339 research outputs found

    Fermi Gamma-ray Imaging of a Radio Galaxy

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    The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved gamma-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy gamma-rays, the lobe flux constitutes a considerable portion (>1/2) of the total source emission. The gamma-ray emission from the lobes is interpreted as inverse Compton scattered relic radiation from the cosmic microwave background (CMB), with additional contribution at higher energies from the infrared-to-optical extragalactic background light (EBL). These measurements provide gamma-ray constraints on the magnetic field and particle energy content in radio galaxy lobes, and a promising method to probe the cosmic relic photon fields.Comment: 27 pages, includes Supplementary Online Material; corresponding authors: C.C. Cheung, Y. Fukazawa, J. Knodlseder, L. Stawar

    A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279

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    It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. The size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. Here we report the coincidence of a gamma-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and gamma-ray emission regions and indicates a highly ordered jet magnetic field. The results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 10^5 gravitational radii.Comment: Published in Nature issued on 18 February 2010. Corresponding authors: Masaaki Hayashida and Greg Madejsk

    Fermi Large Area Telescope observations of PSR J1836+5925

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    The discovery of the gamma-ray pulsar PSR J1836+5925, powering the formerly unidentified EGRET source 3EG J1835+5918, was one of the early accomplishments of the Fermi Large Area Telescope (LAT). Sitting 25 degrees off the Galactic plane, PSR J1836+5925 is a 173 ms pulsar with a characteristic age of 1.8 million years, a spindown luminosity of 1.1×1034\times10^{34} erg s1^{-1}, and a large off-peak emission component, making it quite unusual among the known gamma-ray pulsar population. We present an analysis of one year of LAT data, including an updated timing solution, detailed spectral results and a long-term light curve showing no indication of variability. No evidence for a surrounding pulsar wind nebula is seen and the spectral characteristics of the off-peak emission indicate it is likely magnetospheric. Analysis of recent XMM observations of the X-ray counterpart yields a detailed characterization of its spectrum, which, like Geminga, is consistent with that of a neutron star showing evidence for both magnetospheric and thermal emission.Comment: Accepted to Astrophysical Journa

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Primary sensory and motor cortex excitability are co-modulated in response to peripheral electrical nerve stimulation

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    Peripheral electrical stimulation (PES) is a common clinical technique known to induce changes in corticomotor excitability; PES applied to induce a tetanic motor contraction increases, and PES at sub-motor threshold (sensory) intensities decreases, corticomotor excitability. Understanding of the mechanisms underlying these opposite changes in corticomotor excitability remains elusive. Modulation of primary sensory cortex (S1) excitability could underlie altered corticomotor excitability with PES. Here we examined whether changes in primary sensory (S1) and motor (M1) cortex excitability follow the same timecourse when PES is applied using identical stimulus parameters. Corticomotor excitability was measured using transcranial magnetic stimulation (TMS) and sensory cortex excitability using somatosensory evoked potentials (SEPs) before and after 30 min of PES to right abductor pollicis brevis (APB). Two PES paradigms were tested in separate sessions; PES sufficient to induce a tetanic motor contraction (30–50 Hz; strong motor intensity) and PES at sub motor-threshold intensity (100 Hz). PES applied to induce strong activation of APB increased the size of the N20-P25 component, thought to reflect sensory processing at cortical level, and increased corticomotor excitability. PES at sensory intensity decreased the size of the P25-N33 component and reduced corticomotor excitability. A positive correlation was observed between the changes in amplitude of the cortical SEP components and corticomotor excitability following sensory and motor PES. Sensory PES also increased the sub-cortical P14-N20 SEP component. These findings provide evidence that PES results in co-modulation of S1 and M1 excitability, possibly due to cortico-cortical projections between S1 and M1. This mechanism may underpin changes in corticomotor excitability in response to afferent input generated by PES.Siobhan M. Schabrun, Michael C. Ridding, Mary P. Galea, Paul W. Hodges and Lucinda S. Chipchas

