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Recent papers in Graal
Paradoxically asserting a self-consciously fictional narrative’s participation in sacred meaning, the verse and prose versions of Robert de Boron’s Old French "Joseph d’Arimathie" (late twelfth-early thirteenth century) strategically... more
Paradoxically asserting a self-consciously fictional narrative’s participation in sacred meaning, the verse and prose versions of Robert de Boron’s Old French "Joseph d’Arimathie" (late twelfth-early thirteenth century) strategically repurpose and dismantle the romance topos of the ancient, authoritative source. They mix modesty and self-valorisation in generating deliberately conflicted representations of the Joseph’s own origins and of its ability to contain or communicate, while also conducting an ethically charged negotiation between, different kinds of textual and spiritual truth, especially as modelled by evangelical historiography.
Charged particle detection at GRAAL - Radiation Effects & Defects in Solids, Taylor & Francis, May-June 2009, Vol. 164, N. 5-6, pp. 357-362, ISSN:1042-0150, doi: 10.1080/10420150902811698 di F. Mammoliti, V. Bellini, A. Giusa, C.... more
Charged particle detection at GRAAL - Radiation Effects & Defects in Solids, Taylor & Francis, May-June 2009, Vol. 164, N. 5-6, pp. 357-362, ISSN:1042-0150, doi: 10.1080/10420150902811698
di F. Mammoliti, V. Bellini, A. Giusa, C. Randieri, G. Russo, M. L. Sperduto, M. C. Sutera, A. D’Angelo, R. Di Salvo, A. Fantini, D. Franco, D. Moricciani, C. Schaerf, V. Vegna, P. Levi Sandri, G. Mandaglio, G. Giardina (2009)
Abstract
Experimental results on proton and charged pion detection obtained from a study of the γ+n→p+π− reaction are reported in detail. Data have been collected using the tagged and linearly polarized photon beam, impinging on a deuterium target, and the large solid angle apparatus of the GRAAL facility in Grenoble (France). The energy of the charged particles was measured using a BGO calorimeter. A comparison of the experimental data with a GEANT3-based simulation is also presented.
di F. Mammoliti, V. Bellini, A. Giusa, C. Randieri, G. Russo, M. L. Sperduto, M. C. Sutera, A. D’Angelo, R. Di Salvo, A. Fantini, D. Franco, D. Moricciani, C. Schaerf, V. Vegna, P. Levi Sandri, G. Mandaglio, G. Giardina (2009)
Abstract
Experimental results on proton and charged pion detection obtained from a study of the γ+n→p+π− reaction are reported in detail. Data have been collected using the tagged and linearly polarized photon beam, impinging on a deuterium target, and the large solid angle apparatus of the GRAAL facility in Grenoble (France). The energy of the charged particles was measured using a BGO calorimeter. A comparison of the experimental data with a GEANT3-based simulation is also presented.
- by Cristian Randieri and +1
- •
- Science, Research, Graal, Bgo Calorimeter
Measurement of Σ beam asymmetry in π0 photoproduction off the neutron in the second and third resonances region - The European Physical Journal A, Hadrons and Nuclei, November 2009, Vol. 42, N. 2, pp. 151-157, ISSN: 1434-6001, doi:... more
Measurement of Σ beam asymmetry in π0 photoproduction off the neutron in the second and third resonances region - The European Physical Journal A, Hadrons and Nuclei, November 2009, Vol. 42, N. 2, pp. 151-157, ISSN: 1434-6001, doi: 10.1140/epja/i2009-10870-x
di R. Di Salvo, A. Fantini, G. Mandaglio, F. Mammoliti, O. Bartalini, V. Bellini, J. P. Bocquet, L. Casano, A. D’angelo, J. P. Didelez, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, R. Kunne, A. Lapik, P. Levi Sandri, A. Lleres, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, C. Randieri, D. Rebreyend, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna, A. Fix, S. S. Kamalov, L. Tiator (2009)
Abstract
The Σ beam asymmetry in the photoproduction of neutral pions from quasi-free nucleons in a deuteron target was measured for the first time between 0.60 and 1.50GeV, with the GRAAL polarized and tagged photon beam. The asymmetry values from the quasi-free proton were found equal to the ones extracted from a pure proton target. The asymmetries from quasi-free proton and quasi-free neutron were found equal up to 0.82GeV and substantially different at higher energies. The results are compared with recent partial-wave analyses.
