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Faculty and Research Publications

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Full-Text Articles in Physics

Qcd Corrections In Tqγ Production At Hadron Colliders, Nikolaos Kidonakis, Nodoka Yamanaka Aug 2022

Qcd Corrections In Tqγ Production At Hadron Colliders, Nikolaos Kidonakis, Nodoka Yamanaka

Faculty and Research Publications

We study QCD corrections for the associated production of a single top quark and a photon (tqγ production) at hadron colliders. We calculate the NLO cross section at LHC and future collider energies for a variety of kinematical cuts, and we estimate uncertainties from scale dependence and from parton distributions. We also calculate differential distributions in top-quark transverse-momentum and rapidity as well as photon energy. Finally, we study higher-order corrections from soft-gluon emission for this process, and we provide approximate NNLO (aNNLO) results for the cross section and top-quark differential distributions. We also compare our calculations with recent measurements from …

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Bound States And Energy Eigenvalues Of A Radial Screened Coulomb Potential, Eric Stachura, N. Hancock Jan 2021

Bound States And Energy Eigenvalues Of A Radial Screened Coulomb Potential, Eric Stachura, N. Hancock

Faculty and Research Publications

We analyze bound states and other properties of solutions of a radial Schrödinger equation with a new screened Coulomb potential. In particular, we employ hypervirial relations to obtain eigen-energies for a Hydrogen atom with this potential. Additionally, we appeal to a sharp estimate for a modified Bessel function to estimate the ground state energy of such a system. Finally, when the angular quantum number ℓ ≠ 0, we obtain evidence for a critical screening parameter, above which bound states cease to exist.

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Tz' Production At Hadron Colliders, Marco Guzzi, Nikolaos Kidonakis May 2020

Tz' Production At Hadron Colliders, Marco Guzzi, Nikolaos Kidonakis

Faculty and Research Publications

We study the production of a single top quark in association with a heavy extra Z' at hadron colliders in new physics models with and without flavor-changing neutral-current (FCNC) couplings. We use QCD soft-gluon resummation and threshold expansions to calculate higher-order corrections for the total cross section and transverse momentum distributions for t Z' production. The impact of the uncertainties due to the structure of the proton and scale dependence is also analyzed.

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The Sub-Eddington Boundary For The Quasar Mass–Luminosity Plane: A Theoretical Perspective, David Garofalo, Damian J. Christian, Andrew M. Jones Jun 2019

The Sub-Eddington Boundary For The Quasar Mass–Luminosity Plane: A Theoretical Perspective, David Garofalo, Damian J. Christian, Andrew M. Jones

Faculty and Research Publications

By exploring more than sixty thousand quasars from the Sloan Digital Sky Survey Data Release 5, Steinhardt & Elvis discovered a sub-Eddington boundary and a redshift-dependent drop-off at higher black hole mass, possible clues to the growth history of massive black holes. Our contribution to this special issue of Universe amounts to an application of a model for black hole accretion and jet formation to these observations. For illustrativepurposes,we include~100,000 data points from the Sloan Digital Sky Survey Data Release 7 where the sub-Eddington boundary is also visible andpropose a theoretical picture that explains these features. By appealing to thin …

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Self-Consistent Quantum-Kinetic Theory For Interplay Between Pulsed-Laser Excitation And Nonlinear Carrier Transport In A Quantum-Wire Array, Jeremy R. Gulley, Danghong Huang Jun 2019

Self-Consistent Quantum-Kinetic Theory For Interplay Between Pulsed-Laser Excitation And Nonlinear Carrier Transport In A Quantum-Wire Array, Jeremy R. Gulley, Danghong Huang

