Heavy light tetraquarks from Lattice QCD

We present preliminary results from a lattice calculation of tetraquark states in the charm and bottom sector of the type $ud\bar{b}\bar{b}$, $us\bar{b}\bar{b}$, $ud\bar{c}\bar{c}$ and $sc\bar{b}\bar{b}$. These calculations are performed on $N_f = 2 + 1 + 1$ MILC ensembles with lattice spacing of $a = 0.12~\mathrm{fm}$ and $a=0.06~\mathrm{fm}$. A relativistic action with overlap fermions is employed for the light and charm quarks while a non-relativistic action with non-perturbatively improved coefficients is used in the bottom sector. Preliminary results provide a clear indication of presence of energy levels below the relevant thresholds of different tetraquark states. While in double charm sector we find shallow bound levels, our results suggest deeply bound levels with double bottom tetraquarks.Comment: Corrected threshold for the $ud\bar{c}\bar{c}$ tetraquark state. Proceedings of the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spain. TIFR preprint no : TIFR/TH/17-3

Study of the effect of Bucillamine on the early and late phase of hepatic ischaemia reperfusion injury.

Ischaemia of the liver followed by reperfusion results in endothelial and parenchymal injury through a complex cascade of events. This often occurs in human liver transplantation as well as with major liver resections and is referred to as Ischaemia Reperfusion (IR) Injury. Bucillamine is a low molecular weight thiol antioxidant that is capable of rapidly entering cells. This thesis evaluates the effect of Bucillamine on both the early and late phases of liver warm IR injury with the hypothesis that beneficial effects are induced could be due to its action as a free radical scavenger. The drug was evaluated in an in vivo lobar liver ischemia reperfusion model as previously described. Male Sprague –Dawley rats were subjected to 45 mins of partial hepatic (70 %) ischaemia followed by 3 hrs of reperfusion to investigate the early phase of hepatic IR and 24 hrs of reperfusion to study the late phase of hepatic IR. Changes to the microcirculation, leucocyte adherence and apoptosis were assessed by intra-vital microscopy. Hepatocellular injury was assessed by standard liver function tests. Expression of pro and antiapoptotic gene expression was studied by RT-PCR. Oxidative stress was assessed by measuring plasma and hepatic F2 isoprostane levels and tissue glutathione levels. Cytokine response was assessed by measuring serum CINC-1 levels. Bucillamine improved liver sinusoidal perfusion, reduced leukocyte adherence and apoptosis in both the early and late phases of IR injury. Hepatocellular injury was reduced. There was no difference in the level of tissue glutathione or tissue and plasma F2 isoprostane levels. This study shows that the hepato protective effect of Bucillamine in warm Liver ischemia reperfusion injury is not by direct replenishment of Glutathione level; however, it is through decreased neutrophil activation and recruitment. A clinical trial could hence be undertaken in the future to study its efficacy

Light Hadron Properties From Lattice QCD

The subject of this thesis is mainly concerned with dynamics of light quarks. The question that will be attempted to answer is, What is the quark mass dependence of low lying hadrons ? In particular, this work will focus on the quark mass dependence of mesons and baryons with the tools of lattice calculations and effective field theories. The two and three flavor effective field theories are applied to pions and kaons respectively to study the quark mass dependence of their masses and decay constants. In addition, the phenomenologically interesting ƒ K / ƒpi, is analysed in three flavor theory. It is found that the results of extrapolation agree with experimental results indicating that the effective field theory correctly accounts for effects of lattice calculations. In the baryon sector, a calculation for the scalar strange content of the nucleon is performed. This quantity and the heavy quark matrix elements of the nucleon are of great phenomenological importance as they provide an estimate for the scattering cross-section of a dark matter candidate with nucleon. Within the limitation of this work, it is found the result is in agreement with the lattice average. xii

Monte-Carlo simulation of photoproduction of Omega meson

The null result of December 2004 Sub-threshold photoproduction of J/$psi$ experiment has motivated this thesis. This monte-carlo predicts the cross-section for sub-threshold photoproduction process and provides an insight on the cross-section range of these processess. The experiment was also conducted as a calibration run for Omega and Eta mesons for the verification of correctness of experimental procedure. The results from this experiment are compared with the monte-carlo simulation for the number of omega meson events. This is primarily done as the models for photoproduction of omega meson are well tested. The monte-carlo provides satisfactory results for the photoproduction models and with a crude a spectrometer model predicts the number of events which are off by a factor less than two. A refined model from Jefferson lab will eliminate this discrepancy

Distributed Graph Isomorphism using Quantum Walks

Graph isomorphism being an NP problem, most of the systems that solves the graph isomorphism are constrained with some classes of the graph, and do not work for all types of graphs in polynomial time. We exploited the two particle quantum walks on different classes of graphs including strongly regular graphs which are co-spectral in nature. We simulated two particle quantum walks on graph using distributed algorithm. To show the effectiveness of the technique, we applied it to the large graphs derived from images using Delauney triangulation. The results show a remarkable speedup for large data. The two-particle quantum walks is implemented in map-reduce programming technique which scales the computation as the cluster get scaled to account Big data. We checked the isomorphism of the graphs with upto 100 vertices in polynomial time. The system is scalable to accept big inputs from any other domain in graph format. DOI: 10.17762/ijritcc2321-8169.15021