122340200
Identification of large-transverse-momentum hadrons using a ring-imaging Cherenkov counter
Abstract We have constructed and operated a large-aperture ring-imaging Cherenkov counter in a large-transverse-momentum experiment at Fermilab. Approximately 3 photons per relativistic particle are emitted in helium gas, focused by spherical mirrors and detected by multistep proportional chambers using a He/TEA gas mixture. Hadron identification is obtained from threshold to approximately 200 GeV c .
119540499
Low cost lead glass cherenkov detectors
Abstract We have compared the optical properties of lead glass bars of three different surface qualities. One was ground and polished in the conventional manner; the other two were in the unimproved state resulting from the extrusion or casting process. We find that the three bars exhibit similar optical characteristics. Use of such unpolished lead glass Cherenkov bars in electromagnetic shower detectors should result in considerable cost savings.
118745241
Status of Neutrino Physics Experiments
Relevant results from neutrino physics experiments since FPCP2009 with an emphasis on oscillations and the ability to measure or limit the mixing angle {theta}{sub 13}.
119445846
Comparison of inclusive particle production in 14.6 GeV/c proton-nucleus collisions with simulation
Inclusive charged pion, kaon, proton, and deuteron production in 14.6 GeV/c proton-nucleus collisions measured by BNL experiment E802 is compared with results from the GEANT3, GEANT4, and FLUKA simulation packages. The FLUKA package is found to have the best overall agreement.
14433479
Search for CP violation at CLEO
Abstract Recent results from CLEO on the search for CP violation in beauty and charm meson decays are reviewed.
197497757
LATEST RESULTS FROM MINOS.
Among the goals of the MINOS experiment are the test of the {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillation and the search for sub-dominant {nu}{sub {mu}} {yields} {nu}{sub {tau}} oscillations. The former proceeds by a {nu}{sub {mu}} ''disappearance'' analysis while the latter would involve the ''appearance'' of {nu}{sub e} interactions in a predominantly {nu}{sub {mu}} beam. The disappearance of muon neutrinos is described by P({nu}{sub {mu}} {yields} {mu}{sub {mu}}) = 1 - sin{sup 2} 2{theta}{sub 23} sin{sup 2} (1.27 {Delta} m{sub 23}{sup 2} L/E) in the two-flavor approximation where {theta}{sub 23} is the angle between the second row and third column of the neutrino mixing matrix, {Delta}m{sub 23}{sup 2} = m{sub 2}{sup 2}-m{sub 3}{sup 2} (eV{sup 2}), L is the neutrino flight distance in km and E is the neutrino energy in GeV. A generic disappearance experiment compares a measured muon neutrino energy spectrum at a fixed baseline to the known energy spectrum of muon neutrino beam to extract the oscillation parameters sin{sup 2} 2{theta} which controls the overall magnitude of the disappearance and {Delta}m{sup 2} which controls the energy dependence.
119491777
H2 Pure Rotational Lines in the Orion Bar
Photodissociation regions (PDRs), where UV radiation dominates the energetics and chemistry of the neutral gas, contain most of the mass in the dense interstellar medium of our Galaxy. Observations of H2 rotational and rovibrational lines reveal that PDRs contain unexpectedly large amounts of very warm (400-700 K) molecular gas. Theoretical models have difficulty explaining the existence of so much warm gas. Possible problems include errors in the heating and cooling functions or in the formation rate for H2. To date, observations of H2 rotational lines smear out the structure of the PDR. Only by resolving the hottest layers of H2 can one test the predictions and assumptions of current models. Using the Texas Echelon Cross Echelle Spectrograph (TEXES) we mapped emission in the H2 v = 0-0 S(1) and S(2) lines toward the Orion Bar PDR at 2'' resolution. We also observed H2 v = 0-0 S(4) at selected points toward the front of the PDR. Our maps cover a 12'' by 40'' region of the bar where H2 rovibrational lines are bright. The distributions of H2 0-0 S(1), 0-0 S(2), and 1-0 S(1) line emission agree in remarkable detail. The high spatial resolution (0.002 pc) of our observations allows us to probe the distribution of warm gas in the Orion Bar to a distance approaching the scale length for FUV photon absorption. We use these new observational results to set parameters for the PDR models described in a companion paper in preparation by Draine et al. The best-fit model can account for the separation of the H2 emission from the ionization front and the intensities of the ground-state rotational lines, as well as the 1-0 S(1) and 2-1 S(1) lines. This model requires significant adjustments to the commonly used values for the dust UV attenuation cross section and the photoelectric heating rate.
