arXiv subjects

S. A. Dytman

Publications and source records attributed to S. A. Dytman.

45 records · Page 3Linked to original sources

arXiv2014

Measurement of Muon Antineutrino Quasi-Elastic Scattering on a Hydrocarbon Target at E_ν ~ 3.5 GeV

We have isolated muon anti-neutrino charged-current quasi-elastic interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross-section, dσ/dQ^2, and compare to several theoretical models of quasi-elastic scattering. Good agreement is obtained with a model where the nucleon axial mass, M_A, is set to 0.99 GeV/c^2 but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross-section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q^2 favor this interpretation over an alternative in which the axial mass is increased.

hep-ex↗

arXiv2014

Measurement of Muon Neutrino Quasi-Elastic Scattering on a Hydrocarbon Target at E_ν ~ 3.5 GeV

We report a study of muon neutrino charged-current quasi-elastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ^- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross-section, dσ/dQ^2, and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ^2 and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

hep-ex↗

arXiv2013

Design, Calibration, and Performance of the MINERvA Detector

The MINERvA experiment is designed to perform precision studies of neutrino-nucleus scattering using $ν_μ$ and ${\barν}_μ$ neutrinos incident at 1-20 GeV in the NuMI beam at Fermilab. This article presents a detailed description of the \minerva detector and describes the {\em ex situ} and {\em in situ} techniques employed to characterize the detector and monitor its performance. The detector is comprised of a finely-segmented scintillator-based inner tracking region surrounded by electromagnetic and hadronic sampling calorimetry. The upstream portion of the detector includes planes of graphite, iron and lead interleaved between tracking planes to facilitate the study of nuclear effects in neutrino interactions. Observations concerning the detector response over sustained periods of running are reported. The detector design and methods of operation have relevance to future neutrino experiments in which segmented scintillator tracking is utilized.

physics.ins-det↗

arXiv2012

Demonstration of Communication using Neutrinos

Beams of neutrinos have been proposed as a vehicle for communications under unusual circumstances, such as direct point-to-point global communication, communication with submarines, secure communications and interstellar communication. We report on the performance of a low-rate communications link established using the NuMI beam line and the MINERvA detector at Fermilab. The link achieved a decoded data rate of 0.1 bits/sec with a bit error rate of 1% over a distance of 1.035 km, including 240 m of earth.

hep-ex↗

arXiv2003

Evidence for Two-Body Hadronic Decays of the Upsilon

We describe a search for hadronic decays of the Y(1S), Y(2S), and Y(3S) resonances to the exclusive final states rho pi, K*(892) Kbar, rho a2(1320), omega f2(1270), phi f2'(1525), K*(892) K2*(1430)bar, b1(1235) pi, K1(1270) Kbar, and K1(1400) Kbar. Upper limits at 90% CL are set for all these decays from all three resonances below 33x10**-6; in particular, B(Y(1S)--> rho pi) < 4x10**-6 is the smallest such upper limit. For two modes, a branching fraction of zero can be ruled out with a statistical significance of more than 5sigma: B(Y(1S) --> phi f2'(1525)) = (7 +3-2(stat) +-1(syst)) x 10**-6 and B(Y(1S) --> K1(1400) Kbar) = (14 +4-3(stat) +-2(syst)) x 10**-6. Production of K1(1270) Kbar in Y(1S) decay is suppressed relative to that of K1(1400) Kbar. These results add another piece to the challenging ``rho-pi puzzle'' of the charmonium system, placing constraints on models of how quantum chromodynamics should be applied to heavy quarkonia. All results are preliminary.

hep-ex↗

arXiv2001

Evidence for the Decay $D^0\to K^+ π^-π^+π^-$

We present a search for the ``wrong-sign'' decay D0 -> K+ pi- pi+ pi- using 9 fb-1 of e+e- collisions on and just below the Upsilon(4S) resonance. This decay can occur either through a doubly Cabibbo-suppressed process or through mixing to a D0bar followed by a Cabibbo-favored process. Our result for the time-integrated wrong-sign rate relative to the decay D0 -> K- pi+ pi- pi+ is (0.0041 +0.0012-0.0011(stat.) +-0.0004(syst.))x(1.07 +-0.10)(phase space), which has a statistical significance of 3.9 standard deviations.

hep-ex↗

arXiv1999

Meson Production Experiments with Electromagnetic Beams using CLAS

The CEBAF Large Acceptnace Spectrometer (CLAS) has been taking production data since February, 1998. It takes data for many reactions simultaneously with moderate resolution. Data has been taken for a variety of conditions with polarized and unpolarized beam and target. Preliminary results of the initial experiments run by the CLAS collaboration are shown. The connection with the study of N* resonances is emphasized.

nucl-ex↗

arXiv1999

Baryon Resonance Extraction from piN Data using a Unitary Multichannel Model

A unitary multi-channel approach, first developed by the Carnegie-Mellon- Berkeley group, is applied to extract the pole positions, masses, and partial decay widths of nucleon resonances. Input used are the partial wave amplitudes for the transitions from piN to eight possible final baryon-meson final states. Because the model preserves analyticity, resonances are found as poles in the T matrix. This approach is designed to handle inelastic threshold openings with minimal model dependence. Although many of the known states have the same properties as in previous analyses, others change significantly. We pay particular attention to S11(1535) which is very close to the eta threshold.

nucl-th↗

arXiv1997

Baryon Resonance Extraction from Pi Nucleon Data using a Multichannel Unitary Model

We present organization and solutions for a new analysis of all $πN$ elastic and the major inelastic channels to extract detailed characteristics of the contributing baryon resonances. This work is based on the work of R. Cutkosky and collaborators at CMU about 20 years ago. The model features analyticity at the amplitude level and unitarity. Results are similar to previous analyses for strongly excited states, but can vary considerably from previous analyses when the states are weak, the data is poor, or there is a strong model dependence. We emphasize the S_{11}(1535) resonance which has particularly strong model dependence.

nucl-th↗