S. Malace - HKS - JLab E05-115 and E01-001 - Collaborations

S. Malace
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S. Malace
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HKS - JLab E05-115 and E01-001 - Collaborations
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Nuclear Experiment (21)
 
High Energy Physics - Experiment (7)
 
High Energy Physics - Phenomenology (6)
 
Nuclear Theory (5)
 
Physics - Instrumentation and Detectors (2)

Publications Authored By S. Malace

Structure functions, as measured in lepton-nucleon scattering, have proven to be very useful in studying the quark dynamics within the nucleon. However, it is experimentally difficult to separately determine the longitudinal and transverse structure functions, and consequently there are substantially less data available for the longitudinal structure function in particular. Here we present separated structure functions for hydrogen and deuterium at low four--momentum transfer squared, Q^2< 1 GeV^2, and compare these with parton distribution parameterizations and a k_T factorization approach. Read More

2014Jun
Authors: L. Tang1, C. Chen2, T. Gogami3, D. Kawama4, Y. Han5, L. Yuan6, A. Matsumura7, Y. Okayasu8, T. Seva9, V. M. Rodriguez10, P. Baturin11, A. Acha12, P. Achenbach13, A. Ahmidouch14, I. Albayrak15, D. Androic16, A. Asaturyan17, R. Asaturyan18, O. Ates19, R. Badui20, O. K. Baker21, F. Benmokhtar22, W. Boeglin23, J. Bono24, P. Bosted25, E. Brash26, P. Carter27, R. Carlini28, A. Chiba29, M. E. Christy30, L. Cole31, M. M. Dalton32, S. Danagoulian33, A. Daniel34, R. De Leo35, V. Dharmawardane36, D. Doi37, K. Egiyan38, M. Elaasar39, R. Ent40, H. Fenker41, Y. Fujii42, M. Furic43, M. Gabrielyan44, L. Gan45, F. Garibaldi46, D. Gaskell47, A. Gasparian48, E. F. Gibson49, P. Gueye50, O. Hashimoto51, D. Honda52, T. Horn53, B. Hu54, Ed V. Hungerford55, C. Jayalath56, M. Jones57, K. Johnston58, N. Kalantarians59, H. Kanda60, M. Kaneta61, F. Kato62, S. Kato63, M. Kawai64, C. Keppel65, H. Khanal66, M. Kohl67, L. Kramer68, K. J. Lan69, Y. Li70, A. Liyanage71, W. Luo72, D. Mack73, K. Maeda74, S. Malace75, A. Margaryan76, G. Marikyan77, P. Markowitz78, T. Maruta79, N. Maruyama80, V. Maxwell81, D. J. Millener82, T. Miyoshi83, A. Mkrtchyan84, H. Mkrtchyan85, T. Motoba86, S. Nagao87, S. N. Nakamura88, A. Narayan89, C. Neville90, G. Niculescu91, M. I. Niculescu92, A. Nunez93, Nuruzzaman94, H. Nomura95, K. Nonaka96, A. Ohtani97, M. Oyamada98, N. Perez99, T. Petkovic100, J. Pochodzalla101, X. Qiu102, S. Randeniya103, B. Raue104, J. Reinhold105, R. Rivera106, J. Roche107, C. Samanta108, Y. Sato109, B. Sawatzky110, E. K. Segbefia111, D. Schott112, A. Shichijo113, N. Simicevic114, G. Smith115, Y. Song116, M. Sumihama117, V. Tadevosyan118, T. Takahashi119, N. Taniya120, K. Tsukada121, V. Tvaskis122, M. Veilleux123, W. Vulcan124, S. Wells125, F. R. Wesselmann126, S. A. Wood127, T. Yamamoto128, C. Yan129, Z. Ye130, K. Yokota131, S. Zhamkochyan132, L. Zhu133
