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Baillie N, Tkachenko S, Zhang J, Bosted P, Bültmann S, Christy ME, Fenker H, Griffioen KA, Keppel CE, Kuhn SE, Melnitchouk W, Tvaskis V, Adhikari KP, Adikaram D, Aghasyan M, Amaryan MJ, Anghinolfi M, Arrington J, Avakian H, Baghdasaryan H, Battaglieri M, Biselli AS, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Carman DS, Celentano A, Chandavar S, Charles G, Cole PL, Contalbrigo M, Crede V, D'Angelo A, Daniel A, Dashyan N, De Vita R, De Sanctis E, Deur A, Dey B, Djalali C, Dodge G, Domingo J, Doughty D, Dupre R, Dutta D, Ent R, Egiyan H, El Alaoui A, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fegan S, Fradi A, Gabrielyan MY, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Girod FX, Gohn W, Golovatch E, Gothe RW, Graham L, Guegan B, Guidal M, Guler N, Guo L, Hafidi K, Heddle D, Hicks K, Holtrop M, Hungerford E, Hyde CE, Ilieva Y, Ireland DG, Ispiryan M, Isupov EL, Jawalkar SS, Jo HS, Kalantarians N, Khandaker M, Khetarpal P, Kim A, Kim W, King PM, Klein A, Klein FJ, Klimenko A, Kubarovsky V, Kuleshov SV, Kvaltine ND, Livingston K, Lu HY, MacGregor IJD, Mao Y, Markov N, McKinnon B, Mineeva T, Morrison B, Moutarde H, Munevar E, Nadel-Turonski P, Ni A, Niccolai S, Niculescu I, Niculescu G, Osipenko M, Ostrovidov AI, Pappalardo L, Park K, Park S, Pasyuk E, Anefalos Pereira S, Pisano S, Pozdniakov S, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Rimal D, Ripani M, Rosner G, Rossi P, Sabatié F, Saini MS, Salgado C, Schott D, Schumacher RA, Seder E, Sharabian YG, Sober DI, Sokhan D, Stepanyan S, Stepanyan SS, Stoler P, Strauch S, Taiuti M, Tang W, Ungaro M, Vineyard MF, Voutier E, Watts DP, Weinstein LB, Weygand DP, Wood MH, Zana L, Zhao B. Measurement of the neutron F2 structure function via spectator tagging with CLAS. PHYSICAL REVIEW LETTERS 2012; 108:142001. [PMID: 22540786 DOI: 10.1103/physrevlett.108.142001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Indexed: 05/31/2023]
Abstract
We report on the first measurement of the F(2) structure function of the neutron from the semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to ≲100 MeV/c and their angles to ≳100° relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F(2)(n) data collected cover the nucleon-resonance and deep-inelastic regions over a wide range of Bjorken x for 0.65<Q(2)<4.52 GeV(2), with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F(2)(n)/F(2)(p) at 0.2≲x≲0.8 with little uncertainty due to nuclear effects.
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Keller D, Hicks K, Adhikari KP, Adikaram D, Amaryan MJ, Anghinolfi M, Baghdasaryan H, Ball J, Battaglieri M, Bedlinskiy I, Biselli AS, Bookwalter C, Boiarinov S, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Carman DS, Celentano A, Chandavar S, Cole PL, Contalbrigo M, Crede V, D’Angelo A, Daniel A, Dashyan N, De Vita R, De Sanctis E, Djalali C, Doughty D, Dupre R, El Alaoui A, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Gabrielyan MY, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Gohn W, Golovatch E, Gothe RW, Graham L, Griffioen KA, Guidal M, Guler N, Guo L, Hafidi K, Hakobyan H, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jo HS, Joo K, Khandaker M, Khetarpal P, Kim A, Kim W, Klein FJ, Kubarovsky A, Kubarovsky V, Kuleshov SV, Lu HY, MacGregor IJD, Mao Y, Markov N, Mayer M, McKinnon B, Meyer CA, Mineeva T, Mirazita M, Mokeev V, Moutarde H, Munevar E, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Osipenko M, Ostrovidov AI, Paolone M, Pappalardo L, Paremuzyan R, Park K, Park S, Pasyuk E, Anefalos Pereira S, Pisano S, Pogorelko O, Pozdniakov S, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Rimal D, Ripani M, Ritchie BG, Rosner G, Rossi P, Sabatié F, Saini MS, Salgado C, Schott D, Schumacher RA, Seraydaryan H, Sharabian YG, Smith ES, Smith GD, Sober DI, Sokhan D, Stepanyan SS, Stepanyan S, Stoler P, Strauch S, Taiuti M, Tang W, Taylor CE, Tkachenko S, Vernarsky B, Vineyard MF, Vlassov AV, Voskanyan H, Voutier E, Watts DP, Wood MH, Zachariou N, Zana L, Zhao B, Zhao ZW. Publisher’s Note: Branching ratio of the electromagnetic decay of theΣ+(1385)Phys. Rev. D85, 052004 (2012). Int J Clin Exp Med 2012. [DOI: 10.1103/physrevd.85.059903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hwang SH, Hicks K, Ahn JK, Nakano T, Ahn DS, Chang WC, Chen JY, Daté S, Ejiri H, Fujimura H, Fujiwara M, Fukui S, Gohn W, Hotta T, Imai K, Ishikawa T, Joo K, Kato Y, Kohri H, Kon Y, Lee HS, Maeda Y, Miyabe M, Mibe T, Morino Y, Muramatsu N, Nakatsugawa Y, Niiyama M, Noumi H, Oh Y, Ohashi Y, Ohta T, Oka M, Parker J, Rangacharyulu C, Ryu SY, Sawada T, Sugaya Y, Sumihama M, Tsunemi T, Uchida M, Ungaro M, Yosoi M. Spin-density matrix elements for γp→K*0Σ+ at Eγ=1.85-3.0 GeV with evidence for the κ(800) meson exchange. PHYSICAL REVIEW LETTERS 2012; 108:092001. [PMID: 22463625 DOI: 10.1103/physrevlett.108.092001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Indexed: 05/31/2023]
Abstract
The exclusive reaction γp→K(+)π(-)Σ(+) was measured for the first time using linearly polarized photons at beam energies from 1.85 to 2.96 GeV. Angular distributions in the rest frame of the K(+)π(-) system were fitted to extract spin-density matrix elements of the K(*0) decay. The measured parity spin asymmetry shows that natural-parity exchange is dominant in this reaction. This result clearly indicates the need for t-channel exchange of the κ(800) scalar meson.