Faculty and Research Publications

We propose a self-consistent many-body theory for coupling the ultrafast dipole-transition and carrier-plasma dynamics in a linear array of quantum wires with the scattering and absorption of ultrashort laser pulses. The quantum-wire non-thermal carrier occupations are further driven by an applied DC electric field along the wires in the presence of resistive forces from intrinsic phonon and Coulomb scattering of photo-excited carriers. The same strong DC field greatly modifies the non-equilibrium properties of the induced electron-hole plasma coupled to the propagating light pulse, while the induced longitudinal polarization fields of each wire significantly alters the nonlocal optical response from neighboring …

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Search For X(3872) And X(3915) Decay Into Χc1Π0 In B Decays At Belle, The Belle Collaboration, Luminda Kulasiri Jun 2019

Search For X(3872) And X(3915) Decay Into Χc1Π0 In B Decays At Belle, The Belle Collaboration, Luminda Kulasiri

Faculty and Research Publications

We report a search for X(3872) and X (3915) in B+→χc1π0K+ decays. We set an upper limit of B(B+→X(3872)K+)×B(X(3872)→χc1π0)<8.1×10−6 and B(B+→X(3915)K+)×B(X(3915)→χc1π0)<3.8×10−5 at 90% confidence level. We also measure B(X(3872)→χc1π0)/B(X(3872)→J/ψπ+π−)<0.97 at 90% confidence level. The results reported here are obtained from 772×106 B¯B events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider.

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Fr0 Radio Galaxies And Their Place In The Radio Morphology Classification, David Garofalo, Chandra B. Singh Feb 2019

Fr0 Radio Galaxies And Their Place In The Radio Morphology Classification, David Garofalo, Chandra B. Singh

Faculty and Research Publications

So-called FR0 radio galaxies have recently emerged as a family of active galaxies with all the same properties as FRI radio galaxies except for their ratio of core to total emission, which is about 30 times higher than that of FRI sources. We show how their properties fit within the gap paradigm as low, prograde, spinning black holes whose progenitors are powerful FRII quasars that transitioned rapidly from the cold mode into advection-dominated accretion over a few million years. The prediction is that if sufficient fuel exists, FR0 radio galaxies will evolve into full-fledged FRI radio galaxies and the observational …

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Unpinning The Skyrmion Lattice In Mnsi: Effect Of Substitutional Disorder, Chetan Dhital, L. Debeer-Schmitt, D. P. Young, J. F. Ditusa Jan 2019

Unpinning The Skyrmion Lattice In Mnsi: Effect Of Substitutional Disorder, Chetan Dhital, L. Debeer-Schmitt, D. P. Young, J. F. Ditusa

Faculty and Research Publications

By employing magnetization and small angle neutron scattering measurements, we have investigated the behavior of the skyrmion lattice (SKL) and the helical order in MnS i 0 . 992 G a 0 . 008 Our results indicate that the order of the SKL is sensitive to the orientation of an applied magnetic field with respect to the crystal lattice and to variations in the sequence of small temperature and applied magnetic field changes. The disorder caused by the substitution of the heavier element Ga for Si is sufficient to reduce the pinning of the SKL to the underlying crystalline lattice, …

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Cteq-Tea Parton Distribution Functions With Intrinsic Charm, Marco Guzzi, Tie-Jiun Hou, Sayipjamal Dulat, Jun Gao, Joey Huston, Pavel Nadolsky, Carl Schmidt, Jan Winter, Keping Xie, C.-P. Yuan Nov 2018

Cteq-Tea Parton Distribution Functions With Intrinsic Charm, Marco Guzzi, Tie-Jiun Hou, Sayipjamal Dulat, Jun Gao, Joey Huston, Pavel Nadolsky, Carl Schmidt, Jan Winter, Keping Xie, C.-P. Yuan

Faculty and Research Publications

We present a study in which the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon is investigated together with theoretical issues arising in its interpretation. The separation of the universal component of the nonperturbative charm from the rest of the radiative contributions is also discussed. We illustrate the potential impact of a nonperturbative charm PDF on LHC scattering processes. An estimate of nonperturbative charm magnitude in the CT14 and CT14HERA2 global QCD analyses at the next-to-next-to leading order (NNLO) in the QCD coupling strength is given by including the latest experimental data …