Affiliations: 1HKS - JLab E05-115 and E01-001 - Collaborations, 2HKS - JLab E05-115 and E01-001 - Collaborations, 3HKS - JLab E05-115 and E01-001 - Collaborations, 4HKS - JLab E05-115 and E01-001 - Collaborations, 5HKS - JLab E05-115 and E01-001 - Collaborations, 6HKS - JLab E05-115 and E01-001 - Collaborations, 7HKS - JLab E05-115 and E01-001 - Collaborations, 8HKS - JLab E05-115 and E01-001 - Collaborations, 9HKS - JLab E05-115 and E01-001 - Collaborations, 10HKS - JLab E05-115 and E01-001 - Collaborations, 11HKS - JLab E05-115 and E01-001 - Collaborations, 12HKS - JLab E05-115 and E01-001 - Collaborations, 13HKS - JLab E05-115 and E01-001 - Collaborations, 14HKS - JLab E05-115 and E01-001 - Collaborations, 15HKS - JLab E05-115 and E01-001 - Collaborations, 16HKS - JLab E05-115 and E01-001 - Collaborations, 17HKS - JLab E05-115 and E01-001 - Collaborations, 18HKS - JLab E05-115 and E01-001 - Collaborations, 19HKS - JLab E05-115 and E01-001 - Collaborations, 20HKS - JLab E05-115 and E01-001 - Collaborations, 21HKS - JLab E05-115 and E01-001 - Collaborations, 22HKS - JLab E05-115 and E01-001 - Collaborations, 23HKS - JLab E05-115 and E01-001 - Collaborations, 24HKS - JLab E05-115 and E01-001 - Collaborations, 25HKS - JLab E05-115 and E01-001 - Collaborations, 26HKS - JLab E05-115 and E01-001 - Collaborations, 27HKS - JLab E05-115 and E01-001 - Collaborations, 28HKS - JLab E05-115 and E01-001 - Collaborations, 29HKS - JLab E05-115 and E01-001 - Collaborations, 30HKS - JLab E05-115 and E01-001 - Collaborations, 31HKS - JLab E05-115 and E01-001 - Collaborations, 32HKS - JLab E05-115 and E01-001 - Collaborations, 33HKS - JLab E05-115 and E01-001 - Collaborations, 34HKS - JLab E05-115 and E01-001 - Collaborations, 35HKS - JLab E05-115 and E01-001 - Collaborations, 36HKS - JLab E05-115 and E01-001 - Collaborations, 37HKS - JLab E05-115 and E01-001 - Collaborations, 38HKS - JLab E05-115 and E01-001 - Collaborations, 39HKS - JLab E05-115 and E01-001 - Collaborations, 40HKS - JLab E05-115 and E01-001 - Collaborations, 41HKS - JLab E05-115 and E01-001 - Collaborations, 42HKS - JLab E05-115 and E01-001 - Collaborations, 43HKS - JLab E05-115 and E01-001 - Collaborations, 44HKS - JLab E05-115 and E01-001 - Collaborations, 45HKS - JLab E05-115 and E01-001 - Collaborations, 46HKS - JLab E05-115 and E01-001 - Collaborations, 47HKS - JLab E05-115 and E01-001 - Collaborations, 48HKS - JLab E05-115 and E01-001 - Collaborations, 49HKS - JLab E05-115 and E01-001 - Collaborations, 50HKS - JLab E05-115 and E01-001 - Collaborations, 51HKS - JLab E05-115 and E01-001 - Collaborations, 52HKS - JLab E05-115 and E01-001 - Collaborations, 53HKS - JLab E05-115 and E01-001 - Collaborations, 54HKS - JLab E05-115 and E01-001 - Collaborations, 55HKS - JLab E05-115 and E01-001 - Collaborations, 56HKS - JLab E05-115 and E01-001 - Collaborations, 57HKS - JLab E05-115 and E01-001 - Collaborations, 58HKS - JLab E05-115 and E01-001 - Collaborations, 59HKS - JLab E05-115 and E01-001 - Collaborations, 60HKS - JLab E05-115 and E01-001 - Collaborations, 61HKS - JLab E05-115 and E01-001 - Collaborations, 62HKS - JLab E05-115 and E01-001 - Collaborations, 63HKS - JLab E05-115 and E01-001 - Collaborations, 64HKS - JLab E05-115 and E01-001 - Collaborations, 65HKS - JLab E05-115 and E01-001 - Collaborations, 66HKS - JLab E05-115 and E01-001 - Collaborations, 67HKS - JLab E05-115 and E01-001 - Collaborations, 68HKS - JLab E05-115 and E01-001 - Collaborations, 69HKS - JLab E05-115 and E01-001 - Collaborations, 70HKS - JLab E05-115 and E01-001 - Collaborations, 71HKS - JLab E05-115 and E01-001 - Collaborations, 72HKS - JLab E05-115 and E01-001 - Collaborations, 73HKS - JLab E05-115 and E01-001 - Collaborations, 74HKS - JLab E05-115 and E01-001 - Collaborations, 75HKS - JLab E05-115 and E01-001 - Collaborations, 76HKS - JLab E05-115 and E01-001 - Collaborations, 77HKS - JLab E05-115 and E01-001 - Collaborations, 78HKS - JLab E05-115 and E01-001 - Collaborations, 79HKS - JLab E05-115 and E01-001 - Collaborations, 80HKS - JLab E05-115 and E01-001 - Collaborations, 81HKS - JLab E05-115 and E01-001 - Collaborations, 82HKS - JLab E05-115 and E01-001 - Collaborations, 83HKS - JLab E05-115 and E01-001 - Collaborations, 84HKS - JLab E05-115 and E01-001 - Collaborations, 85HKS - JLab E05-115 and E01-001 - Collaborations, 86HKS - JLab E05-115 and E01-001 - Collaborations, 87HKS - JLab E05-115 and E01-001 - Collaborations, 88HKS - JLab E05-115 and E01-001 - Collaborations, 89HKS - JLab E05-115 and E01-001 - Collaborations, 90HKS - JLab E05-115 and E01-001 - Collaborations, 91HKS - JLab E05-115 and E01-001 - Collaborations, 92HKS - JLab E05-115 and E01-001 - Collaborations, 93HKS - JLab E05-115 and E01-001 - Collaborations, 94HKS - JLab E05-115 and E01-001 - Collaborations, 95HKS - JLab E05-115 and E01-001 - Collaborations, 96HKS - JLab E05-115 and E01-001 - Collaborations, 97HKS - JLab E05-115 and E01-001 - Collaborations, 98HKS - JLab E05-115 and E01-001 - Collaborations, 99HKS - JLab E05-115 and E01-001 - Collaborations, 100HKS - JLab E05-115 and E01-001 - Collaborations, 101HKS - JLab E05-115 and E01-001 - Collaborations, 102HKS - JLab E05-115 and E01-001 - Collaborations, 103HKS - JLab E05-115 and E01-001 - Collaborations, 104HKS - JLab E05-115 and E01-001 - Collaborations, 105HKS - JLab E05-115 and E01-001 - Collaborations, 106HKS - JLab E05-115 and E01-001 - Collaborations, 107HKS - JLab E05-115 and E01-001 - Collaborations, 108HKS - JLab E05-115 and E01-001 - Collaborations, 109HKS - JLab E05-115 and E01-001 - Collaborations, 110HKS - JLab E05-115 and E01-001 - Collaborations, 111HKS - JLab E05-115 and E01-001 - Collaborations, 112HKS - JLab E05-115 and E01-001 - Collaborations, 113HKS - JLab E05-115 and E01-001 - Collaborations, 114HKS - JLab E05-115 and E01-001 - Collaborations, 115HKS - JLab E05-115 and E01-001 - Collaborations, 116HKS - JLab E05-115 and E01-001 - Collaborations, 117HKS - JLab E05-115 and E01-001 - Collaborations, 118HKS - JLab E05-115 and E01-001 - Collaborations, 119HKS - JLab E05-115 and E01-001 - Collaborations, 120HKS - JLab E05-115 and E01-001 - Collaborations, 121HKS - JLab E05-115 and E01-001 - Collaborations, 122HKS - JLab E05-115 and E01-001 - Collaborations, 123HKS - JLab E05-115 and E01-001 - Collaborations, 124HKS - JLab E05-115 and E01-001 - Collaborations, 125HKS - JLab E05-115 and E01-001 - Collaborations, 126HKS - JLab E05-115 and E01-001 - Collaborations, 127HKS - JLab E05-115 and E01-001 - Collaborations, 128HKS - JLab E05-115 and E01-001 - Collaborations, 129HKS - JLab E05-115 and E01-001 - Collaborations, 130HKS - JLab E05-115 and E01-001 - Collaborations, 131HKS - JLab E05-115 and E01-001 - Collaborations, 132HKS - JLab E05-115 and E01-001 - Collaborations, 133HKS - JLab E05-115 and E01-001 - Collaborations