di R. Di Salvo, A. Fantini, G. Mandaglio, F. Mammoliti, O. Bartalini, V. Bellini, J. P. Bocquet, L. Casano, A. D’angelo, J. P. Didelez, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, R. Kunne, A. Lapik, P. Levi Sandri, A. Lleres, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, C. Randieri, D. Rebreyend, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna, A. Fix, S. S. Kamalov, L. Tiator (2009)
Abstract
The Σ beam asymmetry in the photoproduction of neutral pions from quasi-free nucleons in a deuteron target was measured for the first time between 0.60 and 1.50GeV, with the GRAAL polarized and tagged photon beam. The asymmetry values from the quasi-free proton were found equal to the ones extracted from a pure proton target. The asymmetries from quasi-free proton and quasi-free neutron were found equal up to 0.82GeV and substantially different at higher energies. The results are compared with recent partial-wave analyses.
- by Cristian Randieri and +1
- •
- Science, Neutrons, Photoproduction, Graal
Studies of Spin-Orbit Correlations in Kaon Electroproduction in DIS with polarized hydrogen and deuterium targets - A 12 GeV Research Proposal to Jefferson Lab di H. Avakian, A. Bacchetta, V.D. Burkert, L.Elouadrhiri, V. Kubarovsky, S... more
Studies of Spin-Orbit Correlations in Kaon Electroproduction in DIS with polarized hydrogen and deuterium targets - A 12 GeV Research Proposal to Jefferson Lab
di H. Avakian, A. Bacchetta, V.D. Burkert, L.Elouadrhiri, V. Kubarovsky, S Stepanyan E. Cisbani, F. Cusanno, F. Garibaldi, S. Frullani, P. Rossi†, E. De Sanctis, L. Hovsepyan, M. Mirazita, and S. Anefalos Pereira, K. Hafidi, J. Arrington, P. Dupr´e, D. F. Geesaman, R. J. Holt, D. H. Potterveld, P. E. Reimer, P. Solvignon K. Griffioen, Bo Zhao, M. Aghasyan, S.E. Kuhn, Z.-E. Meziani, B. Sawatzky, A. Lukhanin, D. Ireland, R. Kaiser, K. Livingston, D. MacGregor, G. Rosner, B. Seitz, K. Joo, P. Schweitzer, M. Ungaro, P.F. Dalpiaz, G. Ciullo, M. Contalbrigo, F. Giordano, P. Lenisa, L. Pappalardo, A. D’Angelo, C. Schaerf, V. Vegna, R. De Leo, L. Lagamba, S. Marrone, G. Simonetti, E. Nappi, I. Vilardi, G.M. Urciuoli, M. Battaglieri, R. De Vita, V. Drozdov, M. Osipenko, M. Ripani, M. Taiuti, V. Bellini, A. Giusa, F. Mammoliti, C. Randieri, G. Russo, M.L. Sperduto, C.M. Sutera, N. Kalantarians, D. Crabb, L.C. Smith, R. Avagyan, A. Avetisyan, R. Dallakyan, S. Taroyan, F. Benmokhtar, M. Anselmino, A. Kotzinian, B. Parsamyan, A. Prokudin, M. Burkardt, B. Pasquini, L. Gamberg, G.R. Goldstein
Abstract
We are proposing a comprehensive program to study transverse momentum depen- dence of valence quark transverse and longitudinal spin distributions through mea- surements of spin-azimuthal asymmetries in semi-inclusive electroproduction of kaons using the upgraded JLab 11 GeV polarized electron beam and the CLAS12 detector with longitudinally polarized proton and deuteron targets. Main objectives include studies of correlations of the transverse spin of quarks with their transverse momen- tum, leading to observable spin and azimuthal asymmetries. The measurement of the sin 2_ azimuthal moment of the semi-inclusive production of hadrons in DIS with lon- gitudinally polarized targets, in particular will provide direct information on spin-orbit correlations by measuring the leading twist transverse momentum dependent (TMD) parton distributions related to the interference between states with different orbital momenta. Measurements with kaons are complementary to measurements with pions and will provide additional information on the Collins fragmentation mechanism. The PT dependence of the double spin asymmetry will provide additional information on the flavor and polarization dependence of transverse momentum dependence of helicity distributions of quarks, providing complementary to SSA measurements access to spin-orbit correlations. The x, z, PT and Q2 dependences of the sin 2_ and sin _ mo- ments will be studied to probe the underlying T-odd distribution and fragmentation functions. The experiment will use the upgraded CLAS12 detector, 11 GeV highly polarized electron beam and longitudinally polarized solid ammonia targets (NH3 and ND3). Kaon identification in the complete kinematic range...
