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Full-Text Articles in Physics

Line Tension And Its Influence On Droplets And Particles At Surfaces, Bruce M. Law, Sean P. Mcbride, Jiang Yong Wang, Haeng Sub Wi, Govind Paneru, Santigo Betelu, Baku Ushijima, Youichi Takata, Bret Flanders, Fernando Bresme, Hiroki Matsubara, Takanori Takiue, Makoto Aratono Feb 2017

Line Tension And Its Influence On Droplets And Particles At Surfaces, Bruce M. Law, Sean P. Mcbride, Jiang Yong Wang, Haeng Sub Wi, Govind Paneru, Santigo Betelu, Baku Ushijima, Youichi Takata, Bret Flanders, Fernando Bresme, Hiroki Matsubara, Takanori Takiue, Makoto Aratono

Dr. Sean P. McBride

In this review we examine the influence of the line tension s on droplets and particles at surfaces. The line tension influences the nucleation behavior and contact angle of liquid droplets at both liquid and solid surfaces and alters the attachment energetics of solid particles to liquid surfaces. Many factors, occurring over a wide range of length scales, contribute to the line tension. On atomic scales, atomic rearrangements and reorientations of submolecular components give rise to an atomic line tension contribution satom (1 nN), which depends on the similarity/dissimilarity of the droplet/particle surface composition compared with the surface ...


Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G.M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang Nov 2016

Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G.M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang

Ian Morrison

We consider a time-dependent deformation of anti–de Sitter (AdS) space-time which contains a spacelike “singularity”—a spacelike region of high curvature. Making use of the AdS/CFT correspondence we can map the bulk dynamics onto the boundary. The boundary theory has a time dependent coupling constant which becomes small at times when the bulk space-time is highly curved. We investigate the propagation of small fluctuations of a test scalar field from early times before the bulk singularity to late times after the singularity. Under the assumption that the AdS/CFT correspondence extends to deformed AdS space-times, we can map ...


Neutron-Antineutron Oscillations: Theoretical Status And Experimental Prospects, David G. Phillips, William M. Snow, Kaladi Babu, S. Banerjee, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Satyaki Bhattacharya, Gustaaf Brooijmans, Luis Castellanos, Mark C. Chen, C.E. Coppola, Ramanath K. Cowsik, J.A. Crabtree, Pragya Das, Eric Dees, Aleksander D. Dolgov, Phillip D. Ferguson, Matthew Frost, Tony A. Gabriel, A. Gal, Franz X. Gallmeier, Kenneth S. Ganezer, E. Golubeva, Geoffrey L. Greene, B. Hartfiel, Ayman Hawari, Lawrence H. Heilbronn, Colin D. Johnson, Yu A. Kamyshkov, Boris O. Kerbikov, Masaaki Kitaguchi, B.Z. Kopeliovich, V.B. Kopeliovich, Vadim A. Kuzmin, Chenyu Liu, P. Mcgaughey, M. Mocko, Rabindra N. Mohapatra, Nikolai V. Mokhov, Guenter Muhrer, H.P. Pieter Mumm, Lev B. Okun, Robert W. Pattie, C. Quigg, E. Ramberg, A. Ray, A. Roy, A. Ruggles, U. Sarkar, Andy Saunders, A. P. Serebrovv, H. M. Shimizu, R. Shrock, A. K. Sikdara, Sky Sjue, S. Striganov, L. W. Townsend, R. Tschirhart, A. Vainshtein, R Van Kooten, Z. Wang, A. R. Young Feb 2016

