38 research outputs found
Determination of Weak Amplitudes using Bose Symmetry and Dalitz Plots
We present a new method using Dalitz plot and Bose symmetry of pions that
allows the complete determination of the magnitudes and phases of weak decay
amplitudes. We apply the method to process like B->K^* pi, with the subsequent
decay of K^* -> K pi. Our approach enables the additional measurement of an
isospin amplitude without any theoretical assumption. This advance will help in
measuring weak phase and probing for new physics beyond standard model with
fewer assumptions.Comment: 5 pages, 1 figure; Title changed; Conclusions unchanged; Accepted for
publication in Physical Review Letter
Study of inspiratory lung function parameters in Indian children
Background: The inspiratory parameters of pulmonary function test commonly used for various purposes in clinical practice including diagnosing airway obstruction. Expiratory portion of the flow volume loop of the pulmonary function test is studied in detail. The prediction equations for expiratory parameters are available for different population. However, the reference equation for inspiratory parameters is not available in Indian context. The current study derived the prediction equation for inspiratory parameters of pulmonary function test.Methods: The current study was carried out in school going 732 healthy girls and 1377 boys aged 6-15 years in India. The children who meet the inclusion criteria were recruited in the study after detailed medical examination by registered medical practitioner. The lung function parameters were recorded by spirometry. The multivariate regression analysis was done to develop the prediction model.Results: The prediction equation for predicting inspiratory parameter were developed. This study revealed gender-wise and geographical variation in the inspiratory parameters. Hence this study recommends to derive gender wise prediction equations. The reference equations derived in this study can be used in population with similar background.Conclusions: Use of these equations for population having similar backgrounds will help for early and accurate diagnosis of the airway abnormalities in children. The inspiratory parameter assessment shall be included in the routine assessment of respiratory patient
Higher Dimensional Operators and Low Energy Left-Right Symmetry
We consider higher dimensional operators due to quantum gravity or
spontaneous compactification of extra dimensions in Kaluza-Klein type theory
and their effect in the Lagrangian. These operators change the
boundary conditions at the unification scale. As a result one can allow
left-right symmetry to survive till very low energy (as low as TeV) for
a wide range of values for the coupling of these higher dimensional operators
and still make the theory compatible with the latest values of and derived from LEP. We consider both non-supersymmetric
and supersymmetric cases with standard higgses. Proton lifetime is very large
in these theories.Comment: LaTeX 6 pages,UH-511-765-9
Evaluation of the validity of risk malignancy index in clinically diagnosed ovarian masses and to compare it with the validity of individual constituent parameter of risk malignancy index
Background: Pre-operative knowledge regarding the nature of ovarian mass is necessary in order to plan surgery. Risk malignancy index (RMI) is a simple scoring system based on three factors serum CA 125, USG score & menopausal status. The RMI was interpreted as 1) score > 250 = high risk, 2) 25-250 =intermediate risk, 3) score <25 = low risk. The objective of the study was, 1) to evaluate risk malignancy index (RMI) in pre-operatively clinically diagnosed ovarian mass, 2) to compare the validity of individual parameter in RMI i.e. menopausal status, serum CA 125 & USG score with validity of RMI as a comprehensive index .Methods: This was an observational study conducted at department of obstetrics and gynaecology, GMCH Aurangabad from October 2012 to 2014 with sample size of 102 cases with clinical diagnosis of ovarian mass admitted for laparotomy. The validity of RMI and validity of individual parameter was calculated and compared.Results: RMI showed better sensitivity of 85.71%, specificity of 85.07% and ppv of 75%, npv of 91.93% and accuracy of 82.29% as compared to validity of individual parameters.Conclusions: RMI is simple, valuable & highly reliable in pre-operative differentiation of malignant & benign lesion. Simplicity and applicability of this method in the primary evaluation of patients with pelvic masses makes it a good option in daily clinical gynaecological practice.