Since the pioneering experiment, E89-009 studying hypernuclear spectroscopy using the $(e,e^{\prime}K^+)$ reaction was completed, two additional experiments, E01-011 and E05-115, were performed at Jefferson Lab. These later experiments used a modified experimental design, the "tilt method", to dramatically suppress the large electromagnetic background, and allowed for a substantial increase in luminosity. Additionally, a new kaon spectrometer, HKS (E01-011), a new electron spectrometer, HES, and a new splitting magnet were added to produce precision, high-resolution hypernuclear spectroscopy. Read More

Since the discovery that the ratio of inclusive charged lepton (per-nucleon) cross sections from a nucleus A to the deuteron is not unity - even in deep inelastic scattering kinematics - a great deal of experimental and theoretical effort has gone into understanding the phenomenon. The EMC effect, as it is now known, shows that even in the most extreme kinematic conditions the effects of the nucleon being bound in a nucleus can not be ignored. In this paper we collect the most precise data available for various nuclear to deuteron ratios, as well as provide a commentary on the current status of the theoretical understanding of this thirty year old effect. Read More

We perform a global analysis of all available electron-deuteron quasielastic scattering data using Q^2-dependent smearing functions that describe inclusive inelastic e-d scattering within the weak binding approximation. We study the dependence of the cross sections on the deuteron wave function and the off-shell extrapolation of the elastic electron-nucleon cross sections, which show particular sensitivity at x >> 1. The excellent overall agreement with data over a large range of Q^2 and x suggests a limited need for effects beyond the impulse approximation, with the possible exception of the very high-x or very low-Q^2 regions, where short-distance effects or scattering from non-nucleonic constituents in the deuteron become more relevant. Read More

We studied the single-photoelectron detection capabilities of a multianode photomultiplier tube H8500C-03 and its performance in high magnetic field. Our results show that the device can readily resolve signals at the single photoelectron level making it suitable for photon detection in both threshold and ring imaging Cerenkov detectors. We also found that a large longitudinal magnetic field, up to 300 Gauss, induces a change in the relative output of at most 55% for an edge pixel, and of at most 15% for a central pixel. Read More

2012Jul
Affiliations: 1HKS, 2HKS, 3HKS, 4HKS, 5HKS, 6HKS, 7HKS, 8HKS, 9HKS, 10HKS, 11HKS, 12HKS, 13HKS, 14HKS, 15HKS, 16HKS, 17HKS, 18HKS, 19HKS, 20HKS, 21HKS, 22HKS, 23HKS, 24HKS, 25HKS, 26HKS, 27HKS, 28HKS, 29HKS, 30HKS, 31HKS, 32HKS, 33HKS, 34HKS, 35HKS, 36HKS, 37HKS, 38HKS, 39HKS, 40HKS, 41HKS, 42HKS, 43HKS, 44HKS, 45HKS, 46HKS, 47HKS, 48HKS, 49HKS, 50HKS, 51HKS, 52HKS, 53HKS, 54HKS, 55HKS, 56HKS, 57HKS, 58HKS, 59HKS, 60HKS, 61HKS, 62HKS, 63HKS, 64HKS, 65HKS, 66HKS, 67HKS, 68HKS, 69HKS, 70HKS, 71HKS, 72HKS, 73HKS, 74HKS, 75HKS, 76HKS, 77HKS, 78HKS, 79HKS, 80HKS, 81HKS, 82HKS, 83HKS, 84HKS, 85HKS, 86HKS, 87HKS, 88HKS, 89HKS, 90HKS, 91HKS, 92HKS, 93HKS

