Bulk Majorana mass terms and Dirac neutrinos in Randall Sundrum Model

We present a novel scheme where Dirac neutrinos are realized even if lepton number violating Majorana mass terms are present. The setup is the Randall-Sundrum framework with bulk right handed neutrinos. Bulk mass terms of both Majorana and Dirac type are considered. It is shown that massless zero mode solutions exist when the bulk Dirac mass term is set to zero. In this limit, it is found that the effective 4D small neutrino mass is primarily of Dirac nature with the Majorana type contributions being negligible. Interestingly, this scenario is very similar to the one known with flat extra dimensions. Neutrino phenomenology is discussed by fitting both charged lepton masses and neutrino masses simultaneously. A single Higgs localised on the IR brane is highly constrained as unnaturally large Yukawa couplings are required to fit charged lepton masses. A simple extension with two Higgs doublets is presented which facilitates a proper fit for the lepton masses.Comment: 13 Pages, Few clarifications included and added references. Figure removed. Published in PR

Motivations, Capability Handicaps and Firm Responses in the Early Phase of Internationalization from Emerging Economies: A study in the Indian Pharmaceutical Industry

This paper identifies and analyses the motivations, capability handicaps and responses of a sample of Indian pharmaceutical firms in the early phase of internationalization. It distinguishes between the experiences of two types of internationalisers –initial internationalisers and later internationalisers - in the industry. It argues that the initial internationalisers face several discontinuities vis-a-vis the experience of meeting the needs of domestic market. They need to cultivate new capabilities by leveraging on whatever is available within the firms and the external environment. Their capability to cultivate depends on their internal processes to absorb the new experiences. The later internationalisers do not experience these handicaps. They can benefit from the industry experience and congregate capabilities to move faster. Their capability to congregate depends on the initial endowments of the founders. Based on its findings, the paper outlines scope for further research in capability building for internationalization in the context of emerging economies.

International poverty projections

The authors investigate the methodology used in projections of international poverty - particularly those used in many World Bank documents. The methodology, as developed by Ahluwalia, Carter, and Chenery (1979) in an influential paper, is examined critically and subjected to sensitivity analysis. It was found that their projections of poverty are not robust to reasonable changes and improvements in the methodology; in some cases, even the projections'time trend is reversed. Thus, analysts and policymakers should treat such global forecasts of poverty with caution.Economic Theory&Research,Achieving Shared Growth,Economic Conditions and Volatility,Inequality,Environmental Economics&Policies

Numerical Simulations of Turbulent Molecular Clouds Regulated by Radiation Feedback Forces II: Radiation-Gas Interactions and Outflows

Momentum deposition by radiation pressure from young, massive stars may help to destroy molecular clouds and unbind stellar clusters by driving large-scale outflows. We extend our previous numerical radiation hydrodynamic study of turbulent, star-forming clouds to analyze the detailed interaction between non-ionizing UV radiation and the cloud material. Our simulations trace the evolution of gas and star particles through self-gravitating collapse, star formation, and cloud destruction via radiation-driven outflows. These models are idealized in that we include only radiation feedback and adopt an isothermal equation of state. Turbulence creates a structure of dense filaments and large holes through which radiation escapes, such that only ~50% of the radiation is (cumulatively) absorbed by the end of star formation. The surface density distribution of gas by mass as seen by the central cluster is roughly lognormal with sigma_ln(Sigma) = 1.3-1.7, similar to the externally-projected surface density distribution. This allows low surface density regions to be driven outwards to nearly 10 times their initial escape speed v_esc. Although the velocity distribution of outflows is broadened by the lognormal surface density distribution, the overall efficiency of momentum injection to the gas cloud is reduced because much of the radiation escapes. The mean outflow velocity is approximately twice the escape speed from the initial cloud radius. Our results are also informative for understanding galactic-scale wind driving by radiation, in particular the relationship between velocity and surface density for individual outflow structures, and the resulting velocity and mass distributions arising from turbulent sources.Comment: ApJ, in press (28 pages, 14 figures

Type I seesaw mechanism for quasi degenerate neutrinos

We discuss symmetries and scenarios leading to quasi-degenerate neutrinos in type-I seesaw models. The existence of degeneracy in the present approach is not linked to any specific structure for the Dirac neutrino Yukawa coupling matrix $y_D$ and holds in general. Basic input is the application of the minimal flavour violation principle to the leptonic sector. Generalizing this principle, we assume that the structure of the right handed neutrino mass matrix is determined by $y_D$ and the charged lepton Yukawa coupling matrix $y_l$ in an effective theory invariant under specific groups ${\cal G}_F$ contained in the full symmetry group of the kinetic energy terms. ${\cal G}_F$ invariance also leads to specific structure for the departure from degeneracy. The neutrino mass matrix (with degenerate mass $m_0$) resulting after seesaw mechanism has a simple form ${\cal M}_\nu\approx m_0(I-p y_ly_l^T)$ in one particular scenario based on supersymmetry. This form is shown to lead to correct description of neutrino masses and mixing angles. The thermal leptogenesis after inclusion of flavour effects can account for the observed baryon asymmetry of the universe within the present scenario. Rates for lepton flavour violating processes can occur at observable levels in the supersymmetric version of the scenario.Comment: 14 pages; two figure