    Diffractive Dijet Production at s = 630 and 1800 GeV at the Fermilab Tevatron

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    We report a measurement of the diffractive structure function F-jj(D) of the antiproton obtained from a study of dijet events produced in association with a leading antiproton in (p) over barp collisions at roots = 630 GeV at the Fermilab Tevatron. The ratio of F-jj(D) at roots = 630 GeV to F-jj(D) obtained from a similar measurement at roots = 1800 GeV is compared with expectations from QCD factorization and other theoretical predictions. We also report a measurement of the xi (x-Pomeron) and beta (x of parton in Pomeron) dependence of F-jj(D) at roots = 1800 GeV . In the region 0.035 < &xi; < 0.095 , \t\ < 1 GeV2 , and &beta; < 0.5 , F-jj(D)(beta, xi) is found to be of the form beta(-1.0+/-0.1) xi(-0.9+/-0. 1) , which obeys beta-xi factorization

    Direct CP violation searches in charmless hadronic B meson decays

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    This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSWe search for direct CP violation in charmless hadronic B decays observed in a sample of about 22.7 million BB̅ pairs collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- collider. We measure the following charge asymmetries: ACP(B±→η′K±)=-0.11±0.11±0.02, ACP(B±→ωπ±)=-0.01 - 0.31 + 0.29±0.03, ACP(B±→φK±)=-0.05±0.20±0.03, ACP(B±→φK*±)=-0.43 - 0.30 + 0.36±0.06, and ACP(B0→φK*0)=0.00±0.27±0.03.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