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Stamuli E, Cockayne S, Hewitt C, Hicks K, Jayakody S, Kang'ombe AR, Turner G, Thomas K, Curran M, Hashmi F, McIntosh C, McLarnon N, Torgerson DJ, Watt I. Cost-effectiveness of cryotherapy versus salicylic acid for the treatment of plantar warts: economic evaluation alongside a randomised controlled trial (EVerT trial). J Foot Ankle Res 2012; 5:4. [PMID: 22369511 PMCID: PMC3348086 DOI: 10.1186/1757-1146-5-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 02/27/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Plantar warts (verrucae) are extremely common. Although many will spontaneously disappear without treatment, treatment may be sought for a variety of reasons such as discomfort. There are a number of different treatments for cutaneous warts, with salicylic acid and cryotherapy using liquid nitrogen being two of the most common forms of treatment. To date, no full economic evaluation of either salicylic acid or cryotherapy has been conducted based on the use of primary data in a pragmatic setting. This paper describes the cost-effectiveness analysis which was conducted alongside a pragmatic multicentre, randomised trial evaluating the clinical effectiveness of cryotherapy versus 50% salicylic acid of the treatment of plantar warts. METHODS A cost-effectiveness analysis was undertaken alongside a pragmatic multicentre, randomised controlled trial assessing the clinical effectiveness of 50% salicylic acid and cryotherapy using liquid nitrogen at 12 weeks after randomisation of patients. Cost-effectiveness outcomes were expressed as the additional cost required to completely cure the plantar warts of one additional patient. A NHS perspective was taken for the analysis. RESULTS Cryotherapy costs on average £101.17 (bias corrected and accelerated (BCA) 95% CI: 85.09-117.26) more per participant over the 12 week time-frame, while there is no additional benefit, in terms of proportion of patients healed compared with salicylic acid. CONCLUSIONS Cryotherapy is more costly and no more effective than salicylic acid. TRIAL REGISTRATION Current Controlled Trials ISRCTN18994246 [controlled-trials.com] and National Research Register N0484189151.
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Cockayne S, Curran M, Denby G, Hashmi F, Hewitt C, Hicks K, Jayakody S, Kang’ombe A, McIntosh C, McLarnon N, Stamuli E, Thomas K, Turner G, Torgerson D, Watt I. EVerT: cryotherapy versus salicylic acid for the treatment of verrucae – a randomised controlled trial. Health Technol Assess 2011; 15:1-170. [PMID: 21899812 DOI: 10.3310/hta15320] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Cockayne S, Hewitt C, Hicks K, Jayakody S, Kang'ombe AR, Stamuli E, Turner G, Thomas K, Curran M, Denby G, Hashmi F, McIntosh C, McLarnon N, Torgerson D, Watt I. Cryotherapy versus salicylic acid for the treatment of plantar warts (verrucae): a randomised controlled trial. BMJ 2011; 342:d3271. [PMID: 21652750 PMCID: PMC3109952 DOI: 10.1136/bmj.d3271] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/20/2011] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To compare the clinical effectiveness of cryotherapy versus salicylic acid for the treatment of plantar warts. DESIGN A multicentre, open, two arm randomised controlled trial. SETTING University podiatry school clinics, NHS podiatry clinics, and primary care in England, Scotland, and Ireland. PARTICIPANTS 240 patients aged 12 years and over, with a plantar wart that in the opinion of the healthcare professional was suitable for treatment with both cryotherapy and salicylic acid. INTERVENTIONS Cryotherapy with liquid nitrogen delivered by a healthcare professional, up to four treatments two to three weeks apart. Patient self treatment with 50% salicylic acid (Verrugon) daily up to a maximum of eight weeks. MAIN OUTCOME MEASURES Complete clearance of all plantar warts at 12 weeks. Secondary outcomes were (a) complete clearance of all plantar warts at 12 weeks controlling for age, whether the wart had been treated previously, and type of wart, (b) patient self reported clearance of plantar warts at six months, (c) time to clearance of plantar wart, (d) number of plantar warts at 12 weeks, and (e) patient satisfaction with the treatment. RESULTS There was no evidence of a difference between the salicylic acid and cryotherapy groups in the proportions of participants with complete clearance of all plantar warts at 12 weeks (17/119 (14%) v 15/110 (14%), difference 0.65% (95% CI -8.33 to 9.63), P=0.89). The results did not change when the analysis was repeated but with adjustment for age, whether the wart had been treated previously, and type of plantar wart or for patients' preferences at baseline. There was no evidence of a difference between the salicylic acid and cryotherapy groups in self reported clearance of plantar warts at six months (29/95 (31%) v 33/98 (34%), difference -3.15% (-16.31 to 10.02), P=0.64) or in time to clearance (hazard ratio 0.80 (95% CI 0.51 to 1.25), P=0.33). There was also no evidence of a difference in the number of plantar warts at 12 weeks (incident rate ratio 1.08 (0.81 to 1.43), P=0.62). CONCLUSIONS Salicylic acid and the cryotherapy were equally effective for clearance of plantar warts. TRIAL REGISTRATION Current Controlled Trials ISRCTN18994246, National Research Register N0484189151.
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Johnston D, Samus QM, Morrison A, Leoutsakos JS, Hicks K, Handel S, Rye R, Robbins B, Rabins PV, Lyketsos CG, Black BS. Identification of community-residing individuals with dementia and their unmet needs for care. Int J Geriatr Psychiatry 2011; 26:292-8. [PMID: 20658473 PMCID: PMC3039061 DOI: 10.1002/gps.2527] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 03/05/2010] [Indexed: 11/10/2022]
Abstract
BACKGROUND Innovative approaches to the widespread delivery of evidence-based dementia care are needed. The aims of this study were to determine whether a telephone screening method could efficiently identify individuals in the community in need of care for dementia and to develop a multidimensional needs assessment tool for identifying the type and frequency of unmet needs related to memory disorders in the home setting. METHODS This was a cross-sectional evaluation of 292 community-residing individuals aged 70 and older in Maryland. Participants were given a brief cognitive telephone screen. A subsample (n=43) received a comprehensive in-home assessment for dementia and dementia-related needs. Cognitive, functional, behavioral, and clinical factors were assessed. The Johns Hopkins Dementia Care Needs Assessment (JHDCNA) was used to identify unmet needs related to dementia. RESULTS Telephone screening for the sample took 350 h, and 27% screened positive for dementia. Virtually all participants with dementia who received an in-home assessment had at least one unmet need, with the most frequent unmet needs being for a dementia workup, general medical care, environmental safety, assistance with ADL impairments, and access to meaningful activities. Caregivers, when present, also had a number of unmet needs, with the most common being caregiver education about dementia, knowledge of community resources, and caregiver mental health care. CONCLUSIONS Effective and efficient means for identifying community-residing individuals with dementia are needed so that dementia care interventions can be provided to address unmet care needs of patients and their caregivers.