An experiment with a newly developed high-resolution kaon spectrometer (HKS) and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab (JLab). The ground state of a neutron-rich hypernucleus, He 7 Lambda, was observed for the first time with the (e,e'K+) reaction with an energy resolution of ~0.6 MeV. Read More

The electromagnetic calorimeters of the various magnetic spectrometers in Hall C at Jefferson Lab are presented. For the existing HMS and SOS spectrometers design considerations, relevant construction information, and comparisons of simulated and experimental results are included. The energy resolution of the HMS and SOS calorimeters is better than $\sigma/E \sim 6%/\sqrt E $, and pion/electron ($\pi/e$) separation of about 100:1 has been achieved in energy range 1 -- 5 GeV. Read More

A large set of cross sections for semi-inclusive electroproduction of charged pions ($\pi^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4 GeV$^2$ and range in four-momentum transfer squared $2 < Q^2 < 4$ (GeV/c)$^2$, and cover a range in the Bjorken scaling variable 0.2 < x < 0. Read More

Combining data on unpolarized and polarized inclusive proton structure functions, we perform the first detailed study of quark-hadron duality in individual helicity-1/2 and 3/2 virtual photoproduction cross sections. We find that duality is realized more clearly in the helicity-1/2 channel, with duality violating corrections < 10% over the entire nucleon resonance region, while larger, < 20% corrections are found in the helicity-3/2 sector. The results are in general agreement with quark model expectations, and suggest that data above the Delta resonance region may be used to constrain both spin-averaged and spin-dependent parton distributions. Read More

2010Dec
Affiliations: 1for the Jefferson Lab Hall A Collaboration, 2for the Jefferson Lab Hall A Collaboration, 3for the Jefferson Lab Hall A Collaboration

Nucleon properties are modified in the nuclear medium. To understand these modifications and their origin is a central issue in nuclear physics. For example, a wide variety of QCD-based models, including quark-meson coupling and chiral-quark soliton models, predict that the nuclear constituents change properties with increasing density. Read More

We measured with unprecedented precision the induced polarization Py in 4He(e,e'p)3H at Q^2 = 0.8 (GeV/c)^2 and 1.3 (GeV/c)^2. Read More

We present new data on electron scattering from a range of nuclei taken in Hall C at Jefferson Lab. For heavy nuclei, we observe a rapid falloff in the cross section for $x>1$, which is sensitive to short range contributions to the nuclear wave-function, and in deep inelastic scattering corresponds to probing extremely high momentum quarks. This result agrees with higher energy muon scattering measurements, but is in sharp contrast to neutrino scattering measurements which suggested a dramatic enhancement in the distribution of the `super-fast' quarks probed at x>1. Read More

Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium. In experiment E03-104 at Jefferson Lab we measured the proton recoil polarization in the 4He(e,e'p)3H reaction at a Q^2 of 0.8 (GeV/c)^2 and 1. Read More

We apply a recently developed technique to extract for the first time the neutron F_2^n structure function from inclusive proton and deuteron data in the nucleon resonance region, and test the validity of quark-hadron duality in the neutron. We establish the accuracy of duality in the low-lying neutron resonance regions over a range of Q^2, and compare with the corresponding results on the proton and with theoretical expectations. The confirmation of duality in both the neutron and proton opens the possibility of using resonance region data to constrain parton distributions at large x. Read More

Inclusive electron-proton and electron-deuteron inelastic cross sections have been measured at Jefferson Lab (JLab) in the resonance region, at large Bjorken x, up to 0.92, and four-momentum transfer squared Q2 up to 7.5 GeV2 in the experiment E00-116. Read More

Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium, including possible modification of the nucleon form factor and/or spinor. In our recently completed experiment E03-104 at Jefferson Lab we measured the proton recoil polarization in the 4He(e,e'p)3H reaction at a Q^2 of 0.8 (GeV/c)^2 and 1. Read More