Neutron-Antineutron Oscillations: Theoretical Status And Experimental Prospects, David G. Phillips, William M. Snow, Kaladi Babu, S. Banerjee, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Satyaki Bhattacharya, Gustaaf Brooijmans, Luis Castellanos, Mark C. Chen, C.E. Coppola, Ramanath K. Cowsik, J.A. Crabtree, Pragya Das, Eric Dees, Aleksander D. Dolgov, Phillip D. Ferguson, Matthew Frost, Tony A. Gabriel, A. Gal, Franz X. Gallmeier, Kenneth S. Ganezer, E. Golubeva, Geoffrey L. Greene, B. Hartfiel, Ayman Hawari, Lawrence H. Heilbronn, Colin D. Johnson, Yu A. Kamyshkov, Boris O. Kerbikov, Masaaki Kitaguchi, B.Z. Kopeliovich, V.B. Kopeliovich, Vadim A. Kuzmin, Chenyu Liu, P. Mcgaughey, M. Mocko, Rabindra N. Mohapatra, Nikolai V. Mokhov, Guenter Muhrer, H.P. Pieter Mumm, Lev B. Okun, Robert W. Pattie, C. Quigg, E. Ramberg, A. Ray, A. Roy, A. Ruggles, U. Sarkar, Andy Saunders, A. P. Serebrovv, H. M. Shimizu, R. Shrock, A. K. Sikdara, Sky Sjue, S. Striganov, L. W. Townsend, R. Tschirhart, A. Vainshtein, R Van Kooten, Z. Wang, A. R. Young

Robert W. Pattie Jr.

The observation of neutrons turning into antineutrons would constitute a discovery of fundamental importance for particle physics and cosmology. Observing the n–n̄ transition would show that baryonnumber (B) is violated by two units and that matter containing neutrons is unstable. It would provide a clue to how the matter in our universe might have evolved from the B=0 early universe. If seen at rates observable in foreseeable next-generation experiments, it might well help us understand the observed baryon asymmetry of the universe. A demonstration of the violation of B–L by 2 units would have a profound ...


Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann Jan 2016

Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann

Robert A McNees IV

A variational formulation is given for a theory of gravity coupled to a massive vector in four dimensions, with Asymptotically Lifshitz boundary conditions on the fields. For theories with critical exponent z=2 we obtain a well-defined variational principle by explicitly constructing two actions with local boundary counterterms. As part of our analysis we obtain solutions of these theories on a neighborhood of spatial infinity, study the asymptotic symmetries, and consider different definitions of the boundary stress tensor and associated charges. A constraint on the boundary data for the fields figures prominently in one of our formulations, and in that ...


Black Holes In The Conical Ensemble, Robert Mcnees, Daniel Grumiller Jan 2016

Black Holes In The Conical Ensemble, Robert Mcnees, Daniel Grumiller

Robert A McNees IV

We consider black holes in an “unsuitable box”: a finite cavity coupled to a thermal reservoir at a temperature different than the black hole’s Hawking temperature. These black holes are described by metrics that are continuous but not differentiable due to a conical singularity at the horizon. We include them in the Euclidean path integral sum over configurations, and analyze the effect this has on black hole thermodynamics in the canonical ensemble. Black holes with a small deficit (or surplus) angle may have a smaller internal energy or larger density of states than the nearby smooth black hole, but ...


Conventions, Definitions, Identities, And Other Useful Formulae, Robert Mcnees Jan 2016

Conventions, Definitions, Identities, And Other Useful Formulae, Robert Mcnees

Robert A McNees IV

As the name suggests, these notes contain a summary of important conventions, definitions, identities, and various formulas that I often refer to. They may prove useful for researchers working in General Relativity, Supergravity, String Theory, Cosmology, and related areas.


Boundary Terms Unbound! Holographic Renormalization Of Asymptotically Linear Dilaton Gravity, Robert Mcnees, Robert Mann Jan 2016

Boundary Terms Unbound! Holographic Renormalization Of Asymptotically Linear Dilaton Gravity, Robert Mcnees, Robert Mann

Robert A McNees IV

A variational principle is constructed for gravity coupled to an asymptotically linear dilaton and a p-form field strength. This requires the introduction of appropriate surface terms—also known as 'boundary counterterms'—in the action. The variation of the action with respect to the boundary metric yields a boundary stress tensor, which is used to construct conserved charges that generate the asymptotic symmetries of the theory. In most cases a minimal set of assumptions leads to a unique set of counterterms. However, for certain examples we find families of actions that depend on one or more continuous parameters. We show that ...


