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Full-Text Articles in Physics
A Multi-Wavelength Analysis Of Cold Evolving Interstellar Clouds, Mary Spraggs
A Multi-Wavelength Analysis Of Cold Evolving Interstellar Clouds, Mary Spraggs
Mahurin Honors College Capstone Experience/Thesis Projects
The interstellar medium (ISM) is the dynamic system of gas and dust that fills the space between the stars within galaxies. Due to its integral role in star formation and ga-lactic structure, it is important to understand how the ISM itself evolves over time, in-cluding the process of cooling and condensing required to form new stars. This work aims to constrain and better understand the physical properties of the cold ISM with sev-eral different types of data, including large surveys of neutral atomic hydrogen (HI) 21cm spectral line emission and absorption, carbon monoxide (CO) 2.6mm line emission, and multi-band infrared …
Inflation And The Quantum Measurement Problem, Stephon Alexander, Dhrubo Jyoti, João Magueijo
Inflation And The Quantum Measurement Problem, Stephon Alexander, Dhrubo Jyoti, João Magueijo
Dartmouth Scholarship
We propose a solution to the quantum measurement problem in inflation. Our model treats Fourier modes of cosmological perturbations as analogous to particles in a weakly interacting Bose gas. We generalize the idea of a macroscopic wave function to cosmological fields, and construct a self-interaction Hamiltonian that focuses that wave function. By appropriately setting the coupling between modes, we obtain the standard adiabatic, scale-invariant power spectrum. Because of central limit theorem, we recover a Gaussian random field, consistent with observations.
Analytic Models Of Brown Dwarfs And The Substellar Mass Limit, Sree Ram Valluri, Shantanu Basu, Sayantan Auddy
Analytic Models Of Brown Dwarfs And The Substellar Mass Limit, Sree Ram Valluri, Shantanu Basu, Sayantan Auddy
Physics and Astronomy Publications
We present the analytic theory of brown dwarf evolution and the lower mass limit of the hydrogen burning main-sequence stars and introduce some modifications to the existing models. We give an exact expression for the pressure of an ideal nonrelativistic Fermi gas at a finite temperature, therefore allowing for nonzero values of the degeneracy parameter. We review the derivation of surface luminosity using an entropy matching condition and the first-order phase transition between the molecular hydrogen in the outer envelope and the partially ionized hydrogen in the inner region.We also discuss the results of modern simulations of the plasma phase …
Dynamical Mechanisms Leading To Equilibration In Two-Component Gases, Stephan De Bievre, Carlos Mejia-Monasterio, Paul Ernest Parris
Dynamical Mechanisms Leading To Equilibration In Two-Component Gases, Stephan De Bievre, Carlos Mejia-Monasterio, Paul Ernest Parris
Physics Faculty Research & Creative Works
Demonstrating how microscopic dynamics cause large systems to approach thermal equilibrium remains an elusive, longstanding, and actively pursued goal of statistical mechanics. We identify here a dynamical mechanism for thermalization in a general class of two-component dynamical Lorentz gases and prove that each component, even when maintained in a nonequilibrium state itself, can drive the other to a thermal state with a well-defined effective temperature.
