122709605
THE ISGUR–WISE FUNCTION IN AN IMPROVED QCD INSPIRED QUARK MODEL
We calculate the Isgur–Wise function of heavy light mesons and its derivatives — its slope and its curvature, in an improved version of our earlier QCD Inspired Quark Model with two-loop static potential.
119205638
A lower bound on the Longitudinal Structure Function at small x from a self-similarity based model of Proton
Self-similarity based model of proton structure function at small \textit{x} was reported in the literature sometime back. The phenomenological validity of the model is in the kinematical region $ 6.2\, \times \, 10^{-7} \leq x \leq 10^{-2}$ and $ 0.045 \leq Q^{2} \leq 120 \, \mathrm{GeV^{2}} $. We use momentum sum rule to pin down the corresponding self-similarity based gluon distribution function valid in the same kinematical region. The model is then used to compute bound on the longitudinal structure function $F_{L}\left(x,Q^{2} \right)$ for Altarelli-Martinelli equation in QCD and is compared with the recent HERA data.
119568734
Masses in structure functions
We derive an approximate formula for the quark mass in ξ-formalism. Using the QCD-based form of structure function, we analyse the SLAC-MIT data to estimate the experimentally allowed ranges of quark mass. The possible variation of our results with QCD cut-off parameter, gluon distribution, hard intrinsic charm component of the proton wavefunction and the higher twist effects are also discussed.
123165880
A solution of the DGLAP equation for gluon at low x
We obtain a solution of the DGLAP equation for the gluon at low x first by expanding the gluon in a Taylor series and then using the method of characteristics. We test its validity by comparing it with that of Glück, Reya and Vogt. The convergence criteria of the approximation used are also discussed. We also calculate εF2(x,Q)2/ε In Q2 using its approximate relations with the gluon distribution at low x. The predictions are then compared with the HERA data.
118555510
SEMILEPTONIC DECAY OF Bc MESON INTO $c\bar c$ STATES IN A QCD POTENTIAL MODEL
The slope and curvature of Isgur–Wise function for Bc 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 Bc meson into the states are exploited. Spin symmetry breaking effects are ignored up to a particular point and the form factors are connected with Isgur–Wise function for other kinematic point since the recoil momentum of from Bc is small due to its heavy mass.
120396984
Free-field theory, fixed-point theory, and electron-positron annihilation into hadrons
The R problem of electron-positron physics is analyzed within the frameworks of a free-field theory (parton models) and a field theory with an infrared-stable fixed point. Present data do not rule out either of these models and hence they both can survive as alternatives to standard QCD in the R problem.
119329980
Compton Scattering on He-3
We present first calculations for Compton scattering on $^3$He. The objective of the calculation is an extraction of the neutron polarizabilities.
9428112
Investigating neutron polarizabilities through Compton scattering on 3He.
We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the helium-3 nucleus. We calculate gamma3He elastic scattering observables using chiral perturbation theory to next-to-leading order [O(e2Q)]. We find that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities.