Sookyung Choi

Last updated
SooKyung Choi
Alma mater Kyungpook National University
Known for CP Violation
Particle physics
Awards2017 Ho-Am Prize in Science
Scientific career
Institutions Gyeongsang National University
Seoul National University

SooKyung Choi is a South Korean particle physicist at Gyeongsang National University. She is part of the Belle experiment and was the first to observe the X(3872) meson in 2003. She won the 2017 Ho-Am Prize in Science.

Contents

Early life and education

Choi studied physics at the Kyungpook National University, graduating in 1979 with a Bachelor's degree and 1993 with a PhD. Her supervisors were Dongchul Son and C. Joo. [1] After graduating, Choi joined Seoul National University, working on Møller and Bhabha scattering. [2] She was appointed Professor at Gyeongsang National University, where she worked with the High Energy Accelerator Research Organization (KEK). [3]

Career

Choi's work mainly concerns CP violation and decays of the B meson. [4] Choi worked on the Belle experiment, where she identified several new types of fundamental particles. The first results from Belle came in 2002, finding large cross-sections for the e+econtinuum. [5] [6] In 2003 she discovered the X(3872) meson; a new kind of heavy particle, which does not fit the quantum model as it was made up of four quarks. [3] Choi predicted the X(3872) particle could be a charmonium state or a DD* hadronic molecule. The work was confirmed by a team at the Fermi National Accelerator Laboratory. [7] Choi went on to discover the Y(3940), the Zc(3900) and Z(4430) particles, which proved that particles can exist in a range of forms. [8] Choi studied the decays of these extensively. [9] [10] [11]

She was involved with the study of other charmonium states; using the ϒ(4S) and ϒ(5S) resonances at the Belle detector. [12] [13] Choi has collaborated with the BES III experiment, which studied center of mass energies between 2.9 and 4.42 GeV. The BES III experiment identified new charmonium states with non-zero electric charge. [14]

CP violation was first confirmed at the Belle experiment and would go on to win the 2008 Nobel Prize in Physics. [15] [16] [17] [18] [19] [20] The experiments stopped operation in June 2010. [21] Choi is part of the Belle II experiment, which collected their first collisions in 2018. [22] She served on the advisory board of the International Conference on High Energy Physics in Seoul in July 2018. [23]

In 2017 Choi won the Ho-Am Prize in Science. [24] [25] [26] [27]

Related Research Articles

<span class="mw-page-title-main">Charm quark</span> Type of quark

The charm quark, charmed quark, or c quark is an elementary particle found in composite subatomic particles called hadrons such as the J/psi meson and the charmed baryons created in particle accelerator collisions. Several bosons, including the W and Z bosons and the Higgs boson, can decay into charm quarks. All charm quarks carry charm, a quantum number. This second generation is the third-most-massive quark with a mass of 1.27±0.02 GeV/c2 as measured in 2022 and a charge of +2/3 e.

<span class="mw-page-title-main">Pentaquark</span> Human-made subatomic particle

A pentaquark is a human-made subatomic particle, consisting of four quarks and one antiquark bound together; they are not known to occur naturally, or exist outside of experiments specifically carried out to create them.

In physical cosmology, baryogenesis is the physical process that is hypothesized to have taken place during the early universe to produce baryonic asymmetry, i.e. the imbalance of matter (baryons) and antimatter (antibaryons) in the observed universe.

<span class="mw-page-title-main">Tetraquark</span> Exotic meson composed of four valence quarks

In particle physics, a tetraquark is an exotic meson composed of four valence quarks. A tetraquark state has long been suspected to be allowed by quantum chromodynamics, the modern theory of strong interactions. A tetraquark state is an example of an exotic hadron which lies outside the conventional quark model classification. A number of different types of tetraquark have been observed.

<span class="mw-page-title-main">J/psi meson</span> Subatomic particle made of a charm quark and antiquark

The
J/ψ
(J/psi) meson is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium" or psions. The
J/ψ
is the most common form of charmonium, due to its spin of 1 and its low rest mass. The
J/ψ
has a rest mass of 3.0969 GeV/c2, just above that of the
η
c
, and a mean lifetime of 7.2×10−21 s. This lifetime was about a thousand times longer than expected.

<span class="mw-page-title-main">LHCb experiment</span> Experiment at the Large Hadron Collider

The LHCb experiment is a particle physics detector experiment collecting data at the Large Hadron Collider at CERN. LHCb is a specialized b-physics experiment, designed primarily to measure the parameters of CP violation in the interactions of b-hadrons. Such studies can help to explain the matter-antimatter asymmetry of the Universe. The detector is also able to perform measurements of production cross sections, exotic hadron spectroscopy, charm physics and electroweak physics in the forward region. The LHCb collaboration, who built, operate and analyse data from the experiment, is composed of approximately 1650 people from 98 scientific institutes, representing 22 countries. Vincenzo Vagnoni succeeded on July 1, 2023 as spokesperson for the collaboration from Chris Parkes. The experiment is located at point 8 on the LHC tunnel close to Ferney-Voltaire, France just over the border from Geneva. The (small) MoEDAL experiment shares the same cavern.

