Browsing by Author "Venktesh Singh"

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Analysis of Non-isotropic Lorentz Invariance Violation for NOνA Experiment in Disappearance Channel
(Springer Science and Business Media Deutschland GmbH, 2024) Saurabh Shukla; Shashank Mishra; Lakhwinder Singh; Venktesh Singh
Lorentz Invariance Violation (LIV) is a trending topic of Beyond Standard Model Physics. Lorentz symmetry is tasted and well established in the low energy realm of Physics. But there are various theories which suggest its violation for Planck scale phenomenon. As neutrinos, having tiny mass, are the particle that are breaking down the barriers of Standard Model, they may be an excellent tool for searching such Planck-suppressed signals. In order to do this study, we have opted for Standard model extension as the theoretical framewok, which contains all Lorentz violating tems in it. We study the non-isotropic LIV which causes the sidereal effect in the neutrino beamline experiment. Neutrino disappearance channel is simulated for the NOνA far detector. We find that NOνA FD is highly sensitive for the LIV and new limits of LIV coefficients are also predicted. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
Charged and Neutral Current Pion Production in Neutrino-Nucleus Scattering
(Springer Science and Business Media, LLC, 2018) Kapil Saraswat; Prashant Shukla; Vineet Kumar; Venktesh Singh
In this article, we present the charged and neutral current coherent pion production in the neutrino-nucleus interaction in the resonance region using the formalism based on the partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model approach. We calculate the integrated cross sections for neutrino-carbon, neutrino-iron and neutrino-oxygen scattering. The results of integrated cross-section calculations are compared with the measured data. © 2018, Springer International Publishing AG, part of Springer Nature.
Charged current quasi elastic scattering of muon neutrino with nuclei
(Scientific Publishers, 2018) Kapil Saraswat; Prashant Shukla; Vineet Kumar; Venktesh Singh
We present a study on the charge current quasi elastic scattering of νμ from nucleon and nuclei which gives a charged muon in the final state. To describe nuclei, the Fermi Gas model has been used with proposed Pauli suppression factor. The diffuseness parameter of the Fermi distribution has been obtained using experimental data. We also investigate different parametrizations for electric and magnetic Sach’s form factors of nucleons. Calculations have been made for CCQES total and differential cross-sections for the cases of νμ- N, νμ- 12C and νμ- 56Fe scatterings and are compared with the data for different values of the axial mass. The present model gives excellent description of measured differential cross-section for all the systems. © 2017, Indian Association for the Cultivation of Science.
Charged current quasi-elastic scattering of νμ off 12C
(Institute of Physics Publishing, 2018) Deepika Grover; Kapil Saraswat; Prashant Shukla; Venktesh Singh
In this work, we study charged current quasi-elastic scattering (QES) of vμ off nucleon and nucleus using a formalism based on the Llewellyn Smith (LS) model. Parameterizations by Galster et al. are used for electric and magnetic Sach'fs form factors of the nucleons. We use the Fermi gas model along with the Pauli suppression condition to take into account the nuclear effects in the anti-neutrino.nucleus QES. We calculate vμ - p and vμ - 12C charged current quasi-elastic scattering differential and total cross sections for different values of axial mass MA, and compare the results with data from the GGM, SKAT, BNL, NOMAD, MINERA and MiniBooNE experiments. The present theoretical approach gives a good description of differential cross section data. The calculations with axial mass MA=0.979 and 1.05 GeV are compatible with data from most of the experiments. © 2018 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
Charged-current deep-inelastic scattering of muon neutrinos (νμ) off Fe 56
(American Physical Society, 2018) Deepika Grover; Kapil Saraswat; Prashant Shukla; Venktesh Singh
In this paper, we study charged-current deep-inelastic scattering of muon neutrinos off Fe56 nuclei by using the Hirai, Kumano, and Saito model. The LHA parton distribution functions (PDFs) - CT10 are used to describe the partonic content of hadrons. Modification of PDFs inside the nuclei is done by using EPPS16 parametrization at next-to-leading order. Target mass correction has also been incorporated in the calculations. We calculate the structure functions [F2(x,Q2) and xF3(x,Q2)], the ratios [R2(x,Q2)=F2Fe56/F2Nucleon and R3(x,Q2)=F3Fe56/F3Nucleon], and the differential cross sections of νμ deep-inelastic scattering off nucleons and Fe56 nuclei. We compare the results obtained with measured experimental data. The present theoretical approach gives a good description of data. .
