Searcharxiv⌕ Search

arXiv subjects

D K Choudhury

Publications and source records attributed to D K Choudhury.

17 recordsLinked to original sources
arXiv2022

Semileptonic decay of $B_c$ meson into $c\bar c$ states in a QCD potential model

The slope and curvature of Isgur Wise function for $B_{c}$ meson is computed in a QCD potential model in two different approaches of choosing the perturbative term of the Cornell potential. Based on heavy quark effective theory the exclusive semileptonic decay rates of $B_c$ meson into the $c\bar c\ (η_c,J/ψ)$ states are exploited. Spin symmetry breaking effects are ignored upto a particular point and the form factors are connected with Isgur-Wise function for other kinematic point since the recoil momentum of $c\bar c$ from $B_{c}$ is small due to its heavy mass.

hep-ph↗
arXiv2019

Masses and Decay constants of Heavy Flavour mesons in perturbative approach

Determination of the wave-function is very essential in the calculation of static and dynamic properties like masses,decay constants of pseudo-scalar mesons and masses of vector mesons.We use Dalgarno's perturbation theory and Variation-ally Improved Perturbation Theory (VIPT) to solve Schrodinger equation in a QCD inspired potential model wuth Cornell potential,which consists linear and coulomb potential.We use both the options like Columbic parent firstly and then linear parent while using the VIPT method. Comparison of both these methods and also with experimental results are done in the calculation of masses and decay constants.

hep-ph↗
arXiv2017

Charge radii of heavy flavored mesons in a potential model

We report the results for charge radii of heavy flavored mesons ($D^+, D^0, D^+_s, B^+, B^0, B^0_s$) in an improved QCD potential model. To enhance the effectiveness of short range and long range effect of the potential $V(r)=-4\frac{α_s}{3r}+br+c$ in the perturbative procedure a cut-off parameter $r^P$ is introduced as an integration limit. The obtained results are found to be comparable with other available data. The limitation of the approach is discussed in the manuscript.

hep-ph↗
arXiv2017

Froissart Bound and Transverse Momentum Dependent Parton Distribution Functions (TMDPDF) with self-similarity

Froissart Bound implies that the total proton-proton cross-section (or equivalently structure function) cannot rise faster than the logarithmic growth $\log^2 s \sim \log^2 (1/x)$, where \textit{s} is the square of the center of mass energy and \textit{x} is the Bjorken variable. In the present report, compatibility of such behavior will be shown in case of Transverse Momentum Dependent Parton Distributions Functions (TMDPDF) or TMDs for the model of proton based on self-similarity.

hep-ph↗
arXiv2016

A Potential Model Approach in the Study of Static and Dynamic properties of Heavy-Light Quark-Antiquark Systems

We report some approximate analytic form of meson wave function constructed upon solving Schrodinger equation with linear plus Coulomb type Cornell potential. With this wave function, we study Isgur-Wise function and its derivatives for heavy-light mesons in the infinite heavy quark mass limit. We also explore the elastic form factors, charge radii and decay constants of pseudoscalar mesons in this QCD inspired quark model approach.

hep-ph↗
arXiv2016

Momentum Fractions carried by quarks and gluons in models of proton structure functions at small $x$

The paper reports analysis of momentum fractions carried by quarks and gluons in models of Proton structure functions at small $x$. First, we analyze the model proposed by Lastovicka based on self-similarity sometime back. We then make a similar analysis for a second model based on the same notion which is also free from singularity in $x$ : $0<x<1$. The predictions of both the models are then compared with a recent QCD based Froissart bound compatible model of proton structure function at small $x$, suggested by Block, Durand, Ha and McKay. The results are then compared with the corresponding study in perturbative and Lattice QCD.

hep-ph↗
arXiv2013

An Analysis of Momentum Fractions of Quarks and Gluons in a model of Proton

Momentum sum rule can be used as an inequality to estimate the lower and upper bounds of the momentum fractions of quarks and gluons in a model of proton valid in a limited \textit{x} range. We compute such bounds in a self-similarity based model of proton structure function valid in the range $ 6.2\times 10^{-7} \leq x \leq 10^{-2} $. The results conform to the asymptotic QCD expectations.

hep-ph↗
arXiv2013

A Model Construction of Self-similarity based Double Parton Distribution Functions for proton-proton collision at LHC

