Search

Your search keyword '"Opper AK"' showing total 24 results
Start Over Author "Opper AK"
24 results on '"Opper AK"'

2. First determination of the weak charge of the proton.

Author

Androic D, Armstrong DS, Asaturyan A, Averett T, Balewski J, Beaufait J, Beminiwattha RS, Benesch J, Benmokhtar F, Birchall J, Carlini RD, Cates GD, Cornejo JC, Covrig S, Dalton MM, Davis CA, Deconinck W, Diefenbach J, Dowd JF, Dunne JA, Dutta D, Duvall WS, Elaasar M, Falk WR, Finn JM, Forest T, Gaskell D, Gericke MT, Grames J, Gray VM, Grimm K, Guo F, Hoskins JR, Johnston K, Jones D, Jones M, Jones R, Kargiantoulakis M, King PM, Korkmaz E, Kowalski S, Leacock J, Leckey J, Lee AR, Lee JH, Lee L, MacEwan S, Mack D, Magee JA, Mahurin R, Mammei J, Martin JW, McHugh MJ, Meekins D, Mei J, Michaels R, Micherdzinska A, Mkrtchyan A, Mkrtchyan H, Morgan N, Myers KE, Narayan A, Ndukum LZ, Nelyubin V, Nuruzzaman, van Oers WT, Opper AK, Page SA, Pan J, Paschke KD, Phillips SK, Pitt ML, Poelker M, Rajotte JF, Ramsay WD, Roche J, Sawatzky B, Seva T, Shabestari MH, Silwal R, Simicevic N, Smith GR, Solvignon P, Spayde DT, Subedi A, Subedi R, Suleiman R, Tadevosyan V, Tobias WA, Tvaskis V, Waidyawansa B, Wang P, Wells SP, Wood SA, Yang S, Young RD, and Zhamkochyan S

Abstract

The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 μA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in ep scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p)(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of Q(W)(p)(SM)=0.0710±0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be Q(W)(n)(PVES+APV)=-0.975±0.010.

Published
2013
Full Text
View/download PDF

3. New measurements of high-momentum nucleons and short-range structures in nuclei.

Author

Fomin N, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Daniel A, Day DB, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Gaskell D, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Mkrtchyan H, Navasardyan T, Niculescu G, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Seely J, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data also include the kinematic region where three-nucleon correlations are expected to dominate.

Published
2012
Full Text
View/download PDF

4. Scaling of the F2 structure function in nuclei and quark distributions at x>1.

Author

Fomin N, Arrington J, Day DB, Gaskell D, Daniel A, Seely J, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Chudakov E, Clasie B, Connell SH, Dalton MM, Dutta D, Ent R, El Fassi L, Fenker H, Filippone BW, Garrow K, Hill C, Holt RJ, Horn T, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lindgren R, Lung AF, Malace S, Markowitz P, McKee P, Meekins DG, Miyoshi T, Mkrtchyan H, Navasardyan T, Niculescu G, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Solvignon P, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wasko C, Wesselmann FR, Wood SA, Wright J, and Zheng X

Abstract

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 "superfast" quarks probed at x>1. The falloff at x>1 is noticeably stronger in 2H and 3He, but nearly identical for all heavier nuclei.

Published
2010
Full Text
View/download PDF

5. New measurements of the European Muon Collaboration effect in very light nuclei.

Author

Seely J, Daniel A, Gaskell D, Arrington J, Fomin N, Solvignon P, Asaturyan R, Benmokhtar F, Boeglin W, Boillat B, Bosted P, Bruell A, Bukhari MH, Christy ME, Clasie B, Connell S, Dalton MM, Day D, Dunne J, Dutta D, El Fassi L, Ent R, Fenker H, Filippone BW, Gao H, Hill C, Holt RJ, Horn T, Hungerford E, Jones MK, Jourdan J, Kalantarians N, Keppel CE, Kiselev D, Kotulla M, Lee C, Lung AF, Malace S, Meekins DG, Mertens T, Mkrtchyan H, Navasardyan T, Niculescu G, Niculescu I, Nomura H, Okayasu Y, Opper AK, Perdrisat C, Potterveld DH, Punjabi V, Qian X, Reimer PE, Roche J, Rodriguez VM, Rondon O, Schulte E, Segbefia E, Slifer K, Smith GR, Tadevosyan V, Tajima S, Tang L, Testa G, Trojer R, Tvaskis V, Vulcan WF, Wesselmann FR, Wood SA, Wright J, Yuan L, and Zheng X