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Parity-Time Symmetry In Optical Microcavity Systems, Jianming Wen, Xiaoshun Jiang, Liang Jiang, Min Xiao Oct 2018

Parity-Time Symmetry In Optical Microcavity Systems, Jianming Wen, Xiaoshun Jiang, Liang Jiang, Min Xiao

Faculty and Research Publications

Canonical quantum mechanics postulates Hermitian Hamiltonians to ensure real eigenvalues. Counterintuitively, a non-Hermitian Hamiltonian, satisfying combined parity-time (PT) symmetry, could display entirely real spectra above some phase-transition threshold. This stems from the existence of a parameter in the Hamiltonian governing characteristics features of eigenvalues and eigenfunctions. Varying this parameter causes real eigenvalues to coalesce and become complex conjugate pairs, signaling the occurrence of a nontrivial phase transition and the breakdown of PT symmetry. Such an appealing discovery has aroused extensive theoretical interest in extending canonical quantum theory by including non-Hermitian but PT-symmetric operators in the last two decades. Despite much …

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Observation Of Y(4s)→N′Y(1s), Belle Collaboration, Ratnappuli Luminda Kulasiri Oct 2018

Observation Of Y(4s)→N′Y(1s), Belle Collaboration, Ratnappuli Luminda Kulasiri

Faculty and Research Publications

We report the first observation of the hadronic transition Υ(4S)→η′Υ(1S), using 496  fb−1 data collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e−collider. We reconstruct the η′ meson through its decays to ρ0γ and to π+π−η, with η→γγ. We measure B(Υ(4S)→η′Υ(1S))=[3.43±0.88(stat)±0.21(syst)]×10−5, with a significance of 5.7σ.

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Disorder Induced Power-Law Gaps In An Insulator-Metal Mott Transition, Zhenyu Wang, Yoshinori Okada, Jared O'Neal, Wenwen Zhou, Daniel Walkup, Chetan Dhital, Tom Hogan, Patrick Clancy, Young-June Kim, Y. F. Hu, Luiz H. Santos, Stephen D. Wilson, Nandini Trivedi, Vidya Madhavan Oct 2018

Disorder Induced Power-Law Gaps In An Insulator-Metal Mott Transition, Zhenyu Wang, Yoshinori Okada, Jared O'Neal, Wenwen Zhou, Daniel Walkup, Chetan Dhital, Tom Hogan, Patrick Clancy, Young-June Kim, Y. F. Hu, Luiz H. Santos, Stephen D. Wilson, Nandini Trivedi, Vidya Madhavan

Faculty and Research Publications

A correlated material in the vicinity of an insulator-metal transition (IMT) exhibits rich phenomenology and variety of interesting phases. A common avenue to induce IMTs in Mott insulators is doping, which inevitably leads to disorder. While disorder is well known to create electronic inhomogeneity, recent theoretical studies have indicated that it may play an unexpected and much more profound role in controlling the properties of Mott systems. Theory predicts that disorder might play a role in driving a Mott insulator across an IMT, with the emergent metallic state hosting a power law suppression of the density of states (with exponent …

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Top Tagging: An Analytical Perspective, Mrinal Dasgupta, Marco Guzzi, Jacob Rowling, Gregory Soyez Sep 2018

Top Tagging: An Analytical Perspective, Mrinal Dasgupta, Marco Guzzi, Jacob Rowling, Gregory Soyez

Faculty and Research Publications

In this paper we study aspects of top tagging from first principles of QCD. We find that the method known as the CMS top tagger becomes collinear unsafe at high pt and propose variants thereof which are IRC safe, and hence suitable for analytical studies, while giving a comparable performance to the CMS tagger. We also develop new techniques to identify three-pronged jet substructure, based on adaptations of the Y-splitter method and its combination with grooming. A novel feature of our studies, relative to previous calculations of two-pronged substructure, is our use of triple-collinear splitting functions combined with all-order resummation, …

