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Exclusive J/ψ detection and physics with ECCE
The file available on this institutional repository is an arXiv preprint which may not have been certified by peer review. The definitive version of record published by Elsevier is available at https://doi.org/10.48550/arXiv.2207.10356.Copyright © The Authors 2023. The EIC Comprehensive Chromodynamics Experiment (ECCE) detector has been recommended as a reference design for the proposed Electron-Ion Collider (EIC) program. This paper presents simulation studies of exclusive J/ψ detection and selected physics impact results in EIC using the projected ECCE detector concept. Exclusive quarkonium photoproduction is one of the most popular processes in EIC, which has a large cross section and a simple final state. Due to the gluonic nature of the exchange Pomeron, this process can be related to the gluon distributions in the nucleus. Preliminary results estimate the excellent statistics benefited from the large cross section of J/ψ photoproduction and superior performance of ECCE detector concept. The precise measurement of exclusive J/ψ photoproduction at EIC will help us to more deeply understand nuclear gluon distributions, near threshold production mechanism and nucleon mass structure.X. Li and W. Zha are supported by the National Natural Science Foundation of China (12005220, 12175223) and MOST (2018YFE0104900). The authors would like to thank the ECCE Consortium for performing a full simulation of their detector design, for providing up-to-date information on EIC run conditions, and for suggestions and comments on the manuscript. X. Li and W. Zha would like to thank Y. Zhou for useful suggestions and discussions related to this analysis.
W. Zha is supported by Anhui Provincial Natural Science Foundation No. 2208085J23 and Youth Innovation Promotion Association of Chinese Academy of Sciences.
AANL group are supported by the Science Committee of RA , in the frames of the research project
21AG-1C028
Design and Simulated Performance of Calorimetry Systems for the ECCE Detector at the Electron Ion Collider
We describe the design and performance the calorimeter systems used in the
ECCE detector design to achieve the overall performance specifications
cost-effectively with careful consideration of appropriate technical and
schedule risks. The calorimeter systems consist of three electromagnetic
calorimeters, covering the combined pseudorapdity range from -3.7 to 3.8 and
two hadronic calorimeters. Key calorimeter performances which include energy
and position resolutions, reconstruction efficiency, and particle
identification will be presented.Comment: 19 pages, 22 figures, 5 table
Open Heavy Flavor Studies for the ECCE Detector at the Electron Ion Collider
The ECCE detector has been recommended as the selected reference detector for
the future Electron-Ion Collider (EIC). A series of simulation studies have
been carried out to validate the physics feasibility of the ECCE detector. In
this paper, detailed studies of heavy flavor hadron and jet reconstruction and
physics projections with the ECCE detector performance and different magnet
options will be presented. The ECCE detector has enabled precise EIC heavy
flavor hadron and jet measurements with a broad kinematic coverage. These
proposed heavy flavor measurements will help systematically study the
hadronization process in vacuum and nuclear medium especially in the
underexplored kinematic region.Comment: Open heavy flavor studies with the EIC reference detector design by
the ECCE consortium. 11 pages, 11 figures, to be submitted to the Nuclear
Instruments and Methods
ECCE Sensitivity Studies for Single Hadron Transverse Single Spin Asymmetry Measurements
We performed feasibility studies for various single transverse spin
measurements that are related to the Sivers effect, transversity and the tensor
charge, and the Collins fragmentation function. The processes studied include
semi-inclusive deep inelastic scattering (SIDIS) where single hadrons (pions
and kaons) were detected in addition to the scattered DIS lepton. The data were
obtained in {\sc pythia}6 and {\sc geant}4 simulated e+p collisions at 18 GeV
on 275 GeV, 18 on 100, 10 on 100, and 5 on 41 that use the ECCE detector
configuration. Typical DIS kinematics were selected, most notably
GeV, and cover the range from to . The single spin
asymmetries were extracted as a function of and , as well as the
semi-inclusive variables , and . They are obtained in azimuthal moments
in combinations of the azimuthal angles of the hadron transverse momentum and
transverse spin of the nucleon relative to the lepton scattering plane. The
initially unpolarized MonteCarlo was re-weighted in the true kinematic
variables, hadron types and parton flavors based on global fits of fixed target
SIDIS experiments and annihilation data. The expected statistical
precision of such measurements is extrapolated to 10 fb and potential
systematic uncertainties are approximated given the deviations between true and
reconstructed yields. The impact on the knowledge of the Sivers functions,
transversity and tensor charges, and the Collins function has then been
evaluated in the same phenomenological extractions as in the Yellow Report. The
impact is found to be comparable to that obtained with the parameterized Yellow
Report detector and shows that the ECCE detector configuration can fulfill the
physics goals on these quantities.Comment: 22 pages, 22 figures, to be submitted to joint ECCE proposal NIM-A
volum
ECCE unpolarized TMD measurements
We performed feasibility studies for various measurements that are related to
unpolarized TMD distribution and fragmentation functions. The processes studied
include semi-inclusive Deep inelastic scattering (SIDIS) where single hadrons
(pions and kaons) were detected in addition to the scattered DIS lepton. The
single hadron cross sections and multiplicities were extracted as a function of
the DIS variables and , as well as the semi-inclusive variables ,
which corresponds to the momentum fraction the detected hadron carries relative
to the struck parton and , which corresponds to the transverse momentum of
the detected hadron relative to the virtual photon. The expected statistical
precision of such measurements is extrapolated to accumulated luminosities of