Abstract

New Jefferson Lab data are presented on the nuclear dependence of the inclusive cross section from (2)H, (3)He, (4)He, (9)Be and (12)C for 0.3 < x < 0.9, Q(2) approximately 3-6 GeV(2). These data represent the first measurement of the EMC effect for (3)He at large x and a significant improvement for (4)He. The data do not support previous A-dependent or density-dependent fits to the EMC effect and suggest that the nuclear dependence of the quark distributions may depend on the local nuclear environment.

Published
2009
Full Text
View/download PDF

6. Measurement of nuclear transparency for the A(e,e'pi+) reaction.

Author

Clasie B, Qian X, Arrington J, Asaturyan R, Benmokhtar F, Boeglin W, Bosted P, Bruell A, Christy ME, Chudakov E, Cosyn W, Dalton MM, Daniel A, Day D, Dutta D, El Fassi L, Ent R, Fenker HC, Ferrer J, Fomin N, Gao H, Garrow K, Gaskell D, Gray C, Horn T, Huber GM, Jones MK, Kalantarians N, Keppel CE, Kramer K, Larson A, Li Y, Liang Y, Lung AF, Malace S, Markowitz P, Matsumura A, Meekins DG, Mertens T, Miller GA, Miyoshi T, Mkrtchyan H, Monson R, Navasardyan T, Niculescu G, Niculescu I, Okayasu Y, Opper AK, Perdrisat C, Punjabi V, Rauf AW, Rodriquez VM, Rohe D, Ryckebusch J, Seely J, Segbefia E, Smith GR, Strikman M, Sumihama M, Tadevosyan V, Tang L, Tvaskis V, Villano A, Vulcan WF, Wesselmann FR, Wood SA, Yuan L, and Zheng XC

Abstract

We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Published
2007
Full Text
View/download PDF

7. Onset of quark-hadron duality in pion electroproduction.

Author

Navasardyan T, Adams GS, Ahmidouch A, Angelescu T, Arrington J, Asaturyan R, Baker OK, Benmouna N, Bertoncini C, Blok HP, Boeglin WU, Bosted PE, Breuer H, Christy ME, Connell SH, Cui Y, Dalton MM, Danagoulian S, Day D, Dodario T, Dunne JA, Dutta D, El Khayari N, Ent R, Fenker HC, Frolov VV, Gan L, Gaskell D, Hafidi K, Hinton W, Holt RJ, Horn T, Huber GM, Hungerford E, Jiang X, Jones M, Joo K, Kalantarians N, Kelly JJ, Keppel CE, Kubarovski V, Li Y, Liang Y, Malace S, Markowitz P, McGrath E, McKee P, Meekins DG, Mkrtchyan H, Moziak B, Niculescu G, Niculescu I, Opper AK, Ostapenko T, Reimer P, Reinhold J, Roche J, Rock SE, Schulte E, Segbefia E, Smith C, Smith GR, Stoler P, Tadevosyan V, Tang L, Ungaro M, Uzzle A, Vidakovic S, Villano A, Vulcan WF, Wang M, Warren G, Wesselmann F, Wojtsekhowski B, Wood SA, Xu C, Yuan L, Zheng X, and Zhu H

Abstract

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.

Published
2007
Full Text
View/download PDF

8. Observation of an exotic baryon with S=+1 in photoproduction from the proton.

Author

Kubarovsky V, Guo L, Weygand DP, Stoler P, Battaglieri M, DeVita R, Adams G, Li J, Nozar M, Salgado C, Ambrozewicz P, Anciant E, Anghinolfi M, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow S, Beard K, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Butuceanu C, Calarco JR, Carman DS, Carnahan B, Cetina C, Chen S, Ciciani L, Cole PL, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Dharmawardane KV, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Eugenio P, Farhi L, Fatemi R, Feuerbach RJ, Ficenec J, Forest TA, Frolov V, Funsten H, Gaff SJ, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girard P, Gothe R, Gordon CI, Griffioen K, Guidal M, Guillo M, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hancock D, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Holtrop M, Hu J, Ilieva Y, Ito MM, Jenkins D, Joo K, Juengst HG, Kelley JH, Khandaker M, Kim KY, Kim K, Kim W, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Longhi A, Lukashin K, Major RW, Manak JJ, Marchand C, McAleer S, McNabb JW, Mecking BA, Mehrabyan S, Melone JJ, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, O'Brien JT, O'Rielly GV, Opper AK, Osipenko M, Park K, Pasyuk E, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Santoro JP, Sapunenko V, Sargsyan M, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Strakovsky II, Strauch S, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weisberg A, Whisnant CS, Wolin E, Wood MH, Yegneswaran A, and Yun J

