9,424 research outputs found
Constraints on the Neutrino Parameters from the `Rise-up' in the Boron Neutrino Spectrum at Low Energies
The rise-up in boron neutrino spectrum at low energies has been studied
within the framework of `pure LMA' scenario. Indirect bounds on the spectral
`upturn' have been obtained from the available solar neutrino data. These
bounds have been used to demonstrate the efficacy of the precision measurements
of the `upturn' for further constraining the neutrino parameter space allowed
by SNO salt phase data. The sterile neutrino flux has been constrained in the
light of the recent 766.3 Ty KamLAND spectral data.Comment: Latex 10pages including 3 postscript figure
Superfield Approach to Nilpotency and Absolute Anticommutativity of Conserved Charges: 2D non-Abelian 1-Form Gauge Theory
We exploit the theoretical strength of augmented version of superfield
approach (AVSA) to Becchi-Rouet-Stora-Tyutin (BRST) formalism to express the
nilpotency and absolute anticommutativity properties of the (anti-)BRST and
(anti-)co-BRST conserved charges for the two -dimensional (2D)
non-Abelian 1-form gauge theory (without any interaction with matter fields) in
the language of superspace variables, their derivatives and suitable
superfields. In the proof of absolute anticommutativity property, we invoke the
strength of Curci-Ferrari (CF) condition for the (anti-)BRST charges. No such
outside condition/restriction is required in the proof of absolute
anticommutativity of the (anti-)co-BRST conserved charges. The latter
observation (as well as other observations) connected with (anti-)co-BRST
symmetries and corresponding conserved charges are novel results of our present
investigation. We also discuss the (anti-)BRST and (anti-)co-BRST symmetry
invariance of the appropriate Lagrangian densities within the framework of
AVSA. In addition, we dwell a bit on the derivation of the above fermionic
(nilpotent) symmetries by applying the AVSA to BRST formaism where only the
(anti-)chiral superfields are used.Comment: LaTeX file, 33 pages, journal referenc
Solar Neutrinos: Spin Flavour Precession and LMA
The time dependence that appears to be hinted by the data from the first 13
years of the solar neutrino Gallium experiments is viewed as resulting from a
partial conversion of active neutrinos to light sterile ones through the
resonant interaction between the magnetic moment of the neutrino and a varying
solar field. A summary of the model and its predictions are presented for the
forthcoming experiments Borexino and LENS.Comment: 6 pages, 3 figures, contribution to 12th Lomonosov Conference in
Elementary Particle Physics, Moscow, Aug 24-31 (2005
Modified 2D Proca Theory: Revisited Under BRST and (Anti-)Chiral Superfield Formalisms
Within the framework of Becchi-Rouet-Stora-Tyutin (BRST) approach, we discuss
mainly the fermionic (i.e. off-shell nilpotent) (anti-)BRST, (anti-)co-BRST and
some discrete dual-symmetries of the appropriate Lagrangian densities for a two
(1+1)-dimensional (2D) modified Proca (i.e. a massive Abelian 1-form) theory
without any interaction with matter fields. One of the novel observations of
our present investigation is the existence of some kinds of restrictions in the
case of our present St\"{u}ckelberg-modified version of the 2D Proca theory
which is not like the standard Curci-Ferrari (CF)-condition of a non-Abelian
1-form gauge theory. Some kinds of similarities and a few differences between
them have been pointed out in our present investigation. To establish the
sanctity of the above off-shell nilpotent (anti-)BRST and (anti-)co-BRST
symmetries, we derive them by using our newly proposed (anti-)chiral superfield
formalism where a few specific and appropriate sets of invariant quantities
play a decisive role. We express the (anti-)BRST and (anti-)co-BRST conserved
charges in terms of the superfields that are obtained after the applications of
(anti-)BRST and (anti-)co-BRST invariant restrictions and prove their off-shell
nilpotency and absolute anticommutativity properties, too. Finally, we make
some comments on (i) the novelty of our restrictions/obstructions, and (ii) the