Bps Brane Cosmology In N=2 Supergravity, Moataz Emam Aug 2015

Bps Brane Cosmology In N=2 Supergravity, Moataz Emam

Moataz Emam

We study the embedding of flat BPS 3-branes in five dimensional N=2 supergravity theory. We derive the branes' dynamical equations as well as general expressions for the hypermultiplet fields then focus on a single brane and study its time evolution. It is shown that the brane's Hubble parameter correlates with the moduli of the underlying manifold's complex structure. For certain particular solutions, the moduli seem to exhibit an instability; being large valued at early times then rapidly decaying to either zero or some convergent constant value. The possibility of extending these results to the cosmology of our ...


Lorentz Violation With An Antisymmetric Tensor, Brett Altschul, Quentin G. Bailey, V. Alan Kostelecky Jan 2015

Lorentz Violation With An Antisymmetric Tensor, Brett Altschul, Quentin G. Bailey, V. Alan Kostelecky

Quentin Bailey

Field theories with spontaneous Lorentz violation involving an antisymmetric 2-tensor are studied. A general action including nonminimal gravitational couplings is constructed, and features of the Nambu- Goldstone and massive modes are discussed. Minimal models in Minkowski spacetime exhibit dualities with Lorentz-violating vector and scalar theories. The post-Newtonian expansion for nonminimal models in Riemann spacetime involves qualitatively new features, including the absence of an isotropic limit. Certain interactions producing stable Lorentz-violating theories in Minkowski spacetime solve the renormalization-group equations in the tadpole approximation.


Lorentz-Violating Gravitoelectromagnetism, Quentin G. Bailey Jan 2015

Lorentz-Violating Gravitoelectromagnetism, Quentin G. Bailey

Quentin Bailey

The well-known analogy between a special limit of general relativity and electromagnetism is explored in the context of the Lorentz-violating standard-model extension. An analogy is developed for the minimal standard-model extension that connects a limit of the CPT-even component of the electromagnetic sector to the gravitational sector. We show that components of the post-Newtonian metric can be directly obtained from solutions to the electromagnetic sector. The method is illustrated with specific examples including static and rotating sources. Some unconventional effects that arise for Lorentz-violating electrostatics and magnetostatics have an analog in Lorentz-violating post-Newtonian gravity. In particular, we show that even ...


Limits On Violations Of Lorentz Symmetry From Gravity Probe B, Quentin G. Bailey, Ryan D. Everett, James M. Overduin Jan 2015

Limits On Violations Of Lorentz Symmetry From Gravity Probe B, Quentin G. Bailey, Ryan D. Everett, James M. Overduin

Quentin Bailey

Generic violations of Lorentz symmetry can be described by an effective field theory framework that contains both general relativity and the Standard Model of particle physics called the Standard-Model extension (SME). We obtain new constraints on the gravitational sector of the SME using recently published final results from Gravity Probe B. These include for the first time an upper limit at the 10_3 level on the time-time component of the new tensor field responsible for inducing local Lorentz violation in the theory, and an independent limit at the 10_7 level on a combination of components of this tensor field.


Time-Delay And Doppler Tests Of The Lorentz Symmetry Of Gravity, Quentin G. Bailey Jan 2015

Time-Delay And Doppler Tests Of The Lorentz Symmetry Of Gravity, Quentin G. Bailey

Quentin Bailey

Modifications to the classic time-delay effect and Doppler shift in general relativity (GR) are studied in the context of the Lorentz-violating standard-model extension (SME). We derive the leading Lorentz- violating corrections to the time-delay and Doppler shift signals, for a light ray passing near a massive body. It is demonstrated that anisotropic coefficients for Lorentz violation control a time-dependent behavior of these signals that is qualitatively different from the conventional case in GR. Estimates of sensitivities to gravity-sector coefficients in the SME are given for current and future experiments, including the recent Cassini solar conjunction experiment.