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Avakian H, Bosted P, Burkert VD, Elouadrhiri L, Adhikari KP, Aghasyan M, Amaryan M, Anghinolfi M, Baghdasaryan H, Ball J, Battaglieri M, Bedlinskiy I, Biselli AS, Branford D, Briscoe WJ, Brooks W, Carman DS, Casey L, Cole PL, Collins P, Crabb D, Crede V, D'Angelo A, Daniel A, Dashyan N, De Vita R, De Sanctis E, Deur A, Dey B, Dhamija S, Dickson R, Djalali C, Dodge G, Doughty D, Dupre R, El Alaoui A, Eugenio P, Fegan S, Fersch R, Forest TA, Fradi A, Gabrielyan MY, Gavalian G, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Girod FX, Gohn W, Gothe RW, Griffioen KA, Guidal M, Guler N, Guo L, Hafidi K, Hakobyan H, Hanretty C, Hassall N, Heddle D, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Isupov EL, Jawalkar SS, Jo HS, Joo K, Keller D, Khandaker M, Khetarpal P, Kim W, Klein A, Klein FJ, Konczykowski P, Kubarovsky V, Kuhn SE, Kuleshov SV, Kuznetsov V, Livingston K, Lu HY, Markov N, Mayer M, Martinez D, McAndrew J, McCracken ME, McKinnon B, Meyer CA, Mineeva T, Mirazita M, Mokeev V, Moreno B, Moriya K, Morrison B, Moutarde H, Munevar E, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niroula MR, Osipenko M, Ostrovidov AI, Paremuzyan R, Park K, Park S, Pasyuk E, Pereira SA, Perrin Y, Pisano S, Pogorelko O, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Ripani M, Rosner G, Rossi P, Sabatié F, Saini MS, Salamanca J, Salgado C, Schumacher RA, Seder E, Seraydaryan H, Sharabian YG, Sober DI, Sokhan D, Stepanyan SS, Stepanyan S, Stoler P, Strauch S, Suleiman R, Taiuti M, Tedeschi DJ, Tkachenko S, Ungaro M, Vernarsky B, Vineyard MF, Voutier E, Watts DP, Weinstein LB, Weygand DP, Wood MH, Zhang J, Zhao B, Zhao ZW. Measurement of single- and double-spin asymmetries in deep inelastic pion electroproduction with a longitudinally polarized target. PHYSICAL REVIEW LETTERS 2010; 105:262002. [PMID: 21231647 DOI: 10.1103/physrevlett.105.262002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Indexed: 05/30/2023]
Abstract
We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ϕ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.
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Baghdasaryan H, Weinstein LB, Laget JM, Adhikari KP, Aghasyan M, Amarian M, Anghinolfi M, Avakian H, Ball J, Battaglieri M, Bedlinskiy I, Bennett RP, Berman BL, Biselli AS, Bookwalter C, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Carman DS, Crede V, D'Angelo A, Daniel A, Dashyan N, De Vita R, De Sanctis E, Deur A, Dey B, Dickson R, Djalali C, Dodge GE, Doughty D, Dupre R, Egiyan H, El Alaoui A, El Fassi L, Eugenio P, Fegan S, Gabrielyan MY, Gilfoyle GP, Giovanetti KL, Gohn W, Gothe RW, Griffioen KA, Guidal M, Guo L, Gyurjyan V, Hakobyan H, Hanretty C, Hyde CE, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Joo K, Keller D, Khandaker M, Khetarpal P, Kim A, Kim W, Klein A, Klein FJ, Konczykowski P, Kubarovsky V, Kuhn SE, Kuleshov SV, Kuznetsov V, Kvaltine ND, Livingston K, Lu HY, Macgregor IJD, Markov N, Mayer M, McAndrew J, McKinnon B, Meyer CA, Mikhailov K, Mokeev V, Moreno B, Moriya K, Morrison B, Moutarde H, Munevar E, Nadel-Turonski P, Nepali C, Niccolai S, Niculescu G, Niculescu I, Osipenko M, Ostrovidov AI, Paremuzyan R, Park K, Park S, Pasyuk E, Pereira SA, Pisano S, Pogorelko O, Pozdniakov S, Price JW, Procureur S, Protopopescu D, Ricco G, Ripani M, Rosner G, Rossi P, Sabatié F, Salgado C, Schumacher RA, Seraydaryan H, Smith GD, Sober DI, Sokhan D, Stepanyan SS, Stepanyan S, Stoler P, Strauch S, Taiuti M, Tang W, Taylor CE, Tedeschi DJ, Ungaro M, Vineyard MF, Voutier E, Watts DP, Weygand DP, Wood MH, Zhao B, Zhao ZW. Tensor correlations measured in 3He(e,e' pp)n. PHYSICAL REVIEW LETTERS 2010; 105:222501. [PMID: 21231381 DOI: 10.1103/physrevlett.105.222501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Indexed: 05/30/2023]
Abstract
We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum p(tot). For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low p(tot) and rises to approximately 0.5 at large p(tot). This shows the dominance of tensor over central correlations at this relative momentum.
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Wood MH, Nasseripour R, Paolone M, Djalali C, Weygand DP, Adhikari KP, Anghinolfi M, Ball J, Battaglieri M, Batourine V, Bedlinskiy I, Bellis M, Berman BL, Biselli AS, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Careccia SL, Carman DS, Cole PL, Collins P, Crede V, D'Angelo A, Daniel A, De Vita R, De Sanctis E, Deur A, Dey B, Dhamija S, Dickson R, Doughty D, Dupre R, Egiyan H, El Alaoui A, El Fassi L, Eugenio P, Fegan S, Gabrielyan MY, Garçon M, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Gothe RW, Graham L, Guidal M, Guo L, Hafidi K, Hakobyan H, Hanretty C, Hassall N, Hicks K, Holtrop M, Ilieva Y, Ireland DG, Ishkhanov BS, Jawalkar SS, Jo HS, Joo K, Keller D, Khandaker M, Khetarpal P, Kim A, Kim W, Klein A, Klein FJ, Konczykowski P, Kubarovsky V, Kuleshov SV, Kuznetsov V, Livingston K, Martinez D, Mayer M, McAndrew J, McCracken ME, McKinnon B, Meyer CA, Mineeva T, Mirazita M, Mokeev V, Moreno B, Moriya K, Morrison B, Munevar E, Nadel-Turonski P, Ni A, Niccolai S, Niculescu G, Niculescu I, Niroula MR, Osipenko M, Ostrovidov AI, Paremuzyan R, Park K, Park S, Pasyuk E, Anefalos Pereira S, Pisano S, Pogorelko O, Pozdniakov S, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Ripani M, Rosner G, Rossi P, Sabatié F, Saini MS, Salamanca J, Salgado C, Schott D, Schumacher RA, Seder E, Seraydaryan H, Sharabian YG, Smith GD, Sober DI, Sokhan D, Stepanyan S, Stepanyan SS, Stoler P, Strakovsky II, Strauch S, Taiuti M, Tang W, Taylor CE, Tedeschi DJ, Tkachenko S, Ungaro M, Vernarsky B, Vineyard MF, Voutier E, Watts DP, Weinstein LB, Zhang J, Zhao B, Zhao ZW. Absorption of the ω and ϕ mesons in nuclei. PHYSICAL REVIEW LETTERS 2010; 105:112301. [PMID: 20867566 DOI: 10.1103/physrevlett.105.112301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Indexed: 05/29/2023]
Abstract
Because of their long lifetimes, the ω and ϕ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.