    Volume III. DUNE far detector technical coordination

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    open966siAcknowledgments This document was prepared by the DUNE collaboration using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. The DUNE collaboration also acknowledges the international, national, and regional funding agencies supporting the institutions who have contributed to completing this Technical Design Report.The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay-these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- A nd dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module.openAbi B.; Acciarri R.; Acero M.A.; Adamov G.; Adams D.; Adinolfi M.; Ahmad Z.; Ahmed J.; Alion T.; Monsalve S.A.; Alt C.; Anderson J.; Andreopoulos C.; Andrews M.; Andrianala F.; Andringa S.; Ankowski A.; Antonova M.; Antusch S.; Aranda-Fernandez A.; Ariga A.; Arnold L.O.; Arroyave M.A.; Asaadi J.; Aurisano A.; Aushev V.; Autiero D.; Azfar F.; Back H.; Back J.J.; Backhouse C.; Baesso P.; Bagby L.; Bajou R.; Balasubramanian S.; Baldi P.; Bambah B.; Barao F.; Barenboim G.; Barker G.; Barkhouse W.; Barnes C.; Barr G.; Monarca J.B.; Barros N.; Barrow J.L.; Bashyal A.; Basque V.; Bay F.; Alba J.B.; Beacom J.F.; Bechetoille E.; Behera B.; Bellantoni L.; Bellettini G.; Bellini V.; Beltramello O.; Belver D.; Benekos N.; Neves F.B.; Berger J.; Berkman S.; Bernardini P.; Berner R.M.; Berns H.; Bertolucci S.; Betancourt M.; Bezawada Y.; Bhattacharjee M.; Bhuyan B.; Biagi S.; Bian J.; Biassoni M.; Biery K.; Bilki B.; Bishai M.; Bitadze A.; Blake A.; Siffert B.B.; Blaszczyk F.; Blazey G.; Blucher E.; Boissevain J.; Bolognesi S.; Bolton T.; Bonesini M.; Bongrand M.; Bonini F.; Booth A.; Booth C.; Bordoni S.; Borkum A.; Boschi T.; Bostan N.; Bour P.; Boyd S.; Boyden D.; Bracinik J.; Braga D.; Brailsford D.; Brandt A.; Bremer J.; Brew C.; Brianne E.; Brice S.J.; Brizzolari C.; Bromberg C.; Brooijmans G.; Brooke J.; Bross A.; Brunetti G.; Buchanan N.; Budd H.; Caiulo D.; Calafiura P.; Calcutt J.; Calin M.; Calvez S.; Calvo E.; Camilleri L.; Caminata A.; Campanelli M.; Caratelli D.; Carini G.; Carlus B.; Carniti P.; Terrazas I.C.; Carranza H.; Castillo A.; Castromonte C.; Cattadori C.; Cavalier F.; Cavanna F.; Centro S.; Cerati G.; Cervelli A.; Villanueva A.C.; Chalifour M.; Chang C.; Chardonnet E.; Chatterjee A.; Chattopadhyay S.; Chaves J.; Chen H.; Chen M.; Chen Y.; Cherdack D.; Chi C.; Childress S.; Chiriacescu A.; Cho K.; Choubey S.; Christensen A.; Christian D.; Christodoulou G.; Church E.; Clarke P.; Coan T.E.; Cocco A.G.; Coelho J.; Conley E.; Conrad J.; Convery M.; Corwin L.; Cotte P.; Cremaldi L.; Cremonesi L.; Crespo-Anadon J.I.; Cristaldo E.; Cross R.; Cuesta C.; Cui Y.; Cussans D.; Dabrowski M.; Motta H.D.; Peres L.D.S.; David Q.; Davies G.S.; Davini S.; Dawson J.; De K.; Almeida R.M.D.; Debbins P.; Bonis I.D.; Decowski M.; Gouvea A.D.; Holanda P.C.D.; Astiz I.L.D.I.; Deisting A.; Jong P.D.; Delbart A.; Delepine D.; Delgado M.; Dell'acqua A.; Lurgio P.D.; Neto J.R.D.M.; Demuth D.M.; Dennis S.; Densham C.; Deptuch G.; Roeck