Abstract

The reaction gamma p-->pi(+)K(-)K(+)n was studied at Jefferson Laboratory using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state with strangeness S=+1 and mass M=1555+/-10 MeV/c(2) was observed in the nK(+) invariant mass spectrum. The peak's width is consistent with the CLAS resolution (FWHM=26 MeV/c(2)), and its statistical significance is (7.8+/-1.0)sigma. A baryon with positive strangeness has exotic structure and cannot be described in the framework of the naive constituent quark model. The mass of the observed state is consistent with the mass predicted by the chiral soliton model for the Theta(+) baryon. In addition, the pK(+) invariant mass distribution was analyzed in the reaction gamma p-->K(-)K(+)p with high statistics in search of doubly charged exotic baryon states. No resonance structures were found in this spectrum.

Published
2004
Full Text
View/download PDF

9. Observation of an exotic S = +1 baryon in exclusive photoproduction from the deuteron.

Author

Stepanyan S, Hicks K, Carman DS, Pasyuk E, Schumacher RA, Smith ES, Tedeschi DJ, Todor L, Adams G, Ambrozewicz P, Anciant E, Anghinolfi M, Asavapibhop B, Audit G, Avakian H, Bagdasaryan H, Ball JP, Barrow SP, Battaglieri M, Beard K, Bektasoglu M, Bellis M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Butuceanu C, Calarco JR, Carnahan B, Chen S, Ciciani L, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, De Vita R, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Feuerbach RJ, Ficenec J, Forest TA, Funsten H, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Gordon CI, Gothe R, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ito MM, Jenkins D, Joo K, Juengst HG, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kubarovsky V, Kuhn SE, Kuhn J, Lachniet J, Lawrence D, Li J, Lima A, Livingston K, Lukashin K, Manak JJ, McAleer S, McNabb JW, Mecking BA, Mehrabyan S, Melone JJ, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow S, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Brien J, O'Rielly GV, Opper AK, Osipenko M, Park K, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin P, Sabatié F, Salgado C, Santoro J, Sapunenko V, Serov VS, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith LC, Sober DI, Strakovsky II, Stavinsky A, Stoler P, Suleiman R, Taiuti M, Taylor S, Thoma U, Thompson R, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood MH, Yegneswaran A, and Yun J

Abstract

In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K(+)n invariant mass spectrum. The peak is at 1.542+/-0.005 GeV/c(2) with a measured width of 0.021 GeV/c(2) FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2+/-0.6)sigma. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups.

Published
2003
Full Text
View/download PDF

10. Charge symmetry breaking in np-->dpi(0).

Author

Opper AK, Korkmaz E, Hutcheon DA, Abegg R, Davis CA, Finlay RW, Green PW, Greeniaus LG, Jordan DV, Niskanen JA, O'Rielly GV, Porcelli TA, Reitzner SD, Walden PL, and Yen S

Abstract

The forward-backward asymmetry in np-->dpi(0), which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2+/-8.0(stat)+/-5.5(syst)]x10(-4), at an incident neutron energy of 279.5 MeV. This observable is compared to recent chiral effective field theory calculations, with implications regarding the du quark mass difference.

Published
2003
Full Text
View/download PDF

11. Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2.

