A recent study has revealed the existence of a TETRAQUARK composed of charm and beauty quarks, advancing our understanding of STRONG FORCE INTERACTIONS and subatomic particle physics.
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| Scientists Discover a New Tetraquark |
Researchers from Tata Institute of Fundamental Research (TIFR) and Institute
of Mathematical Sciences (IMSc) have
published a new finding in the journal Physical
Review Letters , reflecting their discoveries regarding the complex world of
subatomic particles. Their work expands our knowledge of strong force
interactions and opens up new avenues for the study of exotic subatomic
particles and quantum chromodynamics
(QCD) .
At the heart of this research
lies the mysterious fundamental strong force, which produces almost all the
mass of observable matter in the universe. All composite subatomic particles
that make up observable matter in our world are formed by a few fundamental
particles called quarks interacting with each other through the exchange of
gluons.
The Quantum Chromodynamics (QCD) theory, which governs the dynamics of strong
interactions, is essential for this understanding. According to QCD,
color-neutral quark pairs can transform into subatomic particles called
hadrons.
Hadrons have historically
been divided into two main groups: mesons, consisting of one quark and one
antiquark, such as pions, and baryons, consisting of three quarks, such as
protons. Exotic hadrons with four, five, or six quarks, as well as particles
containing gluons like glueballs, fall outside these categories.
However, until recently, the
existence of these unusual hadrons was largely unknown to particle physicists.
Experimental findings over the past fifteen years have shed light on this
previously dark area, revealing a wide range of extraordinary hadrons that
challenge our understanding of subatomic particles and the strong force.
Discovery of Tetraquarks: A New Frontier in Particle Physics
Tetraquarks , or four quarks (or more
accurately, two quarks and two antiquarks), are among these exotic hadrons.
Their precise forms are still unknown, but they may exist as loosely bound
molecules of two mesons, highly compact forms, or in other configurations.
Additionally, they are among the most commonly observed exotics, and it is
predicted that many more will be found in the future. Theoretical research can
help in their discovery by predicting quark concentrations and potential
energies.
Dr. Nilmani Mathur, Dr. M.
Padmanath from IMSc, and postdoctoral researcher Dr. Archana Radhakrishnan from
TIFR predicted a new tetraquark. This new subatomic particle is a member of the
Tbc tetraquark family , known as beauty-charm tetraquarks . It consists of two
light antiquarks and two beauty and charm quarks.
To perform this calculation,
they utilized the computing capacity of the Indian Lattice Gauge Theory Initiative (ILGTI)
. Interactions between a charm and a light meson were used to examine the
development of this specific tetraquark. This study investigated the energy
eigenvalues of meson systems interacting in finite volumes across a range of
lattice spacings and valence light quark masses, leading to the conclusion that
this tetraquark exists. Similar particles with the same quark composition but different
spins and parities may also exist.
This prediction comes at a
very fortunate time, as a tetraquark composed of two charm quarks and two light
antiquarks ( Tcc ) has recently been discovered. Given that the energy range
and luminosity required for its production and detection have become more
accessible, it is highly likely that the newly predicted particle or a related
variant will be found using similar experimental techniques.
Furthermore, the binding
energy of the predicted particle is greater than that of any tetraquark found
so far, and as the mass of the light quark increases, the binding weakens,
suggesting complex dynamics of strong interactions across a range of quark mass
regimes and shedding light on the fascinating aspects of strong force with
heavy quarks in hadron formation.
This situation provides further incentive for new-generation experiments to search for heavier exotic subatomic particles that could be useful in understanding and realizing the full potential of the strong force.