Catching Relativity Violations With Atoms, Quentin G. Bailey Jan 2015

Catching Relativity Violations With Atoms, Quentin G. Bailey

Quentin Bailey

A Viewpoint on: Atom interferometry tests of local Lorentz invariance in gravity and electrodynamics Keng-Yeow Chung, Sheng-wey Chiow, Sven Herrmann, Steven Chu and Holger Müller Phys. Rev. D 80, 016002 (2009) – Published July 6, 2009.


Light-Bending Tests Of Lorentz Invariance, Quentin G. Bailey, Rhondale Tso Jan 2015

Light-Bending Tests Of Lorentz Invariance, Quentin G. Bailey, Rhondale Tso

Quentin Bailey

Classical light-bending is investigated for weak gravitational fields in the presence of hypothetical local Lorentz violation. Using an effective field theory framework that describes general deviations from local Lorentz invariance, we derive a modified deflection angle for light passing near a massive body. The results include anisotropic effects not present for spherical sources in General Relativity as well as Weak Equivalence Principle violation. We develop an expression for the relative deflection of two distant stars that can be used to analyze data in past and future solar-system observations. The measurement sensitivities of such tests to coefficients for Lorentz violation are ...


The Spatial Distribution Of Electric Field Intensity When The Motion Of Electric Charge In Absolute Space, Vildyan Yanbikov Dec 2014

The Spatial Distribution Of Electric Field Intensity When The Motion Of Electric Charge In Absolute Space, Vildyan Yanbikov

Vildyan Yanbikov

When driving an electric or gravitational charge in absolute space. Field created by these particles will have a different distribution in space. In comparison with by a stationary charge. When the charge motion of the deformation field.


Determination Of The Free Neutron Lifetime, J. David Bowman, Leah J. Broussard, Stephen M. Clayton, M. S. Dewey, Nadia Fomin, Keith B. Grammer, G. L. Greene, Paul R. Huffman, Anthony T. Holley, Geoffrey L. Jones, Chenyu Liu, Mark Makela, Michael P. Mendenhall, Charles L. Morris, Jonathan Mulholland, K. M. Nollett, Robert W. Pattie, Seppo Penttila, M. Ramsey-Musolf, Daniel J. Salvat, Andy Saunders, Susan J. Seestrom, William M. Snow, A. Steyerl, F. E. Wietfeldt, Albert R. Young, Andrew T. Yue Oct 2014

Determination Of The Free Neutron Lifetime, J. David Bowman, Leah J. Broussard, Stephen M. Clayton, M. S. Dewey, Nadia Fomin, Keith B. Grammer, G. L. Greene, Paul R. Huffman, Anthony T. Holley, Geoffrey L. Jones, Chenyu Liu, Mark Makela, Michael P. Mendenhall, Charles L. Morris, Jonathan Mulholland, K. M. Nollett, Robert W. Pattie, Seppo Penttila, M. Ramsey-Musolf, Daniel J. Salvat, Andy Saunders, Susan J. Seestrom, William M. Snow, A. Steyerl, F. E. Wietfeldt, Albert R. Young, Andrew T. Yue

Robert W. Pattie Jr.

We present the status of current US experimental efforts to measure the lifetime of the free neutron by the "beam" and "bottle" methods. BBN nucleosynthesis models require accurate measurements with 1 second uncertainties, which are currently feasible. For tests of physics beyond the standard model, future efforts will need to achieve uncertainties well below 1 second. We outline paths achieve both.