<span class="mw-page-title-main">Quarkonium</span> Meson whose constituents are a quark and its own antiquark of the same flavor

In particle physics, quarkonium is a flavorless meson whose constituents are a heavy quark and its own antiquark, making it both a neutral particle and its own antiparticle. The name "quarkonium" is analogous to positronium, the bound state of electron and anti-electron. The particles are short-lived due to matter-antimatter annihilation.

<span class="mw-page-title-main">Exotic hadron</span> Subatomic particles consisting of quarks and gluons

Exotic hadrons are subatomic particles composed of quarks and gluons, but which – unlike "well-known" hadrons such as protons, neutrons and mesons – consist of more than three valence quarks. By contrast, "ordinary" hadrons contain just two or three quarks. Hadrons with explicit valence gluon content would also be considered exotic. In theory, there is no limit on the number of quarks in a hadron, as long as the hadron's color charge is white, or color-neutral.

<span class="mw-page-title-main">Flavor-changing neutral current</span>

In particle physics, flavor-changing neutral currents or flavour-changing neutral currents (FCNCs) are hypothetical interactions that change the flavor of a fermion without altering its electric charge.

<span class="mw-page-title-main">Belle experiment</span> 1999-2010 Japanese particle physics experiment

The Belle experiment was a particle physics experiment conducted by the Belle Collaboration, an international collaboration of more than 400 physicists and engineers, at the High Energy Accelerator Research Organisation (KEK) in Tsukuba, Ibaraki Prefecture, Japan. The experiment ran from 1999 to 2010.

CLEO was a general purpose particle detector at the Cornell Electron Storage Ring (CESR), and the name of the collaboration of physicists who operated the detector. The name CLEO is not an acronym; it is short for Cleopatra and was chosen to go with CESR. CESR was a particle accelerator designed to collide electrons and positrons at a center-of-mass energy of approximately 10 GeV. The energy of the accelerator was chosen before the first three bottom quark Upsilon resonances were discovered between 9.4 GeV and 10.4 GeV in 1977. The fourth Υ resonance, the Υ(4S), was slightly above the threshold for, and therefore ideal for the study of, B meson production.

The
B
s
meson
is a meson composed of a bottom antiquark and a strange quark. Its antiparticle is the
B
s
meson
, composed of a bottom quark and a strange antiquark.

The X(3872) is an exotic meson candidate with a mass of 3871.68 MeV/c2 which does not fit into the quark model because of its quantum numbers. It was first discovered in 2003 by the Belle experiment in Japan and later confirmed by several other experimental collaborations. Several theories have been proposed for its nature, such as a mesonic molecule or a diquark-antidiquark pair (tetraquark).

Z(4430) is a mesonic resonance discovered by the Belle experiment. It has a mass of 4430 MeV/c2. The resonant nature of the peak has been confirmed by the LHCb experiment with a significance of at least 13.9 σ. The particle is charged and is thought to have a quark content of
c

c

d

u
, making it a tetraquark candidate. It has the spin-parity quantum numbers JP = 1+.

In particle physics, B mesons are mesons composed of a bottom antiquark and either an up, down, strange or charm quark. The combination of a bottom antiquark and a top quark is not thought to be possible because of the top quark's short lifetime. The combination of a bottom antiquark and a bottom quark is not a B meson, but rather bottomonium, which is something else entirely.

The D mesons are the lightest particle containing charm quarks. They are often studied to gain knowledge on the weak interaction. The strange D mesons (Ds) were called "F mesons" prior to 1986.

The Y(4260) is an anomalous particle with an energy of 4260 MeV which does not appear to fit into the quark model. It was discovered by the BaBar experiment at Stanford University for the Department of Energy in California and later confirmed by several other experimental collaborations. It being a Charmonium state is unlikely because the Y(4260) is heavier than the threshold for production of two D mesons, yet sits, surprisingly in a dip in the production rate for pairs of D's. It is a possibility that it is a hybrid—a predicted but not-yet-seen type of particle, where a gluon is actually a permanent part of the makeup of the particle, instead of just an ephemeral messenger keeping the quarks bound together.

The Zc(3900) is a hadron, a type of subatomic particle made of quarks, believed to be the first tetraquark that has been observed experimentally. The discovery was made in 2013 by two independent research groups: one using the BES III detector at the Chinese Beijing Electron Positron Collider, the other being part of the Belle experiment group at the Japanese KEK particle physics laboratory.

<span class="mw-page-title-main">Kam-Biu Luk</span>

Kam-Biu Luk is a professor of physics, with a focus on particle physics, at UC Berkeley and a senior faculty scientist in the Lawrence Berkeley National Laboratory's physics division. Luk has conducted research on neutrino oscillation and CP violation. Luk and his collaborator Yifang Wang were awarded the 2014 Panofsky Prize "for their leadership of the Daya Bay experiment, which produced the first definitive measurement of θ13 angle of the neutrino mixing matrix." His work on neutrino oscillation also received 2016 Breakthrough Prize in Fundamental Physics shared with other teams. He also received a Doctor of Science honoris causa from the Hong Kong University of Science and Technology in 2016. Luk is a fellow of the American Physical Society, and the American Academy of Arts and Sciences.

<span class="mw-page-title-main">Brad Cox (physicist)</span> American physicist

Bradley Cox is an American physicist, academic and researcher. He is a Professor of Physics and the founder of the High Energy Physics Group at the University of Virginia.

References

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