Prafulla Kumar Behera

Bio: Prafulla Kumar Behera is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Large Hadron Collider & Branching fraction. The author has an hindex of 109, co-authored 1204 publications receiving 65248 citations. Previous affiliations of Prafulla Kumar Behera include CERN & Aomori University.

Amplitude analysis of the decay D0→K-K+π0

Abstract: Using 385 fb^-1 of e^+e^- collisions at the CM energies of around 10.6 GeV recorded by the BaBar experiment, we study the amplitudes of the singly Cabibbo-suppressed decay D^0 --> K^- K^+ pi^0. We measure the strong phase difference between the D0bar and D0 decays to the K^*(892)^+ K^- state to be -35.5 +/- 1.9 (stat) +/- 2.2 (syst) degrees, and their amplitude ratio to be 0.599 +/- 0.013 (stat) +/- 0.011 (syst). We observe significant contributions from the Kpi and K^-K^+ scalar and vector amplitudes, and analyze the moments of the cosine of the helicity angle in these systems. We find no evidence for charged, scalar kappa(800) state, nor for higher spin states. We also perform a model-independent partial wave analysis of the K^-K^+ system in a limited mass range around 1 GeV/c^2. We study several models for Kpi S-wave amplitude, and describe which one is favored by our data.

Search for a heavy pseudoscalar Higgs boson decaying into a 125 GeV Higgs boson and a Z boson in final states with two tau and two light leptons at √s = 13 TeV

Abstract: A search is performed for a pseudoscalar Higgs boson, A, decaying into a 125 GeV Higgs boson h and a Z boson. The h boson is specifically targeted in its decay into a pair of tau leptons, while the Z boson decays into a pair of electrons or muons. A data sample of proton-proton collisions collected by the CMS experiment at the LHC at $$ \sqrt{s} $$ = 13 TeV is used, corresponding to an integrated luminosity of 35.9 fb−1. No excess above the standard model background expectations is observed in data. A model-independent upper limit is set on the product of the gluon fusion production cross section for the A boson and the branching fraction to Zh → llττ. The observed upper limit at 95% confidence level ranges from 27 to 5 fb for A boson masses from 220 to 400 GeV, respectively. The results are used to constrain the extended Higgs sector parameters for two benchmark scenarios of the minimal supersymmetric standard model.

Search for dark matter produced in association with a single top quark or a top quark pair in proton-proton collisions at √s = 13 TeV

Abstract: A search for dark matter produced in association with top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The data set used corresponds to an integrated luminosity of 35.9 fb−1 recorded with the CMS detector at the LHC. Whereas previous searches for neutral scalar or pseudoscalar mediators considered dark matter production in association with a top quark pair only, this analysis also includes production modes with a single top quark. The results are derived from the combination of multiple selection categories that are defined to target either the single top quark or the top quark pair signature. No significant deviations with respect to the standard model predictions are observed. The results are interpreted in the context of a simplified model in which a scalar or pseudoscalar mediator particle couples to a top quark and subsequently decays into dark matter particles. Scalar and pseudoscalar mediator particles with masses below 290 and 300 GeV, respectively, are excluded at 95% confidence level, assuming a dark matter particle mass of 1 GeV and mediator couplings to fermions and dark matter particles equal to unity.

Search for resonant t t ¯ production in proton-proton collisions at √s=13 TeV

Abstract: A search for a heavy resonance decaying into a top quark and antiquark $$ \left(\mathrm{t}\overline{\mathrm{t}}\right) $$ pair is performed using proton-proton collisions at $$ \sqrt{s}=13 $$ TeV. The search uses the data set collected with the CMS detector in 2016, which corresponds to an integrated luminosity of 35.9 fb−1. The analysis considers three exclusive final states and uses reconstruction techniques that are optimized for top quarks with high Lorentz boosts, which requires the use of nonisolated leptons and jet substructure techniques. No significant excess of events relative to the expected yield from standard model processes is observed. Upper limits on the production cross section of heavy resonances decaying to a $$ \mathrm{t}\overline{\mathrm{t}} $$ pair are calculated. Limits are derived for a leptophobic topcolor Z′ resonance with widths of 1, 10, and 30%, relative to the mass of the resonance, and exclude masses up to 3.80, 5.25, and 6.65 TeV, respectively. Kaluza-Klein excitations of the gluon in the Randall-Sundrum model are excluded up to 4.55 TeV. To date, these are the most stringent limits on $$ \mathrm{t}\overline{\mathrm{t}} $$ resonances.

Search for b→u transitions in B-→DK- and D*K- decays

Abstract: We report results from an updated study of the suppressed decays B^-→DK^- and B^-→D^*K^- followed by D→K^+π^-, where D^(*) indicates a D^((*)0) or a D^((*)0) meson, and D^*→Dπ^0 or D^*→Dγ. These decays are sensitive to the Cabibbo-Kobayashi-Maskawa unitarity triangle angle γ due to interference between the b→c transition B^-→D^((*))0K^- followed by the doubly Cabibbo-suppressed decay D^0→K^+π^-, and the b→u transition B^-→D^((*)0)K^- followed by the Cabibbo-favored decay D^0→K^+π^-. We also report an analysis of the decay B^-→D^(*)π^- with the D decaying into the doubly Cabibbo-suppressed mode D→K^+π^-. Our results are based on 467× 10^6 Υ(4S)→BB decays collected with the BABAR detector at SLAC. We measure the ratios R^(*) of the suppressed ([K^+π^-]_DK^-/π^-) to favored ([K^-π^+]_DK^-/π^-) branching fractions as well as the CP asymmetries A^(*) of those modes. We see indications of signals for the B^-→DK^- and B^-→D_(Dπ0)^*K^- suppressed modes, with statistical significances of 2.1 and 2.2σ, respectively, and we measure: RDK=(1.1±0.6±0.2)×10^(-2), ADK=-0.86±0.47_(-0.16)^(+0.12), R_((Dπ0))K^*=(1.8±0.9± 0.4)×10^-2, A_((Dπ0))K^*=+0.77±0.35±0.12, R_((Dγ))K^*=(1.3±1.4±0.8)×10^-2,A_((Dγ))K^*=+0.36 ±0.94-_(0.41)^(+0.25), where the first uncertainty is statistical and the second is systematic. We use a frequentist approach to obtain the magnitude of the ratio r_B≡|A(B^-→D ^0K^-)/A(B^-→D^0K^-)|=(9.5_(-4.1)^(+5.1))%, with r_B<16.7% at 90% confidence level. In the case of B^-→D^*K^- we find r_B^*≡|A(B^-→D ^*0K^-)/A(B^-→D^*0K^-)|=(9.6_(-5.1)^(+3.5))%, with rB*<15.0% at 90% confidence level.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These