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other world results, starting with the G0 forward angle measurements to enable the determination of individual strange and axial form factors. Forward measurements results For eighteen values of Q 2 , the asymmetries have been measured simultaneously, the results of Figure 2 Asymmetries and form factors which are presented in Fig.2, together with the linear combinations of G s E, G s M , extracted from the asymmetries [3]. Figure 3 G s E, G s M and G e A determined by the G0 experiment forward and backward angle measurements [4]. Results are compared to other experiments [5], [6] and [9] and to recent calculations [7], [8], [10] and [11]. Backward measurements results Only two Q 2 regions have been explored at backward angle because of time limitation. Combined with the forward angle measurements it was possible to extract all the form factors separately with data from G0 only. The results are presented in Fig.3 with some theoretical calculations. Summary In summary, we have measured forward angle parity violating asymmetries in elastic electron-proton in the range of Q 2 = 0.15 to 1.0 GeV 2 and backward angle parityviolating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at Q 2 = 0.221 and 0.628 GeV 2 . These asymmetries determine the neutral weak interaction analogs of the ordinary charge and magnetic form factors of the nucleon, together with the effective axial form factor. From the asymmetries we have determined G s E, G s M, and G e A T=1 , which indicate that the strange quark contributions to the nucleon form factors are ~ 10%, and provide the first information on the Q 2 dependence of G e A T=1 . Future forward angle experiments at Q 2 = 0.63 GeV 2 at Jefferson Lab and Mainz will further improve the precision of these determinations.Other new data on parity violation will soon complement these studies leading to a better knowledge of hadronic effects at low Q 2 . The next challenge for the parityviolating electron scattering is the search of physics beyond the Standard Model, part for example, of the already planned Qweak experiment at JLab [12]. Acknowledgements We acknowledge all the G0 collaboration and particularly the students in charge of the analysis and the analysis coordinator Fatiha Benmokhtar for providing the material for this paper and the associated talks. References [1] K.A Aniol et al., PRC70, 065501 (2004); K.A Aniol et al., nucl-ex/0506010; Aniol et al., nuclex/0506011 [2] L.Bimbot “ The G0 parity violation experiment: overview and status after the first commissioning run“ proceedings NUPPAC03; L.Bimbot “First results from the g0 parity violation experiment carried out at JLab“ proceedings NUPPAC07. [3] D.S.Armstrong et al., PRL95, 092001 (2005). [4] D.Androic et al.,PRL104, 02001 (2010); arXiv: 0909.5107 [5] J.Liu, R.D.McKeown and M.J.Ramsey-Musolf, PRC 76, 025202 (2007). [6] F.EMass et al., PRL93, 022002 (2004); F.E.Mass et al., PRL94, 152001 (2005), S.Baunach et al. PRL102, 151803 (2009). [7] D.Leinweber et al., PRL94, 212001 (2005); D. Leinweber et al., PRL97, 022001 (2006); P. Wang et al., PRC 79, 065202 (2009). [8] T.Doi et al., arXiv:0903.3232. [9] E.J.Beise, M.L.Pitt and D.T.Spayde, PPNP54, 289 (2005). [10] S.L.Zhu et al., PRD 62, 033008 (2000). [11] L.A.Ahrens et al., PRD 35, 785 (1987). [12] R. Carlini, contact person, The Qweak Experiment: A search for Physics at the TeV Scale via a measurement of the Proton’s Weak Charge, Jefferson Lab. proposals E02-020, E05-008 and E08- 016. 41
GEp-III and GEp-2 at Jefferson Lab IPNO Participation: L. Bimbot and E.Tomasi-Gustafsson Collaboration: Christopher Newport University, College William & Mary, Norfolk State University, Jefferson Lab., Argonne National Laboratory, California State University at Los Angeles, DAPNIA Saclay, Florida State University, IHEP Protvino, INFN-ISS, IPNO, Kent State University, LHE JINR Dubna, M.I.T., Northwestern University, Old Dominion University, Rutgers University, University of Maryland, University of New Hampshire, Universiy of Regina. L’étude des facteurs de forme électrique (GEp) et magnétique (GMp) du proton par la mesure de la polarisation du proton de recul dans une diffusion élastique d’électrons polarisés s’est révélée mieux adaptée à leur détermination que la méthode de séparation de Rosenbluth. Des expériences faites dans le hall A de Jefferson Lab (JLab) ont mis en évidence une décroissance continue de GEp quand Q 2 augmente. De nouvelles expériences dans le hall C ont permis d’étendre les mesures du rapport GEp/GMp [GEp-III] jusqu’à 8,49 (GeV/c) 2 et de valider la méthode qui est basée sur le mécanisme d'échange d'un photon. L'expérience [GEp-2 ] a montré que le rapport des facteurs de forme du proton GEp/GMp est constant en fonction de (polarisation linéaire du photon virtuel) et donc de réfuter un rôle éventuel d’un processus à deux photons. Figure. 