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Item To quarks and quasars : a history of physics and astronomy at Vanderbilt University(Vanderbilt University. Dept. of Physics and Astronomy, 2000) Lagemann, Robert T.; Holladay, Wendell G.Item 16TH INTERNATIONAL SYMPOSIUM ON CAPTURE GAMMA-RAY SPECTROSCOPY AND RELATED TOPICS (CGS16)(16TH Internatinal Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS16), 2018) Luo, Y. X.; Hamilton, J. H.; Rasmussen, J. O.; Ramayya, A. V.; Frauendorf, S.; Wang, E.; Hwang, J. K.; Zhu, S.J.; Liu, Y. X.; Xu, F. R.; Sun, Y.; Liu, S. H.; Oganessian, Yu; Ma, W. C.The paper reviews the systematic studies of triaxial deformations, new mode excitations and shape evolutions with regard to triaxial deformation in the neutron-rich nuclei with Z = 41-46, A similar to 100-116.Item Likelihood non-Gaussianity in Large-scale Structure Analyses(MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2019-02-26) Hahn, ChangHoon; Beutler, Florian; Sinha, Manodeep; Berlind, Andreas; Ho, Shirley; Hogg, David W.Standard present-day large-scale structure (LSS) analyses make a major assumption in their Bayesian parameter inference – that the likelihood has a Gaussian form. For summary statistics currently used in LSS, this assumption, even if the underlying density field is Gaussian, cannot be correct in detail. We investigate the impact of this assumption on two recent LSS analyses: the Beutler et al. power spectrum multipole (Pℓ) analysis and the Sinha et al. group multiplicity function (ζ) analysis. Using non-parametric divergence estimators on mock catalogues originally constructed for covariance matrix estimation, we identify significant non-Gaussianity in both the Pℓ and ζ likelihoods. We then use Gaussian mixture density estimation and independent component analysis on the same mocks to construct likelihood estimates that approximate the true likelihood better than the Gaussian pseudo-likelihood. Using these likelihood estimates, we accurately estimate the true posterior probability distribution of the Beutler et al. and Sinha et al. parameters. Likelihood non-Gaussianity shifts the fσ8 constraint by −0.44σ, but otherwise does not significantly impact the overall parameter constraints of Beutler et al. For the ζ analysis, using the pseudo-likelihood significantly underestimates the uncertainties and biases the constraints of the Sinha et al. halo occupation parameters. For logM1 and α, the posteriors are shifted by +0.43σ and −0.51σ and broadened by 42 per cent and 66 per cent, respectively. The divergence and likelihood estimation methods we present provide a straightforward framework for quantifying the impact of likelihood non-Gaussianity and deriving more accurate parameter constraints.Item Search for a W ' boson decaying to a tau lepton and a neutrino in proton-proton collisions at root s=13 TeV(Physics Letters B, 2019-05-10) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.A search for a new high-mass resonance decaying to a tau lepton and a neutrino is reported. The analysis uses proton-proton collision data collected by the CMS experiment at the LHC at root s= 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). The search utilizes hadronically decaying tau leptons. No excess in the event yield is observed at high transverse masses of the tau and missing transverse momentum. An interpretation of results within the sequential standard model excludes W' boson masses below 4.0 TeV at 95% confidence level. Existing limits are also improved on models in which the W' boson decays preferentially to fermions of the third generation. Heavy W' bosons with masses less than 1.7-3.9 TeV, depending on the coupling in the non-universal G(221) model, are excluded at 95% confidence level. These are the most stringent limits on this model to date. (C) 2019 The Author(s). Published by Elsevier B.V.Item Combined measurements of Higgs boson couplings in proton- proton collisions at v s=13TeV(EUROPEAN PHYSICAL JOURNAL C, 2019-05-20) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Ruiz Alvarez, J. D.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton-proton collision data set recorded with the CMS detector in 2016 at fb-1. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a W or Z boson, or a top quark-antiquark pair) and the following decay modes: H, ZZ, WW, , bb, and . Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be =1.17 +/- 0.10, assuming a Higgs boson mass of 125.09. Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.Item An embedding technique to determine tau tau backgrounds in proton-proton collision data(Journal of Instrumentation, 2019-06) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Item An embedding technique to determine tau tau backgrounds in proton-proton collision data(Journal of Instrumentation, 2019-06) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Item Search for Supersymmetry in Final States with Photons and Missing Transverse Momentum in Proton-proton Colisions at 13 TeV(JOURNAL OF HIGH ENERGY PHYSICS, 2019-06-03) Green, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Sheldon, P.; Tuo, S.; Velkovsk, J.; Verweij, M.; Xu, Q.; Only Vanderbilt University affiliated authors are listed on VUIR. For a full list of authors, access the version of record at https://link.springer.com/content/pdf/10.1140%2Fepjc%2Fs10052-019-6909-y.pdfResults are reported of a search for supersymmetry in final states with photons and missing transverse momentum in proton-proton collisions at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1) collected at a center-of-mass energy of 13 TeV using the CMS detector. The results are interpreted in the context of models of gauge-mediated supersymmetry breaking. Production cross section limits are set on gluino and squark pair production in this framework. Gluino masses below 1.86 TeV and squark masses below 1.59 TeV are excluded at 95% confidence level.Item Search for supersymmetry in Final States with Photons and Missing Transverse Momentum in Proton-proton Collisions at 13 TeV(JOURNAL OF HIGH ENERGY PHYSICS, 2019-06-18) Green, S.; Gurrola, A.; Janjam, W.; Maguire, C.; Melo, A.; Ni, H.; Padekan, K.; Romeo, F.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.Results are reported of a search for supersymmetry in final states with photons and missing transverse momentum in proton-proton collisions at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1) collected at a center-of-mass energy of 13 TeV using the CMS detector. The results are interpreted in the context of models of gauge-mediated supersymmetry breaking. Production cross section limits are set on gluino and squark pair production in this framework. Gluino masses below 1.86 TeV and squark masses below 1.59 TeV are excluded at 95% confidence level.Item Search for a heavy pseudoscalar boson decaying to a Z and a Higgs boson at root s=13TeV(EUROPEAN PHYSICAL JOURNAL C, 2019-07-03) Greene, S. H.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Ruiz-Slvarez, J. D.; Sheldon, P.; Tuo, S.; Velkovska, J.A search is presented for a heavy pseudoscalar boson A decaying to a Z boson and a Higgs boson with mass of 125 GeV. In the final state considered, the Higgs boson decays to a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9 fb-1 collected in 2016 by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 Te. The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the A boson mass range between 225 and 1000.Item Performance of Missing Transverse Momentum Reconstruction in Proton-proton Collisions at Toot s=13 TeV Using the CMS Detector(Journal of Instrumentation, 2019-07-04) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Ruiz-Alvarez, J.D.; Sheldon, P.; Tuo, S.; Velkovskia, J.; Verwij, M.; Xu, Q.The performance of missing transverse momentum (ÆpmissT) reconstruction algorithms for the CMS experiment is presented, using proton-proton collisions at a center-of-mass energy of 13 TeV, collected at the CERN LHC in 2016. The data sample corresponds to an integrated luminosity of 35.9 fb−1. The results include measurements of the scale and resolution of ÆpmissT,and detailed studies of events identified with anomalous ÆpmissT. The performance is presented ofaÆpmissT reconstruction algorithm that mitigates the effects of multiple proton-proton interactions,using the “pileup per particle identification” method. The performance is shown of an algorithmused to estimate the compatibility of the reconstructedÆpmissTwith the hypothesis that it originatesfrom resolution effects.Item Measurement of B-s(0) meson production in pp and PbPb collisions at root S-NN=5.02 TeV(Physics Letter B, 2019-07-14) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Alvarez, J. D. Ruiz; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.The production cross sections of B-s(0) mesons and charge conjugates are measured in proton-proton (pp) and PbPb collisions via the exclusive