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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 ...
Quarks have fractional electric charge values – either (− 1 / 3 ) or (+ 2 / 3 ) times the elementary charge (e), depending on flavor. Up, charm, and top quarks (collectively referred to as up-type quarks) have a charge of + 2 / 3 e; down, strange, and bottom quarks (down-type quarks) have a charge of − 1 / 3 e.
All quarks are assigned a baryon number of 1 / 3 . Up, charm and top quarks have an electric charge of + 2 / 3 , while the down, strange, and bottom quarks have an electric charge of − 1 / 3 . Antiquarks have the opposite quantum numbers. Quarks are spin- 1 / 2 particles, and thus fermions. Each quark or antiquark ...
Mesons named with the letter "f" are scalar mesons (as opposed to a pseudo-scalar meson), and mesons named with the letter "a" are axial-vector mesons (as opposed to an ordinary vector meson) a.k.a. an isoscalar vector meson, while the letters "b" and "h" refer to axial-vector mesons with positive parity, negative C-parity, and quantum numbers I G of 1 + and 0 − respectively.
The double-charm tetraquark (T + cc, cc u d) is a type of long-lived tetraquark that was discovered in 2021 in the LHCb experiment conducted at the Large Hadron Collider. [3] [4] [2] [5] It contains four quarks: two charm quarks, an anti-up and an anti-down quark. [1] It has a theoretical computed mass of 3868 ± 124 MeV/c 2. [1]
1964 Sheldon Glashow and James Bjorken predict the existence of the charm quark. The addition is proposed because it allows for a better description of the weak interaction (the mechanism that allows quarks and other particles to decay), equalizes the number of known quarks with the number of known leptons , and implies a mass formula that ...
The D mesons were discovered in 1976 by the Mark I detector at the Stanford Linear Accelerator Center. [3]Since the D mesons are the lightest mesons containing a single charm quark (or antiquark), they must change the charm (anti)quark into an (anti)quark of another type to decay.
The Higgs–Yukawa couplings of the up, down, charm, strange and bottom quarks are hypothesized to have small values at the extremely high energy scale of grand unification, 10 15 GeV. They increase in value at lower energy scales, at which the quark masses are generated by the Higgs. The slight growth is due to corrections from the QCD ...