32952035
A Spitzer search for planetary-mass brown dwarfs with circumstellar disks: Candidate selection
We report on initial results from a Spitzer program to search for very low mass brown dwarfs in Ophiuchus. This program is an extension of an earlier study by Allers et al. which had resulted in an extraordinary success rate, 18 confirmed out of 19 candidates. Their program combined near-infrared and Spitzer photometry to identify objects with very cool photospheres together with circumstellar disk emission to indicate youth. Our new program has obtained deep IRAC photometry of a 0.5 deg 2 field that was part of the original Allers et al. study. We report 18 new candidates whose luminosities extend down to 10 −4 L� , which suggests masses down to ∼2 MJ if confirmed. We describe our
14365004
High-resolution observations of the near-infrared emission from NGC 6822 Hubble
We have observed Hubble V, the brightest H II region complex in the dwarf irregular galaxy NGC 6822, at near-infrared (near-IR; 1.8–2.4 μm) wavelengths. The line emission maps of Hubble V show the typical structure of a photodissociation region (PDR) where an ionized core, traced by compact He I emission (2.0587 μm) and Brγ emission (2.1661 μm), is surrounded by an outer layer traced by molecular hydrogen (H2) emission. The measured line ratios of H2 2– 1 S(1) (2.2477 μm)/1–0 S(1) (2.1218 μm) from 0.2 to 0.6 and the unshifted and unresolved line profiles suggest that the H2 emission originates purely from a PDR. We find no evidence for shock activity. By comparing the H2 results with a PDR model, we conclude that Hubble V includes dense (104.5 cm−3) and warm PDRs. In this environment, most of the H2 molecules are excited by far-ultraviolet photons (with a field strength of 102–4 times that of the average interstellar field), although collisional processes de-excite H2 and contribute significantly to the excitation of the first vibrational level. We expect that Hubble V is in the early stage of molecular cloud dissolution.
118394652
Dust, Ice, and Gas In Time (DIGIT) Herschel program first results A full PACS-SED scan of the gas line emission in protostar DK Chamaeleontis
Aims. We aim to study the composition and energetics of the circumstellar material of DK Cha, an intermediate-mass star in transition from an 
embedded configuration to a star plus disk stage, during this pivotal stage of its evolution. 
Methods. Using the range scan mode of PACS on the Herschel Space Observatory, we obtained a spectrum of DK Cha from 55 to 210 μm as part 
of the DIGIT key program. 
Results. Almost 50 molecular and atomic lines were detected, many more than the 7 lines detected in ISO-LWS. Nearly the entire ladder of CO 
from J = 14–13 to 38–37 (E_u/k = 4080 K), water from levels as excited as J_(K−1 K+1) = 7_(07) (E_u/k = 843 K), and OH lines up to E_u/k = 290 K were 
detected. 
Conclusions. The continuum emission in our PACS SED scan matches the flux expected by a model consisting of a star, a surrounding disk of 
0.03 M_⊙, and an envelope of a similar mass, supporting the suggestion that the object is emerging from its main accretion stage. Molecular, atomic, 
and ionic emission lines in the far-infrared reveal the outflow’s influence on the envelope. The inferred hot gas may be photon-heated, but some 
emission may be caused by C-shocks in the walls of the outflow cavity.
119456805
Extended CO(7-6) emission from warm gas in Orion
We mapped the quiescent emission from the 807 GHz J=7→6 transition of CO in Orion along a strip in R.A. extending from 0.7 pc west to 1.2 pc east of θ 1 C Orionis. The lines arise in warm gas with temperatures greater than 40 K. The line brightness temperature is greater than 160 K in the direction of θ 1 C, more than twice the dust temperature, and still exceeds 35 K more than a parsec east of θ 1 C. The lines are narrow, with a maximum velocity width of 7 km s -1 near θ 1 C and decreasing to 1.5-3 km s -1 at the map boundaries