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Kohri H, Ahn DS, Ahn JK, Akimune H, Asano Y, Chang WC, Daté S, Ejiri H, Fukui S, Fujimura H, Fujiwara M, Hasegawa S, Hicks K, Hosaka A, Hotta T, Imai K, Ishikawa T, Iwata T, Kawai H, Kim ZY, Kino K, Kumagai N, Makino S, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi Y, Morita M, Muramatsu N, Nakano T, Nam SI, Niiyama M, Nomachi M, Ohashi Y, Ohkuma H, Ooba T, Oshuev DS, Rangacharyulu C, Sakaguchi A, Sasaki T, Shagin PM, Shiino Y, Shimizu A, Shimizu H, Sugaya Y, Sumihama M, Titov AI, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles. PHYSICAL REVIEW LETTERS 2010; 104:172001. [PMID: 20482102 DOI: 10.1103/physrevlett.104.172001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Indexed: 05/29/2023]
Abstract
Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6<cos(theta){c.m.}{K}<1. A new bump structure was found at W approximately 2.11 GeV in the cross sections. The bump is not well reproduced by theoretical calculations introducing a nucleon resonance with J<or=3/2. This result suggests that the bump might be produced by a nucleon resonance possibly with J>or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.
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Bobbink R, Hicks K, Galloway J, Spranger T, Alkemade R, Ashmore M, Bustamante M, Cinderby S, Davidson E, Dentener F, Emmett B, Erisman JW, Fenn M, Gilliam F, Nordin A, Pardo L, De Vries W. Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2010; 20:30-59. [PMID: 20349829 DOI: 10.1890/08-1140.1] [Citation(s) in RCA: 926] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now and in the future. This synthesis paper clearly shows that N accumulation is the main driver of changes to species composition across the whole range of different ecosystem types by driving the competitive interactions that lead to composition change and/or making conditions unfavorable for some species. Other effects such as direct toxicity of nitrogen gases and aerosols, long-term negative effects of increased ammonium and ammonia availability, soil-mediated effects of acidification, and secondary stress and disturbance are more ecosystem- and site-specific and often play a supporting role. N deposition effects in mediterranean ecosystems have now been identified, leading to a first estimate of an effect threshold. Importantly, ecosystems thought of as not N limited, such as tropical and subtropical systems, may be more vulnerable in the regeneration phase, in situations where heterogeneity in N availability is reduced by atmospheric N deposition, on sandy soils, or in montane areas. Critical loads are effect thresholds for N deposition, and the critical load concept has helped European governments make progress toward reducing N loads on sensitive ecosystems. More needs to be done in Europe and North America, especially for the more sensitive ecosystem types, including several ecosystems of high conservation importance. The results of this assessment show that the vulnerable regions outside Europe and North America which have not received enough attention are ecoregions in eastern and southern Asia (China, India), an important part of the mediterranean ecoregion (California, southern Europe), and in the coming decades several subtropical and tropical parts of Latin America and Africa. Reductions in plant diversity by increased atmospheric N deposition may be more widespread than first thought, and more targeted studies are required in low background areas, especially in the G200 ecoregions.
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Chen W, Mibe T, Dutta D, Gao H, Laget JM, Mirazita M, Rossi P, Stepanyan S, Strakovsky II, Amaryan MJ, Anghinolfi M, Bagdasaryan H, Battaglieri M, Bellis M, Berman BL, Biselli AS, Bookwalter C, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Careccia SL, Carman DS, Casey L, Cole PL, Collins P, Crede V, Daniel A, Dashyan N, De Vita R, De Sanctis E, Deur A, Dhamija S, Dickson R, Djalali C, Dodge GE, Doughty D, Egiyan H, Eugenio P, Fedotov G, Fradi A, Garçon M, Gilfoyle GP, Giovanetti KL, Girod FX, Gohn W, Gothe RW, Griffioen KA, Guidal M, Hakobyan H, Hanretty C, Hassall N, Heddle D, Hicks K, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Jo HS, Johnstone JR, Joo K, Keller D, Khandaker M, Khetarpal P, Kim W, Klein A, Klein FJ, Kramer LH, Kubarovsky V, Kuhn SE, Kuleshov SV, Kuznetsov V, Livingston K, Lu HY, Markov N, McCracken ME, McKinnon B, Meyer CA, Mineeva T, Mokeev V, Moreno B, Moriya K, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu I, Niroula MR, Osipenko M, Ostrovidov AI, Park K, Park S, Pereira SA, Pogorelko O, Pozdniakov S, Price JW, Procureur S, Protopopescu D, Raue BA, Ricco G, Ripani M, Ritchie BG, Rosner G, Sabatié F, Saini MS, Salamanca J, Salgado C, Schumacher RA, Sharabian YG, Sober DI, Sokhan D, Stepanyan SS, Strauch S, Taiuti M, Tedeschi DJ, Tkachenko S, Ungaro M, Vineyard MF, Watts DP, Weinstein LB, Weygand DP, Wood MH, Yegneswaran A, Zhang J, Zhao B. Measurement of the differential cross section for the reaction gamman-->pi- p from deuterium. PHYSICAL REVIEW LETTERS 2009; 103:012301. [PMID: 19659138 DOI: 10.1103/physrevlett.103.012301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Indexed: 05/28/2023]
Abstract
We report a measurement of the differential cross section for the gamman-->pi- p process from the CLAS detector at Jefferson Laboratory in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (thetac.m.) between 50 degrees and 115 degrees. We confirm a previous indication of a broad enhancement around a c.m. energy ([sqrt]s) of 2.1 GeV at thetac.m.=90 degrees in the scaled differential cross section s7dsigma/dt and a rapid falloff in a center-of-mass energy region of about 400 MeV following the enhancement. Our data show an angular dependence of this enhancement as the suggested scaling region is approached for thetac.m. from 70 degrees to 105 degrees.