A.D.; Romeri V.D.; Vries J.D.; Dharmapalan R.; Dias M.; Diaz F.; Diaz J.; Domizio S.D.; Giulio L.D.; Ding P.; Noto L.D.; Distefano C.; Diurba R.; Diwan M.; Djurcic Z.; Dokania N.; Dolinski M.; Domine L.; Douglas D.; Drielsma F.; Duchesneau D.; Duffy K.; Dunne P.; Durkin T.; Duyang H.; Dvornikov O.; Dwyer D.; Dyshkant A.; Eads M.; Edmunds D.; Eisch J.; Emery S.; Ereditato A.; Escobar C.; Sanchez L.E.; Evans J.J.; Ewart E.; Ezeribe A.C.; Fahey K.; Falcone A.; Farnese C.; Farzan Y.; Felix J.; Fernandez-Martinez E.; Menendez P.F.; Ferraro F.; Fields L.; Filkins A.; Filthaut F.; Fitzpatrick R.S.; Flanagan W.; Fleming B.; Flight R.; Fowler J.; Fox W.; Franc J.; Francis K.; Franco D.; Freeman J.; Freestone J.; Fried J.; Friedland A.; Fuess S.; Furic I.; Furmanski A.P.; Gago A.; Gallagher H.; Gallego-Ros A.; Gallice N.; Galymov V.; Gamberini E.; Gamble T.; Gandhi R.; Gandrajula R.; Gao S.; Garcia-Gamez D.; Garcia-Peris M.A.; Gardiner S.; Gastler D.; Ge G.; Gelli B.; Gendotti A.; Gent S.; Ghorbani-Moghaddam Z.; Gibin D.; Gil-Botella I.; Girerd C.; Giri A.; Gnani D.; Gogota O.; Gold M.; Gollapinni S.; Gollwitzer K.; Gomes R.A.; Bermeo L.G.; Fajardo L.S.G.; Gonnella F.; Gonzalez-Cuevas J.; Goodman M.C.; Goodwin O.; Goswami S.; Gotti C.; Goudzovski E.; Grace C.; Graham M.; Gramellini E.; Gran R.; Granados E.; Grant A.; Grant C.; Gratieri D.; Green P.; Green S.; Greenler L.; Greenwood M.; Greer J.; Griffith C.; Groh M.; Grudzinski J.; Grzelak K.; Gu W.; Guarino V.; Guenette R.; Guglielmi A.; Guo B.; Guthikonda K.; Gutierrez R.; Guzowski P.; Guzzo M.M.; Gwon S.; Habig A.; Hackenburg A.; Hadavand H.; Haenni R.; Hahn A.; Haigh J.; Haiston J.; Hamernik T.; Hamilton P.; Han J.; Harder K.; Harris D.A.; Hartnell J.; Hasegawa T.; Hatcher R.; Hazen E.; Heavey A.; Heeger K.M.; Hennessy K.; Henry S.; Morquecho M.H.; Herner K.; Hertel L.; Hesam A.S.; Hewes J.; Pichardo A.H.; Hill T.; Hillier S.J.; Himmel A.; Hoff J.; Hohl C.; Holin A.; Hoppe E.; Horton-Smith G.A.; Hostert M.; Hourlier A.; Howard B.; Howell R.; Huang J.; Huang J.; Hugon J.; Iles G.; Iliescu A.M.; Illingworth R.; Ioannisian A.; Itay R.; Izmaylov A.; James E.; Jargowsky B.; Jediny F.; Jesus-Valls C.; Ji X.; Jiang L.; Jimenez S.; Jipa A.; Joglekar A.; Johnson C.; Johnson R.; Jones B.; Jones S.; Jung C.; Junk T.; Jwa Y.; Kabirnezhad M.; Kaboth A.; Kadenko I.; Kamiya F.; Karagiorgi G.; Karcher A.; Karolak M.; Karyotakis Y.; Kasai S.; Kasetti S.P.; Kashur L.; Kazaryan N.; Kearns E.; Keener P.; Kelly K.J.; Kemp E.; Ketchum W.; Kettell S.; Khabibullin M.; Khotjantsev A.; Khvedelidze A.; Kim D.; King B.; Kirby B.; Kirby M.; Klein J.; Koehler K.; Koerner L.W.; Kohn S.; Koller P.P.; Kordosky M.; Kosc T.; Kose U.; Kostelecky V.; Kothekar K.; Krennrich F.; Kreslo I.; Kudenko Y.; Kudryavtsev V.; Kulagin S.; Kumar J.; Kumar R.; Kuruppu C.; Kus V.; Kutter T.; Lambert A.; Lande K.; Lane C.E.; Lang K.; Langford T.; Lasorak P.; Last D.; Lastoria C.; Laundrie A.; Lawrence A.; Lazanu I.; Lazur R.; Le T.; Learned J.; Lebrun P.; Miotto G.L.; Lehnert R.; De Oliveira M.L.; Leitner M.; Leyton M.; Li L.; Li S.; Li