We construct a model for double parton distribution functions (dPDFs) based on the notion of self-similarity, pursued earlier for small \textit{x} physics at HERA. The most general form of dPDFs contains total thirteen parameters to be fitted from data of proton-proton collision at LHC. It is shown that the constructed dPDF does not factorize into two single PDFs in conformity with QCD expectation, and it satisfies the condition that at the kinematic boundary $x_{1}+x_{2}=1 $ (where $x_{1}$ and $x_{2}$ are the longitudinal fractional momenta of two partons), the dPDF vanishes.

hep-ph↗
arXiv2013

Constrains on treating linear part as perturbation in a QCD Potential Model

We make a review of the different works of Quark Model which are based on Perturbation theory. We make a critical analysis of taking linear part of the Potential as perturbation with Coulombic part as parent and its reverse case. We find in the analysis that the linear part can be treated as perturbation for a set of larger values of $α_{s}$ in the range $0.37 \leq α_{s}\leq 0.75$ with a constant shift in the Cornell potential within range of $-0.4 GeV \leq c \leq -1 GeV$. Moreover with the same range of constant shift in the Potential, we expect better results with coulombic part as perturbation for $α_{s}\leq 0.37$.

hep-ph↗
arXiv2013

CKM matrix element Vcb in a QCD Potential model

We study the slope $ρ^{2}$ and curvature $C$ of Isgur Wise function for the heavy-light mesons in general with particular emphasis on $B$ meson in a QCD Potential model. The IW function is then used to compute the partial decay width and branching ratio for the semileptonic decay of $\left(B^{0}\rightarrow{D,D^{*}lν}\right)$. The computed value of the CKM element $|V_{cb}|=0.040$ is found to be in agreement with the available data.

hep-ph↗
arXiv2011

Semileptonic decay of Bc meson into S wave charmonium in a QCD potential model with coulombic part as perturbation

We present the semileptonic decay of $B_{c}$ meson in a QCD potential model with the coulombic part of the Cornell potential $-\frac{4α_{S}}{3r}+br+c$ as perturbation. Computing the slope and curvature of Isgur Wise function in this approach, we study the pseudoscalar and vector form factors for the transition of $B_{c}$ meson to its S wave charmonium $c\bar{c}$ states. Numerical estimates of widths for the transitions of $B_{c}\rightarrow J/ψ(η_{c})lν_{l}$ are presented. The results are found to be in good agreement with other theoretical values.

hep-ph↗
arXiv2011

Oscillation frequency of B and B mesons in a QCD potential model with relativistic effect

Wavefunction at the origin with the incorporation of relativistic effect leads to singularity in a specific potential model. To regularise the wavefunction, we introduce a short distance scale here and use it to estimate masses and decay constants of Bd and Bs mesons within the QCD potential model.These values are then used to compute the oscillation frequency ΔmB of Bd and Bs mesons. The values are found to be in good agreement with experiment and other theoretical values.

hep-ph↗
arXiv2011

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$-\frac{4α_{S}}{3r}+br+c$. Here we consider the linear term $br$ as the parent and $-\frac{4α_{S}}{3r}+c$ 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.

hep-ph↗
arXiv2011

DGLAP Evolutions and cross-sections of Neutrino-Nucleon interaction at Ultra High energy

We determine the UHE neutrino-nucleon cross-sections analytically both for charged and neutral current in the leading order by using the solutions of non-singlet DGLAP equation as well as singlet DGLAP equation respectively. Next we determine the cross-sections for both charged and neutral current at one loop level by carring out numerical integration of the double differential cross-section. For analytical solution, we take the standard MRST 2004 f4 LO parton distributions at $Q_0^2=1$ \,GeV$^2$ as input and for numerical solution (exact), we consider the GRV 94 parton distributions. Our analytical as well as numerically determined results are compared with the NLO results of various authors. We find our numerically determined result in sufficient agreement with the results obtained by those authors. On the other hand, our analytical result matches better with other results at lower end of the energy spectrum of the UHE neutrino rather than the higher end.

hep-ph↗
arXiv2011

Isgur-Wise function in a QCD inspired potential model with confinement as parent in the Variationally Improved Perturbation Theory (VIPT)

We have recently reported the calculation of slope and curvature of Isgur-Wise function based on Variationally Improved Perturbation Theory (VIPT) in a QCD inspired potential model. In that work, Coulombic potential was taken as the parent while the linear one as the perturbation.In this work, we choose the linear one as the parent with Coulombic one as the perturbation and see the consequences. Keywords: VIPT,Isgur-Wise function, charge radii and convexity pa- rameter.

hep-ph↗