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Muramatsu N, Chen JY, Chang WC, Ahn DS, Ahn JK, Akimune H, Asano Y, Daté S, Ejiri H, Fujimura H, Fujiwara M, Fukui S, Hasegawa S, Hicks K, Horie K, Hotta T, Imai K, Ishikawa T, Iwata T, Kato Y, Kawai H, Kino K, Kohri H, Kumagai N, Makino S, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi M, Nakano T, Niiyama M, Nomachi M, Ohashi Y, Ohkuma H, Ooba T, Oshuev DS, Rangacharyulu C, Sakaguchi A, Shagin PM, Shiino Y, Shimizu H, Sugaya Y, Sumihama M, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Near-threshold photoproduction of Lambda(1520) from protons and deuterons. PHYSICAL REVIEW LETTERS 2009; 103:012001. [PMID: 19659135 DOI: 10.1103/physrevlett.103.012001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2009] [Indexed: 05/28/2023]
Abstract
Photoproduction of Lambda(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.
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Lachniet J, Afanasev A, Arenhövel H, Brooks WK, Gilfoyle GP, Higinbotham D, Jeschonnek S, Quinn B, Vineyard MF, Adams G, Adhikari KP, Amaryan MJ, Anghinolfi M, Asavapibhop B, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Beard K, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Bonner BE, Bookwalter C, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Bültmann S, Burkert VD, Calarco JR, Careccia SL, Carman DS, Casey L, Cheng L, Cole PL, Coleman A, Collins P, Cords D, Corvisiero P, Crabb D, Crede V, Cummings JP, Dale D, Daniel A, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dhamija S, Dharmawardane KV, Dhuga KS, Dickson R, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Fersch R, Feuerbach RJ, Forest TA, Fradi A, Gabrielyan MY, Garçon M, Gavalian G, Gevorgyan N, Giovanetti KL, Girod FX, Goetz JT, Gohn W, Golovatch E, Gothe RW, Graham L, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hanretty C, Hardie J, Hassall N, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hu J, Huertas M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Johnstone JR, Joo K, Juengst HG, Kageya T, Kalantarians N, Keller D, Kellie JD, Khandaker M, Khetarpal P, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klusman M, Konczykowski P, Kossov M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Kuznetsov V, Laget JM, Langheinrich J, Lawrence D, Lima ACS, Livingston K, Lowry M, Lu HY, Lukashin K, Maccormick M, Malace S, Manak JJ, Markov N, Mattione P, McAleer S, McCracken ME, McKinnon B, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Mineeva T, Minehart R, Mirazita M, Miskimen R, Mokeev V, Moreno B, Moriya K, Morrow SA, Moteabbed M, Mueller J, Munevar E, Mutchler GS, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Park S, Pasyuk E, Paterson C, Pereira SA, Philips SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Popa I, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Rosner G, Rossi P, Rowntree D, Rubin PD, Sabatié F, Saini MS, Salamanca J, Salgado C, Sandorfi A, Santoro JP, Sapunenko V, Schott D, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shaw J, Shvedunov NV, Skabelin AV, Smith ES, Smith LC, Sober DI, Sokhan D, Starostin A, Stavinsky A, Stepanyan S, Stepanyan SS, Stokes BE, Stoler P, Stopani KA, Strakovsky II, Strauch S, Suleiman R, Taiuti M, Taylor S, Tedeschi DJ, Thompson R, Tkabladze A, Tkachenko S, Ungaro M, Vlassov AV, Watts DP, Wei X, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yun J, Yurov M, Zana L, Zhang J, Zhao B, Zhao ZW. Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region. PHYSICAL REVIEW LETTERS 2009; 102:192001. [PMID: 19518944 DOI: 10.1103/physrevlett.102.192001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Indexed: 05/27/2023]
Abstract
The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.
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Hoblit S, Sandorfi AM, Ardashev K, Bade C, Bartalini O, Blecher M, Caracappa A, D'Angelo A, d'Angelo A, Di Salvo R, Fantini A, Gibson C, Glückler H, Hicks K, Honig A, Kageya T, Khandaker M, Kistner OC, Kizilgul S, Kucuker S, Lehmann A, Lowry M, Lucas M, Mahon J, Miceli L, Moricciani D, Norum B, Pap M, Preedom B, Seyfarth H, Schaerf C, Ströher H, Thorn CE, Whisnant CS, Wang K, Wei X. Measurements of H-->D-->(gamma-->,pi) and implications for the convergence of the Gerasimov-Drell-Hern integral. PHYSICAL REVIEW LETTERS 2009; 102:172002. [PMID: 19518773 DOI: 10.1103/physrevlett.102.172002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Indexed: 05/27/2023]
Abstract
We report new measurements of inclusive pi production from frozen-spin HD for polarized photon beams covering the Delta(1232) resonance. These provide data simultaneously on both H and D with nearly complete angular distributions of the spin-difference cross sections entering the Gerasimov-Drell-Hearn (GDH) sum rule. Recent results from Mainz and Bonn exceed the GDH prediction for the proton by 22 microb, suggesting as yet unmeasured high-energy components. Our pi0 data reveal a different angular dependence than assumed in Mainz analyses and integrate to a value that is 18 microb lower, suggesting a more rapid convergence. Our results for deuterium are somewhat lower than published data, considerably more precise, and generally lower than available calculations.
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Nozar M, Salgado C, Weygand DP, Guo L, Adams G, Li J, Eugenio P, Amaryan MJ, Anghinolfi M, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Battaglieri M, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Blaszczyk L, Bonner BE, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Carnahan B, Casey L, Cazes A, Chen S, Cheng L, Cole PL, Collins P, Coltharp P, Cords D, Corvisiero P, Crabb D, Crannell H, Crede V, Cummings JP, Dale D, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Dhuga KS, Dickson R, Djalali C, Dodge GE, Doughty D, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Fatemi R, Fedotov G, Feuerbach RJ, Forest TA, Fradi A, Funsten H, Garçon M, Gavalian G, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gothe RW, Griffioen KA, Guidal M, Guillo M, Guler N, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hanretty C, Hardie J, Hassall N, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Johnstone JR, Joo K, Juengst HG, Kalantarians N, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Kossov M, Krahn Z, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Kuznetsov V, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Livingston K, Lu HY, Maccormick M, Markov N, Mattione P, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mehrabyan S, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Moreno B, Moriya K, Morrow SA, Moteabbed M, Mueller J, Munevar E, Mutchler GS, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Anefalos Pereira S, Philips SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Popa I, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Rubin PD, Sabatié F, Salamanca J, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shvedunov NV, Skabelin AV, Smith ES, Smith LC, Sober DI, Sokhan D, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Stoler P, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Thoma U, Tkabladze A, Tkachenko S, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Watts DP, Weinstein LB, Williams M, Wolin E, Wood MH, Yegneswaran A, Zana L, Zhang J, Zhao B, Zhao ZW. Search for the photoexcitation of exotic mesons in the pi+pi+pi- system. PHYSICAL REVIEW LETTERS 2009; 102:102002. [PMID: 19392105 DOI: 10.1103/physrevlett.102.102002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Indexed: 05/27/2023]
Abstract
A search for exotic mesons in the pi;{+}pi;{+}pi;{-} system photoproduced by the charge exchange reaction gammap-->pi;{+}pi;{+}pi;{-}(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic J;{PC}=1;{-+} resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a_{2}(1320) and the pi_{2}(1670) mesons, but no evidence for the a_{1}(1260), nor the pi_{1}(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic pi_{1}(1600) cross section, less than 2% of the a_{2}(1320) production.