Coherent pion production in neutrino-nucleus scattering
(American Physical Society, 2016) Kapil Saraswat; Prashant Shukla; Vineet Kumar; Venktesh Singh
In this article, we study the coherent pion production in the neutrino-nucleus interaction in the resonance region using the formalism based on the partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion-nucleus elastic cross section is calculated using the Glauber model in terms of pion-nucleon cross sections obtained by parametrizing the experimental data. We calculate the differential and integrated cross sections for charged current coherent pion production in neutrino-carbon scattering. The results of integrated cross-section calculations are compared with the measured data. Predictions for the differential and integrated cross sections for coherent pion productions in neutrino-iron scattering using the above formalism are also made. © 2016 American Physical Society.
Constraining heavy quark energy loss using B and D meson measurements in heavy ion collision at RHIC and LHC energies
(Elsevier B.V., 2015) Kapil Saraswat; Prashant Shukla; Venktesh Singh
In this work, we calculate energy loss of heavy quark (charm and bottom) due to elastic collisions and gluon radiation in hot/dense medium. The collisional energy loss has been obtained using QCD calculations. The radiative energy loss is calculated using reaction operator formalism and generalized dead cone approach. We rederive the energy loss expression using same assumptions as generalized dead cone approach but obtain slightly different results. We also improve the model employed to calculate path length and the system evolution. The nuclear modification factors RAA including shadowing and energy loss are evaluated for B and D mesons and are compared with the measurements in PbPb collision at sNN=2.76 TeV and with the D meson and Heavy flavor (HF) electrons measurements in AuAu collision at sNN=200 GeV. The radiative energy loss calculated by reaction operator formalism added with collisional energy loss describes the RHIC HF electron suppression in high pT range. It also describes the LHC measurement of B meson suppression but overestimates the suppression of D meson. The radiative energy loss from generalized dead cone approach describes the charm suppression at both RHIC as well as LHC energies and requires energy loss due to collisions to be added in order to describe the bottom suppression at LHC. © 2015.
Constraints on bosonic dark matter with low threshold germanium detector at Kuo-Sheng reactor neutrino laboratory
(Physical Society of the Republic of China, 2019) Manoj Kumar Singh; Lakhwinder Singh; Mehmet Agartioglu; Vivek Sharma; Venktesh Singh; Henry Tsz-king Wong
We report results from searches of pseudoscalar and vector bosonic super-weakly interacting massive particles (super-WIMP) in the TEXONO experiment at the Kuo-Sheng Nuclear Power Station, using 314.15 kg days of data from n-type Point-Contact Germanium detector. The super-WIMPs are absorbed and deposit total energy in the detector, such that the experimental signatures are spectral peaks corresponding to the super-WIMP mass. Measured data are compatible with the background model, and no significant excess of super-WIMP signals are observed. We derived new upper limits on couplings of electrons with the pseudoscalar and vector bosonic super-WIMPs in the sub-keV mass region, assuming they are the dominant contributions to the dark matter density of our galaxy. © 2019 The Physical Society of the Republic of China (Taiwan)
Constraints on new physics with light mediators and generalized neutrino interactions via coherent elastic neutrino nucleus scattering
(American Physical Society, 2025) Sevgi Karadaǧ; Muhammed Deniz; S. Karmakar; Major Kumar Singh; Mehmet Demirci; C. Greeshma; Haubin Li; Shinted Lin; M. F. Mustamin; Vivek Sharma; Lakhwinder Singh; M. K. Singh; Venktesh Singh; Henry Tsz King Wong
Weinvestigate new physics effects on coherent elastic neutrino nucleus scattering within the framework of nonstandard interactions and generalized neutrino interactions. Additionally, we examine the possibility of light mediators from a simplified model that includes all possible Lorentz-invariant interactions of vector, axialvector, scalar, pseudoscalar, and tensor types. Constraints and allowed regions at the 90% CL for masses and couplings in each new physics scenario have been obtained through the analysis of TEXONOdata,whichincludes two datasets from a high-purity n-type point contact germanium detector in 2016 and an advanced p-type point contact Ge detector in 2025. The results are presented in comparison with other reactor and accelerator-based neutrino experiments for complementarity. © (2025), (Web Portal American Physical Society). All Rights Reserved.