1 Experimental results from Rosenbluth separation (red) and recoil polarisations (blue). When CEBAF started to deliver intense beam of electrons it was possible to consider measuring polarisation of the exit particles by means of a second scattering. The hall A was first equipped with a polarimeter for proton placed at the focal plane of one the two identical spectrometers. This made possible the use of the polarisation of the recoiled proton from electron elastic scattering on hydrogen to determine precisely the ratio of the electric to magnetic form factor of the proton [1]. From the theoretical formalism, this ratio is directly proportional to the measured polarisations: Due to precession in the magnet the transverse and longitudinal polarisations, P t and P l are measured simultaneously. In the formula E e and E’ e are the electron energies before and after scattering, e is the electron scattering angle and M is the proton mass. Before these measurements, this ratio was supposed to be constant, this assumption being consistent with the measurements using the Rosenbluth separation method: see results in Fig. 1. The results obtained with the recoil polarisation method are shown in blue on the same figure and present a different behaviour: a continous decreasing of GEp for increasing Q 2 up to 6 (GeV/c) 2. . This puzzling observation has been confirmed by 2 sets of measurements perfectly overlapping. The results of these specific measurements are presented separateley, with a linear scale in Q 2 in Figure 2, together with the expected error bars for the measurements to come, in red for the present experiment and in black for the submitted experiment to be run after the upgrade of JLab at 12 GeV. Since fall 2007 a new setup is being used to implement the results obtained using the recoil polarisation, in the hall C at JLab. The focal plane polari- Figure 2. Results from recoil polarisation method: previous data (black full square), this experiment (red open circle) and expected measurement at JLab 12 GeV with the new spectrometer SHMS in hall C (open symbols). meter is completely new and is working in two stages with additionnal tracking chambers placed between two analyzer blocks to improve the factor of merit of proton polarization determination at higher energies. The electron is detected in coincidence in a lead glass calorimeter. 42
Page 1 and 2: EXOTIC NUCLEI STRUCTURE AND REACTIO
Page 3 and 4: in the spectra by analyzing their t
Page 5 and 6: were taken from ref. [5]. Concernin
Page 7 and 8: keV -ray with the particles and the
Page 9 and 10: the 605.9 keV line of the 74 Zn 2+
Page 11 and 12: Figure 2 a n d analysis. Figure 2 s
Page 13 and 14: ing particles was thus obtained by
Page 15 and 16: First p-p p collisions in the ALICE
Page 17 and 18: Quarkonia physics with ALICE IPNO P
Page 19 and 20: NA50 updated puzzle IPNO Participat
Page 21 and 22: Status of the HADES experiment (I):
Page 23 and 24: Status of the HADES experiments (II
Page 25 and 26: Status of the HADES experiment (III
Page 27 and 28: Hadron physics in pbar-p p annihila
Page 29 and 30: Hadron Electrodynamics IPNO Partici
Page 31: G0 experiment at Jefferson Lab. IPN
Page 35 and 36: Exotic low mass narrow baryons from
Page 37 and 38: The PVA4 parity violation experimen
Page 39 and 40: Etude des Distributions de Partons
Page 41 and 42: Latest Results from GRAAL IPNO Part
Page 43 and 44: Persistence of the Polarization in
Page 45 and 46: The northern site of the Pierre Aug
Page 47 and 48: The Pierre Auger southern Observato
Page 49 and 50: In figure 4 we plot the differentia
Page 51 and 52: THEORETICAL PHYSICS Research in the
Page 53 and 54: transfer reaction, the 34 Si(d, 3 H
Page 55 and 56: Collective excitations with SKYRME
Page 57 and 58: Pairing and nuclear incompressibili
Page 59 and 60: Pairing properties in nuclei and in
Page 61 and 62: Evaporation-residue residue cross s
Page 63 and 64: Extending the VMI model: normal and
Page 65 and 66: Alpha particle condensation in nucl
Page 67 and 68: Collective Modes in Ultracold Trapp
Page 69 and 70: Exploring key unknown neutrino prop
Page 71 and 72: Relic astrophysical and cosmologica
Page 73 and 74: After a term by term Borel resummat
Page 75 and 76: Chiral expansions of the π 0 lifet
Page 77 and 78: IPNO Participation: H. Sazdjian Eff
Page 79 and 80: fer is used to extract f + (0). We
Page 81 and 82: cleon. The spectrum becomes strongl
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A pseudo Coulombian potential in D=
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The many-body problem with an energ
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The rotational spectrum and the att
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Z-identification of very heavy nucl
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The Pegase project, a new solid sur
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But at 80 keV total energy ( 200 eV
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Isospin effects on fragment and par
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Radial collective energy and fragme
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Latent heat of the phase transition
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Alpha-particle particle condensatio
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Fluo X: Deexcitation time measureme
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ENERGY AND ENVIRONMENT The increasi
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toe/cap/y which energy access inequ
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nides. A global comparison can be p
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3D coupling of Monte-Carlo neutroni
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Fission cross sections of actinides
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Studies and synthesis of specific m
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Chemistry and Electrochemistry of T
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function of temperature. The recent
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global electron number of the redox
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(D 0 /D)-1 ln complexes of Pa(V). I
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