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Battaglieri M, De Vita R, Szczepaniak AP, Adhikari KP, Aghasyan M, Amaryan MJ, Ambrozewicz P, Anghinolfi M, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Batourine V, Bedlinskiy I, Bellis M, Benmouna N, Berman BL, Bibrzycki L, Biselli AS, Bookwalter C, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Calarco JR, Careccia SL, Carman DS, Casey L, Chen S, Cheng L, Clinton E, Cole PL, Collins P, Crabb D, Crannell H, Crede V, Cummings JP, Dale D, Daniel A, Dashyan N, De Masi R, De Sanctis E, Degtyarenko PV, Deur A, Dhamija S, Dharmawardane KV, Dickson R, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Fersch R, Forest TA, Fradi A, Gabrielyan MY, Gan L, Garçon M, Gasparian A, Gavalian G, Gevorgyan N, Gilfoyle GP, Giovanetti KL, Girod FX, Glamazdin O, Goett J, Goetz JT, Gohn W, Golovatch E, Gordon CIO, Gothe RW, Graham L, Griffioen KA, Guidal M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hakobyan RS, Hanretty C, Hardie J, Hassall N, Heddle D, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Johnstone JR, Joo K, Juengst HG, Kageya T, Kalantarians N, Keller D, Kellie JD, Khandaker M, Khetarpal P, Kim W, Klein A, Klein FJ, Klimenko AV, Konczykowski P, Kossov M, Krahn Z, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Kuznetsov V, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Lesniak L, Li J, Livingston K, Lowry M, Lu HY, Maccormick M, Malace S, Markov N, Mattione P, McCracken ME, McKinnon B, Mecking BA, Melone JJ, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Mineeva T, Minehart R, Mirazita M, Miskimen R, Mochalov V, Mokeev V, Moreno B, Moriya K, Morrow SA, Moteabbed M, Munevar E, Mutchler GS, Nadel-Turonski P, Nakagawa I, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, Osipenko M, Ostrovidov AI, Park K, Park S, Pasyuk E, Paris M, Paterson C, Pereira SA, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Pozdniakov S, Price JW, Prok Y, Protopopescu D, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Rosner G, Rossi P, Sabatié F, Saini MS, Salamanca J, Salgado C, Sandorfi A, Santoro JP, Sapunenko V, Schott D, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shvedunov NV, Smith ES, Smith LC, Sober DI, Sokhan D, Starostin A, Stavinsky A, Stepanyan S, Stepanyan SS, Stokes BE, Stoler P, Stopani KA, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Teymurazyan A, Tkabladze A, Tkachenko S, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Watts DP, Wei X, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Yurov M, Zana L, Zhang J, Zhao B, Zhao ZW. Measurement of direct f0(980) photoproduction on the proton. PHYSICAL REVIEW LETTERS 2009; 102:102001. [PMID: 19392104 DOI: 10.1103/physrevlett.102.102001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Indexed: 05/27/2023]
Abstract
We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.
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Hicks K, Keller D, Kohri H, Ahn DS, Ahn JK, Akimune H, Asano Y, Chang WC, Daté S, Ejiri H, Fukui S, Fujimura H, Fujiwara M, Hasegawa S, Hotta T, Imai K, Ishikawa T, Iwata T, Kato Y, Kawai H, Kim ZY, Kino K, Kumagai N, Makino S, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi Y, Morita M, Muramatsu N, Nakano T, Niiyama M, Nomachi M, Oh Y, Ohashi Y, Ohkuma H, Ooba T, Parker J, Rangacharyulu C, Sakaguchi A, Sasaki T, Shagin PM, Shiino Y, Shimizu A, Shimizu H, Sugaya Y, Sumihama M, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Cross sections and beam asymmetry for K;{+}Sigma;{*-} photoproduction from the deuteron at E_{gamma}=1.5-2.4 GeV. PHYSICAL REVIEW LETTERS 2009; 102:012501. [PMID: 19257183 DOI: 10.1103/physrevlett.102.012501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Indexed: 05/27/2023]
Abstract
The Sigma(1385) resonance, or Sigma;{*}, is well known as part of the standard baryon decuplet with spin J=3/2. Measurements of the reaction gammap-->K;{+}Sigma;{*0} are difficult to extract due to overlap with the nearby Lambda(1405) resonance. However, the reaction gamman-->K;{+}Sigma;{*-} has no overlap with the Lambda(1405) due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the Sigma;{*-} from a deuteron target. The cross sections at forward angles range from 0.4 to 1.2 mub, with a broad maximum near E_{gamma} approximately 1.8 GeV. The beam asymmetries are negative, in contrast with positive values for the gamman-->K;{+}Sigma;{-} reaction.
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Girod FX, Niyazov RA, Avakian H, Ball J, Bedlinskiy I, Burkert VD, De Masi R, Elouadrhiri L, Garçon M, Guidal M, Jo HS, Joo K, Kubarovsky V, Kuleshov SV, MacCormick M, Niccolai S, Pogorelko O, Sabatié F, Stepanyan S, Stoler P, Ungaro M, Zhao B, Amaryan MJ, Ambrozewicz P, Anghinolfi M, Asryan G, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Batourine V, Battaglieri M, Bellis M, Benmouna N, Berman BL, Biselli AS, Blaszczyk L, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Casey L, Chen S, Cheng L, Cole PL, Collins P, Coltharp P, Crabb D, Crede V, Dashyan N, De Sanctis E, De Vita R, Degtyarenko PV, Deur A, Dharmawardane KV, Dickson R, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Eugenio P, Fedotov G, Feldman G, Funsten H, Gavalian G, Gilfoyle GP, Giovanetti KL, Goetz JT, Gonenc A, Gothe RW, Griffioen KA, Guler N, Guo L, Gyurjyan V, Hafidi K, Hakobyan H, Hanretty C, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Johnstone JR, Juengst HG, Kalantarians N, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Kossov M, Krahn Z, Kramer LH, Kuhn J, Kuhn SE, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Livingston K, Lu HY, Markov N, Mattione P, Mazouz M, McKinnon B, Mecking BA, Mestayer MD, Meyer CA, Mibe T, Michel B, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Moriya K, Morrow SA, Moteabbed M, Munevar E, Mutchler GS, Nadel-Turonski P, Nasseripour R, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Nozar M, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Anefalos Pereira S, Pierce J, Pivnyuk N, Pocanic D, Pozdniakov S, Price JW, Procureur S, Prok Y, Protopopescu D, Raue BA, Ricco G, Ripani M, Ritchie BG, Rosner G, Rossi P, Salamanca J, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shvedunov NV, Smith ES, Smith LC, Sober DI, Sokhan D, Stavinsky A, Stepanyan SS, Stokes BE, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Tkabladze A, Tkachenko S, Tur C, Vineyard MF, Vlassov AV, Voutier E, Watts DP, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Zana L, Zhang J, Zhao ZW. Measurement of deeply virtual compton scattering beam-spin asymmetries. PHYSICAL REVIEW LETTERS 2008; 100:162002. [PMID: 18518188 DOI: 10.1103/physrevlett.100.162002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Indexed: 05/26/2023]
Abstract
The beam-spin asymmetries in the hard exclusive electroproduction of photons on the proton (e p-->epgamma) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (x(B) from 0.11 to 0.58, Q2 from 1 to 4.8 GeV2, -t from 0.09 to 1.8 GeV2), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A approximately a sinphi/(1+c cosphi). This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector.