S.; Li T.; Li Y.; Liao H.; Lin C.; Lin S.; Lister A.; Littlejohn B.R.; Liu J.; Lockwitz S.; Loew T.; Lokajicek M.; Lomidze I.; Long K.; Loo K.; Lorca D.; Lord T.; Losecco J.; Louis W.C.; Luk K.; Luo X.; Lurkin N.; Lux T.; Luzio V.P.; MacFarland D.; MacHado A.; MacHado P.; MacIas C.; MacIer J.; Maddalena A.; Madigan P.; Magill S.; Mahn K.; Maio A.; Maloney J.A.; Mandrioli G.; Maneira J.C.; Manenti L.; Manly S.; Mann A.; Manolopoulos K.; Plata M.M.; Marchionni A.; Marciano W.; Marfatia D.; Mariani C.; Maricic J.; Marinho F.; Marino A.D.; Marshak M.; Marshall C.; Marshall J.; Marteau J.; Martin-Albo J.; Martinez N.; Caicedo D.A.M.; Martynenko S.; Mason K.; Mastbaum A.; Masud M.; Matsuno S.; Matthews J.; Mauger C.; Mauri N.; Mavrokoridis K.; Mazza R.; Mazzacane A.; Mazzucato E.; McCluskey E.; McConkey N.; McFarland K.S.; McGrew C.; McNab A.; Mefodiev A.; Mehta P.; Melas P.; Mellinato M.; Mena O.; Menary S.; Mendez H.; Menegolli A.; Meng G.; Messier M.; Metcalf W.; Mewes M.; Meyer H.; Miao T.; Michna G.; Miedema T.; Migenda J.; Milincic R.; Miller W.; Mills J.; Milne C.; Mineev O.; Miranda O.G.; Miryala S.; Mishra C.; Mishra S.; Mislivec A.; Mladenov D.; Mocioiu I.; Moffat K.; Moggi N.; Mohanta R.; Mohayai T.A.; Mokhov N.; Molina J.A.; Bueno L.M.; Montanari A.; Montanari C.; Montanari D.; Zetina L.M.M.; Moon J.; Mooney M.; Moor A.; Moreno D.; Morgan B.; Morris C.; Mossey C.; Motuk E.; Moura C.A.; Mousseau J.; Mu W.; Mualem L.; Mueller J.; Muether M.; Mufson S.; Muheim F.; Muir A.; Mulhearn M.; Muramatsu H.; Murphy S.; Musser J.; Nachtman J.; Nagu S.; Nalbandyan M.; Nandakumar R.; Naples D.; Narita S.; Navas-Nicolas D.; Nayak N.; Nebot-Guinot M.; Necib L.; Negishi K.; Nelson J.K.; Nesbit J.; Nessi M.; Newbold D.; Newcomer M.; Newhart D.; Nichol R.; Niner E.; Nishimura K.; Norman A.; Northrop R.; Novella P.; Nowak J.A.; Oberling M.; Campo A.O.D.; Olivier A.; Onel Y.; Onishchuk Y.; Ott J.; Pagani L.; Pakvasa S.; Palamara O.; Palestini S.; Paley J.M.; Pallavicini M.; Palomares C.; Pantic E.; Paolone V.; Papadimitriou V.; Papaleo R.; Papanestis A.; Paramesvaran S.; Parke S.; Parsa Z.; Parvu M.; Pascoli S.; Pasqualini L.; Pasternak J.; Pater J.; Patrick C.; Patrizii L.; Patterson R.B.; Patton S.; Patzak T.; Paudel A.; Paulos B.; Paulucci L.; Pavlovic Z.; Pawloski G.; Payne D.; Pec V.; Peeters S.J.; Penichot Y.; Pennacchio E.; Penzo A.; Peres O.L.; Perry J.; Pershey D.; Pessina G.; Petrillo G.; Petta C.; Petti R.; Piastra F.; Pickering L.; Pietropaolo F.; Pillow J.; Plunkett R.; Poling R.; Pons X.; Poonthottathil N.; Pordes S.; Potekhin M.; Potenza R.; Potukuchi B.V.; Pozimski J.; Pozzato M.; Prakash S.; Prakash T.; Prince S.; Prior G.; Pugnere D.; Qi K.; Qian X.; Raaf J.; Raboanary R.; Radeka V.; Rademacker J.; Radics B.; Rafique A.; Raguzin E.; Rai M.; Rajaoalisoa M.; Rakhno I.; Rakotondramanana H.; Rakotondravohitra L.; Ramachers Y.; Rameika R.; Delgado M.R.; Ramson B.; Rappoldi A.; Raselli G.; Ratoff P.; Ravat S.; Razafinime H.; Real J.; Rebel B.; Redondo D.; Reggiani-Guzzo M.; Rehak T.; Reichenbacher J.; Reitzner S.D.; Renshaw A.; Rescia S.; Resnati