10 fb and potential systematic uncertainties are approximated given the
deviations between true and reconstructed yields.Comment: 12 pages, 9 figures, to be submitted in joint ECCE proposal NIM-A
volum
AI-assisted Optimization of the ECCE Tracking System at the Electron Ion Collider
The Electron-Ion Collider (EIC) is a cutting-edge accelerator facility that
will study the nature of the "glue" that binds the building blocks of the
visible matter in the universe. The proposed experiment will be realized at
Brookhaven National Laboratory in approximately 10 years from now, with
detector design and R&D currently ongoing. Notably, EIC is one of the first
large-scale facilities to leverage Artificial Intelligence (AI) already
starting from the design and R&D phases. The EIC Comprehensive Chromodynamics
Experiment (ECCE) is a consortium that proposed a detector design based on a
1.5T solenoid. The EIC detector proposal review concluded that the ECCE design
will serve as the reference design for an EIC detector. Herein we describe a
comprehensive optimization of the ECCE tracker using AI. The work required a
complex parametrization of the simulated detector system. Our approach dealt
with an optimization problem in a multidimensional design space driven by
multiple objectives that encode the detector performance, while satisfying
several mechanical constraints. We describe our strategy and show results
obtained for the ECCE tracking system. The AI-assisted design is agnostic to
the simulation framework and can be extended to other sub-detectors or to a
system of sub-detectors to further optimize the performance of the EIC
detector.Comment: 16 pages, 18 figures, 2 appendices, 3 table
Measurement of the production of (anti)nuclei in p–Pb collisions at sNN=8.16TeV
Measurements of (anti)proton, (anti)deuteron, and (anti)3He production in the rapidity range -1 > y > 0 as a function of the transverse momentum and event multiplicity in p–Pb collisions at a center-of-mass energy per nucleon–nucleon pair sqrt(sNN) = 8.16 TeV are presented. The coalescence parameters B2 and B3, measured as a function of the transverse momentum per nucleon and of the mean charged-particle multiplicity density, confirm a smooth evolution from low to high multiplicity across different collision systems and energies. The ratios between (anti)deuteron and (anti)3He yields and those of (anti)protons are also reported as a function of the mean charged-particle multiplicity density. A comparison with the predictions of the statistical hadronization and coalescence models for different collision systems and center-of-mass energies favors the coalescence description for the deuteron-to-proton yield ratio with respect to the canonical statistical model
Photoproduction of low-pT J/ψ from peripheral to central Pb–Pb collisions at 5.02 TeV
An excess of J/ψ yield at very low transverse momentum (pT < 0.3 GeV/c), originating from coherent photoproduction, is observed in peripheral and semicentral hadronic Pb–Pb collisions at a center-of-mass energy per nucleon pair of sqrt(sNN) = 5.02 TeV. The measurement is performed with the ALICE detector via the dimuon decay channel at forward rapidity (2.5 < y <4). The nuclear modification factor at very low pT and the coherent photoproduction cross section are measured as a function of centrality down to the 10% most central collisions. These results extend the previous study at sqrt(sNN) = 2.76 TeV, confirming the clear excess over hadronic production in the pT range 0-0.3 GeV/c and the centrality range 70–90%, and establishing an excess with a significance greater than 5σ also in the 50–70% and 30–50% centrality ranges. The results are compared with earlier measurements at sqrt(sNN) = 2.76 TeV and with different theoretical predictions aiming at describing how coherent photoproduction occurs in hadronic interactions with nuclear overlap
Measurement of beauty-strange meson production in Pb–Pb collisions at sNN=5.02TeV via non-prompt Ds + mesons
The production yields of non-prompt D_s^+ mesons, namely D_s^+ mesons from beauty-hadron decays, were measured for the first time as a function of the transverse momentum (pT) at midrapidity (|y| phi pi+, with phi -> K+ K-, in the 4 < pT < 36 GeV/c and 2 < pT < 24 GeV/c intervals for the 0–10% and 30–50% centrality classes, respectively. The measured yields of non-prompt D_S^+ mesons are compared to those of prompt D_s^+ and non-prompt D0 mesons by calculating the ratios of the production yields in Pb–Pb collisions and the nuclear modification factor RAA. The ratio between the RAA of non-prompt D_s^+ and prompt D_s^+ mesons, and that between the RAA of non-prompt D_s^+ and non-prompt D0 mesons in central Pb–Pb collisions are found to be on average higher than unity in the 4 < pT < 12 GeV/c interval with a statistical significance of about 1.6 sigma and 1.7 sigma, respectively. The measured RAA ratios are compared with the predictions of theoretical models of heavy-quark transport in a hydrodynamically expanding QGP that incorporate hadronisation via quark recombination
Measurement of electrons from beauty-hadron decays in pp and Pb-Pb collisions at sNN=5.02 TeV
The production of electrons from beauty-hadron decays was measured at midrapidity in proton-proton (pp)
and central Pb-Pb collisions at center-of-mass energy per nucleon-nucleon pair √s NN = 5.02 TeV, using the
ALICE detector at the LHC. The cross section measured in pp collisions in the transverse momentum interval
2 < pT < 8 GeV/c was compared with models based on perturbative quantum chromodynamics calculations.
The yield in the 10% most central Pb-Pb collisions, measured in the interval 2 < pT < 26 GeV/c, was used
to compute the nuclear modification factor RAA, extrapolating the pp reference cross section to pT larger than
8 GeV/c. The measured R AA shows significant suppression of the yield of electrons from beauty-hadron decays
at high pT and does not show a significant dependence above 8 GeV/c within uncertainties. The results are de-
scribed by several theoretical models based on different implementations of the interaction of heavy quarks with
a quark-gluon plasma, which predict a smaller energy loss for beauty quarks compared to light and charm quark
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