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Nasseripour R, Wood MH, Djalali C, Weygand DP, Tur C, Mosel U, Muehlich P, Adams G, Amaryan MJ, Ambrozewicz P, Anghinolfi M, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Battaglieri M, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Blaszczyk L, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Carnahan B, Casey L, Chen S, Cole PL, Collins P, Coltharp P, Crabb D, Crannell H, Crede V, Cummings JP, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Dickson R, Dodge GE, Doughty D, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, El Fassi L, Elouadrhiri L, Eugenio P, Fedotov G, Feldman G, Feuerbach RJ, Funsten H, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gordon CIO, Gothe RW, Griffioen KA, Guidal M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hakobyan RS, Hanretty C, Hardie J, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Johnstone JR, Joo K, Juengst HG, Kalantarians N, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Kossov M, Krahn Z, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Kuleshov SV, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Li J, Livingston K, Lu HY, Maccormick M, Markov N, Mattione P, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mehrabyan S, Melone JJ, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Moriya K, Morrow SA, Moteabbed M, Mueller J, Munevar E, Mutchler GS, Nadel-Turonski P, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Anefalos Pereira S, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Sabatié F, Salamanca J, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Sharov D, Shvedunov NV, Smith ES, Smith LC, Sober DI, Sokhan D, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Stoler P, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Tkabladze A, Tkachenko S, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Watts DP, Weinstein LB, Williams M, Wolin E, Yegneswaran A, Zana L, Zhang B, Zhang J, Zhao B, Zhao ZW. Search for medium modifications of the rho meson. PHYSICAL REVIEW LETTERS 2007; 99:262302. [PMID: 18233570 DOI: 10.1103/physrevlett.99.262302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Indexed: 05/25/2023]
Abstract
The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and varphi, are observed via their decay to e;{+}e;{-}, in order to reduce the effects of final-state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, 2H, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson.
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Egiyan KS, Asryan G, Gevorgyan N, Griffioen KA, Laget JM, Kuhn SE, Adams G, Amaryan MJ, Ambrozewicz P, Anghinolfi M, Audit G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Bedlinskiy I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Blaszczyk L, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Cazes A, Chen S, Cole PL, Collins P, Coltharp P, Cords D, Corvisiero P, Crabb D, Crede V, Cummings JP, Dashyan N, De Masi R, De Vita R, De Sanctis E, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Dickson R, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dytman S, Dzyubak OP, Egiyan H, El Fassi L, Elouadrhiri L, Eugenio P, Fatemi R, Fedotov G, Feldman G, Feuerbach RJ, Fersch R, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz JT, Gonenc A, Gordon CIO, Gothe RW, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan H, Hakobyan RS, Hanretty C, Hardie J, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Joo K, Juengst HG, Kalantarians N, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Kossov M, Krahn Z, Kramer LH, Kubarovsky V, Kuhn J, Kuleshov SV, Lachniet J, Langheinrich J, Lawrence D, Li J, Livingston K, Lu HY, Maccormick M, Marchand C, Markov N, Mattione P, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mehrabyan S, Melone JJ, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Moriya K, Morrow SA, Moteabbed M, Mueller J, Munevar E, Mutchler GS, Nadel-Turonski P, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, O'Rielly GV, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Anefalos Pereira S, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Sabatié F, Salamanca J, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shvedunov NV, Skabelin AV, Smith ES, Smith LC, Sober DI, Sokhan D, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Stoler P, Strauch S, Taiuti M, Tedeschi DJ, Thoma U, Tkabladze A, Tkachenko S, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Watts DP, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Zana L, Zhang J, Zhao B, Zhao ZW. Experimental study of exclusive 2H(e,e'p)n reaction mechanisms at high Q2. PHYSICAL REVIEW LETTERS 2007; 98:262502. [PMID: 17678084 DOI: 10.1103/physrevlett.98.262502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Indexed: 05/16/2023]
Abstract
The reaction 2H(e,e'p)n has been studied with full kinematic coverage for photon virtuality 1.75<Q2<5.5 GeV2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (p(n)<100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100<p(n)<750 MeV/c, proton-neutron rescattering dominates the cross section, while Delta production followed by the NDelta-->NN transition is the primary contribution at higher momenta.
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73
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Ungaro M, Stoler P, Aznauryan I, Burkert VD, Joo K, Smith LC, Adams G, Amarian M, Ambrozewicz P, Anghinolfi M, Asryan G, Audit G, Avakian H, Bagdasaryan H, Ball JP, Baltzell NA, Barrow S, Batourine V, Battaglieri M, Bedliski I, Bektasoglu M, Bellis M, Benmouna N, Berman BL, Biselli AS, Bonner BE, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Cazes A, Chen S, Cole PL, Coltharp P, Cords D, Corvisiero P, Crabb D, Cummings JP, Sanctis ED, Devita R, Degtyarenko PV, Denizli H, Dennis L, Deur A, Dharmawardane KV, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dytman S, Dzyubak OP, Egiyan H, Egiyan KS, Elouadrhiri L, Eugenio P, Fatemi R, Fedotov G, Feldman G, Feuerbach RJ, Funsten H, Garçon M, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Goetz J, Gordon CIO, Gothe RW, Griffioen KA, Guidal M, Guillo M, Guler N, Guo L, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hardie J, Heddle D, Hersman FW, Hleiqawi I, Holtrop M, Hicks K, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Ito MM, Jenkins D, Jo HS, Juengst HG, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Kossov M, Kramer LH, Kubarovsky V, Kuhn J, Kuhn SE, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Li J, Livingston K, Marchand C, Markov N, McAleer S, McKinnon B, McNabb JWC, Mecking BA, Mehrabyan S, Melone JJ, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow SA, Mueller J, Mutchler GS, Napolitano J, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula M, Niyazov RA, Nozar M, O'rielly GV, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, 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, Rosner G, Rossi P, Rubin PD, Sabatié F, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Skabelin AV, Smith ES, Sober DI, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Thoma U, Tkabladze A, Todor L, Tkachenko S, Tur C, Vineyard MF, Vlassov AV, Weinstein LB, Weygand DP, Williams M, Wolin E, Wood MH, Yegneswaran A, Zana L, Zhang B, Zhang J, Zhao B. Measurement of the N-->Delta(+)(1232) transition at high-momentum transfer by pi(0) electroproduction. PHYSICAL REVIEW LETTERS 2006; 97:112003. [PMID: 17025879 DOI: 10.1103/physrevlett.97.112003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Indexed: 05/12/2023]
Abstract
We report a new measurement of the exclusive electroproduction reaction gamma(*)p-->pi(0)p to explore the evolution from soft nonperturbative physics to hard processes via the Q(2) dependence of the magnetic (M(1+)), electric (E(1+)), and scalar (S(1+)) multipoles in the N-->Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c(2), 4pi center-of-mass solid angle, and Q(2) from 3 to 6 GeV(2)/c(2), the highest yet achieved. It is found that the magnetic form factor G(M)(*) decreases with Q(2) more steeply than the proton magnetic form factor, the ratio E(1+)/M(1+) is small and negative, indicating strong helicity nonconservation, and the ratio S(1+)/M(1+) is negative, while its magnitude increases with Q(2).
