arXiv subjects

K. Chaturvedi

Publications and source records attributed to K. Chaturvedi.

10 recordsLinked to original sources

arXiv2019

Nuclear transition matrix elements for neutrinoless double-$β$ decay within mechanisms involving light Majorana neutrino mass and right-handed current

Employing the projected-Hartree-Fock-Bogoliubov (PHFB) model in conjunction with four different parametrizations of pairing plus multipolar effective two body interaction and three different parametrizations of Jastrow short range correlations, nuclear transition matrix elements for the neutrinoless double-$β$ decay of $^{94,96}$Zr, $^{100}$Mo, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes are calculated within mechanisms involving light Majorana neutrino mass and right handed current. Statistically, model specific uncertainties in sets of twelve nuclear transition matrix elements are estimated by calculating the averages along with the standard deviations. For the considered nuclei, \ the most stringent extracted on-axis limits on the effective light Majorana neutrino mass $ $, the effective weak coupling of right-handed leptonic current with right-handed hadronic current $<λ>$, and the effective weak coupling of right-handed leptonic current with left-handed hadronic current $<η>$ \ from the observed limit on half-life $T_{1/2}^{0ν}$ of $^{130}$Te isotope are $0.33$ eV, $4.57\times 10^{-7}$ and $4.72\times 10^{-9}$, respectively.

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arXiv2013

Neutrinoless $ββ$ decay transition matrix elements within mechanisms involving light Majorana neutrinos, classical Majorons and sterile neutrinos

In the PHFB model, uncertainties in the nuclear transition matrix elements for the neutrinoless double-$β$ decay of $\ ^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes within mechanisms involving light Majorana neutrinos, classical Majorons and sterile neutrinos are statistically estimated by considering sets of sixteen (twenty-four) matrix elements calculated with four different parametrization of the pairing plus multipolar type of effective two-body interaction, two sets of form factors and two (three) different parameterizations of Jastrow type of short range correlations. In the mechanisms involving the light Majorana neutrinos and classical Majorons, the maximum uncertainty is about 15% and in the scenario of sterile neutrinos, it varies in between approximately 4 (9)%--20 (36)% without(with) Jastrow short range correlations with Miller-Spencer parametrization, depending on the considered mass of the sterile neutrinos.

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arXiv2012

Uncertainties in nuclear transition matrix elements for $β^{+}β^{+}$ and $\varepsilon β^{+}$ modes of neutrinoless positron double-$β$ decay within PHFB model

Uncertainties in the nuclear transition matrix elements $M^{(0ν)}$ and $M^{(0N)}$ of the double-positron emission $(β^{+}β^{+})_{0ν}$ and electron-positron conversion $(\varepsilon β^{+})_{0ν}$ modes due to the exchange of light and heavy Majorana neutrinos, respectively, are calculated for $^{96}$Ru, $^{102}$Pd, $^{106}$Cd, $^{124}$Xe, $^{130}$Ba and $^{156}$Dy isotopes by employing the PHFB model with four different parameterization of the pairing plus multipolar two-body interactions and three different parameterizations of the Jastrow short range correlations. In all cases but for $^{130}$Ba, the uncertainties are smaller than 14% for light Majorana neutrino exchange and 35% for the exchange of a heavy Majorana neutrino.

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arXiv2012

Uncertainties in nuclear transition matrix elements for neutrinoless $ββ$ decay II: the heavy Majorana neutrino mass mechanism

Employing four different parametrization of the pairing plus multipolar type of effective two-body interaction and three different parametrizations of Jastrow-type of short range correlations, the uncertainties in the nuclear transition matrix elements $M_{N}^{(0ν)}$ due to the exchange of heavy Majorana neutrino for the $0^{+}\rightarrow 0^{+}$ transition of neutrinoless double beta decay of $^{94}$Zr, $^{96}$Zr, $^{98}$Mo, $^{100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes in the PHFB model are estimated to be around 25%. Excluding the nuclear transition matrix elements calculated with Miller-Spenser parametrization of Jastrow short range correlations, the uncertainties are found to be 10%-15% smaller.

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arXiv2011

Analytic Calculation of Neutrino Mass Eigenvalues

Implicaion of the neutrino oscillation search for the neutrino mass square difference and mixing are discussed. We have considered the effective majorana mass m_{ee}, related for ββ_{0ν}decay. We find limits for neutrino mass eigen value m_{i} in the different neutrino mass spectrum,which explain the different neutrino data.

hep-ph↗

arXiv2011

Uncertainties in nuclear transition matrix elements for neutrinoless $ββ$ decay within the PHFB model

The nuclear transition matrix elements $M^{(0ν)}$ for the neutrinoless double beta decay of $^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes in the case of $0^{+}\rightarrow 0^{+}$ transition are calculated using the PHFB wave functions, which are eigenvectors of four different parameterizations of a Hamiltonian with pairing plus multipolar effective two-body interaction. \QCOM{35}{In addition, the consideration of} Employing two (three) different parameterizations of Jastrow-type short range correlations, \QCOM{19}{provides us with} a set of eight (twelve) different nuclear transition matrix elements $M^{(0ν)}$ is built for each decay, whose averages in conjunction with their standard deviations provide an estimate of the model uncertainties.

