Conductivity of Highly Concentrated Aqueous Electrolyte Solutions: Ammonium Nitrate-Water System

84-8

Electrical Conductance of Molten Salts: Part IV - Mixtures of Lithium, Sodium & Potassium Nitrates with Magnesium Nitrate

447-44

Electrical Conductance in Molten Salts: Part VI - potassium Nitrate-Strontium Nitrate Mixtures

645-64

Electrical Conductance in Molten Salts: Part V- Mixtures of Lithium, Sodium, Potassium & Thallium Nitrates with Cadmium Nitrate

579-58

Chronopotentiometry with Spherical Electrodes – Sphericity Correction to Sand's Equation

150-15

Multi-band optical variability of three TeV Blazars on Diverse Timescales

We present our optical photometric observations of three TeV blazars, PKS 1510-089, PG 1553+113 and Mrk 501 taken using two telescopes in India, one in Bulgaria, one in Greece and one in Serbia during 2012 - 2014. These observations covered a total of 95 nights with a total of 202 B filter frames, 247 images in V band, 817 in R band while 229 images were taken in the I filter. This work is focused on multi-band flux and colour variability studies of these blazars on diverse timescales which are useful in understanding the emission mechanisms. We studied the variability characteristics of above three blazars and found all to be active over our entire observational campaigns. We also searched for any correlation between the brightness of the sources and their colour indices. During the times of variability, no significant evidence for the sources to display spectral changes correlated with magnitude was found on timescales of a few months. We briefly discuss the possible physical mechanisms most likely responsible for the observed flux variability.Comment: 11 pages, 7 figures, 9 tables. Accepted for publication in MNRA

Multi-band optical-NIR variability of blazars on diverse timescales

To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of two flat spectrum radio quasars, 3C 454.3 and 3C 279, plus one BL Lac, S5 0716+714, all of which have been exhibiting remarkably high activity and pronounced variability at all wavelengths. CCD magnitudes in B, V, R and I pass-bands were determined for $\sim$ 7000 new optical observations from 114 nights made during 2011 - 2014, with an average length of $\sim$ 4 h each, at seven optical telescopes: four in Bulgaria, one in Greece, and two in India. We measured multiband optical flux and colour variations on diverse timescales. Discrete correlation functions were computed among B, V, R, and I observations, to search for any time delays. We found weak correlations in some cases with no significant time lags. The structure function method was used to estimate any characteristic time-scales of variability. We also investigated the spectral energy distribution of the three blazars using B, V, R, I, J and K pass-band data. We found that the sources almost always follows a bluer-when-brighter trend. We discuss possible physical causes of the observed spectral variability.Comment: Accepted for publication in MNRAS, 16 pages, 11 figures, 5 tables, plus supplementary material containing additional figures and tables (please contact authors for it

Little Higgs model effects in γγ→γγ\gamma \gamma \to \gamma \gamma

Though the predictions of the Standard Model (SM) are in excellent agreement with experiments there are still several theoretical problems associated with the Higgs sector of the SM, where it is widely believed that some ``{\it new physics}'' will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (LH) model. In this work we have investigated the effects of the LH model on \gggg scattering \cite{Choudhury:2006xa}.Comment: Talk given at LCWS06, Bangalore, 4 pages (style files included

B \to K(K^*) missing energy in Unparticle physics

In the present work we study the effects of an unparticle \unpart as the possible source of missing energy in the decay $B \to K (K^*) + {\rm missing energy}$. We find that the dependence of the differential branching ratio on the $K$($K^*$)-meson's energy in the presence of the vector unparticle operators is very distinctive from that of the SM. Moreover, in using the existing upper bound on $B \to K (K^*) + {\rm missing energy}$ decays, we have been able to put more stringent constraints on the parameters of unparticle stuff.Comment: 13 pages, 5 figure