di H. Avakian, A. Bacchetta, V.D. Burkert, L.Elouadrhiri, V. Kubarovsky, S Stepanyan E. Cisbani, F. Cusanno, F. Garibaldi, S. Frullani, P. Rossi†, E. De Sanctis, L. Hovsepyan, M. Mirazita, and S. Anefalos Pereira, K. Hafidi, J. Arrington, P. Dupr´e, D. F. Geesaman, R. J. Holt, D. H. Potterveld, P. E. Reimer, P. Solvignon K. Griffioen, Bo Zhao, M. Aghasyan, S.E. Kuhn, Z.-E. Meziani, B. Sawatzky, A. Lukhanin, D. Ireland, R. Kaiser, K. Livingston, D. MacGregor, G. Rosner, B. Seitz, K. Joo, P. Schweitzer, M. Ungaro, P.F. Dalpiaz, G. Ciullo, M. Contalbrigo, F. Giordano, P. Lenisa, L. Pappalardo, A. D’Angelo, C. Schaerf, V. Vegna, R. De Leo, L. Lagamba, S. Marrone, G. Simonetti, E. Nappi, I. Vilardi, G.M. Urciuoli, M. Battaglieri, R. De Vita, V. Drozdov, M. Osipenko, M. Ripani, M. Taiuti, V. Bellini, A. Giusa, F. Mammoliti, C. Randieri, G. Russo, M.L. Sperduto, C.M. Sutera, N. Kalantarians, D. Crabb, L.C. Smith, R. Avagyan, A. Avetisyan, R. Dallakyan, S. Taroyan, F. Benmokhtar, M. Anselmino, A. Kotzinian, B. Parsamyan, A. Prokudin, M. Burkardt, B. Pasquini, L. Gamberg, G.R. Goldstein
Abstract
We are proposing a comprehensive program to study transverse momentum depen- dence of valence quark transverse and longitudinal spin distributions through mea- surements of spin-azimuthal asymmetries in semi-inclusive electroproduction of kaons using the upgraded JLab 11 GeV polarized electron beam and the CLAS12 detector with longitudinally polarized proton and deuteron targets. Main objectives include studies of correlations of the transverse spin of quarks with their transverse momen- tum, leading to observable spin and azimuthal asymmetries. The measurement of the sin 2_ azimuthal moment of the semi-inclusive production of hadrons in DIS with lon- gitudinally polarized targets, in particular will provide direct information on spin-orbit correlations by measuring the leading twist transverse momentum dependent (TMD) parton distributions related to the interference between states with different orbital momenta. Measurements with kaons are complementary to measurements with pions and will provide additional information on the Collins fragmentation mechanism. The PT dependence of the double spin asymmetry will provide additional information on the flavor and polarization dependence of transverse momentum dependence of helicity distributions of quarks, providing complementary to SSA measurements access to spin-orbit correlations. The x, z, PT and Q2 dependences of the sin 2_ and sin _ mo- ments will be studied to probe the underlying T-odd distribution and fragmentation functions. The experiment will use the upgraded CLAS12 detector, 11 GeV highly polarized electron beam and longitudinally polarized solid ammonia targets (NH3 and ND3). Kaon identification in the complete kinematic range...
