1,016 research outputs found
Fluctuation, time-correlation function and geometric Phase
We establish a fluctuation-correlation theorem by relating the quantum
fluctuations in the generator of the parameter change to the time integral of
the quantum correlation function between the projection operator and force
operator of the ``fast'' system. By taking a cue from linear response theory we
relate the quantum fluctuation in the generator to the generalised
susceptibility. Relation between the open-path geometric phase, diagonal
elements of the quantum metric tensor and the force-force correlation function
is provided and the classical limit of the fluctuation-correlation theorem is
also discussed.Comment: Latex, 12 pages, no figures, submitted to J. Phys. A: Math & Ge
Associated single photons and doubly charged scalar at linear e-e- colliders
Doubly charged scalars, predicted in many models having exotic Higgs
representations, can in general have lepton-number violating (LFV) couplings.
We show that by using an associated monoenergetic final state photon seen at a
future linear e-e- collider, we can have a clear and distinct signature for a
doubly-charged resonance. The strength of the Delta L=2 coupling can also be
probed quite effectively as a function of the recoil mass of the doubly-charged
scalar.Comment: Reference adde
Proton Decay and Related Processes in Unified Models with Gauged Baryon Number:
In unification models based on SU(15) or SU(16), baryon number is part of the
gauge symmetry, broken spontaneously. In such models, we discuss various
scenarios of important baryon number violating processes like proton decay and
neutron-antineutron oscillation. Our analysis depends on the effective operator
method, and covers many variations of symmetry breaking, including different
intermediate groups and different Higgs boson content. We discuss processes
mediated by gauge bosons and Higgs bosons parallely. We show how accidental
global or discrete symmetries present in the full gauge invariant Lagrangian
restrict baryon number violating processes in these models. In all cases, we
find that baryon number violating interactions are sufficiently suppressed to
allow grand unification at energies much lower than the usual GeV.Comment: (32 pages LATEX) [DOE-ER\,40757-022, CPP-93-22] {Small changes made
and two references added. This version will appear in Phys. Rev. D
Non SUSY Unification in Left-Right Models
We explore in a model independent way the possibility of achieving the non
supersymmetric gauge coupling unification within left-right symmetric models,
with the minimal particle content at the left-right mass scale which could be
as low as 1 TeV in a variety of models, and with a unification scale M in the
range GeV GeV.Comment: 18 pages, Latex file, uses epsf style, four figures. Submitted for
publication to Phys. Rev. D on Oct. 13, 199
Baryon and Lepton Number Assignment in Models
In models there are new particles whose baryon number is not uniquely
assigned. We point out that the baryon and lepton number assignment to these
particles can change the baryogenesis scenario significantly. We consider
left-right symmetric extension of the standard model in which quantum
number is gauged. The identification of with a generator of is
used to define the baryon and lepton numbers for the exotic particles in a way
that the electroweak baryon and lepton number anomaly corresponding to the
group vanishes, {\it i.e.}, there is no non-perturbative baryon or
lepton number violation during the electroweak phase transition. We study some
consequences of the new assignment.Comment: 14 pages, LaTeX file, 1 submitted Figure file(.eps
Mixed state geometric phases, entangled systems, and local unitary transformations
The geometric phase for a pure quantal state undergoing an arbitrary
evolution is a ``memory'' of the geometry of the path in the projective Hilbert
space of the system. We find that Uhlmann's geometric phase for a mixed quantal
state undergoing unitary evolution not only depends on the geometry of the path
of the system alone but also on a constrained bi-local unitary evolution of the
purified entangled state. We analyze this in general, illustrate it for the
qubit case, and propose an experiment to test this effect. We also show that
the mixed state geometric phase proposed recently in the context of
interferometry requires uni-local transformations and is therefore essentially
a property of the system alone.Comment: minor changes, journal reference adde
Reply to "comment on Geometric phases for mixed states during cyclic evolutions"
We show that the geometric phase for mixed state during a cyclic evolution
suggested in 2004 J. Phys. A 37 3699 is U(1) invariant and can be observed by
nowaday techniques.Comment: Reply to the comment of Erik Sjoqvis
SU(16) grandunification: breaking scales, proton decay and neutrino magnetic moment
We give a detailed renormalization group analysis for the SU(16) grandunified
group with general breaking chains in which quarks and leptons transform
separately at intermediate energies. Our analysis includes the effects of Higgs
bosons. We show that the grandunification scale could be as low as GeV and give examples where new physics could exist at relatively low
energy ( GeV). We consider proton decay in this model and show that
it is consistent with a low grandunification scale. We also discuss the
possible generation of a neutrino magnetic moment in the range of to
with a very small mass by the breaking of the embedded
SU(2) symmetry at a low energy.Comment: (16 pages in REVTEX + 6 figures not included) OITS-49
Superfluid-spiral state of quantum ferrimagnets in magnetic field
We study the phase diagram of one-dimensional quantum ferrimagnets by using a
numerical exact diagonalization of a finite size system along with a
field-theoretical non-linear model of the quantum ferrimagnets at zero
temperature and its effective description in the presence of the external
magnetic field in terms of the quantum XY-model. The low- and the high-field
phases correspond respectively to the classical N\'eel and the fully polarized
ferromagnetic states where in the intermediate magnetic field (), it is an XXZ+h model with easy plane anisotropy, which possess the
spiral (superfluid) states that carry the dissipationless spin-supercurrent. We
derive the critical exponents, and then will study the stability of the XY
spiral state against these spin-supercurrents and the hard axis fluctuations.
We will show a first order phase transition from the easy plane spiral state to
a saturated ferromagnetic state occurs at if the spin-supercurrent
reaches to its critical value.Comment: 6 pages and 4 figure
Probing SO(10) symmetry breaking patterns through sfermion mass relations
We consider supersymmetric SO(10) grand unification where the unified gauge
group can break to the Standard Model gauge group through different chains. The
breaking of SO(10) necessarily involves the reduction of the rank, and
consequent generation of non-universal supersymmetry breaking scalar mass
terms. We derive squark and slepton mass relations, taking into account these
non-universal contributions to the sfermion masses, which can help distinguish
between the different chains through which the SO(10) gauge group breaks to the
Standard Model gauge group. We then study some implications of these
non-universal supersymmetry breaking scalar masses for the low energy
phenomenology.Comment: 13 pages, latex using revtex4, contains 2 figures, replaced with
version accepted for publicatio
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