0000000000560749
AUTHOR
Jeongsu Bok
Experimental Evidence for an Attractive p-φ Interaction
Physical review letters 127(17), 172301 (2021). doi:10.1103/PhysRevLett.127.172301
Soft-dielectron excess in proton-proton collisions at $\sqrt{s}$ = 13 TeV
Physical review letters 127(4), 042302 (2021). doi:10.1103/PhysRevLett.127.042302
Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sNN=5.02 TeV
The elliptic flow of electrons from beauty hadron decays at midrapidity ($|y|$ $<$ 0.8) is measured in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parameterized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, $v_{\rm 2}$. The $v_{\rm 2}$ coefficient is measured for the first time in transverse momentum ($p_{\rm{T}}$) range 1.3-6 GeV/$c$ in the centrality class 30-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length $c\tau \approx$ 500 $\mu$m compared to that of charm had…
Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC
Physics letters / B 822, 136708 (2021). doi:10.1016/j.physletb.2021.136708
First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV
Abstract The first measurement of the coherent photoproduction of ρ 0 vector mesons in ultra-peripheral Xe–Xe collisions at s NN = 5.44 TeV is presented. This result, together with previous HERA γp data and γ–Pb measurements from ALICE, describes the atomic number (A) dependence of this process, which is particularly sensitive to nuclear shadowing effects and to the approach to the black-disc limit of QCD at a semi-hard scale. The cross section of the Xe + Xe → ρ 0 + Xe + Xe process, measured at midrapidity through the decay channel ρ 0 → π + π − , is found to be d σ / d y = 131.5 ± 5.6 ( stat . ) − 16.9 + 17.5 ( syst . ) mb. The ratio of the continuum to resonant contributions for the prod…
Multiplicity dependence of inclusive J/ψ production at midrapidity in pp collisions at s=13 TeV
Measurements of the inclusive J/ψ yield as a function of charged-particle pseudorapidity density dNch/dη in pp collisions at √s = 13 TeV with ALICE at the LHC are reported. The J/ψ meson yield is measured at midrapidity (|y| < 0.9) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity (|η| < 1) and at forward rapidity (−3.7 < η < −1.7 and 2.8 < η < 5.1); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/ψ yield with normalized dNch/dη is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which de…
Measurement of the low-energy antideuteron inelastic cross section
In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of $0.3 \leq p < 4$ GeV/$c$. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the GEANT4 toolkit for the propagation of antiparticles through the detector material. The analysis of th…
Study of very forward energy and its correlation with particle production at midrapidity in pp and p-Pb collisions at the LHC
Journal of high energy physics 08(8), 86 (2022). doi:10.1007/JHEP08(2022)086
ϒ production and nuclear modification at forward rapidity in Pb–Pb collisions at sNN=5.02TeV
Abstract The production of ϒ mesons in Pb–Pb collisions at a centre-of-mass energy per nucleon pair s NN = 5.02 TeV is measured with the muon spectrometer of the ALICE detector at the LHC. The yields as well as the nuclear modification factors are determined in the forward rapidity region 2.5 y 4.0 , as a function of rapidity, transverse momentum and collision centrality. The results show that the production of the ϒ ( 1S ) meson is suppressed by a factor of about three with respect to the production in proton–proton collisions. For the first time, a significant signal for the ϒ ( 2S ) meson is observed at forward rapidity, indicating a suppression stronger by about a factor 2–3 with respec…
Jet-associated deuteron production in pp collisions at s=13 TeV
Author(s): Acharya, S; Adamova, D; Adler, A; Adolfsson, J; Aglieri Rinella, G; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, SU; Akbar, Z; Akindinov, A; Al-Turany, M; Albuquerque, DSD; Aleksandrov, D; Alessandro, B; Alfanda, HM; Alfaro Molina, R; Ali, B; Ali, Y; Alici, A; Alizadehvandchali, N; Alkin, A; Alme, J; Alt, T; Altenkamper, L; Altsybeev, I; Anaam, MN; Andrei, C; Andreou, D; Andronic, A; Angeletti, M; Anguelov, V; Anticic, T; Antinori, F; Antonioli, P; Apadula, N; Aphecetche, L; Appelshauser, H; Arcelli, S; Arnaldi, R; Arratia, M; Arsene, IC; Arslandok, M; Augustinus, A; Averbeck, R; Aziz, S; Azmi, MD; Badala, A; Baek, YW; Bai, X; Bailhache, R; Bala, R; Balbino, A; Baldisseri, …
Unveiling the strong interaction among hadrons at the LHC
One of the key challenges for nuclear physics today is to understand from first principles the effective interaction between hadrons with different quark content. First successes have been achieved using techniques that solve the dynamics of quarks and gluons on discrete space-time lattices1,2. Experimentally, the dynamics of the strong interaction have been studied by scattering hadrons off each other. Such scattering experiments are difficult or impossible for unstable hadrons3–6 and so high-quality measurements exist only for hadrons containing up and down quarks7. Here we demonstrate that measuring correlations in the momentum space between hadron pairs8–12 produced in ultrarelativistic…
Λc+ Production and Baryon-to-Meson Ratios in pp and p -Pb Collisions at sNN=5.02 TeV at the LHC
The prompt production of the charm baryon Λ c + and the Λ c + / D 0 production ratios were measured at midrapidity with the ALICE detector in p p and p -Pb collisions at s NN = 5.02 TeV . These new measurements show a clear decrease of the Λ c + / D 0 ratio with increasing transverse momentum ( p T ) in both collision systems in the range 2 p T 12 GeV / c , exhibiting similarities with the light-flavor baryon-to-meson ratios p / π and Λ / K S 0 . At low p T , predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the dat…
Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at ...