- by Cristian Randieri and +1
- •
- Research, Deuterium, Dis, Graal
[PT] Enigma em texto arturiano do século XIII é investigado por meio do exame de fontes, bem como de considerações históricas e linguísticas. A obra estudada se insere na Matéria de Bretanha, representada de forma significativa na... more
[PT] Enigma em texto arturiano do século XIII é investigado por meio do exame de fontes, bem como de considerações históricas e linguísticas. A obra estudada se insere na Matéria de Bretanha, representada de forma significativa na literatura portuguesa medieval.
[EN] An enigma in a text of the XIIIth century is investigated through the study of soucers, as well as historic and linguistic considerations. The work under scrutiny belongs to the Matter of Britain, significantly represented in medieval Portuguese literature.
[EN] An enigma in a text of the XIIIth century is investigated through the study of soucers, as well as historic and linguistic considerations. The work under scrutiny belongs to the Matter of Britain, significantly represented in medieval Portuguese literature.
Disintegration of 12C nuclei by 700–1500 MeV photons - Elsevier Science, Nuclear Physics A, August 2015, Vol. 940, pp. 264-278, DOI: 10.1016/j.nuclphysa.2015.05.001 di V. Nedorezov, A. D’Angelo, O. Bartalini, V. Bellini, M. Capogni,... more
Disintegration of 12C nuclei by 700–1500 MeV photons - Elsevier Science, Nuclear Physics A, August 2015, Vol. 940, pp. 264-278, DOI: 10.1016/j.nuclphysa.2015.05.001
di V. Nedorezov, A. D’Angelo, O. Bartalini, V. Bellini, M. Capogni, L.E. Casano, M. Castoldi, F. Curciarello, V. De Leo, J.-P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Lapik, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, I. Pshenichnov, C. Randieri, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M.-C. Sutera, A. Turinge, V. Vegna, I. Zonta (2015)
Abstract
Disintegration of 12C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of 12C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on 12C in the same energy range is also reported.
di V. Nedorezov, A. D’Angelo, O. Bartalini, V. Bellini, M. Capogni, L.E. Casano, M. Castoldi, F. Curciarello, V. De Leo, J.-P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Lapik, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, I. Pshenichnov, C. Randieri, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M.-C. Sutera, A. Turinge, V. Vegna, I. Zonta (2015)
Abstract
Disintegration of 12C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of 12C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on 12C in the same energy range is also reported.
- by Cristian Randieri and +1
- •
- Nuclear Physics, Research, Photons, Graal
Latest results from GRAAL collaboration - Chinese Physics C (HEP & NP), December 2009, Vol. 33, N. 12, pp. 1249-1253, ISSN: 1674-1137, doi: 10.1088/1674-1137/33/12/032 di V. Vegna, V. Bellini, J. P. Bouquet, L. Casano, A. D'Angelo, J.... more
Latest results from GRAAL collaboration - Chinese Physics C (HEP & NP), December 2009, Vol. 33, N. 12, pp. 1249-1253, ISSN: 1674-1137, doi: 10.1088/1674-1137/33/12/032
di V. Vegna, V. Bellini, J. P. Bouquet, L. Casano, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, A. S. Ignatov, R. Kunnel, A. Lapik, A. Lleres, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, M. Moricciani, A.N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge (2009)
Abstract
The GRAAL experimental set-up consists of a polarized and tagged photon beam that covers an energy range from a minimum of 600 MeV up to a maximum of 1500 MeV, of a liquid Hydrogen or Deuterium target and of the 4π Lagrange detector optimized for photon detection. It allows the study of pseudo-scalar and vector meson photoproduction on the nucleon in the energy range corresponding to the second and the third resonance regions. In the following, the σ beam asymmetries in η and π0 photoproduction on quasi-free nucleon are shown. Also single and double polarization observables in K+Λ photoproduction on free proton are shown; they are important to confirm the role of new or poorly known resonances in the 1900 MeV mass region.