Dark matter annual modulation analysis with combined nuclear and electron recoil channels
(American Physical Society, 2025) Haubin Li; Mukesh Kumar Pandey; C. H. Leung; Lakhwinder Singh; Henry Tsz King Wong; Hsinchang Chi; Muhammed Deniz; C. Greeshma; Jiunn Wei Chen; H. C. Hsu; Sevgi Karadaǧ; S. Karmakar; V. Kumar; Jin Li; Fong Kay Lin; Shinted Lin; Chengpang Liu; Shukui Liu; Hao Ma; Devendra Kumar Mishra; Kapil Saraswat; Vivek Sharma; Manoj Kumar Singh; Venktesh Singh; D. Tanabe; Jiashian Wang; Chihpan Wu; Litao Yang; C. H. Yeh; Qian Yue
After decades of experimental efforts, the DAMA/LIBRA(DL) annual modulation (AM) analysis on the χN (WIMP dark matter interactions on nucleus) channel remains the only one which can be interpreted as positive signatures. This has been refuted by numerous time-integrated (TI) and AM analysis. It has been shown that χe (WIMP interactions with electrons) alone is not compatible with the DL AM data. We expand the investigations by performing an AM analysis with the addition of χe long-range and short-range interactions to χN, derived using the frozen core approximation method. Two scenarios are considered, where the χN and χe processes are due to a single χ (Γtot1χ) or two different χ's (Γtot2χ). The combined fits with χN and χe provide stronger significance to the DL AM data which are compatible with the presence of additional physical effects beyond χN alone. This is the first analysis which explores how χe AM can play a role in DL AM. The revised allowed regions as well as the exclusion contours from the other null AM experiments are presented. All DL AM allowed parameter spaces in χN and χe channels under both Γtot1χ and Γtot2χ are excluded at the 90% confidence level by the combined null AM results. It can be projected that DL-allowed parameter spaces from generic models with interactions induced by two-WIMPs are ruled out. © 2025 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.
Energy loss of B and D mesons in PbPb collisions at sNN = 2.76 TeV
(Sissa Medialab Srl, 2015) Kapil Saraswat; Prashant Shukla; Venktesh Singh
We present the calculations of collisional and radiative energy loss of B and D mesons in the medium produced in PbPb collisions at sNN = 2.76 TeV. The nuclear modification factor RAA of B and D mesons including shadowing and energy loss are calculated and compared with the measured data. While the D meson RAA can be described in terms of the radiative energy loss alone, both the collisional as well as radiative energy loss are required to explain the B meson measurements. © Copyright owned by the author(s) under the terms of the Creative Commons
Energy loss of heavy quarks and B and D meson spectra in PbPb collisions at LHC energies
(Elsevier B.V., 2017) Kapil Saraswat; Prashant Shukla; Vineet Kumar; Venktesh Singh
We study the production and evolution of charm and bottom quarks in hot partonic medium produced in heavy ion collisions. The heavy quarks loose energy in the medium which is reflected in the transverse momentum spectra of heavy mesons. The collisional energy loss of heavy quarks has been calculated using QCD calculations. The radiative energy loss is obtained using two models namely reaction operator formalism and generalized dead cone approach. The nuclear modification factors, RAA as a function of transverse momentum by including shadowing and energy loss are calculated for D0 and B+ mesons in PbPb collisions at sNN=5.02 TeV and for D0 mesons at sNN=2.76 TeV and are compared with the recent measurements. The radiative energy loss from generalized dead cone approach alone is sufficient to produce measured D0 meson RAA at both the LHC energies. The radiative energy loss from reaction operator formalism plus collisional energy loss gives good description of D0 meson RAA. For the case of B+ meson, the radiative energy loss from generalized dead cone approach plus collisional energy loss gives good description of the CMS data. The radiative process is dominant for charm quarks while for the bottom, both the radiative process and the elastic collisions are important. © 2017 Elsevier B.V.