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arXiv2009

Deformation effects and neutrinoless positron $ββ$ decay of $^{96}$Ru, $^{102}$Pd, $^{106}$Cd, $^{124}$Xe, $^{130}$Ba and $^{156}$Dy isotopes within Majorona neutrino mass mechanism

The $(β^{+}β^{+})_{0ν}$ and $(\varepsilon β^{+})_{0ν}$ modes of $^{96}$Ru, $^{102}$Pd, $^{106}$Cd, $^{124}$Xe, $^{130}$Ba and $^{156}$Dy isotopes are studied in the Projected Hartree-Fock-Bogoliubov framework for the $0^{+}\to 0^{+}$ transition. The reliability of the intrinsic wave functions required to study these decay modes has been established in our earlier works by obtaining an overall agreement between the theoretically calculated spectroscopic properties, namely yrast spectra, reduced $B(E2$:$0^{+}\to 2^{+})$ transition probabilities, quadrupole moments $Q(2^{+})$ and gyromagnetic factors $g(2^{+})$ and the available experimental data in the parent and daugther even-even nuclei. In the present work, the required nuclear transition matrix elements are calculated in the Majorana neutrino mass mechanism using the same set of intrinsic wave functions as used to study the two neutrino positron double-$β$ decay modes. Limits on effective light neutrino mass $< m_ν >$ and effective heavy neutrino mass $< M_{N} >$ are extracted from the observed limits on half-lives $T_{1/2}^{0ν}(0^{+}\to 0^{+})$ of $(β^{+}β^{+})_{0ν}$ and $(\varepsilon β^{+})_{0ν}$ modes. We also investigate the effect of quadrupolar correlations vis-a-vis deformation on NTMEs required to study the $(β^{+}β^{+})_{0ν}$ and $(\varepsilon β^{+})_{0ν}$ modes.

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arXiv2009

Nuclear deformation and neutrinoless double-$β$ decay of $^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd nuclei in mass mechanism

The $(β^{-}β^{-})_{0ν}$ decay of $^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes for the $0^{+}\to 0^{+}$ transition is studied in the Projected Hartree-Fock-Bogoliubov framework. In our earlier work, the reliability of HFB intrinsic wave functions participating in the $β^{-}β^{-}$ decay of the above mentioned nuclei has been established by obtaining an overall agreement between the theoretically calculated spectroscopic properties, namely yrast spectra, reduced $B(E2$:$0^{+}\to 2^{+})$ transition probabilities, quadrupole moments $Q(2^{+})$, gyromagnetic factors $g(2^{+})$ as well as half-lives $T_{1/2}^{2ν}$ for the $0^{+}\to 0^{+}$ transition and the available experimental data. In the present work, we study the $(β^{-}β^{-})_{0ν}$ decay for the $0^{+}\to 0^{+}$ transition in the mass mechanism and extract limits on effective mass of light as well as heavy neutrinos from the observed half-lives $T_{1/2}^{0ν}(0^{+}\to 0^{+})$ using nuclear transition matrix elements calculated with the same set of wave functions. Further, the effect of deformation on the nuclear transition matrix elements required to study the $(β^{-}β^{-})_{0ν}$ decay in the mass mechanism is investigated. It is noticed that the deformation effect on nuclear transition matrix elements is of approximately same magnitude in $(β^{-}β^{-})_{2ν}$ and $(β^{-}β^{-})_{0ν}$ decay.

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arXiv2009

Multipolar correlations and deformation effect on nuclear transition matrix elements of double-$β$ decay

The two neutrino and neutrinoless double beta decay of $^{94,96}$Zr, $^{98,100}$Mo, $^{104}$Ru, $^{110}$Pd, $^{128,130}$Te and $^{150}$Nd isotopes for the $0^{+}\to 0^{+}$ transition is studied within the PHFB framework along with an effective two-body interaction consisting of pairing, quadrupole-quadrupole and hexadecapole-hexadecapole correlations. It is found that the effect of hexadecapolar correlations can be assimilated substantially as a renormalization of the quadrupole-quadrupole interaction. The effect of deformation on nuclear transition matrix elements is investigated by varying the strength of quadrupolar correlations in the parent and daughter nuclei independently. The variation of the nuclear transition matrix elements as a function of the difference in deformation parameters of parent and daughter nuclei reveals that in general, the former tend to be maximum for equal deformation and they decrease as the difference in deformation parameters increases, exhibiting a very similar trend for the $(β^{-}β^{-})_{2ν}$ and $(β^{-}β^{-})_{0ν}$ transition matrix elements.

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arXiv2004

n-p Interaction Effects on the Double Beta Decay Nuclear Matrix Elements for Medium Mass Nuclei

The quality of HFB wave functions are tested by comparing the theoretically calculated results with the available experimental data for a number of spectroscopic properties like yrast spectra, reduced B(E2) transition probabilities, quadrupole moments and g-factors for the nuclei involved in 2$ν$ $ββ$ decay. It is observed that the np interactions vis-à-vis the deformations of the intrinsic ground states of medium mass nuclei play a crucial role in the fine tuning of the nuclear matrix elements, M$_{2ν}.$

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