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The Distribution And Lifetime Of Powerful Radio Galaxies As A Function Of Environment And Redshift, David Garofalo, Chandra B. Singh, Alexa Zack Sep 2018

The Distribution And Lifetime Of Powerful Radio Galaxies As A Function Of Environment And Redshift, David Garofalo, Chandra B. Singh, Alexa Zack

Faculty and Research Publications

Correlations between jet power and active time for z < 0.1 high excitation and low excitation radio galaxies are explored as well as evidence in favor of a specific, non-random distribution for these objects including mid-infrared emitting radio galaxies as a function of environment and redshift. In addition, so-called weak line radio galaxies with FRII jet morphology have been identified as a class of active galaxies in the process of shutting down. This paper identifies common features between these seemingly disparate phenomena described above for the population of radio galaxies, and strings them together by way of a simple phenomenological framework that has shed light on the radio loud/radio quiet dichotomy, the jet-disk connection, and the distribution of all active galaxies as a function of redshift.

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Observation Of E +E − → Π +Π −Π 0Χb1,2(1p ) And Search For E +E √ − → Φχb1,2(1p ) At S =10.96—11.05 Gev, J. H. Yin Et Al., Ratnappuli L. Kulasiri Jun 2018

Observation Of E +E − → Π +Π −Π 0Χb1,2(1p ) And Search For E +E √ − → Φχb1,2(1p ) At S =10.96—11.05 Gev, J. H. Yin Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report searches for the processes e+e−→π+π−π0χbJ and e+e−→ϕχbJ (J=1,2) in the vicinity of the Υ(11020) resonance using energy scan data collected by the Belle experiment at the KEKB collider. We observe e+e−→π+π−π0χb1 and find evidence for e+e−→ωχb2 processes for data with center-of-mass energies from 10.96 to 11.05~GeV for the first time. The statistical significance for π+π−π0χb1 and ωχb2 are 6.1σ and 4.0σ, respectively. We investigate energy dependence of the e+e−→π+π−π0χbJ cross section and find that it is consistent with production of Υ(10860) and Υ(11020) resonances without significant non-resonant contribution. Assuming e+e−→π+π−π0χbJ proceeds via Υ(10860) and Υ(11020), the branching fraction …

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Soft-Gluon Corrections In Top-Quark Production, Nikolaos Kidonakis Jun 2018

Soft-Gluon Corrections In Top-Quark Production, Nikolaos Kidonakis

Faculty and Research Publications

I review calculations of soft-gluon corrections for top-quark production in hadron collisions. I describe theoretical formalisms for their resummation and for finite-order expansions. I show that soft-gluon corrections are dominant for a large number of top-quark processes. I discuss top-antitop pair production as well as single-top production, including total cross sections and differential distributions, and compare with data from the LHC and the Tevatron. I also discuss top-quark production in association with charged Higgs bosons, Z bosons, and other particles in models of new physics.

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Measurement Of Eta_C(1s), Eta_C(2s) And Non-Resonant Eta' Pi+ Pi- Production Via Two-Photon Collisions, Q. N. Xu Et Al., Ratnappuli L. Kulasiri May 2018

Measurement Of Eta_C(1s), Eta_C(2s) And Non-Resonant Eta' Pi+ Pi- Production Via Two-Photon Collisions, Q. N. Xu Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report the measurement of gamma gamma to eta_c(1S), eta_c(2S) to eta' pi+ pi- with eta' decays to gamma rho and eta pi+ pi- using 941 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The eta_c(1S) mass and width are measured to be M = [2984.6\pm0.7 (stat.)\pm2.2 (syst.)] MeV/c^{2} and \Gamma = [30.8^{+2.3}_{-2.2}~(stat.) \pm 2.5~(syst.)] MeV, respectively. First observation of eta_c(2S) to eta' pi+ pi- with a significance of 5.5sigma including systematic error is obtained, and the eta_c(2S) mass is measured to be M = [3635.1\pm3.7~(stat.)\pm2.9~(syst.)] MeV/c^{2}. The products of the two-photon decay width …