Dark Matter As An Integral Part Of An Alternative Gravity Model, Hontas Farmer Apr 2014

Dark Matter As An Integral Part Of An Alternative Gravity Model, Hontas Farmer

Hontas F Farmer

The purpose of this paper is to reconcile observations of dark matter effects on the galactic and cosmological scales with the null results of astroparticle physics observations such as CDMS and ANTARES. This paper will also provide a candidate unified and simpler mathematical formulation for the Lambda CDM model. Unification is achieved by a combination of the f(R) approach, with the standard LCDM approach and inflationary models. It is postulated that dark matter-energy fields depend on the Ricci curvature R. Standard methods of classical and quantum field theory on curved space time are applied. When this model is treated ...


A Method For Measuring Coherent Elastic Neutrino-Nucleus Scattering At A Far Off-Axis High-Energy Neutrino Beam Target Apr 2014

A Method For Measuring Coherent Elastic Neutrino-Nucleus Scattering At A Far Off-Axis High-Energy Neutrino Beam Target

Robert W. Pattie Jr.

We present an experimental method for measuring the process of coherent elastic neutrino-nucleus scattering (CENNS). This method uses a detector situated transverse to a high-energy neutrino beam production target. This detector would be sensitive to the low-energy neutrinos arising from decay-at-rest pions in the target. We discuss the physics motivation for making this measurement and outline the predicted backgrounds and sensitivities using this approach. We report a measurement of neutron backgrounds as found in an off-axis surface location of the Fermilab Booster Neutrino Beam (BNB) target. The results indicate that the Fermilab BNB target is a favorable location for a ...


Conformal Gravity Holography In Four Dimensions, Robert Mcnees Mar 2014

Conformal Gravity Holography In Four Dimensions, Robert Mcnees

Robert A McNees IV

We formulate four-dimensional conformal gravity with (anti–)de Sitter boundary conditions that are weaker than Starobinsky boundary conditions, allowing for an asymptotically subleading Rindler term concurrent with a recent model for gravity at large distances. We prove the consistency of the variational principle and derive the holographic response functions. One of them is the conformal gravity version of the Brown–York stress tensor, the other is a “partially massless response”. The on shell action and response functions are finite and do not require holographic renormalization. Finally, we discuss phenomenologically interesting examples, including the most general spherically symmetric solutions and rotating ...


Project X: Physics Opportunities, Andreas S. Kronfeld, Robert S. Tschirhart, Usama Al-Binni, Wolfgang Altmannshofer, Charles Ankenbrandt, Kaladi Babu, Sunanda Banerjee, Matthew Bass, Brian Batell, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Robert Bernstein, Sudeb Bhattacharya, Mary Bishai, Thomas Blum, S. Alex Bogacz, Stephen J. Brice, Joachim Brod, Alan Bross, Michael Buchoff, Thomas W. Burgess, Marcela Carena, Luis A. Castellanos, Subhasis Chattopadhyay, Mu-Chun Chen, Daniel Cherdack, Norman H. Christ, Tim Chupp, Vincenzo Cirigliano, Pilar Coloma, Christopher E. Coppola, Ramanath Cowsik, J. Allen Crabtree, André De Gouvêa, Jean-Pierre Delahaye, Dmitri Denisov, Patrick Deniverville, Ranjan Dharmapalan, Alexander Dolgov, Georgi Dvali, Estia Eichten, Jürgen Engelfried, Phillip D. Ferguson, Tony Gabriel, Avraham Gal, Franz Gallmeier, Kenneth S. Ganezer, Susan Gardner Jul 2013