di V. Vegna, V. Bellini, J. P. Bouquet, L. Casano, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, M. Guidal, E. Hourany, A. S. Ignatov, R. Kunnel, A. Lapik, A. Lleres, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, M. Moricciani, A.N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge (2009)
Abstract
The GRAAL experimental set-up consists of a polarized and tagged photon beam that covers an energy range from a minimum of 600 MeV up to a maximum of 1500 MeV, of a liquid Hydrogen or Deuterium target and of the 4π Lagrange detector optimized for photon detection. It allows the study of pseudo-scalar and vector meson photoproduction on the nucleon in the energy range corresponding to the second and the third resonance regions. In the following, the σ beam asymmetries in η and π0 photoproduction on quasi-free nucleon are shown. Also single and double polarization observables in K+Λ photoproduction on free proton are shown; they are important to confirm the role of new or poorly known resonances in the 1900 MeV mass region.
Così, in settenari, un poeta breve. L’inconveniente capitò alla poesia, alla filosofia, e alla scienza poi non ne parliamo. E alla musica? Anche alla musica. Prendiamo il Parsifal, prendiamo Wagner e certe cose che gli nacquero intorno,... more
Così, in settenari, un poeta breve. L’inconveniente capitò alla poesia, alla filosofia, e alla scienza poi non ne parliamo. E alla musica? Anche alla musica. Prendiamo il Parsifal, prendiamo Wagner e certe cose che gli nacquero intorno, che riguardarono ciò che era stato e ciò che sarebbe avvenuto. Il 18 maggio 1939, quattro mesi prima dello scoppio della Seconda Guerra Mondiale, il generale delle SS Karl Wolff fece pubblicare sul “Berliner Ausgabe” un afflitto inconsueto necrologio, riguardante l’Obertsturmführer Otto Rahn, il quale aveva perso la vita durante una solitaria escursione sulle Alpi austriache, in una tormenta di neve. Non si trattava del dolore per la perdita di un qualsiasi tenente delle Schutz-Staffeln, e per un preciso motivo: Otto Rahn era un valente storico, che si era dedicato al Parsifal, l’eroe consacrato alla ricerca del Graal. A quel che se ne sapeva, Himmler, comandante in capo di tutte le organizzazioni poliziesche del Reich e patologicamente ossessionato ...
Search for light-speed anisotropies using Compton scattering of high-energy electrons - Proceedings of the Fifth Meeting on CPT and Lorentz Symmetry, Indiana University of Bloomington (USA), 28 June-2 July 2010. CPT and Lorentz Symmetry,... more
Search for light-speed anisotropies using Compton scattering of high-energy electrons - Proceedings of the Fifth Meeting on CPT and Lorentz Symmetry, Indiana University of Bloomington (USA), 28 June-2 July 2010. CPT and Lorentz Symmetry, December 2011, pp. 35-39, doi: 10.1142/9789814327688_0008
di J. P. Bocquet, V. Bellini, M. Beretta, L. Casano, A. D’Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, V. G. Gurzadyan, A. Kashin, S. Knyazyan, A. Lapik, R. Lehnert, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, A. Margarian, S. Mehrabyan, R. Messi, D. Moricciani, V. Nedorezov, C. Perrin, C. Randieri, D. Rebreyend, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the γ-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 × 10-14 at 95% confidence level on a combination of photon and electron coefficients of the minimal Standard-Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.
di J. P. Bocquet, V. Bellini, M. Beretta, L. Casano, A. D’Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, V. G. Gurzadyan, A. Kashin, S. Knyazyan, A. Lapik, R. Lehnert, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, A. Margarian, S. Mehrabyan, R. Messi, D. Moricciani, V. Nedorezov, C. Perrin, C. Randieri, D. Rebreyend, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the γ-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 × 10-14 at 95% confidence level on a combination of photon and electron coefficients of the minimal Standard-Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.