decay channel B-s(0)-> J/ psi phi ->mu(+) mu(-) K+K- at a center-of-mass energy of 5.02 TeV per nucleon pair and within the rapidity range vertical bar y vertical bar < 2.4 using the CMS detector at the LHC. The pp measurement is performed as a function of transverse momentum (P-T) of the B-s(0), mesons in the range of 7 to 50 GeV/c and is compared to the predictions of perturbative QCD calculations. The B s production yield in PbPb collisions is measured in two F t intervals, 7 to 15 and 15 to 50 GeV/c, and compared to the yield in pp collisions in the same kinematic region. The nuclear modification factor (R-AA) is found to be 1.5 +/- 0.6(stat) +/- 0.5(syst) for 7-15 GeV/c, and 0.87 +/- 0.30(stat) +/- 0.1 7(syst) for 15-50 GeV/c, respectively. Within current uncertainties, the B-s(0) results are consistent with models of strangeness enhancement, and suppression by parton energy loss, as observed for the B+ mesons. Published by Elsevier B.V.Item H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia(ASTRONOMY & ASTROPHYSICS, 2019-07-22) Majewski, S.R.We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522.Item Search for charged Higgs bosons in the H-+/- -> tau(+/-)nu(tau) decay channel in proton-proton collisions at s=13 TeV(Journal of High Energy Physics, 2019-07-24) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.A search is presented for charged Higgs bosons in the H-+/- -> tau(+/-)nu(tau) decay mode in the hadronic final state and in final states with an electron or a muon. The search is based on proton-proton collision data recorded by the CMS experiment in 2016 at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). The results agree with the background expectation from the standard model. Upper limits at 95% confidence level are set on the production cross section times branching fraction to tau(+/-)nu(tau) for an H-+/- in the mass range of 80GeV to 3TeV, including the region near the top quark mass. The observed limit ranges from 6 pb at 80 GeV to 5 fb at 3 TeV. The limits are interpreted in the context of the minimal supersymmetric standard model m(h)(mod-) scenario.Item Anapole dark matter via vector boson fusion processes at the LHC(Physical Review D, 2019-07-29) Florez, Andres; Gurrola, Alfredo; Johns, Will; Maruri, Jessica; Sheldon, Paul; Sinha, Kuver; Starko, Savanna RaeDark matter that is electrically neutral but couples to the electromagnetic current through higher-dimensional operators constitutes an interesting class of models. We investigate this class of models at the Large Hadron Collider, focusing on the anapole moment operator in an effective field theory (EFT) framework, and utilizing the vector boson fusion (VBF) topology. Assuming proton-proton collisions at root s = 13 TeV, we present the VBF anapole dark matter (ADM) cross sections and kinematic distributions as functions of the free parameters of the EFT, the cutoff scale Lambda and the ADM mass m(chi). We find that the distinctive VBF topology of two forward jets and large dijet pseudorapidity gap is effective at reducing SM backgrounds, leading to a 5 sigma discovery reach for all kinematically allowed ADM masses with Lambda <= 1.62 (1.1) TeV, assuming an integrated luminosity of 3000 (100) fb(-1).Item Centrality and pseudorapidity dependence of the transverse energy density in pPb collisions ats root s(NN)=5.02 TeV(Physical Review C, 2019-08-01) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Alvarez, J. D. Ruiz; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.The almost hermetic coverage of the CMS detector is used to measure the distribution of transverse energy, E-T, over 13.2 units of pseudorapidity, eta, for pPb collisions at a center-of-mass energy per nucleon pair of root s(NN) = 5.02 TeV. The huge angular acceptance exploits the fact that the CASTOR calorimeter at -6.6 < eta < -5.2 is effectively present on both sides of the colliding system because of a switch in the proton-going and lead-going beam directions. This wide acceptance enables the study of correlations between well-separated angular regions and makes the measurement a particularly powerful test of event generators. For minimum bias pPb collisions the maximum value of dE(T)/d eta is 22 GeV, which implies an E-T per participant nucleon pair comparable to that of peripheral PbPb collisions at root s(NN) 7 = 2.76 TeV. The increase of dE(T)/d eta with centrality is much stronger for the lead-going side than for the proton-going