Survey of vector-like fermion extensions of the Standard Model and their phenomenological implications

With the renewed interest in vector-like fermion extensions of the Standard Model, we present here a study of multiple vector-like theories and their phenomenological implications. Our focus is mostly on minimal flavor conserving theories that couple the vector-like fermions to the SM gauge fields and mix only weakly with SM fermions so as to avoid flavor problems. We present calculations for precision electroweak and vector-like state decays, which are needed to investigate compatibility with currently known data. We investigate the impact of vector-like fermions on Higgs boson production and decay, including loop contributions, in a wide variety of vector-like extensions and their parameter spaces.Comment: 43 pages, 17 figures; v2: text modified to improve readability, references added, journal versio

Pengaruh Penambahan Na-alginat Dalam Proses Eksfoliasi Grafit Dengan Metode Pencampuran

Studi pengaruh penambahan Na-alginat dalam proses eksfoliasi grafit telah dilakukan melalui sintesis dan kajian komputasi menggunakan teori fungsi kerapatan pada level B3LYP/6-31G(d). Penelitian ini bertujuan mengkaji pengaruh Na-alginat terhadap pembentukkan partikel grafen sebagai bentuk interaksi elektrostatik antar keduanya. Pencampuran material dilakukan menggunakan metode percampuran kimia. Karakterisasi komposit dilakukan menggunakan spektrofotometer inframerah (FT-IR) untuk mengamati Perubahan serapan dan gugus fungsi komposit. Energi disosiasi ikatan (BDE) didapatkan 14 kali lebih besar akibat pengaruh interaksi Na-alginat dalam proses exfoliasi membentuk kompleks komposit. Kajian ini akan sangat berkontribusi dalam mendesain dan sintesis senyawa lapis tipis semikonduktor dari bahan grafit

A 9-Bit Flash Analog to Digital Convertor

Need constantly exists for converters with higher resolution, faster conversion speed and lower power dissipation. High-speed analog to digital converters (ADC’s) have been based on flash architecture, because all comparators sample the analog input voltage simultaneously, this ADC is thus inherently fast. Unfortunately, flash ADC requires 2N - 1 comparators to convert N bit digital code from an analog sample. This makes flash ADC’s unsuitable for high-resolution applications. This paper demonstrates a simple technique to reduce comparator requirement of 9-bit flash ADC that requires as few as 256 comparators for 9-bit conversion. In this approach, the analog input range is partitioned into 256 quantization cells, separated by 255 boundary points. A 8-bit binary code 00000000 to 11111111 is assigned to each cell. A 9-bit flash converter requires 512 comparators, while proposed technique reduces number of comparator requirements to 256 for 9-bit conversion

Phytochemicals characterization of nutraceutical enriched fruits and nuts spread

The present study aimed to formulate a nutraceutical enriched fruits and nuts spreads and analyze the presence of phytochemicals in the formulated spread. The pumpkin seeds and cucumber seeds were roasted at 150° C for 15 mins and made into powder. The seed powder was mixed to the pulp of ?-carotene rich fruits like mango, papaya and muskmelon in order to make fruits and nuts spread. Treatments like Mango with pumpkin seed powder (T1), Papaya with pumpkin seed powder (T2), Muskmelon with pumpkin seed powder (T3), Mango with cucumber seed powder (T4), Papaya with cucumber seed powder (T5) and Muskmelon with cucumber seed powder (T6). The fruits and nuts spreads were analyzed for the presence of phytochemicals ?-carotene, polyphenols, tannins, flavonoids and antioxidant activity. The formulated fruits and nuts spreads were packed in polypropylene boxes, glass bottles and stored under refrigerated condition at 4°C. ?-carotene content was found to be high (634.21?g/g) in Mango with Pumpkin seed powder spread (T1), tannin content was higher (52.61 mg/g) in Papaya with Pumpkin seed powder spread (T2), flavonoid components were higher (3.25 mg/g) in Mango with Pumpkin seed powder spread (T1), and polyphenols content were found to be high (59.33 mg/g) in Papaya with Cucumber seed powder spread (T5). The antioxidant property was high in the Mango with Pumpkin seed powder spread (T1) when compared to all other treatments. Pumpkin seeds comprised of excellent amount of bioactive compounds. The pumpkin seed incorporated spread showed a high level of phytochemicals when compared to other spreads. This was ready to eat spread which had 3 months of shelf life under refrigerated condition is preferred for people of all age groups

Higgs Physics at the Large Hadron Collider

In this talk I will begin by summarising the importance of the Higgs physics studies at the LHC. I will then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at the LHC. In addition to the material covered in the presented talk, I have included in the writeup, a critical appraisal of the theoretical uncertainties in the Higgs cross-sections at the Tevatron as well as a discussion of the recent experimental results from the LHC which have become available since the time of the workshop.Comment: LateX, 12 figures, 15 pages, Presented at the XIth Workshop on High Energy Physics Phenomenology, 2010, Ahmedabad, Indi

Probing CP-violating Higgs contributions in gamma-gamma -> f anti-f through fermion polarization