physics behind the negative kinetic term associated with the pseudo-scalar
field of our present theory.Comment: LaTeX file, 58 pages, Journal reference give
Christ-Lee Model: (Anti-)Chiral Supervariable Approach to BRST Formalism
We derive the off-shell nilpotent of order two and absolutely anti-commuting
Becchi-Rouet-Stora-Tyutin (BRST), anti-BRST and (anti-)co-BRST symmetry
transformations for the Christ--Lee (CL) model in one (0 + 1)-dimension (1D) of
spacetime by exploiting the (anti-)chiral supervariable approach (ACSA) to BRST
formalism where the quantum symmetry [i.e. (anti-)BRST along with
(anti-)co-BRST] invariant quantities play a crucial role. We prove the
nilpotency and absolute anti-commutativity properties of the (anti-) BRST along
with (anti-)co-BRST conserved charges within the scope of ACSA to BRST
formalism where we take only one Grassmannian variable into account. We also
show the (anti-)BRST and (anti-)co-BRST invariances of the Lagrangian within
the scope of ACSA.Comment: LaTeX file, 19 pages, version to appear in AHE
Measurement Uncertainty in Vibration Calibration in Frequency Range of 5 Hz to 10 kHz
The paper evaluates the measurement uncertainty in realizing the secondary vibration standard at CSIR-National Physical Laboratory, India, and presents a comparison of the measurement uncertainty of secondary standard with that of primary vibration standard. The relative expanded measurement uncertainty of 0.80% to 2.2% in frequency range of 5 Hz to 10 kHz is evaluated. The measurement uncertainty so calculated is verified by comparison with the results from primary vibration calibration standard of CSIR-National Physical Laboratory, New Delhi, and SPEKTRA Schwingungstechnik und Akustik GmbH Dresden, Germany primary calibrations. The study recommends calibrating the back-to-back accelerometer with minimal uncertainty by using a primary calibrated single-ended accelerometer mounted on the top of the back-to-back transducer.The paper serves a guiding document to the calibration laboratories, industries and other stake holders in India to understand the concept of traceability in vibration measurements and formulation of uncertainty budget as per the international standard
Predictions from non trivial Quark-Lepton complementarity
The complementarity between the quark and lepton mixing matrices is shown to
provide robust predictions. We obtain these predictions by first showing that
the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices,
may have a zero (1,3) entry which is favored by experimental data.
We obtain that any theoretical model with a vanishing (1,3) entry of V_M that
is in agreement with quark data, solar, and atmospheric mixing angle leads to
. This value is consistent with the
present 90% CL experimental upper limit. We also investigate the prediction on
the lepton phases. We show that the actual evidence, under the only assumption
that the correlation matrix V_M product of CKM and PMNS has a zero in the entry
(1,3), gives us a prediction for the three CP-violating invariants J, S_1, and
S_2. A better determination of the lepton mixing angles will give stronger
prediction for the CP-violating invariants in the lepton sector. These will be
tested in the next generation experiments. Finally we compute the effect of non
diagonal neutrino mass in "l_i -> l_j gamma" in SUSY theories with non trivial
Quark-Lepton complementarity and a flavor symmetry. The Quark-Lepton
complementarity and the flavor symmetry strongly constrain the theory and we
obtain a clear prediction for the contribution to "mu -> e gamma" and the "tau"
decays "tau -> e gamma" and "tau -> mu gamma". If the Dirac neutrino Yukawa
couplings are degenerate but the low energy neutrino masses are not degenerate,
then the lepton decays are related among them by the V_M entries. On the other
hand, if the Dirac neutrino Yukawa couplings are hierarchical or the low energy
neutrino masses are degenerate, then the prediction for the lepton decays comes
from the CKM hierarchy.Comment: 15 pages, 5 figures, ws-ijmpa class included, Proceedings of the CTP
Symposium on Sypersymmetry at LH
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