Author

Madey R, Semenov AY, Taylor S, Plaster B, Aghalaryan A, Crouse E, MacLachlan G, Tajima S, Tireman W, Yan C, Ahmidouch A, Anderson BD, Arenhövel H, Asaturyan R, Baker OK, Baldwin AR, Barkhuff D, Breuer H, Carlini R, Christy E, Churchwell S, Cole L, Danagoulian S, Day D, Eden T, Elaasar M, Ent R, Farkhondeh M, Fenker H, Finn JM, Gan L, Garrow K, Gasparian A, Gueye P, Howell CR, Hu B, Jones MK, Kelly JJ, Keppel C, Khandaker M, Kim WY, Kowalski S, Lai A, Lung A, Mack D, Manley DM, Markowitz P, Mitchell J, Mkrtchyan H, Opper AK, Perdrisat C, Punjabi V, Raue B, Reichelt T, Reinhold J, Roche J, Sato Y, Savvinov N, Semenova IA, Seo W, Simicevic N, Smith G, Stepanyan S, Tadevosyan V, Tang L, Ulmer PE, Vulcan W, Watson JW, Wells S, Wesselmann F, Wood S, Yan C, Yang S, Yuan L, Zhang WM, Zhu H, and Zhu X

Abstract

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Published
2003
Full Text
View/download PDF

12. Measurement of ep-->e' ppi+ pi- and baryon resonance analysis.

Author

Ripani M, Burkert VD, Mokeev V, Battaglieri M, De Vita R, Golovach E, Taiuti M, Adams G, Anciant E, Anghinolfi M, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow S, Beard K, Bektasoglu M, Bellis M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Calarco JR, Carman DS, Carnahan B, Cazes A, Cetina C, Ciciani L, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Dharmawardane KV, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Fatemi R, Fedotov G, Feldman G, Feuerbach RJ, Ficenec J, Forest TA, Funsten H, Gaff SJ, Gai M, Garçon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ishkhanov B, Ito MM, Jenkins D, Joo K, Kelley JH, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Lukashin K, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Rielly GV, Opper AK, Osipenko M, Park K, Pasyuk E, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Quinn B, Raue BA, Riccardi G, Ricco G, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith ES, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Strakovsky II, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood MH, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

The cross section for the reaction ep-->e(')ppi(+)pi(-) was measured in the resonance region for 1.4

Published
2003
Full Text
View/download PDF

13. First measurement of transferred polarization in the exclusive ep-->e'K+Lambda--> reaction.

Author

Carman DS, Joo K, Mestayer MD, Raue BA, Adams G, Ambrozewicz P, Anciant E, Anghinolfi M, Armstrong DS, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow SP, Battaglieri M, Beard K, Bektasoglu M, Bellis M, Bennhold C, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Butuceanu C, Calarco JR, Carnahan B, Cazes A, Cetina C, Ciciani L, Clark R, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Denizli H, Dennis L, DeVita R, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Feuerbach RJ, Ficenec J, Forest TA, Funsten H, Gaff SJ, Gai M, Garçon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Golovach E, Gordon CI, Griffioen K, Grimes S, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ishkhanov B, Ito MM, Jenkins D, Kelley JH, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Lukashin K, Manak JJ, Marchand C, Mart T, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mehrabyan S, Melone JJ, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Rielly GV, Opper AK, Osipenko M, Park K, Paschke K, Pasyuk E, Peterson G, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin P, Sabatié F, Sabourov K, Salgado C, Santoro J, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith ES, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood MH, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

The first measurements of the transferred polarization for the exclusive e-->p-->e(')K+Lambda--> reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q2 from 0.3 to 1.5 (GeV/c)(2), W from 1.6 to 2.15 GeV, and over the full K+ center-of-mass angular range. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A nonrelativistic quark-model interpretation of our data suggests that the ssmacr; quark pair is produced with spins predominantly antialigned. Implications for the validity of the most widely used quark-pair creation operator are discussed.

Published
2003
Full Text
View/download PDF

14. Photoproduction of the omega meson on the proton at large momentum transfer.

Author

Battaglieri M, Brunoldi M, De Vita R, Laget JM, Osipenko M, Ripani M, Taiuti M, Adams G, Amaryan MJ, Anciant E, Anghinolfi M, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Barrow S, Beard K, Bektasoglu M, Berman BL, Bersani A, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Cetina C, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Feuerbach RJ, Ficenec J, Forest TA, Freyberger AP, Frolov V, Funsten H, Gaff SJ, Gai M, Garcon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Golovach E, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Joo K, Kelley JH, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lachniet J, Lawrence D, Lucas M, Lukashin K, Major RW, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Morrow S, Mozer MU, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niccolai S, Niczyporuk BB, Niyazov RA, Nozar M, O'Brien JT, Opper AK, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabourov K, Salgado C, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taylor S, Tedeschi DJ, Todor L, Thoma U, Thompson R, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood M, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