Ultracold Trimer Ion Formation Of Rb And K, Michael Cantara
Ultracold Trimer Ion Formation Of Rb And K, Michael Cantara
University Scholar Projects
The cooling of molecules into the ultracold regime allows for high resolution laser spectroscopy that reveals their complex rotational and vibrational structure. As the temperature is lowered towards absolute zero, the kinetic energy of the particles approaches zero, and therefore the Doppler shift approaches zero. With the Doppler shift negligibly small, spectral resolution is now primarily limited by the natural linewidth of the molecular peaks. Further, ultracold temperatures make possible the production of atoms or molecules that will reside in the lowest few states of the system. The high population in a few select states provides stronger and less congested …
Spatio-Temporal Generalization Of The Harris Criterion And Its Application To Diffusive Disorder, Thomas Vojta, Ronald Dickman
Spatio-Temporal Generalization Of The Harris Criterion And Its Application To Diffusive Disorder, Thomas Vojta, Ronald Dickman
Physics Faculty Research & Creative Works
We investigate how a clean continuous phase transition is affected by spatiotemporal disorder, i.e., by an external perturbation that fluctuates in both space and time. We derive a generalization of the Harris criterion for the stability of the clean critical behavior in terms of the space-time correlation function of the external perturbation. As an application, we consider diffusive disorder, i.e., an external perturbation governed by diffusive dynamics, and its effects on a variety of equilibrium and nonequilibrium critical points. We also discuss the relation between diffusive disorder and diffusive dynamical degrees of freedom in the example of model C of …
The Acoustics Of Harmon Mutes, Zachary T. Armstrong
The Acoustics Of Harmon Mutes, Zachary T. Armstrong
Summer Research
The acoustic properties of trumpets have been studied thoroughly, but little to no previous work has been done regarding the acoustics of trumpet mutes. Harmon mutes have a distinctively "buzzy" sound when they are used in performance and it is the opinion of a large number of trumpet players who use Harmon mutes that they should be dented before they are used in performance. The work presented here is an attempt to determine the acoustical properties of Harmon mutes and how they change when the mute is dented. If Harmon mutes are better understood, then a more informed decision as …
Measurement Of The Cp-Violating Weak Phase Φs And The Decay Width Difference Δγs Using The B0s→J/Ψφ(1020)Decay Channel In Pp Collisions At √S=8tev, M M. Baarnand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Measurement Of The Cp-Violating Weak Phase Φs And The Decay Width Difference Δγs Using The B0s→J/Ψφ(1020)Decay Channel In Pp Collisions At √S=8tev, M M. Baarnand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The CP-violating weak phase φsof the B0smeson and the decay width difference δΓs of the B0slight and heavy mass eigenstates are measured with the CMS detector at the LHC using a data sample of B0s→J/ψφ(1020)→μ+μ−K+K−decays. The analysed data set corresponds to an integrated luminosity of 19.7 fb−1collected in pp collisions at a centre-of-mass energy of 8 TeV. A total of 49200 reconstructed B0s decays are used to extract the values of φs and δΓs by performing a time-dependent and flavour-tagged angular analysis of the μ+μ−K+K−final state. The weak phase is mea-sured to be φs=−0.075 ±0.097 (stat) ±0.031 (syst)rad, and the …
Angular Analysis Of The Decay B0→K∗0Μ+Μ− From Pp Collisions At √S=8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Angular Analysis Of The Decay B0→K∗0Μ+Μ− From Pp Collisions At √S=8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The angular distributions and the differential branching fraction of the decay B0→K*(892)0μ+μ- are studied using data corresponding to an integrated luminosity of 20.5 fb-1 collected with the CMS detector at the LHC in pp collisions at s=8 TeV. From 1430 signal decays, the forward-backward asymmetry of the muons, the K*(892)0 longitudinal polarization fraction, and the differential branching fraction are determined as a function of the dimuon invariant mass squared. The measurements are among the most precise to date and are in good agreement with standard model predictions.
Search For Supersymmetry In Events With A Photon, A Lepton, And Missing Transverse Momentum In Pp Collisions At √S=8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Supersymmetry In Events With A Photon, A Lepton, And Missing Transverse Momentum In Pp Collisions At √S=8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for supersymmetry involving events with at least one photon, one electron or muon, and large missing transverse momentum has been performed by the CMS experiment. The data sample corresponds to an integrated luminosity of 19.7 fb-1 of pp collisions at s=8 TeV, produced at the CERN LHC. No excess of events is observed beyond expectations from standard model processes. The result of the search is interpreted in the context of a general model of gauge-mediated supersymmetry breaking, where the charged and neutral winos are the next-to-lightest supersymmetric particles. Within this model, winos with a mass up to 360 …