side. The i dependence of dE(T)/d eta is sensitive to the eta range in which the centrality variable is defined. Several modern generators are compared to these results but none is able to capture all aspects of the eta and centrality dependence of the data and the correlations observed between different eta regions.Item Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum(Astrophysical Journal, 2019-08-20) Somers, G.We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Ly alpha and C IV, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Ly alpha and C IV have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show a delayed response to continuum variations corresponding to recombination in gas with a density of similar to 10(5) cm(-3). The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in similar to 2012 corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state.Item Measurement of exclusive ρ(770)0 photoproduction in ultraperipheral pPb collisions at sNN−−−√=5.02TeV(Experimental Physics, 2019-08-21) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Ruiz Alvarez, J. D.; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.Exclusive ρ(770)0 photoproduction is measured for the first time in ultraperipheral pPb collisions at sNN−−−√=5.02TeV with the CMS detector. The cross section σ(γp→ρ(770)0p) is 11.0±1.4(stat)±1.0(syst) μb at ⟨Wγp⟩=92.6GeV for photon–proton centre-of-mass energies Wγp between 29 and 213GeV. The differential cross section dσ/d|t| is measured in the interval 0.025<|t|<1GeV2 as a function of Wγp, where t is the squared four-momentum transfer at the proton vertex. The results are compared with previous measurements and theoretical predictions. The measured cross section σ(γp→ρ(770)0p) has a power-law dependence on the photon–proton centre-of-mass, consistent with electron–proton collision measurements performed at HERA. The Wγp dependence of the exponential slope of the differential cross section dσ/d|t| is also measured.Item Search for vectorlike leptons in multilepton final states in proton-proton collisions at root s=13 TeV(Physical Review D, 2019-09-06) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Alvarez, . D. Ruiz; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.A search for vectorlike leptons in multilepton final states is presented. The data sample corresponds to an integrated luminosity of 77.4 fb(-1) of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC in 2016 and 2017. Events are categorized by the multiplicity of electrons, muons, and hadronically decaying tau leptons. The missing transverse momentum and the scalar sum of the lepton transverse momenta are used to distinguish the signal from background. The observed results are consistent with the expectations from the standard model hypothesis. The existence of a vectorlike lepton doublet, coupling to the third-generation standard model leptons in the mass range of 120-790 GeV, is excluded at 95% confidence level. These are the most stringent limits yet on the production of a vectorlike lepton doublet, coupling to the third-generation standard model leptons.Item A search for pair production of new light bosons decaying into muons in proton-proton collisions at 13 TeV(Physics Letters B, 2019-09-10) Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Padeken, K.; Romeo, F.; Alvarez, J. D. Ruiz; Sheldon, P.; Tuo, S.; Velkovska, J.; Verweij, M.; Xu, Q.A search for new light bosons decaying into muon pairs is presented using a data sample corresponding to an integrated luminosity of 35.9 fb(-1) of proton-proton collisions at a center-of-mass energy root s = 13 TeV, collected with the CMS detector at the CERN LHC. The search is model independent, only requiring the pair production of a new light boson and its subsequent decay to a pair of muons. No significant deviation from the predicted background is observed. A model independent limit is set on the product of the production cross section times branching fraction to dimuons squared times acceptance as a function of new light boson mass. This limit varies between 0.15 and 0.39 fb over a range of new light boson masses from 0.25 to 8.5 GeV. It is then interpreted in the context of the next-to-minimal supersymmetric standard model and a dark supersymmetry model that allows for nonnegligible light boson lifetimes. In both cases, there is significant improvement over previously published limits. (C) 2019 The Author(s). Published by Elsevier B.V.