Project X: Physics Opportunities, Andreas S. Kronfeld, Robert S. Tschirhart, Usama Al-Binni, Wolfgang Altmannshofer, Charles Ankenbrandt, Kaladi Babu, Sunanda Banerjee, Matthew Bass, Brian Batell, David V. Baxter, Zurab Berezhiani, Marc Bergevin, Robert Bernstein, Sudeb Bhattacharya, Mary Bishai, Thomas Blum, S. Alex Bogacz, Stephen J. Brice, Joachim Brod, Alan Bross, Michael Buchoff, Thomas W. Burgess, Marcela Carena, Luis A. Castellanos, Subhasis Chattopadhyay, Mu-Chun Chen, Daniel Cherdack, Norman H. Christ, Tim Chupp, Vincenzo Cirigliano, Pilar Coloma, Christopher E. Coppola, Ramanath Cowsik, J. Allen Crabtree, André De Gouvêa, Jean-Pierre Delahaye, Dmitri Denisov, Patrick Deniverville, Ranjan Dharmapalan, Alexander Dolgov, Georgi Dvali, Estia Eichten, Jürgen Engelfried, Phillip D. Ferguson, Tony Gabriel, Avraham Gal, Franz Gallmeier, Kenneth S. Ganezer, Susan Gardner

Robert W. Pattie Jr.

Part 2 of "Project X: Accelerator Reference Design, Physics Opportunities, Broader Impacts". In this Part, we outline the particle-physics program that can be achieved with Project X, a staged superconducting linac for intensity-frontier particle physics. Topics include neutrino physics, kaon physics, muon physics, electric dipole moments, neutron-antineutron oscillations, new light particles, hadron structure, hadron spectroscopy, and lattice-QCD calculations. Part 1 is available as arXiv:1306.5022 [physics.acc-ph] and Part 3 is available as arXiv:1306.5024 [physics.acc-ph].


A Lagrangian Which Mathematically Models Lambda Cdm Cosmology And Explains The Null Results Of Dark Astroparticle Searches., Hontas Farmer Dec 2012

A Lagrangian Which Mathematically Models Lambda Cdm Cosmology And Explains The Null Results Of Dark Astroparticle Searches., Hontas Farmer

Hontas F Farmer

Background: The Lambda CDM model or is the standard model of modern cosmology. It is named for dark energy and cold dark matter. This model contains a number of separate components with different mathematical formulations. Strong observational evidence for dark matter has been found by astronomy. At the same time astroparticle physics observations have not found solid evidence of dark matter. Purpose: The purpose of this paper is to reconcile observations of dark matter effects on the galactic and cosmological scales with the null results of astroparticle physics observations such as CDMS and ANTARES. This paper will also provide a ...


Supersymmetric Multi-Higgs Doublet Model With Non-Linear Electroweak Symmetry Breaking, T. E. Clark, S. T. Love, Tonnis Ter Veldhuis Dec 2011

Supersymmetric Multi-Higgs Doublet Model With Non-Linear Electroweak Symmetry Breaking, T. E. Clark, S. T. Love, Tonnis Ter Veldhuis

Tonnis ter Veldhuis

No abstract provided.


Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann Sep 2011

Holographic Renormalization Of Asymptotically Lifshitz Spacetimes, Robert Mcnees, Robert Mann

Robert A McNees IV

A variational formulation is given for a theory of gravity coupled to a massive vector in four dimensions, with Asymptotically Lifshitz boundary conditions on the fields. For theories with critical exponent z = 2 we obtain a well-defined variational principle by explicitly constructing two actions with local boundary counterterms. As part of our analysis we obtain solutions of these theories on a neighborhood of spatial infinity, study the asymptotic symmetries, and consider different definitions of the boundary stress tensor and associated charges. A constraint on the boundary data for the fields figures prominently in one of our formulations, and in that ...