Searches For A Heavy Scalar Boson H Decaying To A Pair Of 125 Gev Higgs Bosons Hh Or For A Heavy Pseudoscalar Boson A Decaying To Zh, In The Final States With H→Ττ, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Searches For A Heavy Scalar Boson H Decaying To A Pair Of 125 Gev Higgs Bosons Hh Or For A Heavy Pseudoscalar Boson A Decaying To Zh, In The Final States With H→Ττ, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for a heavy scalar boson H decaying into a pair of lighter standard-model-like 125 GeV Higgs bosons hh and a search for a heavy pseudoscalar boson A decaying into a Z and an h boson are presented. The searches are performed on a data set corresponding to an integrated luminosity of 19.7 fb-1 of pp collision data at a centre-of-mass energy of 8 TeV, collected by CMS in 2012. A final state consisting of two τ leptons and two b jets is used to search for the H→hh decay. A final state consisting of two τ leptons from …
Search For A Higgs Boson Decaying Into Γ*Γ→ℓℓγ With Low Dilepton Mass In Pp Collisions At √S=8 Tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For A Higgs Boson Decaying Into Γ*Γ→ℓℓγ With Low Dilepton Mass In Pp Collisions At √S=8 Tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair (ℓℓγ). The analysis is performed using proton-proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120
Search For R-Parity Violating Decays Of A Top Squark In Proton–Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For R-Parity Violating Decays Of A Top Squark In Proton–Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton–proton collisions at s=8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb−1 collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, and upper limits are placed …
Search For Supersymmetry In The Multijet And Missing Transverse Momentum Final State In Pp Collisions At 13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Supersymmetry In The Multijet And Missing Transverse Momentum Final State In Pp Collisions At 13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at s=13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 fb-1, was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of events in all search regions are found to be consistent with the expectations from standard model processes. Exclusion limits are presented for simplified supersymmetric …
Inclusive And Differential Measurements Of The Tt Charge Asymmetry In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Inclusive And Differential Measurements Of The Tt Charge Asymmetry In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The tt- charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 fb-1. Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010±0.0068 (stat)±0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the tt- system are studied. For the first time at the LHC, the measurements …
Search For Neutral Mssm Higgs Bosons Decaying To Μ+Μ− In Pp Collisions At √S=7and8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Neutral Mssm Higgs Bosons Decaying To Μ+Μ− In Pp Collisions At √S=7and8tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for neutral Higgs bosons predicted in the minimal supersymmetric standard model (MSSM) for μ+μ- decay channels is presented. The analysis uses data collected by the CMS experiment at the LHC in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.3 fb-1, respectively. The search is sensitive to Higgs bosons produced either through the gluon fusion process or in association with a bb quark pair. No statistically significant excess is observed in the μ+μ- mass spectrum. Results are interpreted in the framework of several benchmark scenarios, and the data are …
Search For Exotic Decays Of A Higgs Boson Into Undetectable Particles And One Or More Photons, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Exotic Decays Of A Higgs Boson Into Undetectable Particles And One Or More Photons, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search is presented for exotic decays of a Higgs boson into undetectable particles and one or two isolated photons in pp collisions at a center-of-mass energy of 8TeV. The data correspond to an inte-grated luminosity of up to 19.4fb−1collected with the CMS detector at the LHC. Higgs bosons produced in gluon–gluon fusion and in association with a Z boson are investigated, using models in which the Higgs boson decays into a gravitino and a neutralino or a pair of neutralinos, followed by the decay of the neutralino to a gravitino and a photon. The selected events are consistent with …
Search For Supersymmetry In Electroweak Production With Photons And Large Missing Transverse Energy In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Supersymmetry In Electroweak Production With Photons And Large Missing Transverse Energy In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Results are reported from a search for supersymmetry with gauge-mediated supersymmetry breaking in electroweak production. Final states with photons and large missing transverse energy (EmissT) were examined. The data sample was collected in pp collisions at √s=8 TeVwith the CMS detector at the LHC and corresponds to 7.4fb−1. The analysis focuses on scenarios in which the lightest neutralino has bino-or wino-like components, resulting in decays to photons and gravitinos, where the gravitinos escape undetected. The data were obtained using a specially designed trigger with dedicated low thresholds, providing good sensitivity to signatures with photons, EmissT, and low hadronic energy. No …