We discuss the use of fermion polarization for studying neutral Higgs bosons at a photon collider. To this aim we construct polarization asymmetries which can isolate the contribution of a Higgs boson $\phi$ in $\gamma\gamma\to f \bar f$, $f=\tau/t$, from that of the QED continuum. This can help in getting information on the $\gamma\gamma\phi$ coupling in case $\phi$ is a CP eigenstate. We also construct CP-violating asymmetries which can probe CP mixing in case $\phi$ has indeterminate CP. Furthermore, we take the MSSM with CP violation as an example to demonstrate the potential of these asymmetries in a numerical analysis. We find that these asymmetries are sensitive to the presence of a Higgs boson as well as its CP properties over a wide range of MSSM parameters. In particular, the method suggested can cover the region where a light Higgs boson may have been missed by LEP due to CP violation in the Higgs sector, and may be missed as well at the LHC.Comment: 14 pages, 14 figures, typeset in revtex4. Version which has appeared in Physical Review D; typos in two references correcte

Contrasting seed biology of two ornamental palms: Pygmy Date Palm (Phoenix roebelenii O’Brien) and Fishtail Palm (Caryota urens L.)

The Arecaceae family includes palm trees of economic importance both as a source of agricultural produce and asornamental components in landscaping projects. Pygmy date palm (Phoenix roebelenii) and solitary fishtail palm (Caryotaurens) are well known landscaping plants today. Both species have their origin in Southeast Asia and, especially C. urens iswidespread in peninsular India and Sri Lanka. They are multipurpose species with a variety of applications and thus veryheavily utilized. Knowledge of palm seed storage biology will improve their conservation prospects. In present studies, freshseed moisture content in P. roebelenii was recorded to be 30% with germinability of 98%. After desiccation to 8% moisturegerminability was reduced to 90% and the seeds survived cryo-exposure. Fresh seeds of C. urens, with initial moisturecontent of 34% and 95% germinability could be desiccated to lowest level of only 29% moisture content, with complete lossof germinability. Fresh as well as desiccated seeds of this species did not survive cryo-exposure. While the seeds of C. urensstored at room temperature lost their germinability by 110 days, seeds of P. roebelenii could germinate even after 9 monthsof storage. P. roebelenii is proven to exhibit orthodox seed storage behaviour while C. urens is found to exhibit recalcitrantseed storage behaviour. Long-term ex situ cryo-conservation in the form of seed gene banks would be suitable for seedpropagated orthodox palm species and a few germplasm centres may be established for recalcitrant Indian palms in suitablebio-geographic regions as a complimentary ex situ conservation

Unusual Charged Higgs Signals at LEP-2

We have made a detailed study of the signals produced at LEP-2 from charged scalar bosons whose dominant decay channels are into four fermions. The event rates as well as kinematics of the final states are discussed when such scalars are either pair-produced or are generated through a tree-level interaction involving a charged scalar, the W and the Z. The backgrounds in both cases are discussed. We also suggest the possibility of reconstructing the mass of such a scalar at LEP-2.Comment: 12 pages, LateX, 9 Postscript figures, uses eps

The blending effect of natural polysaccharides with nano-zirconia towards the removal of fluoride and arsenate from water

Nano-zirconia (ZO) was synthesized using a microwave-assisted one-pot precipitation route. Two biopolymers, chitosan (CTS) and carboxymethyl cellulose were blended with ZO at different w/w ratios. The formulation with 30% w/w chitosan (ZO-CTS) was found to give enhanced uptake of F− and As(V). ZO and the most effective ZO-CTS system were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. These confirmed the formation of a composite system containing nanoparticles of 50 nm in size, in which ZO was present in the amorphous form. It was observed that the combination of ZO with CTS improved the F− and As(V) adsorption capacity most notably at pH 5.5. Fluoride adsorption by ZO-CTS followed the Freundlich isotherm model, with an adsorption capacity of 120 mg g−1. Adsorption of As(V) by ZO-CTS could be fitted with both the Langmuir and Freundlich isotherm models and was found to have a capacity of 14.8 mg g−1. Gravity filtration studies conducted for groundwater levels indicated the effectiveness of ZO-CTS in adsorbing As(V) and F− at a pH of 5.5. The ability of the ZO-CTS in removing Cd(II) and Pb(II) was also investigated, and no such enhancement was observed, and found the neat ZO was the most potent sorbent here

Virtual Photon Strucutre Functions and the Parton Content of the Electron

We point out that in processes involving the parton content of the photon the usual effective photon approximation should be modified. The reason is that the parton content of virtual photons is logarithmically suppressed compared to real photons. We describe this suppression using several simple, physically motivated ans\"atze. Although the parton content of the electron in general no longer factorizes into an electron flux function and a photon structure function, it can still be expressed as a single integral. Numerical examples are given for the \eplem\ collider TRISTAN as well as the $ep$ collider HERA.Comment: 16 pages and 3 figures (available from DREES@WSICPHEN as topdraw or PS files); LaTeX with equation.sty; MAD/PH/819, BU 94-0