Gravitational rescue of minimal gauge mediation

Gravity mediation supersymmetry breaking become comparable to gauge mediated supersymmetry breaking contributions when messenger masses are close to the GUT scale. By suitably tuning the gravity contributions one can then modify the soft supersymmetry breaking sector to generate a large stop mixing parameter and a light higgs mass of 125 GeV. In this kind of hybrid models, however the nice features of gauge mediation like flavour conservation etc, are lost. To preserve the nice features, gravitational contributions should become important for lighter messenger masses and should be important only for certain fields. This is possible when the hidden sector contains multiple (at least two) spurions with hierarchical vaccum expectation values. In this case, the gravitational contribtutions can be organised to be `just right'. We present a complete model with two spurion hidden sector where the gravitational contribution is from a warped flavour model in a Randall-Sundrum setting. Along the way, we present simple expressions to handle renormalisation group equations when supersymmetry is broken by two different sectors at two different scales.Comment: 24 Pages, 3 figures, Detailed discussions on flavour violation included, added figure and references, Matches published versio

Indirect Searches of the Degenerate MSSM

A degenerate sfermionic particle spectrum can escape constraints from flavor physics, and at the same time evade the limits from the direct searches if the degeneracy extends to the gaugino-higgsino sector. Inspired by this, we consider a scenario where all the soft terms have an approximately common mass scale at $M_{\text{SUSY}}$, with splittings $\lesssim \mathcal{O}(10\%)$. As a result, the third generation sfermions have large to maximal (left-right) mixing, the same being the case with charginos and some sectors of the neutralino mass matrix. We study this scenario in the light of discovery of the Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$-physics, the anomalous magnetic moment of the muon and the dark matter relic density. We find that a supersymmetric spectrum as light as 600 GeV could be consistent with all current data and also account for the observed anomalous magnetic moment of the muon within $2\sigma$. The neutralino relic density is generally too small to saturate the measured cold dark matter relic density. Direct detection limits from XENON100 and LUX put severe constraints on this scenario which will be conclusively probed by XENONnT experiment.Comment: 27 pages, 8 figures; Comments welcom

Critical behavior in ultra-strong-coupled oscillators

We investigate the strong coupling regime of a linear $x$-$x$ coupled harmonic oscillator system, by performing a direct diagonalization of the hamiltonian. It is shown that the $x$-$x$ coupled hamiltonian can be equivalently described by a Mach-Zehnder-type interferometer with a quadratic unitary operation in each of its arms. We show a sharp transition of the unitary operation from an elliptical phase rotator to an elliptical squeezer as the coupling gets stronger, which leads to the continuous generation of entanglement, even for a significantly thermal state, in the ultra-strong coupled regime. It is also shown that this critical regime cannot be achieved by a classical Hookian coupling. Finally, the effect of a finite-temperature environment is analyzed, showing that entanglement can still be generated from a thermal state in the ultra-strong coupled regime, but is destroyed rapidly

Non recurrent laryngeal nerve with right aberrant subclavian artery in recurrent case of papillary carcinoma of thyroid: an interesting clinical entity.

Background/objectives: A nonrecurrent laryngeal nerve is a rare anatomical variant and a routine preoperative imaging studies are not indicated. NRLN is related with absence of the brachiocephalic trunk and aberrant (mainly retroesophageal) course of theright subclavian artery which is evident on contrast enhanced CT scan of the chest.Case report: The patient presented with a swelling in the neck for 4 months which is slowly increasing in size. Patient gives history of a surgery done in the neck with an old midlinesuprasternal scar which was done 40 years earlier.laryngoscopic mirror examinartion was normal with moving vocal cords. Rest of the oral and oropharyngeal examination along with completeblood picture and biochemical investigations were normal. The patient was not a known diabetic or hypertensive.Conclusion: Accurate knowledge of frequent variations of the nerve along with the non recurrent variant reduces the risk of intraoperative injury. A nonrecurrent laryngealnerve(NRLN) is a rare anatomical variant and a routine preoperative imaging studies are not indicated. NRLN is related with absence of the brachiocephalic trunk and aberrant(mainly retroesophageal) course of the right subclavian artery which is evident on contrast enhanced CT scan of the chest.