X and Y bosons

X and Y bosons
Composition Elementary particle
Statistics Bosonic
Status Hypothetical
Types 12
Mass ≈ 1015 GeV/c2
Decays into X: two quarks, or one antiquark and one charged antilepton
Y: two quarks, or one antiquark and one charged antilepton, or one antiquark and one antineutrino
Electric charge X: +4/3 e
Y: +1/3 e
Color charge triplet or antitriplet
Spin 1
Spin states 3
Weak isospin projection X: +1/2
Y: −1/2
Weak hypercharge 5/3
B − L 2/3

In particle physics, the X and Y bosons (sometimes collectively called "X bosons"[1]) are hypothetical elementary particles analogous to the W and Z bosons, but corresponding to a new type of force predicted by the Georgi–Glashow model, a grand unified theory.

Details

The X and Y bosons couple quarks to leptons, allowing violation of the conservation of baryon number, and thus permitting proton decay.

An X boson would have the following decay modes:[2]


X
 →
u
 +
u

X
 →
e+
 +
d

where the two decay products in each process have opposite chirality,
u
 is an up quark,
d
 is a down antiquark and
e+
 is a positron.

A Y boson would have the following decay modes:[2]


Y
 →
e+
 +
u

Y
 →
d
 +
u

Y
 →
d
 +
ν
e

where the first decay product in each process has left-handed chirality and the second has right-handed chirality and
ν
e is an electron antineutrino.

Similar decay products exist for the other quark-lepton generations

In these reactions, neither the lepton number (L) nor the baryon number (B) is conserved, but B − L is. Different branching ratios between the X boson and its antiparticle (as is the case with the K-meson) would explain baryogenesis. For instance, if a
X
+/
X
- pair are created out of energy, and they follow the two branches described above:
X
+ →
u
 +
u
,
X
- →
d
 +
e−
; re-grouping the result (
u
 +
u
 +
d
 ) +
e−
 =
p
 +
e−
 shows it to be a Hydrogen atom.

See also

References

  1. ↑ Ta-Pei Cheng; Ling-Fong Li (1983). Gauge Theory of Elementary Particle Physics. Oxford University Press. p. 437. ISBN 0-19-851961-3.
  2. 1 2 Ta-Pei Cheng; Ling-Fong Li (1983). Gauge Theory of Elementary Particle Physics. Oxford University Press. p. 442. ISBN 0-19-851961-3.


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