12,068 research outputs found
Isgur-Wise function in a QCD potential model with coulombic potential as perturbation
We study heavy light mesons in a QCD inspired quark model with the Cornell
potential. Here we consider the linear term
as the parent and i.e.the Coloumbic part as the
perturbation.The linear parent leads to Airy function as the unperturbed
wavefunction. We then use the Dalgarno method of perturbation theory to obtain
the total wavefunction corrected upto first order with Coulombic peice as the
perturbation.With these wavefunctions, we study the Isgur-Wise function and
calculate its slope and curvature.Comment: paper has been modified in Airy functions calculation upto o(r^3
An analysis of the Isgur-Wise Function and its derivatives within a Heavy-Light QCD Quark Model
In determining the mesonic wave function from QCD inspired potential model,
if the linear confinement term is taken as parent (with columbic term as
perturbation), Airy's function appears in the resultant wave function - which
is an infinite series. In the study of Isgur-Wise function (IWF) and its
derivatives with such a wave function, the infinite upper limit of integration
gives rise to divergence. In this paper, we have proposed some reasonable
cut-off values for the upper limit of such integrations and studied the
subsequent effect on the results. We also study the sensitivity of the order of
polynomial approximation of the infinite Airy series in calculating the
derivatives of IWF.Comment: 14 pages,6 tables 8 figure
Unparticle physics in diphoton production at the CERN LHC
We have considered the di-photon production with unparticle at LHC. The
contributions of spin-0 and spin-2 unparticle to the di-photon production are
studied in the invariant mass and other kinematical distributions, along with
their dependencies on the model dependent parameters. The signal corresponding
to the unparticle is significant for moderate coupling constant values.Comment: 17 pages, 15 eps figure
IN SILICO STUDY FOR IDENTIFICATION OF DRUG LIKE INHIBITOR FROM NATURAL COMPOUNDS AGAINST INHA REDUCTASE OF MYCOBACTERIUM TUBERCULOSIS
Objective: Natural products have played an important role for developing new drugs and becoming popular due to toxicity and side effects of allopathic medicine. The main objective of this research work is to find drug-like inhibitor from natural compounds that can help to treat tuberculosis. Methods: In silico docking studies were performed with four different compounds (isopimpinellin, pimpinellin, malic acid, and psoralen) from Angelica archangelica against enoyl acyl carrier protein reductase of Mycobacterium tuberculosis i.e., drug target. Flex X and Autodock Vina were used to dock the compound onto an active site of InhA to determine the probable binding of these inhibitors.Results: Among various natural compounds that were screened as inhibitors, psoralen was found to bind in closest proximity to the InhA binding site. This is compared to the commonly recommended anti-tubercular drugs. Drug like properties of these compounds were calculated by ADME/Tox calculations.Conclusion: According to molecular docking studies and ADME values the compound (psoralen) from Angelica archangelica was conformed as a promising lead compound and also will be the good starting point for natural plant based pharmaceutical chemistry.Â
4D Topological Mass by Gauging Spin
We propose a spin gauge field theory in which the curl of a Dirac fermion
current density plays the role of the pseudovector charge density. In this
field-theoretic model, spin interactions are mediated by a single scalar gauge
boson in its antisymmetric tensor formulation. We show that these long range
spin interactions induce a gauge invariant photon mass in the one-loop
effective action. The fermion loop generates a coupling between photons and the
spin gauge boson, which acquires thus charge. This coupling represents also an
induced, gauge invariant, topological mass for the photons, leading to the
Meissner effect. The one-loop effective equations of motion for the charged
spin gauge boson are the London equations. We propose thus spin gauge
interactions as an alternative, topological mechanism for superconductivity in
which no spontaneous symmetry breaking is involved.Comment: 4 pages, no figures. arXiv admin note: substantial text overlap with
arXiv:1310.210
Anatomy of neck configuration in fission decay
The anatomy of neck configuration in the fission decay of Uranium and Thorium
isotopes is investigated in a microscopic study using Relativistic mean field
theory. The study includes and in the valley of stability
and exotic neutron rich isotopes , , , ,
, likely to play important role in the r-process
nucleosynthesis in stellar evolution. Following the static fission path, the
neck configurations are generated and their composition in terms of the number
of neutrons and protons are obtained showing the progressive rise in the
neutron component with the increase of mass number. Strong correlation between
the neutron multiplicity in the fission decay and the number of neutrons in the
neck is seen. The maximum neutron-proton ratio is about 5 for U and
Th suggestive of the break down of liquid-drop picture and inhibition
of the fission decay in still heavier isotopes. Neck as precursor of a new mode
of fission decay like multi-fragmentation fission may also be inferred from
this study.Comment: 16 pages, 5 figures (Accepted
Unparticle physics in top pair signals at the LHC and ILC
We study the effects of unparticle physics in the pair productions of top
quarks at the LHC and ILC. By considering vector, tensor and scalar unparticle
operators, as appropriate, we compute the total cross sections for pair
production processes depending on scale dimension d_{\U}. We find that the
existence of unparticles would lead to measurable enhancements on the SM
predictions at the LHC. In the case of ILC this may become two orders of
magnitude larger than that of SM, for smaller values of d_\U, a very striking
signal for unparticles.Comment: 19 pages, 9 figures, analysis for ILC has been adde
Tetramer Orbital-Ordering induced Lattice-Chirality in Ferrimagnetic, Polar MnTi2O4
Using density-functional theory calculations and experimental investigations
on structural, magnetic and dielectric properties, we have elucidated a unique
tetragonal ground state for MnTi2O4, a Ti^{3+} (3d^1)-ion containing
spinel-oxide. With lowering of temperature around 164 K, cubic MnTi2O4
undergoes a structural transition into a polar P4_1 tetragonal structure and at
further lower temperatures, around 45 K, the system undergoes a paramagnetic to
ferrimagnetic transition. Magnetic superexchange interactions involving Mn and
Ti spins and minimization of strain energy associated with co-operative
Jahn-Teller distortions plays a critical role in stabilization of the unique
tetramer-orbital ordered ground state which further gives rise to lattice
chirality through subtle Ti-Ti bond-length modulations
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