Results From A Beam Test Of A Prototype Plt Diamond Pixel Telescope, R. Hall-Wilton, R. Loos, V. Ryjov, M. Pernicka, S. Schmied, H. Steninger, V. Halyo, B. Harrop, A. Hunt, D. Marlow, B. Sands, D. Strickland, O. Atramentov, E. Bartz, J. Doroshenko, Y. Gershtein, D. Hits, S. Schnetzer, R. Stone, P. Bulter, S. Lansley, N. Rodrigues, W. Bugg, M Hollingsworth, Stefan Spanier, W. Johns Dec 2009

Results From A Beam Test Of A Prototype Plt Diamond Pixel Telescope, R. Hall-Wilton, R. Loos, V. Ryjov, M. Pernicka, S. Schmied, H. Steninger, V. Halyo, B. Harrop, A. Hunt, D. Marlow, B. Sands, D. Strickland, O. Atramentov, E. Bartz, J. Doroshenko, Y. Gershtein, D. Hits, S. Schnetzer, R. Stone, P. Bulter, S. Lansley, N. Rodrigues, W. Bugg, M Hollingsworth, Stefan Spanier, W. Johns

stefan spanier

We describe results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors. This telescope is a prototype for a small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS. We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes. We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking. These results show that the PLT design meets all required specifications.


Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, Stefan Spanier Dec 2009

Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, Stefan Spanier

stefan spanier

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle (phi). Short-range correlations in Delta(eta), which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in eta (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 inverse ...


Commissioning And Performance Of The Cms Pixel Tracker With Cosmic Ray, Serguei Chatrchyan Muons, Stefan Spanier Dec 2009

Commissioning And Performance Of The Cms Pixel Tracker With Cosmic Ray, Serguei Chatrchyan Muons, Stefan Spanier

stefan spanier

The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.


The Many Symmetries Of Calabi–Yau Compactifications, Moataz Emam Dec 2009

The Many Symmetries Of Calabi–Yau Compactifications, Moataz Emam

Moataz Emam

No abstract provided.


Polarimetry Studies For The Npdgamma Experiment At The Sns, Jonny Dadras Nov 2009

Polarimetry Studies For The Npdgamma Experiment At The Sns, Jonny Dadras

Jonny Dadras

The NPDGamma collaboration aims to measure a parity-violating directional gamma-ray asymmetry from the capture of polarized cold neutrons on protons. The asymmetry, predicted to be on the order of 50 ppb, is a result of the weak interaction between mesons and nucleons during the neutron capture reaction. The experiment is designed to make a statistics limited measurement of the asymmetry at the level of about 20%. The experiment will be carried out at the Fundamental neutron Physics Beamline (FnPB) at the Spallation Neutron Source (SNS). The neutron beam is polarized by a super-mirror polarizer. A 9.5 G magnetic field ...


Performance Of A Single-Crystal Diamond-Pixel Telescope, R. Hall-Wilton, V. Ryjov, M. Pernicka, V. Halyo, B. Harrop, A. Hunt, D. Marlow, E. Bartz, J. Doroshenko, D. Hits, S. Schnetzer, R. Stone, W. Bugg, M. Hollingsworth, Stefan Spanier, W. Johns Dec 2008

Performance Of A Single-Crystal Diamond-Pixel Telescope, R. Hall-Wilton, V. Ryjov, M. Pernicka, V. Halyo, B. Harrop, A. Hunt, D. Marlow, E. Bartz, J. Doroshenko, D. Hits, S. Schnetzer, R. Stone, W. Bugg, M. Hollingsworth, Stefan Spanier, W. Johns

stefan spanier

We describe the results from a beam test of a telescope consisting of three planes of single-crystal, diamond pixel detectors. This telescope is a prototype for a proposed small-angle luminosity monitor, the Pixel Luminosity Telescope (PLT), for CMS. We recorded the pixel addresses and pulse heights of all pixels over threshold as well as the fast-or signals from all three telescope planes. We present results on the telescope performance including occupancies, pulse heights, fast-or efficiencies and particle tracking. These results show that the PLT design concept is sound and indicate that the project is ready to proceed with the next ...


The Cms Experiment At The Cern Lhc, Cms Collaboration, R. Adolphi, Stefan Spanier Dec 2007

The Cms Experiment At The Cern Lhc, Cms Collaboration, R. Adolphi, Stefan Spanier

stefan spanier

No abstract provided.