Bulk gauge and matter fields in nested warping: I. the formalism

The lack of evidence for a TeV-mass graviton has been construed as constricting the Randall-Sundrum model. However, a doubly-warped generalization naturally avoids such restrictions. We develop, here, the formalism for extension of the Standard Model gauge bosons and fermions into such a six-dimensional bulk. Apart from ameliorating the usual problems such as flavour-changing neutral currents, this model admits two very distinct phases, with their own unique phenomenologies.Comment: 44 pages, 5 figures, version to appear in JHEP. Corrected minor typographical error

The Effect Of Four Endodontic Irrigants on the Shear Bond Strength of a Self Etch Resin Based Sealer to Dentin: An Invitro Study

The present in vitro study was undertaken to evaluate the effect of four different irrigants namely Sodium hypochlorite, Chlorhexidine, Triphala and Morinda citrifolia on the shear bond strength of a self etch sealer, Real Seal SE to dentin by using with and without EDTA as the final irrigant using an Universal Testing Machine. The study was done using one hundred and twenty extracted maxillary and mandibular human molars. A low speed diamond disk saw with Water coolant was used to slice off the occlusal 2mm of the samples whereby a flat dentinal surface surrounded by a thin rim of enamel was obtained. This section of tooth, which included the roots, were embedded in a self cure acrylic resin. A smear layer was created on the sectioned teeth using a 320 grit silicon carbide paper on a Handimet grinder (Buehler, Ltd) under Water irrigation for a time period of 15 seconds. The dentin disks with the smear layer were then randomly divided into 2 groups namely Group I-without EDTA and Group II-with EDTA. Each of the Group was further divided into four Subgroups namely Sodium hypochlorite, Morinda citrifolia, Triphala and Chlorhexidine respectively. The dentin discs were air dried using a air-water syringe. A brass tube of 4mm internal diameter and 3mm height was placed onto the dentin surface. The brass tube was filled with Real Seal SE, (Fig.4H) which was mixed according to the manufacturer’s instructions. The sealer was then light cured using a light curing unit (QHL-75,Dentsply) for 40 seconds and allowed to set for forty five minutes. The samples were immediately stored in distilled water at 37oC and maintained at 100% humidity for 7 days. The specimens were then engaged perpendicularly at their bases on a Universal Testing Machine (INSTRON 3365). Each specimen was evaluated for its shear bond strength values, at a cross head speed of 1mm/minute. The shear force required to separate the cylinder from dentin was recorded in Newtons (N) for each specimen, then divided by contact surface area to determine the shear bond strength in Megapascals. The results were then statistically analyzed using a paired One way ANOVA, Students ‘T’ test and Duncan’s Multiple Range Test. The results revealed that Subgroup Sodium hypochlorite had the highest shear bond strength in Group I (without EDTA) and Group II (with EDTA) followed in order by Subgroups Morinda citrifolia, Triphala and Chlorhexidine in both groups. When both Group I and Group II were compared, the Group II (with EDTA), all the Subgroups showed highest bond strength to dentin with resin sealer (Real Seal SE). CONCLUSION: Within the limitations of the study it can be concluded that 1. Sodium hypochlorite Subgroup in both the Group I (without EDTA) and Group II (with EDTA) showed the maximum shear bond strength values. 2. Chlorhexidine Subgroup in both the Group I (without EDTA) and Group II (with EDTA) showed the minimum shear bond strength values. 3.Triphala and Morinda citrifolia Subgroups showed shear bond strength values more than Chlorhexidine but less than Sodium hypochlorite in both the groups. 4. Triphala and Morinda citrifolia could be used as herbal alternative irrigants during the cleaning and shaping of the root canals. It is seen that they are as effective but are less toxic and more biocompatible than the traditionally used irrigants. 5. Further studies with more parameters are necessary to validate these results and to determine the suitability of this material for invivo use

Universal Extra Dimensions and the Graviton Portal to Dark Matter

The Universal Extra Dimension (UED) paradigm is particularly attractive as it not only includes a natural candidate for the Dark Matter particle but also addresses several issues related to particle physics. Non-observations at the Large Hadron Collider, though, has brought the paradigm into severe tension. However, a particular 5-dimensional UED model emerges from a six-dimensional space-time with nested warping. The $AdS_6$ bulk protects both the Higgs mass as well as the UED scale without invoking unnatural parameter values. The graviton excitations in the sixth direction open up new (co-)annihilation channels for the Dark Matter particle, thereby allowing for phenomenological consistency, otherwise denied to the minimal UED scenario. The model leads to unique signatures in both satellite-based experiments as well as the LHC.Comment: 16 pages, 4 figures, To be published in JCA

