A Note on Zipf's Law, Natural Languages, and Noncoding DNA regions

In Phys. Rev. Letters (73:2, 5 Dec. 94), Mantegna et al. conclude on the basis of Zipf rank frequency data that noncoding DNA sequence regions are more like natural languages than coding regions. We argue on the contrary that an empirical fit to Zipf's ``law'' cannot be used as a criterion for similarity to natural languages. Although DNA is a presumably an ``organized system of signs'' in Mandelbrot's (1961) sense, an observation of statistical features of the sort presented in the Mantegna et al. paper does not shed light on the similarity between DNA's ``grammar'' and natural language grammars, just as the observation of exact Zipf-like behavior cannot distinguish between the underlying processes of tossing an $M$ sided die or a finite-state branching process.Comment: compressed uuencoded postscript file: 14 page

Constraining compressed versions of MUED and MSSM using soft tracks at the LHC

A compressed spectrum is an anticipated hideout for many beyond standard model scenarios. Such a spectrum naturally arises in the minimal universal extra dimension framework and also in supersymmetric scenarios. Low $p_T$ leptons and jets are characteristic features of such situations. Hence, a monojet with $\not E_T$ has been the conventional signal at the Large Hadron Collider (LHC). However, we stress that inclusion of $p_T$-binned track observables from such soft objects provide very efficient discrimination of new physics signals against various SM backgrounds. We consider two benchmark points each for minimal universal extra dimension (MUED) and minimal supersymmetric standard model (MSSM) scenarios. We perform a detailed cut-based and multivariate analysis (MVA) to show that the new physics parameter space can be probed in the ongoing run of LHC at 13 TeV center-of-mass energy with an integrated luminosity $\sim$ 20-50 fb$^{-1}$. When studied in conjunction with the dark matter relic density constraint assuming standard cosmology, we find that compressed MUED (with $\Lambda R=2$) can be already excluded from the existing data. Also, MVA turns out to be a better technique than regular cut-based analysis since tracks provide uncorrelated observables which would extract more information from an event.Comment: 26 pages, 7 figures. Minor modifications in the text, references added, accepted for publication in JHE

ttHttH Anomalous Coupling in Double Higgs Production

We study the effects of top-Higgs anomalous coupling in the production of a pair of Higgs boson via gluon fusion at the Large Hadron Collider (LHC). The introduction of anomalous $ttH$ coupling can alter the hadronic double Higgs boson cross section and can lead to characteristic changes in certain kinematic distributions. We perform a global analysis based on available LHC data on the Higgs to constrain the parameters of $ttH$ anomalous coupling. Possible overlap of the predictions due to anomalous $ttH$ coupling with those due to anomalous trilinear Higgs coupling is also studied. We briefly discuss the effect of the anomalous $ttH$ coupling on the $HZ$ production via gluon fusion which is one of the main backgrounds in the $HH \to \gamma\gamma b {\bar b}$ channel.Comment: 22 pages, 22 figures, 4 tables. Text reorganized, main results unchanged, new plots and references added. Journal versio

Non-Standard Neutrino Interactions : Obviating Oscillation Experiments

Searching for non-standard neutrino interactions, as a means for discovering physics beyond the Standard Model, has one of the key goals of dedicated neutrino experiments, current and future. We demonstrate here that much of the parameter space accessible to such experiments is already ruled out by the RUN II data of the Large Hadron Collider experiment.Comment: 5 pages, 2 figure

Multi-leptons and Top-jets in the Hunt for Gluinos in R-parity Violating Supersymmetry