- by Cristian Randieri and +1
- •
- Research, Anisotropy, Electrons, Speed of Light
First measurement of the Σ beam asymmetry in η photoproduction on the neutron - The American Physical Society, Physical Review C, 11 July 2008, Vol. 78, pp. 015203-1-015203-12, ISSN: 0556-2813, doi: 10.1103/PhysRevC.78.015203 di A.... more
First measurement of the Σ beam asymmetry in η photoproduction on the neutron - The American Physical Society, Physical Review C, 11 July 2008, Vol. 78, pp. 015203-1-015203-12, ISSN: 0556-2813, doi: 10.1103/PhysRevC.78.015203
di A. Fantini, R. Di Salvo, O. Bartalini, V. Bellini, J. P. Bocquet, L. Casano, M. Castoldi, A. D'Angelo, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, V. Kuznetsov, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2008)
Abstract
We present the first measurement of the Σ beam asymmetry in η photoproduction on the neutron in the photon energy range from threshold to 1.5 GeV. Data have been collected by using the tagged and linearly polarized photon beam and the large solid angle apparatus of the GRAAL facility. Neutron data have been selected among η photoproduction events on the deuteron in the quasi-free kinematics approximation. Proton data, extracted in the same way, are within errors identical to those previously obtained on free protons at the GRAAL facility, except for a few points falling in certain energy bins. This difference is, however, well understood in terms of the Fermi motion of the nucleons in the deuteron. We take the consistency of free and quasi-free proton data as an indication that nuclear effects are negligible also for neutron data. The ETAMAID model, in which a strong coupling of the D15(1675) resonance to the η-neutron channel is introduced, can explain the proton data very well, but it cannot describe the beam asymmetry for the neutron.
di A. Fantini, R. Di Salvo, O. Bartalini, V. Bellini, J. P. Bocquet, L. Casano, M. Castoldi, A. D'Angelo, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, V. Kuznetsov, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, V. Nedorezov, L. Nicoletti, C. Randieri, D. Rebreyend, F. Renard, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2008)
Abstract
We present the first measurement of the Σ beam asymmetry in η photoproduction on the neutron in the photon energy range from threshold to 1.5 GeV. Data have been collected by using the tagged and linearly polarized photon beam and the large solid angle apparatus of the GRAAL facility. Neutron data have been selected among η photoproduction events on the deuteron in the quasi-free kinematics approximation. Proton data, extracted in the same way, are within errors identical to those previously obtained on free protons at the GRAAL facility, except for a few points falling in certain energy bins. This difference is, however, well understood in terms of the Fermi motion of the nucleons in the deuteron. We take the consistency of free and quasi-free proton data as an indication that nuclear effects are negligible also for neutron data. The ETAMAID model, in which a strong coupling of the D15(1675) resonance to the η-neutron channel is introduced, can explain the proton data very well, but it cannot describe the beam asymmetry for the neutron.
Evidence for a narrow N* (1685) resonance in quasifree Compton scattering on the neutron - The American Physical Society, Physical Review C, February 2011, Vol. 83, N. 2, pp. 022201-1-022201-4, ISSN: 0556-2813, doi:... more
Evidence for a narrow N* (1685) resonance in quasifree Compton scattering on the neutron - The American Physical Society, Physical Review C, February 2011, Vol. 83, N. 2, pp. 022201-1-022201-4, ISSN: 0556-2813, doi: 10.1103/PhysRevC.83.022201
di V. Kuznetsov, M. V. Polyakov, V. Bellini, T. Boiko, S. Chebotaryov, H.-S. Dho, G. Gervino, F. Ghio, A. Giusa, A. Kim, W. Kim, F. Mammoliti, E. Milman, A. Ni, I. A. Perevalova, C. Randieri, G. Russo, M. L. Sperduto, C. M. Sutera, A. N. Vall (2011)
Abstract
The study of quasifree Compton scattering on the neutron in the energy range of Eγ=0.75–1.5 GeV is presented. The data reveal a narrow peak at W~1.685 GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at W~1.68 GeV in η photoproduction on the neutron, suggests the existence of a nucleon resonance with unusual properties: a mass M~1.685GeV, a narrow width Γ⩽30 MeV, and the much stronger photoexcitation on the neutron than on the proton.