Measurements Of Tt‾ Charge Asymmetry Using Dilepton Final States In Pp Collisions At S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Measurements Of Tt‾ Charge Asymmetry Using Dilepton Final States In Pp Collisions At S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The charge asymmetry in tt‾ events is measured using dilepton final states produced in pp collisions at the LHC at s=8TeV. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.5fb−1. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The charge asymmetry is measured from differences in kinematic distributions, unfolded to the parton level, of positively and negatively charged top quarks and leptons. The tt‾ and leptonic inclusive charge …
Combined Search For Anomalous Pseudoscalar Hvv Couplings In Vh(H→Bb‾) Production And H → Vv Decay, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Combined Search For Anomalous Pseudoscalar Hvv Couplings In Vh(H→Bb‾) Production And H → Vv Decay, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for anomalous pseudoscalar couplings of the Higgs boson H to electroweak vector bosons V (=W or Z) in a sample of proton–proton collision events corresponding to an integrated luminosity of 18.9 fb−1 at a center-of-mass energy of 8 TeV is presented. Events consistent with the topology of associated VH production, where the Higgs boson decays to a pair of bottom quarks and the vector boson decays leptonically, are analyzed. The consistency of data with a potential pseudoscalar contribution to the HVV interaction, expressed by the effective pseudoscalar cross section fractions fa3, is assessed by means of profile likelihood …
Search For Supersymmetry In Events With Soft Leptons, Low Jet Multiplicity, And Missing Transverse Energy In Proton-Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Supersymmetry In Events With Soft Leptons, Low Jet Multiplicity, And Missing Transverse Energy In Proton-Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Results are presented from a search for supersymmetric particles in scenarios with small mass splittings. The data sample corresponds to 19.7 fb-1 of proton-proton collisions recorded by the CMS experiment at s=8 TeV. The search targets top squark (t~) pair production in scenarios with mass differences δm=m(t~)-m(χ~10) below the W-boson mass and with top-squark decays in the four-body mode (t~→bℓνχ~10), where the neutralino (χ~10) is assumed to be the lightest supersymmetric particle (LSP). The signature includes a high transverse momentum (pT) jet associated with initial-state radiation, one or two low-pT leptons, and significant missing transverse energy. The event yields observed …
Vibrational Patterns In Curved Metal Plates, Samuel D. Berling
Vibrational Patterns In Curved Metal Plates, Samuel D. Berling
Summer Research
This summer, I investigated the factors affecting the vibrational patterns of curved metal plates. This research was inspired by the musical saw instrument which is played by bending a large handsaw into an s-curve and then bowing it like a violin. In our results, we identified the local confinement of the vibrational patterns due to the plate's curvature, the variation of resonant frequencies due to the geometry of the plate, and we determined that the stress in the metal created by bending the plate into its shape has a negligible effect on the resonant frequencies.
Search For Neutral Resonances Decaying Into A Z Boson And A Pair Of B Jets Or Τ Leptons, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Neutral Resonances Decaying Into A Z Boson And A Pair Of B Jets Or Τ Leptons, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search is performed for a new resonance decaying into a lighter resonance and a Z boson. Two channels are studied, targeting the decay of the lighter resonance into either a pair of oppositely charged τ leptons or a bb pair. The Z boson is identified via its decays to electrons or muons. The search exploits data collected by the CMS experiment at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.8 fb-1. No significant deviations are observed from the standard model expectation and limits are set on production cross sections and parameters of two-Higgs-doublet models.
Search For A Low-Mass Pseudoscalar Higgs Boson Produced In Association With A Bb̅ Pair In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For A Low-Mass Pseudoscalar Higgs Boson Produced In Association With A Bb̅ Pair In Pp Collisions At √S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search is reported for a light pseudoscalar Higgs boson decaying to a pair of τ leptons, produced in association with a bb pair, in the context of two-Higgs-doublet models. The results are based on pp collision data at a centre-of-mass energy of 8 TeV collected by the CMS experiment at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. Pseudoscalar boson masses between 25 and 80 GeV are probed. No evidence for a pseudoscalar boson is found and upper limits are set on the product of cross section and branching fraction to τ pairs between 7 and …