Accurate measurement of the D0-D0bar mixing parameters
We propose a new method to determine the mass and width differences of the
two D meson mass-eigenstates as well as the CP violating parameters associated
with D^0-\bar{D}^0 mixing. We show that an accurate measurement of all the
mixing parameters is possible for an arbitrary CP violating phase, by combining
observables from a time dependent study of D decays to a doubly Cabibbo
suppressed mode with information from a CP eigenstate. As an example we
consider D^0-> K^{*0} \pi^0 decays where the K^{*0} is reconstructed in both
K^+\pi^- and K_S\pi^0. We also show that decays to the CP eigenstate D-> K^+K^-
together with D-> K^+\pi^- can be used to extract all the mixing parameters. A
combined analysis using D^0-> K^{*0} \pi^0 and D-> K^+K^- can also be used to
reduce the ambiguity in the determination of parameters.Comment: 4 pages, minor changes, few references adde
Design Space and Variability Analysis of SOI MOSFET for Ultra-Low Power Band-to-Band Tunneling Neurons
Large spiking neural networks (SNNs) require ultra-low power and low
variability hardware for neuromorphic computing applications. Recently, a
band-to-band tunneling-based (BTBT) integrator, enabling sub-kHz operation of
neurons with area and energy efficiency, was proposed. For an ultra-low power
implementation of such neurons, a very low BTBT current is needed, so
minimizing current without degrading neuronal properties is essential. Low
variability is needed in the ultra-low current integrator to avoid network
performance degradation in a large BTBT neuron-based SNN. To address this, we
conducted design space and variability analysis in TCAD, utilizing a
well-calibrated TCAD deck with experimental data from GlobalFoundries 32nm
PD-SOI MOSFET. First, we discuss the physics-based explanation of the tunneling
mechanism. Second, we explore the impact of device design parameters on SOI
MOSFET performance, highlighting parameter sensitivities to tunneling current.
With device parameters' optimization, we demonstrate a ~20x reduction in BTBT
current compared to the experimental data. Finally, a variability analysis that
includes the effects of random dopant fluctuations (RDF), oxide thickness
variability (OTV), and channel-oxide interface traps DIT in the BTBT, SS, and
ON regimes of operation is shown. The BTBT regime shows high sensitivity to the
RDF and OTV as any variation in them directly modulates the tunnel length or
the electric field at the drain-channel junction, whereas minimal sensitivity
to DIT is observed
Unparticle Induced Baryon Number Violating Nucleon Decays
We study baryon number violating nucleon decays induced by unparticle
interactions with the standard model particles. We find that the lowest
dimension operators which cause nucleon decays can arise at dimension 6 +
(d_s-3/2) with the unparticles being a spinor of dimension d_s=d_\U +1/2. For
scalar and vector unparticles of dimension d_\U, the lowest order operatoers
arise at 6+d_\U and 7+d_\U dimensions,respectively. Comparing the spinor
unparticle induced n \to O^s_\U and experimental bound on invisible decay of a
neutron from KamLAND, we find that the scale for unparticle physics is required
to be larger than 10^{10} GeV for d_\U < 2 if the couplings are set to be of
order one. For scalar and vector unparticles, the dominant baryon number
violating decay modes are n\to \bar \nu + O_\U (O^\mu_\U) and p \to e^+ + O_\U
(O^\mu_\U). The same experimental bound puts the scales for scalar and vector
unparticle to be larger than 10^{7} and 10^{5} GeV for d_\U <2 with couplings
set to be of order one. Data on, p \to e^+ invisible, puts similar constraints
on unparticle interactions.Comment: Latex 10 pages with two figure
Rare Charm Decays in the Standard Model and Beyond
We perform a comprehensive study of a number of rare charm decays,
incorporating the first evaluation of the QCD corrections to the short distance
contributions, as well as examining the long range effects. For processes
mediated by the transitions, we show that sensitivity to
short distance physics exists in kinematic regions away from the vector meson
resonances that dominate the total rate. In particular, we find that
and are sensitive to non-universal
soft-breaking effects in the Minimal Supersymmetric Standard Model with
R-parity conservation. We separately study the sensitivity of these modes to
R-parity violating effects and derive new bounds on R-parity violating
couplings. We also obtain predictions for these decays within extensions of the
Standard Model, including extensions of the Higgs, gauge and fermion sectors,
as well as models of dynamical electroweak symmetry breaking.Comment: 45 pages, typos fixed, discussions adde