The presence of R-parity ($\mathcal{R}_p$) violation offers intersting decay channels for the gluinos. In this work we present a new search strategy for the gluinos in the presence of semileptonic $\mathcal{R}_p$ violating couplings $\lambda^{'}_{133}$ and $\lambda^{'}_{233}$. We consider two scenarios (i) $\lambda^{'}$ induced 3-body decay of gluinos to a top quark ($t$), a bottom quark ($b$) and a light lepton ($\ell$) (ii) cascade decay of gluinos to top quarks and neutralinos ($\widetilde{\chi}_1^0$) followed by the decay of $\widetilde{\chi}_1^0$ to $t$, $b$ and $\ell$ through $\lambda^{'}$ couplings. We present two different search procedures which are common to both the scenarios. While the first one involves the traditional approach with multi-leptons and $b$-tagged jets, the second one employs the more recent technique to reconstruct highly energetic hadronically decaying top quarks. We perform a detailed simulation of the signal as well as all the relevant Standard Model backgrounds to show that the second procedure offers slightly better sensitivity for gluino discovery. In both the procedures, a $\geq$ 5$\sigma$ discovery is possible for the gluino mass in the range 1.5 -1.7 TeV at 14 TeV LHC with 50 fb$^{-1}$ integrated luminosity.Comment: Event selection cuts optimized, results significantly improved, more discussions added. Version to appear in JHE

Changes in moisture and energy fluxes due to agricultural land use and irrigation in the Indian Monsoon Belt

We present a conceptual synthesis of the impact that agricultural activity in India can have on land-atmosphere interactions through irrigation. We illustrate a “bottom up” approach to evaluate the effects of land use change on both physical processes and human vulnerability. We compared vapor fluxes (estimated evaporation and transpiration) from a pre-agricultural and a contemporary land cover and found that mean annual vapor fluxes have increased by 17% (340 km3) with a 7% increase (117 km3) in the wet season and a 55% increase (223 km3) in the dry season. Two thirds of this increase was attributed to irrigation, with groundwater-based irrigation contributing 14% and 35% of the vapor fluxes in the wet and dry seasons, respectively. The area averaged change in latent heat flux across India was estimated to be 9 Wm−2. The largest increases occurred where both cropland and irrigated lands were the predominant contemporary land uses

Macroeconomic Stress Testing and the Resilience of the Indian Banking System: A Focus on Credit Risk

The paper undertakes a macroprudential analysis of the credit risk of Public Sector Banks during the liberalization period. Using the Vector Autoregression methodology, the paper investigates the dynamic impact of changes in the macroeconomic variables on the default rate, the Financial Stability Indicator of banks by simulating interactions among all the variables included in the model. Feedback effects from the banking sector to the real economy are also estimated. The impact of variations in different Monetary Policy Instruments such as Bank Rate, Repo Rate and Reverse Repo Rate on the asset quality of banks is examined using three alternative baseline models. Impulse Response Functions of the estimated models are augmented by conducting sensitivity and scenario stress testing exercises to assess the banking sector’s vulnerability to credit risk in the face of hypothetically generated adverse macroeconomic shocks. Results indicate the absence of cyclicality and pro-cyclicality of the default rate. Adverse shocks to output gap, Real Effective Exchange Rate appreciation above its trend value, inflation rate and policy-induced monetary tightening significantly affect bank asset quality. Of the three policy rates, Bank Rate affects bank soundness with a lag and is more persistent while the two short-term rates impact default rate instantaneously but is much less persistent. Scenario stress tests reveal default rate of Public Sector Banks could increase on an average from 4% to 7% depending on the type of hypothetical macroeconomic scenario generated. An average buffer capital of 3% accumulated during the period under consideration could thus be inadequate for nearly twice the amount of Non-Performing Assets generated if macroeconomic conditions worsened. An important policy implication of the paper is that as the Indian economy moves gradually to Full Capital Account Convertibility, the banking sector is likely to come under increased stress in view of the exchange rate volatility with adverse repercussions on interest rates and bank default rates. In this emerging scenario, monetary policy stance thus emerges as an important precondition for banking stability. The study also highlights the inadequacy of existing capital reserves should macroeconomic conditions deteriorate and the urgency to strengthen the buffer capital position.Banks, Macro Prudential analysis, Stress test