We show how the traditional grid based method for finding neutrino oscillation parameters △m2 and tan2θ can be combined with an optimization technique, Differential Evolution （DE）, to get a significant decrease in...We show how the traditional grid based method for finding neutrino oscillation parameters △m2 and tan2θ can be combined with an optimization technique, Differential Evolution （DE）, to get a significant decrease in computer processing time required to obtain minimal chi-square （χ2） in four different regions of the parameter space. We demonstrate efficiency for the two-neutrinos case. For this, the χ2 function for neutrino oscillations is evaluated for grids with different density of points in standard allowed regions of the parameter space of △m2 and tan2θ using experimental and theoretical total event rates of ehlorine （Homestake）, Gallex＋GNO, SAGE, Superkamiokande, and SNO detectors. We find that using DE in combination with the grid based method with smail density of points can produce the results comparable with the one obtained using high density grid, in much lesser computation time.展开更多
We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons.We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporat...We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons.We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporating both spin and S-D mixing effects and fit parameters of the potential model with known experimental states using differential evolution techniques.Using leading Born-Oppenheimer expansion,we compute the spectrum and wave functions of the first gluonic excited state of charmed and charmed strange mesons.We examine the effects of gluonic excitation on the spectrum of the resulting hybrid mesons.Using our calculated spectrum and wave functions,we determine the radiative transitions of the conventional and hybrid open charm mesons.We compare our calculations with experimental data and other works.We expect our results will be beneficial in the detection of charmed and charmed strange conventional and hybrid mesons.展开更多
For a system of current interest（composed of charm, anticharm and a pair of light quarks）, we show trends in phenomenological implications of QCD-based improvements to a simple quark model treatment. We employ a res...For a system of current interest（composed of charm, anticharm and a pair of light quarks）, we show trends in phenomenological implications of QCD-based improvements to a simple quark model treatment. We employ a resonating group method to render this difficult four-body problem manageable. We use a quadratic confinement so as to be able to improve beyond the Born approximation. We report the position of the pole corresponding to the D^0D^0＊ molecule for the best fit of a model parameter to the relevant QCD simulations. We point out the interesting possibility that the pole can be shifted to 3872 Me V by introducing another parameter I0 that changes the strength of the interaction in this one component of X（3872）. The revised value of this second parameter can guide future trends in modeling of the full exotic meson X（3872）. We also report the changes with I_0 in the S-wave spin averaged cross sections for D^0D^0＊-→ωJ/ψ and D^0D^0＊-→ρJ/ψ. These cross sections are important regarding the study of QGP（quark gluon plasma）.展开更多
基金the Higher Education Commission(HEC) of Pakistan for its financial support through Grant No.17-5-2(Ps2-044) HEC/Sch/2004
文摘We show how the traditional grid based method for finding neutrino oscillation parameters △m2 and tan2θ can be combined with an optimization technique, Differential Evolution （DE）, to get a significant decrease in computer processing time required to obtain minimal chi-square （χ2） in four different regions of the parameter space. We demonstrate efficiency for the two-neutrinos case. For this, the χ2 function for neutrino oscillations is evaluated for grids with different density of points in standard allowed regions of the parameter space of △m2 and tan2θ using experimental and theoretical total event rates of ehlorine （Homestake）, Gallex＋GNO, SAGE, Superkamiokande, and SNO detectors. We find that using DE in combination with the grid based method with smail density of points can produce the results comparable with the one obtained using high density grid, in much lesser computation time.
基金F.A.acknowledges HEC grant 20-15728/NRPU/R&D/HEC/2021,Pakistan。
文摘We use a modified relativistic quark model to study the properties of excited charmed and charmed strange mesons.We calculate the masses and wave functions of conventional charmed and charmed strange mesons incorporating both spin and S-D mixing effects and fit parameters of the potential model with known experimental states using differential evolution techniques.Using leading Born-Oppenheimer expansion,we compute the spectrum and wave functions of the first gluonic excited state of charmed and charmed strange mesons.We examine the effects of gluonic excitation on the spectrum of the resulting hybrid mesons.Using our calculated spectrum and wave functions,we determine the radiative transitions of the conventional and hybrid open charm mesons.We compare our calculations with experimental data and other works.We expect our results will be beneficial in the detection of charmed and charmed strange conventional and hybrid mesons.
基金support of PU research (D/605/Est.I Sr. 20 Project 2014-15, D/34/Est.1 Sr. 109 Project 2013-14)the Higher Education Commission (HEC) of Pakistan for its financial support through (17-5-4(Ps3-128) HEC/Sch/2006)
文摘For a system of current interest（composed of charm, anticharm and a pair of light quarks）, we show trends in phenomenological implications of QCD-based improvements to a simple quark model treatment. We employ a resonating group method to render this difficult four-body problem manageable. We use a quadratic confinement so as to be able to improve beyond the Born approximation. We report the position of the pole corresponding to the D^0D^0＊ molecule for the best fit of a model parameter to the relevant QCD simulations. We point out the interesting possibility that the pole can be shifted to 3872 Me V by introducing another parameter I0 that changes the strength of the interaction in this one component of X（3872）. The revised value of this second parameter can guide future trends in modeling of the full exotic meson X（3872）. We also report the changes with I_0 in the S-wave spin averaged cross sections for D^0D^0＊-→ωJ/ψ and D^0D^0＊-→ρJ/ψ. These cross sections are important regarding the study of QGP（quark gluon plasma）.