The event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions, using higher-order symmetric cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium when compared to correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements since contributions from two-harmonic correlations are explicitly removed in the new observables. A comparison to Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions. © 2021…
First measurement of quarkonium polarization in nuclear collisions at the LHC
The polarization of inclusive J/$\psi$ and $\Upsilon(1{\rm S})$ produced in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=5.02$ TeV at the LHC is measured with the ALICE detector. The study is carried out by reconstructing the quarkonium through its decay to muon pairs in the rapidity region $2.5<y<4$ and measuring the polar and azimuthal angular distributions of the muons. The polarization parameters $\lambda_{\theta}$, $\lambda_{\phi}$ and $\lambda_{\theta\phi}$ are measured in the helicity and Collins-Soper reference frames, in the transverse momentum interval $2<p_{\rm T}<10$ GeV/$c$ and $p_{\rm T}<15$ GeV/$c$ for the J/$\psi$ and $\Upsilon(1{\rm S})$, respectively. The polarization parameter…
First study of the two-body scattering involving charm hadrons
Physical review / D 106(5), 052010 (2022). doi:10.1103/PhysRevD.106.052010
Production of muons from heavy-flavour hadron decays at high transverse momentum in Pb–Pb collisions atsNN=5.02and 2.76 TeV
Abstract Measurements of the production of muons from heavy-flavour hadron decays in Pb–Pb collisions at s NN = 5.02 and 2.76 TeV using the ALICE detector at the LHC are reported. The nuclear modification factor R AA at s NN = 5.02 TeV is measured at forward rapidity ( 2.5 y 4 ) as a function of transverse momentum p T in central, semi-central, and peripheral collisions over a wide p T interval, 3 p T 20 GeV/c, in which muons from beauty-hadron decays are expected to take over from charm as the dominant source at high p T ( p T > 7 GeV/c). The R AA shows an increase of the suppression of the yields of muons from heavy-flavour hadron decays with increasing centrality. A suppression by a fact…
Inclusive heavy-flavour production at central and forward rapidity in Xe–Xe collisions at TeV
The first measurements of the production of muons and electrons from heavy-flavour hadron decays in Xe–Xe collisions at sNN=5.44 TeV, using the ALICE detector at the LHC, are reported. The measurement of the nuclear modification factor RAA is performed as a function of transverse momentum pT in several centrality classes at forward rapidity (2.5<y<4) and midrapidity (|y|<0.8) for muons and electrons from heavy-flavour hadron decays, respectively. A suppression by a factor up to about 2.5 compared to the binary-scaled pp reference is observed in central collisions at both central and forward rapidities. The RAA of muons from heavy-flavour hadron decays is compared to previous measur…
Pion–kaon femtoscopy and the lifetime of the hadronic phase in Pb−Pb collisions at sNN=2.76 TeV
Abstract In this paper, the first femtoscopic analysis of pion–kaon correlations at the LHC is reported. The analysis was performed on the Pb–Pb collision data at s NN = 2.76 TeV recorded with the ALICE detector. The non-identical particle correlations probe the spatio-temporal separation between sources of different particle species as well as the average source size of the emitting system. The sizes of the pion and kaon sources increase with centrality, and pions are emitted closer to the centre of the system and/or later than kaons. This is naturally expected in a system with strong radial flow and is qualitatively reproduced by hydrodynamic models. ALICE data on pion–kaon emission asymm…
Transverse-momentum and event-shape dependence of D-meson flow harmonics in Pb–Pb collisions at
A. I. Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation (ANSL), State Committee of Science and World Federation of Scientists (WFS), Armenia; Austrian Academy of Sciences, Austrian Science Fund (FWF): [M 2467-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; Ministry of Education of China (MOEC), Ministry …
Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC
Physical review / D 105(1), L011103 (2022). doi:10.1103/PhysRevD.105.L011103
Characterizing the initial conditions of heavy-ion collisions at the LHC with mean transverse momentum and anisotropic flow correlations
Physics letters / B 834, 137393 (2022). doi:10.1016/j.physletb.2022.137393