Erratum: Differentiating dilatons from the axions by their mixing with photons(Eur. Phys. J. C, (2024), 84, (627), 10.1140/epjc/s10052-024-12851-1)
(Springer Nature, 2024) Ankur Chaubey; Manoj K. Jaiswal; Damini Singh; Venktesh Singh; Avijit K. Ganguly
In this article the title was incorrectly given as ‘Final-REVISION “Differentiating dilatons from axions by their mixing with photons”’ but should have been ‘Differentiating dilatons from the axions by their mixing with photons’. The original article has been corrected. © The Author(s) 2024.
Final-REVISION “Differentiating dilatons from axions by their mixing with photons”
(Springer Nature, 2024) Ankur Chaubey; Manoj K. Jaiswal; Damini Singh; Venktesh Singh; Avijit K. Ganguly
The quanta of scalar fields like the dilaton (ϕ) of scale symmetry origin and those of pseudoscalar fields like the axion (ϕ′) of Peccei–Quinn symmetry origin couple to di-photons through dimension-5 operators. In a magnetized medium (MM), they in principle can interact with the two transverse (A‖,⊥) and one longitudinal (AL) degree of freedom of photons (γ) as long as the total spin is conserved. However, of ϕ and ϕ′, only one interacts with AL. We found that the ambient external magnetic field B and media break the intrinsic Lorentz symmetry of the system affecting the dispersion relation of the propagating modes. The boost and the rotational symmetry along and around B are however the ones that are preserved. Invoking C, P, and T symmetries, we analyze the mixing dynamics of ϕγ and ϕ′γ systems and the structural difference in their mixing pattern. It is noted that while the ϕγ mixing matrix is 3×3, the ϕ′γ is governed by a 4×4 mixing matrix. Using the exact solutions of both systems in MM, we estimate the strength of the electromagnetic (EM) signals available due to these interactions, which are found to be different in strength. We conclude by commenting on (a) the possibility of detecting this difference in polarimetric observables of the EM signal, (b) the implications of these different mixing patterns with respect to the minimum detectable signal for astrophysical observations, and (c) the variation in the energy of the dispersed photons of different polarization with the variation in B. © The Author(s) 2024.
Freeze-Out of Strange Hadron in pp, pPb and PbPb Collisions at LHC Energies
(Springer Science and Business Media, LLC, 2018) Kapil Saraswat; Prashant Shukla; Vineet Kumar; Venktesh Singh
A study of the transverse momentum (formula presented) spectra of the strange hadron (formula presented) for various multiplicity classes in proton-proton (pp), proton-lead (pPb) and lead-lead collisions at different center of mass energies at LHC is presented. The Tsallis distribution with including transverse flow is used to study the (formula presented) spectra of the (formula presented) under the differential freeze out scenario. The parameters Tsallis temperature (T), power (n) and average transverse flow velocity (formula presented) are obtained after fitting the (formula presented) spectra of the (formula presented). © 2018, Springer International Publishing AG, part of Springer Nature.