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Measurement Of Time-Dependent C P Asymmetries In B 0 → K 0 S Η Γ Decays, H. Nakano Et Al., Ratnappuli L. Kulasiri May 2018

Measurement Of Time-Dependent C P Asymmetries In B 0 → K 0 S Η Γ Decays, H. Nakano Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report a measurement of time-dependent CP violation parameters in B0→K0Sηγ decays. The study is based on a data sample, containing 772×106B¯B pairs, that was collected at the Υ(4S)resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We obtain the CPviolation parameters of S=−1.32±0.77(stat)±0.36(syst) and A=−0.48±0.41(stat)±0.07(syst) for the invariant mass of the K0Sη system up to 2.1 GeV/c2.

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Search For Υ ( 1 S , 2 S ) → Z + C Z ( ' ) C − And E + E − → Z + C Z ( ' ) C − At √ S = 10.52 , 10.58, And 10.867 Gev, S. Jia Et Al., Ratnappuli L. Kulasiri May 2018

Search For Υ ( 1 S , 2 S ) → Z + C Z ( ' ) C − And E + E − → Z + C Z ( ' ) C − At √ S = 10.52 , 10.58, And 10.867 Gev, S. Jia Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

The first search for double charged charmoniumlike state production in Υ(1S) and Υ(2S) decays and in e+e− annihilation at √s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in Υ(1S) and Υ(2S) decays [B(Υ(1S,2S)→Z+cZ(')−c)×B(Z+c→π++c¯c) (c¯c=J/ψ, χc1(1P), ψ(2S))] and the product of Born cross section and branching fraction for e+e−→Z+cZ(')−c (σ(e+e−→Z+cZ(')−c)×B(Z+c→π++c¯c)) at √s=10.52, 10.58, and 10.867 GeV are determined. Here, Zc refers to the Zc(3900) and …

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First Evidence For Cos2Β>0 And Resolution Of The Ckm Unitarity Triangle Ambiguity By A Time-Dependent Dalitz Plot Analysis Of B0→D(∗)H0 With D→K0sπ+Π− Decays, I. Adachi Et Al., Ratnappuli L. Kulasiri Apr 2018

First Evidence For Cos2Β>0 And Resolution Of The Ckm Unitarity Triangle Ambiguity By A Time-Dependent Dalitz Plot Analysis Of B0→D(∗)H0 With D→K0sπ+Π− Decays, I. Adachi Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the CKM Unitarity Triangle using a time-dependent Dalitz plot analysis of B0→D(∗)h0 with D→K0Sπ+π− decays, where h0∈{π0,η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BaBar and Belle experiments collected at the Υ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×106BB¯ pairs recorded by the BaBar detector and (772±11)×106BB¯ pairs recorded by the Belle detector. The results …

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Production Cross Sections Of Hyperons And Charmed Baryons From E + E − Annihilation Near √ S = 10.52 Gev, M. Niiyama Et Al., D. Joffe, Ratnappuli L. Kulasiri Apr 2018

Production Cross Sections Of Hyperons And Charmed Baryons From E + E − Annihilation Near √ S = 10.52 Gev, M. Niiyama Et Al., D. Joffe, Ratnappuli L. Kulasiri

Faculty and Research Publications

We measure the inclusive production cross sections of hyperons and charmed baryons from e+e−annihilation using a 800 fb−1 data sample taken near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S=−1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385)+ resonance. Suppression for Σ(1385)+ and Ξ(1530)0 hyperons is observed. Among the production cross sections of …