Graviton modes in multiply warped geometry

The negative results in the search for Kaluza-Klein graviton modes at the LHC, when confronted with the discovery of the Higgs, has been construed to have severely limited the efficacy of the Randall-Sundrum model as an explanation of the hierarchy problem. We show, though, that the presence of multiple warping offers a natural resolution of this conundrum through modifications in both the graviton spectrum and their couplings to the Standard Model fields.Comment: 16 pages, 6 figure

Skyrmion in teleparallel gravity

The Einstein-Skyrme system became famous for its black hole solutions that admits fractional baryon number outside the horizon, thus violating the "{\it no hair}" conjecture. In this article, we extend the Skyrmion to teleparallel gravity framework and investigate the teleparallel-Skyrme system in the context of the Teleparallel Equivalent of General Relativity (TEGR) and $f(T)$ power law gravity. We demonstrate the emergence of the fractional baryon number outside the horizon and its dependence on the cosmological constant ($\Lambda$). The solutions in TEGR ($f(T) = -T-2\Lambda$), as expected, matches with the Einstein-Skyrme system with the requirement of $\Lambda > 0$. Interestingly, in power law gravity ($f(T) = -T - \tau T^2 -2\Lambda$), the reality conditions requires the cosmological constant to be positive and stay within the range $\Lambda_{min} < \Lambda < \Lambda_{max}$. And, in the limit power law gravity reaches TEGR ($\tau \rightarrow 0$), we get back the condition on the cosmological constant with $\Lambda_{min}\rightarrow 0$ and $\Lambda_{max} \rightarrow \infty$.Comment: 19 pages, 6 figure

Living Orthogonally: Quasi-universal Extra Dimensions

The minimal Universal Extra Dimension scenario is highly constrained owing to opposing constraints from the observed relic density on the one hand, and the non-observation of new states at the LHC on the other. Simple extensions in five-dimensions can only postpone the inevitable. Here, we propose a six-dimensional alternative with the key feature being that the SM quarks and leptons are localized on orthogonal directions whereas gauge bosons traverse the entire bulk. Several different realizations of electroweak symmetry breaking are possible, while maintaining agreement with low energy observables. This model is not only consistent with all the current constraints opposing the minimal Universal Extra Dimension scenario but also allows for a multi-TeV dark matter particle without the need for any fine-tuning. In addition, it promises a plethora of new signatures at the LHC and other future experiments.Comment: 43 pages, 5 figures, accepted for publication in JHE

Constraining SMEFT BSM scenarios with EWPO and ΔCKM\Delta_{CKM}

Precision observables are well known for constraining most of the Beyond Standard Model (BSM) scenarios tightly. We present here a simple and comprehensive fitting framework for various BSM scenarios to these observables. We start with the fit of $S$, $T$ and $V$ parameter and their correlations using the Electroweak Precision Observables (EWPO) including the recent $m_W$ measurement from CDF-II. Utilizing these observables, we also fit various New Physics (NP) scenarios consisting of different subsets of dimension-6 Standard Model Effective Field Theory (SMEFT) operators out of a total of 10 appearing at tree level in EWPO. To further constrain these scenarios, we augment these observables with $\Delta_{CKM}$ measurement using 1-loop matching of the Low Energy Effective Field Theory (LEFT) to SMEFT operators at the Z-pole. We show that the inclusion of $\Delta_{CKM}$ constraint indeed results in stronger bounds on the SMEFT Wilson Coefficients. We also constrain the UV parameters of BSM extensions like Vectorlike leptons (VLL) and find out that such a minimal extension is in tension with the forward-backward asymmetry in $b$-sector ($A_b^{FB}$) and the recent measurement of $M_W$. In order to lift the two blind directions, which one encounters while fitting all the 10 SMEFT WCs at tree-level, we also include the LEP-II observables pertaining to the $WW$ production and present the results for the fits with and without $\Delta_{CKM}$ constraint.Comment: 32 pages, 6 figures, 19 table