Global properties in high energy collisions
(Hindawi Limited, 2015) Bao-Chun Li; Edward Sarkisyan-Grinbaum; Andrey Leonidov; Venktesh Singh; C. Wu
[No abstract available]
India-based neutrino observatory
(2013) B.S. Acharya; Sanjib Kumar Agarwalla; Prafulla Kumar Behera; Anju Bhasin; Subhasish Chattopadhyay; Sandhya Choubey; Vivek Datar; Raj Gandhi; Gautam Gangopadhyay; Srubabati Goswami; Rashid Hasan; D. Indumathi; Naba K. Mondal; M.V.N. Murthy; M.D. Naimuddin; G. Rajasekaran; C. Ranganathaiah; Amitava Raychaudhuri; Venktesh Singh; Nita Sinha; A.M. Vinodkumar; Y.P. Viyogi
[No abstract available]
Induced Neutrino Charge in a Magnetized Medium
(Springer Science and Business Media Deutschland GmbH, 2024) Ankur Chaubey; Damini Singh; R.R. Jaiswal; Venktesh Singh; Avijit K. Ganguly
In this paper we estimate the contribution to neutrino effective charge from the vector type (coupling constant gV) vertex eeffνV coming from the polarization tensor Πμν in a magnetized medium. For electron type neutrinos gV=1-(1-4sin2θW)/2, and for tau and mu type neutrino gV=-(1-4sin2θW)/2. We note that keeping PCT symmetry in view, the leading powers of B and μ that appears in the expression of eeffνV is of order (eB)2 and μ2. We further elucidate on the direction dependence of this charge that’s a manifestation of loss of isotropy due to the presence of an external field. We conclude this work by inferring on astrophysical and cosmological consequences of the same. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
Investigating Lorentz invariance violation effects on CP violation and mass hierarchy sensitivity at DUNE
(American Physical Society, 2024) Saurabh Shukla; Shashank Mishra; Lakhwinder Singh; Venktesh Singh
One of the current goals of neutrino experiments is to precisely determine standard unknown oscillation parameters such as the leptonic CP phase and mass hierarchy. Lorentz invariance violation represents a potential physics factor that could influence the experiment's ability to achieve these precise determinations. This study investigates the influence of Lorentz invariance violation on oscillation dynamics, particularly through nonisotropic CPT-violating (aeμX, aeτX, aμτX) and CPT-conserving (ceμXY, ceτXY, cμτXY) parameters within the Deep Underground Neutrino Experiment. We analyze the impact of these parameters on the mass hierarchy (MH) and Dirac CP phase sensitivity measurements. Our findings indicate that while MH sensitivity remains relatively unaffected, only the presence of cμτXY significantly deteriorates MH sensitivity, albeit remaining above the 5σ threshold. Additionally, we observe a substantial compromise in CP sensitivity due to the ceμXY and ceτXY parameters. © 2024 authors. Published by the American Physical Society.
Invited review: Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO)
(Indian Academy of Sciences, 2017) A. Kumar; A.M. Vinod Kumar; Abhik Jash; Ajit K Mohanty; Aleena Chacko; Ali Ajmi; Ambar Ghosal; Amina Khatun; Amitava Raychaudhuri; Amol Dighe; Animesh Chatterjee; Ankit Gaur; Anushree Ghosh; Ashok Kumar; Asmita Redij; B. Satyanarayana; B.S. Acharya; Brajesh C Choudhary; C. Ranganathaiah; C.D. Ravikumar; Chandan Gupta; D. Indumathi; Daljeet Kaur; Debasish Majumdar; Deepak Samuel; Deepak Tiwari; G. Rajasekaran; Gautam Gangopadhyay; Gobinda Majumder; H.B. Ravikumar; J.B. Singh; J.S. Shahi; James Libby; Jyotsna Singh; K. Raveendrababu; K.K. Meghna; K.R. Rebin; Kamalesh Kar; Kolahal Bhattacharya; Lalit M Pant; M Sajjad Athar; M.V.N. Murthy; Manzoor A Malik; M.D. Naimuddin; Mohammad Salim; Monojit Ghosh; Moon Moon Devi; Naba K Mondal; Nayana Majumdar; Nita Sinha; Nitali Dash; Pomita Ghoshal; Poonam Mehta; Prafulla Behera; R. Kanishka; Raj Gandhi; Rajesh Ganai; Rashid Hasan; S. Krishnaveni; S.M. Lakshmi; S.K. Singh; S.S.R. Inbanathan; S. Uma Sankar; Sadiq Jafer; Saikat Biswas; Sanjeev Kumar; Sanjib Kumar Agarwalla; Sandhya Choubey; Satyajit Saha; Shakeel Ahmed; Shiba Prasad Behera; Srubabati Goswami; Subhasis Chattopadhyay; Sudeb Bhattacharya; Sudeshna Banerjee; Sudeshna Dasgupta; Sumanta Pal; Supratik Mukhopadhyay; Sushant Raut; Suvendu Bose; Swapna Mahapatra; Tapasi Ghosh; Tarak Thakore; V.K.S. Kashyap; V.S. Subrahmanyam; Venktesh Singh; Vinay B Chandratre; Vipin Bhatnagar; Vivek M Datar; Waseem Bari; Y.P. Viyogi
The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles. © Indian Academy of Sciences.