di V. Kuznetsov, M. V. Polyakov, V. Bellini, T. Boiko, S. Chebotaryov, H.-S. Dho, G. Gervino, F. Ghio, A. Giusa, A. Kim, W. Kim, F. Mammoliti, E. Milman, A. Ni, I. A. Perevalova, C. Randieri, G. Russo, M. L. Sperduto, C. M. Sutera, A. N. Vall (2011)
Abstract
The study of quasifree Compton scattering on the neutron in the energy range of Eγ=0.75–1.5 GeV is presented. The data reveal a narrow peak at W~1.685 GeV. This result, being considered in conjunction with the recent evidence for a narrow structure at W~1.68 GeV in η photoproduction on the neutron, suggests the existence of a nucleon resonance with unusual properties: a mass M~1.685GeV, a narrow width Γ⩽30 MeV, and the much stronger photoexcitation on the neutron than on the proton.
- by Cristian Randieri and +1
- •
- Research, Resonance, Neutrons, Compton Scattering
Beam asymmetry Σ measurements on the π- Photoproduction off neutrons - The American Physical Society, Physical Review C, Nuclear Physics, October 2010, Vol. 82, N. 4, pp. 045209-1-045209-7, ISSN: 0556-2813, doi:... more
Beam asymmetry Σ measurements on the π- Photoproduction off neutrons - The American Physical Society, Physical Review C, Nuclear Physics, October 2010, Vol. 82, N. 4, pp. 045209-1-045209-7, ISSN: 0556-2813, doi: 10.1103/PhysRevC.82.045209
di G. Mandaglio, F. Mammoliti, M. Manganaro, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Ignatov, A. Lapik, P. Levi Sandri, A. Lleres, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna, W. J. Briscoe, I. I. Strakovsky (2010)
Abstract
The Σ beam asymmetry in the photoproduction of negative pions from quasi-free neutrons in a deuterium target was measured at Graal in the energy interval 700 - 1500 MeV and a wide angular range, using polarized and tagged photons. The results are compared with recent partial wave analyses.
di G. Mandaglio, F. Mammoliti, M. Manganaro, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Ignatov, A. Lapik, P. Levi Sandri, A. Lleres, D. Moricciani, A. N. Mushkarenkov, V. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna, W. J. Briscoe, I. I. Strakovsky (2010)
Abstract
The Σ beam asymmetry in the photoproduction of negative pions from quasi-free neutrons in a deuterium target was measured at Graal in the energy interval 700 - 1500 MeV and a wide angular range, using polarized and tagged photons. The results are compared with recent partial wave analyses.
- by Cristian Randieri and +1
- •
- Science, Research, MEASUREMENTS, Graal
Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 965-976, doi: 10.1142/S0218301310015412 di G. Mandaglio, V. Bellini, J. P. Bocquet, L. Casano, A.... more
Beam Asymmetry Σ of the π- Photoproduction off Neutron - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 965-976, doi: 10.1142/S0218301310015412
di G. Mandaglio, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. M. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
We present the analysis of data performed in order to identify the events of the γ + n → π- + p reaction obtained by bombarding a liquid Deuterium target with a polarised γ beam of 0.55-1.5 GeV at the Graal-experiment. We show the effect of different kinematic and hardware constraints used to reduce the contamination coming from the concurrent reaction channels. By the simulation we estimate the contamination degree due to the other reaction channels so we can test the reliability of our method. We describe a new three-dimensional cut based on the Fermi momentum reconstruction and its effect on the suppression of the concurrent double charged pion photoproduction. We present the preliminary beam asymmetry Σ of the π- fotoproduction off quasi-free neutron up to about θc.m., π- = 165° together with some theoretical multipolar analysis. For a comparison we also report the data present in literature on the same reaction for Eγ =850-1740 MeV and θc.m., π- ≤105°.