F.; Reynolds A.; Riccobene G.; Rice L.C.; Rielage K.; Rigaut Y.; Rivera D.; Rochester L.; Roda M.; Rodrigues P.; Alonso M.R.; Rondon J.R.; Roeth A.; Rogers H.; Rosauro-Alcaraz S.; Rossella M.; Rout J.; Roy S.; Rubbia A.; Rubbia C.; Russell B.; Russell J.; Ruterbories D.; Saakyan R.; Sacerdoti S.; Safford T.; Sahu N.; Sala P.; Samios N.; Sanchez M.; Sanders D.A.; Sankey D.; Santana S.; Santos-Maldonado M.; Saoulidou N.; Sapienza P.; Sarasty C.; Sarcevic I.; Savage G.; Savinov V.; Scaramelli A.; Scarff A.; Scarpelli A.; Schaffer T.; Schellman H.; Schlabach P.; Schmitz D.; Scholberg K.; Schukraft A.; Segreto E.; Sensenig J.; Seong I.; Sergi A.; Sergiampietri F.; Sgalaberna D.; Shaevitz M.; Shafaq S.; Shamma M.; Sharma H.R.; Sharma R.; Shaw T.; Shepherd-Themistocleous C.; Shin S.; Shooltz D.; Shrock R.; Simard L.; Simos N.; Sinclair J.; Sinev G.; Singh J.; Singh V.; Sipos R.; Sippach F.; Sirri G.; Sitraka A.; Siyeon K.; Smargianaki D.; Smith A.; Smith A.; Smith E.; Smith P.; Smolik J.; Smy M.; Snopok P.; Nunes M.S.; Sobel H.; Soderberg M.; Salinas C.J.S.; Soldner-Rembold S.; Solomey N.; Solovov V.; Sondheim W.E.; Sorel M.; Soto-Oton J.; Sousa A.; Soustruznik K.; Spagliardi F.; Spanu M.; Spitz J.; Spooner N.J.; Spurgeon K.; Staley R.; Stancari M.; Stanco L.; Steiner H.; Stewart J.; Stillwell B.; Stock J.; Stocker F.; Stokes T.; Strait M.; Strauss T.; Striganov S.; Stuart A.; Summers D.; Surdo A.; Susic V.; Suter L.; Sutera C.; Svoboda R.; Szczerbinska B.; Szelc A.; Talaga R.; Tanaka H.; Oregui B.T.; Tapper A.; Tariq S.; Tatar E.; Tayloe R.; Teklu A.; Tenti M.; Terao K.; Ternes C.A.; Terranova F.; Testera G.; Thea A.; Thompson J.L.; Thorn C.; Timm S.; Tonazzo A.; Torti M.; Tortola M.; Tortorici F.; Totani D.; Toups M.; Touramanis C.; Trevor J.; Trzaska W.H.; Tsai Y.T.; Tsamalaidze Z.; Tsang K.; Tsverava N.; Tufanli S.; Tull C.; Tyley E.; Tzanov M.; Uchida M.A.; Urheim J.; Usher T.; Vagins M.; Vahle P.; Valdiviesso G.; Valencia E.; Vallari Z.; Valle J.W.; Vallecorsa S.; Berg R.V.; De Water R.G.V.; Forero D.V.; Varanini F.; Vargas D.; Varner G.; Vasel J.; Vasseur G.; Vaziri K.; Ventura S.; Verdugo A.; Vergani S.; Vermeulen M.A.; Verzocchi M.; De Souza H.V.; Vignoli C.; Vilela C.; Viren B.; Vrba T.; Wachala T.; Waldron A.V.; Wallbank M.; Wang H.; Wang J.; Wang Y.; Wang Y.; Warburton K.; Warner D.; Wascko M.; Waters D.; Watson A.; Weatherly P.; Weber A.; Weber M.; Wei H.; Weinstein A.; Wenman D.; Wetstein M.; While M.R.; White A.; Whitehead L.H.; Whittington D.; Wilking M.J.; Wilkinson C.; Williams Z.; Wilson F.; Wilson R.J.; Wolcott J.; Wongjirad T.; Wood K.; Wood L.; Worcester E.; Worcester M.; Wret C.; Wu W.; Wu W.; Xiao Y.; Yang G.; Yang T.; Yershov N.; Yonehara K.; Young T.; Yu B.; Yu J.; Zalesak J.; Zambelli L.; Zamorano B.; Zani A.; Zazueta L.; Zeller G.; Zennamo J.; Zeug K.; Zhang C.; Zhao M.; Zhivun E.; Zhu G.; Zimmerman E.D.; Zito M.; Zucchelli S.; Zuklin J.; Zutshi V.; Zwaska R.Abi B.; Acciarri R.; Acero M.A.; Adamov G.; Adams D.; Adinolfi M.; Ahmad Z.; Ahmed J.; Alion T.; Monsalve S.A.; Alt C.; Anderson J.; Andreopoulos C.; Andrews