The differential cross section, dsigma/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.6

Published
2003
Full Text
View/download PDF

15. Eta photoproduction on the proton for photon energies from 0.75 to 1.95 GeV.

Author

Dugger M, Ritchie BG, Ball J, Pasyuk E, Adams G, Anciant E, Anghinolfi M, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Barrow S, Battaglieri M, Beard K, Bektasoglu M, Bellis M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cetina C, Clark R, Cole PL, Coleman A, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, DeVita R, Degtyarenko PV, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Fatemi R, Feldman G, Feuerbach RJ, Ficenec J, Forest TA, Frolov V, Funsten H, Gaff SJ, Gai M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Gordon CI, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Jenkins D, Joo K, Kelley JH, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Koubarovski V, Kramer LH, Kuang Y, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Lucas M, Lukashin K, Major W, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mehrabyan S, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Brien JT, O'Rielly GV, Opper AK, Park K, Peterson G, Philips SA, Pivnyuk N, Pocanić D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Salgado C, Santoro JP, Sanzone-Arenhovel M, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Strakovsky II, Strauch S, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Witkowski M, Wolin E, Wood MH, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

Differential cross sections for gammap-->etap have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W=1.75 GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass approximately 1.8 GeV couples to the etaN channel.

Published
2002
Full Text
View/download PDF

16. First measurement of the double spin asymmetry in (-->)e(-->)p-->e(prime)pi(+)n in the resonance region.

Author

De Vita R, Anghinolfi M, Burkert VD, Dodge GE, Minehart R, Taiuti M, Weller H, Adams G, Amaryan MJ, Anciant E, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow S, Battaglieri M, Beard K, Bektasoglu M, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Bosted P, Bouchigny S, Branford D, Brooks WK, Bueltmann S, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Ciciani L, Cole PL, Coleman A, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Farhi L, Fatemi R, Feuerbach RJ, Ficenec J, Forest TA, Frolov V, Funsten H, Gaff SJ, Gai M, Garçon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Golovatch E, Griffioen K, Guidal M, Guillo M, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ishkanov BS, Ito MM, Jenkins D, Joo K, Kelley JH, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Loukachine K, Lucas M, Major W, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Opper AK, O'Rielly GV, Osipenko M, Park K, Pasyuk E, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ripani M, Ritchie BG, Rock S, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Salgado C, Sapunenko V, Sargsyan M, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Sorrell L, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Strakovsky II, Taylor S, Tedeschi DJ, Thompson R, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weisberg A, Weygand DP, Whisnant CS, Wolin E, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data.

Published
2002
Full Text
View/download PDF

17. Photoproduction of the rho(0) meson on the proton at large momentum transfer.

Author

Battaglieri M, Anciant E, Anghinolfi M, De Vita R, Golovach E, Laget JM, Mokeev V, Ripani M, Adams G, Amaryan MJ, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Barrow S, Beard K, Bektasoglu M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Cetina C, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Feuerbach RJ, Ficenec J, Forest TA, Freyberger AP, Frolov V, Funsten H, Gaff SJ, Gai M, Gilad S, Gilfoyle GP, Giovanetti KL, Griffioen K, Guidal M, Guillo M, Gyurjyan V, Hancock D, Hardie J, Heddle D, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Joo K, Kelley JH, Khandaker M, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lawrence D, Lucas M, Lukashin K, Major RW, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niczyporuk BB, Niyazov RA, O'Brien JT, Opper AK, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabourov K, Salgado C, Sanzone-Arenhovel M, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taiuti M, Taylor S, Tedeschi DJ, Todor L, Thompson R, Vineyard MF, Vlassov AV, Weinstein LB, Weisberg A, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood M, Yegneswaran A, Yun J, Zhang B, Zhao J, and Zhou Z

Abstract

The differential cross section, d sigma/dt, for rho(0) meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho(0) channel was extracted from the measured two charged-pion cross sections by fitting the pi(+)pi(-) and p pi(+) invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe rho photoproduction.

Published
2001
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results