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Kubarovsky V, Battaglieri M, De Vita R, Goett J, Guo L, Mutchler GS, Stoler P, Weygand DP, Ambrozewicz P, Anghinolfi M, Asryan G, Avakian H, Bagdasaryan H, Baillie N, Ball JP, Baltzell NA, Batourine V, Bedlinskiy I, Bellis M, Benmouna N, Berman BL, Biselli AS, Bouchigny S, Boiarinov S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Bültmann S, Burkert VD, Butuceanu C, Calarco JR, Careccia SL, Carman DS, Chen S, Clinton E, Cole PL, Collins P, Coltharp P, Crabb D, Crannell H, Crede V, Cummings JP, De Masi R, Dale D, De Sanctis E, Degtyarenko PV, Deur A, Dharmawardane KV, Djalali C, Dodge GE, Donnelly J, Doughty D, Dugger M, Dzyubak OP, Egiyan H, Egiyan KS, Elouadrhiri L, Eugenio P, Fedotov G, Funsten H, Gabrielyan MY, Gan L, Garçon M, Gasparian A, Gavalian G, Gilfoyle GP, Giovanetti KL, Girod FX, Glamazdin O, Goetz JT, Golovach E, Gonenc A, Gordon CIO, Gothe RW, Griffioen KA, Guidal M, Guler N, Gyurjyan V, Hadjidakis C, Hafidi K, Hakobyan RS, Hardie J, Hersman FW, Hicks K, Hleiqawi I, Holtrop M, Hyde-Wright CE, Ilieva Y, Ireland DG, Ishkhanov BS, Isupov EL, Ito MM, Jenkins D, Jo HS, Joo K, Juengst HG, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Kossov M, Kramer LH, Kuhn J, Kuhn SE, Kuleshov SV, Lachniet J, Laget JM, Langheinrich J, Lawrence D, Lee T, Li J, Livingston K, Lu H, MacCormick M, Markov N, McKinnon B, Mecking BA, Melone JJ, Mestayer MD, Meyer CA, Mibe T, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mochalov V, Mokeev V, Morand L, Morrow SA, Moteabbed M, Nadel-Turonski P, Nakagawa I, Nasseripour R, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niroula MR, Niyazov RA, Nozar M, Osipenko M, Ostrovidov AI, Park K, Pasyuk E, Paterson C, Pierce J, Pivnyuk N, Pocanic D, Pogorelko O, Pozdniakov S, Price JW, Prok Y, Protopopescu D, Raue BA, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rosner G, Rossi P, Sabatié F, Salgado C, Santoro JP, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shvedunov NV, Smith ES, Smith LC, Sober DI, Stavinsky A, Stepanyan SS, Stepanyan S, Stokes BE, Strakovsky II, Strauch S, Taiuti M, Tedeschi DJ, Teymurazyan A, Thoma U, Tkabladze A, Tkachenko S, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Weinstein LB, Williams M, Wolin E, Wood MH, Yegneswaran A, Zana L, Zhang J, Zhao B. Search for Theta++ pentaquarks in the exclusive reaction gammap-->K+K-p. PHYSICAL REVIEW LETTERS 2006; 97:102001. [PMID: 17025804 DOI: 10.1103/physrevlett.97.102001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Indexed: 05/12/2023]
Abstract
The reaction gammap --> pK+K- was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a Theta++ pentaquark, a narrow, doubly charged baryon state having strangeness S=+1 and isospin I=1, in the pK+ invariant mass spectrum. No statistically significant evidence of a Theta++ was found. Upper limits on the total and differential cross section for the reaction gammap --> K-Theta++ were obtained in the mass range from 1.5 to 2.0 GeV/c2, with an upper limit for a narrow resonance with a mass M(Theta++) = 1.54 GeV/c2 of about 0.15 nb, 95% C.L.. This result places a stringent upper limit on the Theta++ width Gamma(Theta++) <0.1 MeV/c2.
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Kohri H, Ahn DS, Ahn JK, Akimune H, Asano Y, Chang WC, Date' S, Ejiri H, Fukui S, Fujimura H, Fujiwara M, Hasegawa S, Hicks K, Hotta T, Imai K, Ishikawa T, Iwata T, Kawai H, Kim ZY, Kino K, Kumagai N, Makino S, Mart T, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi Y, Morita M, Muramatsu N, Nakano T, Niiyama M, Nomachi M, Ohashi Y, Ohkuma H, Ooba T, Oshuev DS, Rangacharyulu C, Sakaguchi A, Sasaki T, Shagin PM, Shiino Y, Shimizu A, Shimizu H, Sugaya Y, Sumihama M, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Differential cross section and photon-beam asymmetry for the gamma n --> K+ Sigma- reaction at E gamma = 1.5-2.4 GeV. PHYSICAL REVIEW LETTERS 2006; 97:082003. [PMID: 17026294 DOI: 10.1103/physrevlett.97.082003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Indexed: 05/12/2023]
Abstract
Differential cross sections and photon-beam asymmetries have been measured for the gamma n --> K+ Sigma- and gamma p --> K+Sigma0 reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of E gamma = 1.5-2.4 GeV at 0.6 < cos ThetacmK< 1. The cross section ratio of sigma K+ Sigma-/sigma K+ Sigma0, expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+ Sigma- reaction, large positive asymmetries are observed, indicating the dominance of K* exchange. The large difference between the asymmetries for the K+ Sigma- and K+ Sigma0 reactions cannot be explained by simple theoretical considerations based on Regge model calculations.
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