M.; Andrianala F.; Andringa S.; Ankowski A.; Antonova M.; Antusch S.; Aranda-Fernandez A.; Ariga A.; Arnold L.O.; Arroyave M.A.; Asaadi J.; Aurisano A.; Aushev V.; Autiero D.; Azfar F.; Back H.; Back J.J.; Backhouse C.; Baesso P.; Bagby L.; Bajou R.; Balasubramanian S.; Baldi P.; Bambah B.; Barao F.; Barenboim G.; Barker G.; Barkhouse W.; Barnes C.; Barr G.; Monarca J.B.; Barros N.; Barrow J.L.; Bashyal A.; Basque V.; Bay F.; Alba J.B.; Beacom J.F.; Bechetoille E.; Behera B.; Bellantoni L.; Bellettini G.; Bellini V.; Beltramello O.; Belver D.; Benekos N.; Neves F.B.; Berger J.; Berkman S.; Bernardini P.; Berner R.M.; Berns H.; Bertolucci S.; Betancourt M.; Bezawada Y.; Bhattacharjee M.; Bhuyan B.; Biagi S.; Bian J.; Biassoni M.; Biery K.; Bilki B.; Bishai M.; Bitadze A.; Blake A.; Siffert B.B.; Blaszczyk F.; Blazey G.; Blucher E.; Boissevain J.; Bolognesi S.; Bolton T.; Bonesini M.; Bongrand M.; Bonini F.; Booth A.; Booth C.; Bordoni S.; Borkum A.; Boschi T.; Bostan N.; Bour P.; Boyd S.; Boyden D.; Bracinik J.; Braga D.; Brailsford D.; Brandt A.; Bremer J.; Brew C.; Brianne E.; Brice S.J.; Brizzolari C.; Bromberg C.; Brooijmans G.; Brooke J.; Bross A.; Brunetti G.; Buchanan N.; Budd H.; Caiulo D.; Calafiura P.; Calcutt J.; Calin M.; Calvez S.; Calvo E.; Camilleri L.; Caminata A.; Campanelli M.; Caratelli D.; Carini G.; Carlus B.; Carniti P.; Terrazas I.C.; Carranza H.; Castillo A.; Castromonte C.; Cattadori C.; Cavalier F.; Cavanna F.; Centro S.; Cerati G.; Cervelli A.; Villanueva A.C.; Chalifour M.; Chang C.; Chardonnet E.; Chatterjee A.; Chattopadhyay S.; Chaves J.; Chen H.; Chen M.; Chen Y.; Cherdack D.; Chi C.; Childress S.; Chiriacescu A.; Cho K.; Choubey S.; Christensen A.; Christian D.; Christodoulou G.; Church E.; Clarke P.; Coan T.E.; Cocco A.G.; Coelho J.; Conley E.; Conrad J.; Convery M.; Corwin L.; Cotte P.; Cremaldi L.; Cremonesi L.; Crespo-Anadon J.I.; Cristaldo E.; Cross R.; Cuesta C.; Cui Y.; Cussans D.; Dabrowski M.; Motta H.D.; Peres L.D.S.; David Q.; Davies G.S.; Davini S.; Dawson J.; De K.; Almeida R.M.D.; Debbins P.; Bonis I.D.; Decowski M.; Gouvea A.D.; Holanda P.C.D.; Astiz I.L.D.I.; Deisting A.; Jong P.D.; Delbart A.; Delepine D.; Delgado M.; 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    Measurement of the Ratio of b Quark Production Cross Sections in Antiproton-Proton Collisions at 630 GeV and 1800 GeV

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    We report a measurement of the ratio of the bottom quark production cross section in antiproton-proton collisions at 630 GeV to 1800 GeV using bottom quarks with transverse momenta greater than 10.75 GeV identified through their semileptonic decays and long lifetimes. The measured ratio sigma(630)/sigma(1800) = 0.171 +/- .024 +/- .012 is in good agreement with next-to-leading order (NLO) quantum chromodynamics (QCD)

    Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV

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    This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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