Search For Supersymmetry In The Multijet And Missing Transverse Momentum Final State In Pp Collisions At 13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Supersymmetry In The Multijet And Missing Transverse Momentum Final State In Pp Collisions At 13tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for new physics is performed based on all-hadronic events with large missing transverse momentum produced in proton-proton collisions at s=13 TeV. The data sample, corresponding to an integrated luminosity of 2.3 fb-1, was collected with the CMS detector at the CERN LHC in 2015. The data are examined in search regions of jet multiplicity, tagged bottom quark jet multiplicity, missing transverse momentum, and the scalar sum of jet transverse momenta. The observed numbers of events in all search regions are found to be consistent with the expectations from standard model processes. Exclusion limits are presented for simplified supersymmetric …
Search For W' Decaying To Tau Lepton And Neutrino In Proton-Proton Collisions At S=8 Tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For W' Decaying To Tau Lepton And Neutrino In Proton-Proton Collisions At S=8 Tev, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Mareskas-Palcek, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The first search for a heavy charged vector boson in the final state with a tau lepton and a neutrino is reported, using 19.7 fb-1 of LHC data at s=8 TeV. A signal would appear as an excess of events with high transverse mass, where the standard model background is low. No excess is observed. Limits are set on a model in which the W' decays preferentially to fermions of the third generation. These results substantially extend previous constraints on this model. Masses below 2.0 to 2.7 TeV are excluded, depending on the model parameters. In addition, the existence of …
Search For New Phenomena In Monophoton Final States In Proton-Proton Collisions At √S=Tev, M M. Baarmand, Marcus Hohlmann, H Kalakhety, Francisco X. Yumiceva, Cms Collaboration
Search For New Phenomena In Monophoton Final States In Proton-Proton Collisions At √S=Tev, M M. Baarmand, Marcus Hohlmann, H Kalakhety, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Results are presented from a search for new physics in final states containing a photon and missing transverse momentum. The data correspond to an integrated luminosity of 19.6 fb-1 collected in proton-proton collisions at √s=TeV with the CMS experiment at the LHC. No deviation from the standard model predictions is observed for these final states. New, improved limits are set on dark matter production and on parameters of models with large extra dimensions. In particular, the first limits from the LHC on branon production are found and significantly extend previous limits from LEP and the Tevatron. An upper limit of …
Transverse Momentum Spectra Of Inclusive B Jets In Ppb Collisions At √Snn=5.02 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Transverse Momentum Spectra Of Inclusive B Jets In Ppb Collisions At √Snn=5.02 Tev, M M. Baarmand, Vallary Bhopatkar, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
We present a measurement of b jet transverse momentum (pT) spectra in proton-lead (pPb) collisions using a dataset corresponding to about 35 nb-1 collected with the CMS detector at the LHC. Jets from b quark fragmentation are found by exploiting the long lifetime of hadrons containing a b quark through tagging methods using distributions of the secondary vertex mass and displacement. Extracted cross sections for b jets are scaled by the effective number of nucleon-nucleon collisions and are compared to a reference obtained from pythia simulations of pp collisions. The pythia-based estimate of the nuclear modification factor is found to …
Measurement Of The W Boson Helicity Fractions In The Decays Of Top Quark Pairs To Lepton + Jets Final States Produced In Pp Collisions At S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Measurement Of The W Boson Helicity Fractions In The Decays Of Top Quark Pairs To Lepton + Jets Final States Produced In Pp Collisions At S=8tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The W boson helicity fractions from top quark decays in tt‾ events are measured using data from proton–proton collisions at a centre-of-mass energy of 8TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8fb−1. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding F0=0.681±0.012(stat)±0.023(syst), FL=0.323±0.008(stat)±0.014(syst), and FR=−0.004±0.005(stat)±0.014(syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. …
Search For Lepton Flavour Violating Decays Of The Higgs Boson To Eτ And Eμ In Proton–Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Search For Lepton Flavour Violating Decays Of The Higgs Boson To Eτ And Eμ In Proton–Proton Collisions At S=8 Tev, M M. Baarmand, Vallary Bhopatkar, Stefano Colafranceschi, Marcus Hohlmann, H Kalakhety, D Noonan, Tuhin S. Roy, Francisco X. Yumiceva, Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A direct search for lepton flavour violating decays of the Higgs boson (H) in the H→eτ and H→eμ channels is described. The data sample used in the search was collected in proton–proton collisions at s=8 TeV with the CMS detector at the LHC and corresponds to an integrated luminosity of 19.7 fb−1. No evidence is found for lepton flavour violating decays in either final state. Upper limits on the branching fractions, B(H→eτ)<0.69% and B(H→eμ)<0.035%, are set at the 95% confidence level. The constraint set on B(H→eτ) is an order of magnitude more stringent than the existing indirect limits. The limits are used to constrain the corresponding flavour violating Yukawa couplings, absent in the standard model.