pakistan Atomic Energy Commission, PAEC; Ministry of Science,Technology and Research, MoSTR; Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie, BMBWF; Institut National de Physique Nucléaire et de Physique des Particules, IN2P3; Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA; National Research Center Kurchatov Institute, NRC KI  Grant

published in

• Physical Review Letters  Journal

keywords

• Binary alloys; Bosons; Colliding beam accelerators; Hadrons; Lead alloys; Center-of-mass energies; Charged hadrons; Measurements of; Nucleon-nucleon; Parton showers; Pb-Pb collisions; Proton proton collisions; Reference data; Spectrum measurement; Z Bosons; Heavy ions

Digital Object Identifier (DOI)

• 10.1103/PhysRevLett.128.122301

PubMed ID

• 35394329

start page

end page

volume

• 128

issue

• 12