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Measurement Of Cos2Β In B0→D(∗)H0 With D→K0sπ+Π− Decays By A Combined Time-Dependent Dalitz Plot Analysis Of Babar And Belle Data, I. Adachi Et Al., Ratnappuli L. Kulasiri Apr 2018

Measurement Of Cos2Β In B0→D(∗)H0 With D→K0sπ+Π− Decays By A Combined Time-Dependent Dalitz Plot Analysis Of Babar And Belle Data, I. Adachi Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report measurements of sin2β and cos2β from a time-dependent Dalitz plot analysis of B0→D(∗)h0 with D→K0Sπ+π−decays, where the light unflavored and neutral hadron h0 is a π0, η, or ω meson. The analysis is performed with a combination of the final data sets of the \babar\ and Belle experiments containing 471×106 and 772×106 BB¯ pairs collected at the Υ(4S)resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. We measure sin2β=0.80±0.14(stat.)±0.06(syst.)±0.03(model) and cos2β=0.91±0.22(stat.)±0.09(syst.)±0.07(model). The result for the direct measurement of the angle is β=(22.5±4.4(stat.)±1.2(syst.)±0.6(model))∘. The last quoted uncertainties are due to the composition of the …

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Measurement Of The Branching Fraction Of B → D(∗)Π`Ν At Belle Using Hadronic Tagging In Fully Reconstructed Events, A. Vossen Et Al. Mar 2018

Measurement Of The Branching Fraction Of B → D(∗)Π`Ν At Belle Using Hadronic Tagging In Fully Reconstructed Events, A. Vossen Et Al.

Faculty and Research Publications

We report a measurement of the branching fraction of the decay B→D(∗)πℓν. The analysis uses 772×106 BB¯ pairs produced in e+e−→Υ(4S) data recorded by the Belle experiment at the KEKB asymmetric-energy e+e− collider. The tagging B meson in the decay is fully reconstructed in a hadronic decay mode. On the signal side, we reconstruct the decay B→D(∗)πℓν (ℓ=e,μ). The measured branching fractions are (B+→D−π+ℓ+ν) = [4.55 ± 0.27 (stat.) ± 0.39 (syst.)]×10−3, (B0→D¯0π−ℓ+ν) = [4.05 ± 0.36 (stat.) ± 0.41 (syst.)]×10−3, (B+→D∗−π+ℓ+ν) = [6.03 ± 0.43 (stat.) ± 0.38 (syst.)]×10−3, and (B0→D¯∗0π−ℓ+ν) = [6.46 ± 0.53 (stat.) ± 0.52 (syst.)]×10−3. …

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Observation Of Υ(4s)→Η′Υ(1s), E. Guido Et Al., Ratnappuli L. Kulasiri Mar 2018

Observation Of Υ(4s)→Η′Υ(1s), E. Guido Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report the first observation of the hadronic transition Υ(4S)→η′Υ(1S), using 496 fb−1 data collected at the Υ(4S)resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We reconstruct the η′ meson through its decays to ρ0γ and to π+π−η, with η→γγ. We measure: (Υ(4S)→η′Υ(1S))=(3.43±0.88(stat.)±0.21(syst.))×10−5, with a significance of 5.7σ.

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Observation Of Excited Ω C Charmed Baryons In E + E − Collisions, J. Yelton, Ratnappuli L. Kulasiri Mar 2018

Observation Of Excited Ω C Charmed Baryons In E + E − Collisions, J. Yelton, Ratnappuli L. Kulasiri

Faculty and Research Publications

Using the entire Belle data sample of 980  fb−1 of e+e− collisions, we present the results of a study of excited Ωc charmed baryons in the decay mode Ξ+cK−. We show confirmation of four of the five narrow states reported by the LHCb Collaboration: the Ωc(3000), Ωc(3050), Ωc(3066), and Ωc(3090).