di G. Mandaglio, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. M. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, M. Manganaro, D. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
We present the analysis of data performed in order to identify the events of the γ + n → π- + p reaction obtained by bombarding a liquid Deuterium target with a polarised γ beam of 0.55-1.5 GeV at the Graal-experiment. We show the effect of different kinematic and hardware constraints used to reduce the contamination coming from the concurrent reaction channels. By the simulation we estimate the contamination degree due to the other reaction channels so we can test the reliability of our method. We describe a new three-dimensional cut based on the Fermi momentum reconstruction and its effect on the suppression of the concurrent double charged pion photoproduction. We present the preliminary beam asymmetry Σ of the π- fotoproduction off quasi-free neutron up to about θc.m., π- = 165° together with some theoretical multipolar analysis. For a comparison we also report the data present in literature on the same reaction for Eγ =850-1740 MeV and θc.m., π- ≤105°.
- by Cristian Randieri and +1
- •
- Science, Research, Graal, Beam Asymmetry
Photoproduction of π0π+ on the proton and deuteron at Eγ = 0.7 - 1.5 GEV - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 1197-1204, ISSN: 0218-3013, doi: 10.1142/S0218301310015679 di A. Mushkarenkov, V.... more
Photoproduction of π0π+ on the proton and deuteron at Eγ = 0.7 - 1.5 GEV - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 1197-1204, ISSN: 0218-3013, doi: 10.1142/S0218301310015679
di A. Mushkarenkov, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
The preliminary results obtained by the GRAAL collaboration for the π0π+ photoproduction on the free and quasi-free proton (deuteron) at Eγ = 0.7-1.5 GeV are presented. The total cross section of the γp → π0π+n reaction and invariant mass spectra for the π+π0, π+n and π0n systems are presented in the photon energy range from 0.7 to 1.5 GeV. These results are in good agreement with the 2π-MAID calculations.
di A. Mushkarenkov, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. Lapik, P. Levi Sandri, A. Lleres, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
The preliminary results obtained by the GRAAL collaboration for the π0π+ photoproduction on the free and quasi-free proton (deuteron) at Eγ = 0.7-1.5 GeV are presented. The total cross section of the γp → π0π+n reaction and invariant mass spectra for the π+π0, π+n and π0n systems are presented in the photon energy range from 0.7 to 1.5 GeV. These results are in good agreement with the 2π-MAID calculations.
- by Cristian Randieri and +1
- •
- Science, Research, Protons, Photoproduction
Preliminary results on η' Photoproduction at GRAAL - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 1177-1182, ISSN: 0218-3013, doi: 10.1142/S0218301310015643 di M. Manganaro, V. Bellini, J. P. Bocquet, L.... more
Preliminary results on η' Photoproduction at GRAAL - International Journal of Modern Physics E, June 2010, Vol. 19, N. 5-6, pp. 1177-1182, ISSN: 0218-3013, doi: 10.1142/S0218301310015643
di M. Manganaro, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. Lapik, A. Lleres, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
The γp → η‧p reaction was studied near the threshold, in the 1.44 GeV> Eγ < 1.55GeV energy range with the tagged photons of the former GRAAL experiment. The two neutral decays γγ(Γi/Γ = 2.10 ± 0.12%) and π0π0η(Γi/Γ = 20.7 ± 1.2%) were analized and preliminary results of the beam asymmetry were extracted together with the invariant masses.
di M. Manganaro, V. Bellini, J. P. Bocquet, L. Casano, A. D'Angelo, J. P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. S. Ignatov, A. Lapik, A. Lleres, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Moricciani, A. N. Mushkarenkov, V. G. Nedorezov, C. Randieri, D. Rebreyend, N. V. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M. C. Sutera, A. Turinge, V. Vegna (2010)
Abstract
The γp → η‧p reaction was studied near the threshold, in the 1.44 GeV> Eγ < 1.55GeV energy range with the tagged photons of the former GRAAL experiment. The two neutral decays γγ(Γi/Γ = 2.10 ± 0.12%) and π0π0η(Γi/Γ = 20.7 ± 1.2%) were analized and preliminary results of the beam asymmetry were extracted together with the invariant masses.
- by Cristian Randieri and +1
- •
- Physics, Science, Research, Photoproduction