48 research outputs found
A Modern Introduction To Particle Physics (3rd Edition)
The book provides a comprehensive account of particle physics linking various aspects of particle physics in a coherent manner. This self-contained book not only cover basic concepts and recent developments but also overlaps between Astrophysics, Cosmology and Particle Physics, known as astroparticle physics. Several appendices are included to make the book self-contained
model for electroweak unification and sterile neutrinos
Some of basic problems in neutrino physics such as new energy scales, the
enormous gap between neutrino masses and the lightest charged fermion mass,
possible existance of sterile neutrinos in eV mass range are studied in the
local gauge group for electroweak unification, which
does not contain fermions with exotic electric charges. It is shown that
neutrino mass spectrum can be decoupled from that of the other fermions.
Further normal seesaw mechanism for neutrinos, with right handed neutrino
Majorana masses to be of order as well a new eV-scale
can be accomodated. The eV-scale seesaw may manifest itself in experiments like
Liquid Scintilation Neutrino Detector (LSND) and MiniBooNE (MB) experimental
results and future neutrino experiments.Comment: 13 page
Boson mass spectrum in model with exotic electric charges
The boson mass spectrum of the electro-weak \textbf{} model with exotic electric charges is investigated by using the
algebraical approach supplied by the method of exactly solving gauge models
with high symmetries. Our approach predicts for the boson sector a
one-parameter mass scale to be tuned in order to match the data obtained at
LHC, LEP, CDF.Comment: 12 pages, 1 Table with numerical estimates and 1 Figure added,
mistaken results correcte
SU_L(4) x U(1) model for electroweak unification
After some general remarks about SU_L(4) electroweak unification, the model
is extended to SU_L(4)xU_X(1) to accomodate fractionally charged quarks. The
unification scale is expected to be in TeV region. A right-handed Majorana
neutrino along with known lepton are put in the fundamental representation of
SU_L(4) with Y_X=0. The see-saw mechanism for neutrino masses and flavor mixing
in neutrino sector is a natural feature of the model. The lepton number
violating processes can occure through dilepton gauge bosons contained in the
model.Comment: RevTeX, 9 pages, no figure: replaced with revised versio
Off-diagonal structure of neutrino mass matrix in see-saw mechanism and electron-muon-tau lepton universality
By a simple extension of the standard model in which ()
universality is not conserved, we present a scenario within the framework of
see-saw mechanism in which the neutrino mass matrix is strictly off-diagonal in
the flavor basis. We show that a version of this scenario can accomodate the
atmospheric neutrino oscillations and
oscillations claimed by the LSND collaboration.
PACS: 14.60.Pq; 14.60.St;13.15.+gComment: 5 pages, Revtex, 1 figure: The model accomodate another version which
explains atmospheric neutrino data and the observed solar neutrino
oscillations (large angle solution). In the previous version the value of
\lambda parameter is changed to the expected one. This version now
accomodates LSND result and solar neutrino oscillations (small angle MSW
solution
Vector Meson Contributions in epsilon'/epsilon
The CP violating parameter epsilon'/epsilon is computed using the low-energy
dynamics of a chiral theory supplemented by vector resonances. The divergent
contributions coming from strong pi-pi scattering are tamed by vector-meson
exchange terms. This amounts to softening the fast growing high-energy
behaviour of pi-pi scattering. The final result for epsilon'/epsilon shows a
smooth dependence on the cut-off where low energy dynamics is matched with that
of QCD.Comment: 11 pages, 2 figures. published versio
Two body non-leptonic decays in quark model with factorization ansatz
The two body non-leptonic decays are analyzed in factorization
approximation, using quark model, as a free parameter. It is
shown that the experimental branching ratio for restricts and this ratio can be understood for a value
of which lies in the range suggested by two body
B meson decays. The branching ratios for are predicted to be larger than the previous estimates. Finally it
is pointed that CKM-Wolfenstein parameter , where is CP
phase, can be determined from the ratio of widths of and or that of
and
independent of the parameter .Comment: 18 pages, latex, 1 figure available on request, please send any
questions or comments to [email protected]
Spin-orbit splittings in heavy-light mesons and Dirac equation
The spin-orbit splitting in heavy-light mesons is seen to be suppressed
experimentally. It is shown that it can be understood qualitatively in the
frame work of Dirac theory. An alternative derivation of a relativistic
dynamical symmetry for the Dirac Hamiltonian, which suppresses spin orbit
splitting, is also given. However it is shown that such a symmetry is not
needed since the spin-orbit splitting in Dirac theory with Coulomb like
potential (as is the case for the one gluon exchange potential in pQCD) is
small anyway.Comment: 9 pages, 1 fi