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Observation Of Ξc(2930)0 And Updated Measurement Of B−→K−Λ+Cλ¯−C At Belle, Y. B. Li Et Al., Ratnappuli L. Kulasiri Mar 2018

Observation Of Ξc(2930)0 And Updated Measurement Of B−→K−Λ+Cλ¯−C At Belle, Y. B. Li Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report the first observation of the Ξc(2930)0" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Ξc(2930)0Ξc(2930)0 charmed-strange baryon with a significance greater than 5σ" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">σσ. The Ξc(2930)0" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: …

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Study Of K 0 S Pair Production In Single-Tag Two-Photon Collisions, M. Masuda Et Al., Ratnappuli L. Kulasiri Mar 2018

Study Of K 0 S Pair Production In Single-Tag Two-Photon Collisions, M. Masuda Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report a measurement of the cross section for K0S pair production in single-tag two-photon collisions, γ∗γ→K0SK0S, for Q2 up to 30  GeV2, where Q2 is the negative of the invariant mass squared of the tagged photon. The measurement covers the kinematic range 1.0  GeV

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Measurement Of The Τ Michel Parameters Η¯ And Ξκ In The Radiative Leptonic Decay Τ−→ℓ−Ντν¯ℓγ, N. Shimizu Et Al., Ratnappuli L. Kulasiri Feb 2018

Measurement Of The Τ Michel Parameters Η¯ And Ξκ In The Radiative Leptonic Decay Τ−→ℓ−Ντν¯ℓγ, N. Shimizu Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We present a measurement of the Michel parameters of the τ lepton, η¯ and ξκ , in the radiative leptonic decay τ−→ℓ−ντν¯ℓγ using 711 f b−1 of collision data collected with the Belle detector at the KEKB e+e− collider. The Michel parameters are measured in an unbinned maximum likelihood fit to the kinematic distribution of e+e−→τ+τ−→(π+π0ν¯τ)(ℓ−ντν¯ℓγ) (ℓ=e or μ) . The measured values of the Michel parameters are η¯=−1.3±1.5±0.8 and ξκ=0.5±0.4±0.2 , where the first error is statistical and the second is systematic. This is the first measurement of these parameters. These results are consistent with the Standard Model predictions …

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Measurement Of The Decays Λc→Σππ At Belle, M. Berger Et Al., Ratnappuli L. Kulasiri Feb 2018

Measurement Of The Decays Λc→Σππ At Belle, M. Berger Et Al., Ratnappuli L. Kulasiri

Faculty and Research Publications

We report measurements of the branching fractions of the decays Λ+c→Σ+π−π+, Λ+c→Σ0π+π0 and Λ+c→Σ+π0π0 relative to the reference channel Λ+c→pK−π+. The analysis is based on the full data sample collected at and close to Υ(4S)resonance by the Belle detector at the KEKB asymmetric-energy e+e− collider corresponding to the integrated luminosity of 711 fb−1. We measure (Λ+c→Σ+π−π+)/(Λ+c→pK−π+)=0.706 ±0.003 ±0.029, (Λ+c→Σ0π+π0)/(Λ+c→pK−π+)=0.491 ±0.005 ±0.028 and (Λ+c→Σ+π0π0)/(Λ+c→pK−π+)=0.198 ±0.006 ±0.016. The listed uncertainties are statistical and systematic, respectively.

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Ct14 Intrinsic Charm Parton Distribution Functions From Cteq-Tea Global Analysis, Tie-Jiun Hou, Sayipjamal Dulat, Jun Gao, Marco Guzzi, Joey Huston, Pavel Nadolsky, Carl Schmidt, Jan Winter, Keping Xie, C.-P. Yuan Feb 2018

Ct14 Intrinsic Charm Parton Distribution Functions From Cteq-Tea Global Analysis, Tie-Jiun Hou, Sayipjamal Dulat, Jun Gao, Marco Guzzi, Joey Huston, Pavel Nadolsky, Carl Schmidt, Jan Winter, Keping Xie, C.-P. Yuan

Faculty and Research Publications

We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The “fitted charm” PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling …

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