С.Белостоцкий сессия ОФВЭ Эксперимент HERMES Поляризованные позитроны (электроны) 27.6 ГэВ поляризованные H или D мишени, неполяризованные ядерные мишени С.Белостоцкий Д.Веретенников В.Вихров Г.Гаврилов О.Гребенюк А.Жгун А.Изотов А.Киселев П.Кравченко А.Крившич С.Манаенков О.Миклухо Ю.Нарышкин Ю.Санжиев + Отд.трек.дет. Лаб.крио.тех. КБ Инст.Ефремова

Hermes spectrometer Resolution: Δp/p~1%, ΔΘ

Вклад ПИЯФ в эксперимент Hardware: Магнит спектрометра (раразработка концепции, организация производства, частично инвестирование, магнитные измерения карты поля); Пропорцианальные камеры (11тыс.каналов) в зазоре магнита; Инвестирование (частично) системы считывания PCOS-4; Автоматизированная система охлаждения для frontend PCOS-4 и TRD; Система охлаждения для силикон-стрип детектора Lambda Wheels; Software Разработка программ кодирования события HERMES Decoding; Разработка программы улучшенного трекинга HERMES TC; Производство файлов данных HERMES HRC /DST files; Программа выстройки элементов детектора по трекам, и пр. Разработка программ SLOW CONTROL; DATA TAKING Поддержание MCs, TRD; Поддержание силикон.-стрип дет. LW; Поддержание DAQ; Газообеспечение ; Поддержание Slow Control; Обработка сырых данных; Работа в качестве период координатора; DATA ANALYSIS

Summary of HERMES data-taking Longitudinal beam polarization PB=0.5 Longitudinal and transverse target polarization PT= Unpolarized nucleus targets

Исследование вклада кварков и глюонов в спин нуклона; Полина Кравченко Δq from SIDIS and DIS, kinematic distributions Поляризационные параметры в рождении векторных мезонов; Сергей Манаенков ρ,φ,ω SDME, direct amplitude reconstruction Параметры передачи спина и поляризация в рождении Λ; Денис Веретенников, Юрий Нарышкин, Станислав Белостоцкий DLL, KLL, Pn-tranasverse Lambda and Lbar Ядерные эффекты в рождении гиперонов; Юрий Нарышкин, Станислав Белостоцкий Study of nuclear medium effects on transverse Λ hyperon polarization Oбработка сырых данных. Модернизация кода восстановления треков. Александр Киселевnew Hermes Track Reconstruction Code HTC Вклад ПИЯФ в HERMES анализ

Поляризация кварков в нуклоне (спиновый кризис ??) quarks Inclusive polarized DIS Gluons high PT Semi nclusive polarized DIS

Поляризация кварков в нуклоне (спиновый кризис ??) quarks Inclusive polarized DIS Gluons high PT Semi nclusive polarized DIS Conclusion. Quark and gluon contributions account for 50% of nucleon spin. Is the rest due to orbital motion of nucleon constituents ?

Control of factorization theorem; Control of P T dependence Taking into account Cahn effect ; NLO corrections. Small Q 2 3d unfolding Поляризация кварков в нуклоне. Окончательные результаты Полина Кравченко PhD- 2010

VM production in DIS. Direct reconstruction of amplitudes С. Манаенков Нарушение SCHC Signal from T 01

Продольная передача спина Λ (анти Λ ) гиперону. Окончательные результаты. 10 Semi Inclusive DIS at Q 2 > 0.8 GeV 2 For the first time 3-d analysis HTC Д.Веретенников

Compilation of world data on longitudinal spin transfer

Constituent quark model (CQM) u= d=0, s=1 Lattice QCD u= d= =-0.02±0.04, s=0.68±0.04 SU(3) flavor symmetry u= d=-0.09±0.06, s=0.47±0.07 Burkard/Jaffe u= d=-0.23±0.06, s=0.58±0.07 Various Λ-spin structure tests

Constituent quark model (CQM) u= d=0, s=1 Lattice QCD u= d= =-0.02±0.04, s=0.68±0.04 SU(3) flavor symmetry u= d=-0.09±0.06, s=0.47±0.07 Burkard/Jaffe u= d=-0.23±0.06, s=0.58±0.07 Various Λ-spin structure tests Conclusion. Contribution of strange quark at small x and FF(sΛ) is essentially larger than in LUND MC.

Strong A-dependence of Λ yields and transverse polarization in photoproduction Ю. Нарышкин preliminary In disagreement with hadron- hadron Lambda production

1.Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on a longitudinally polarized deuterium target A. Airapetian et al, Nucl. Phys. B842 (2011) Eprint numbers: arXiv: (hep-ex) and DESY Leading Order Determination of the Gluon Polarization from high-pT Hadron Electroproduction A. Airapetian et al, JHEP 08 (2010) 130 Eprint numbers: arXiv: (hep-ex) and DESY Effects of transversity in deep-inelastic scattering by polarized protons A. Airapetian et al, Phys. Lett. B 693 (2010) Eprint numbers: arXiv: (hep-ex) and DESY Exclusive Leptoproduction of Real Photons on a Longitudinally Polarised Hydrogen target A. Airapetian et al, JHEP 06 (2010) 019 Eprint numbers: arXiv: (hep-ex) and DESY Nuclear-mass dependence of beam-helicity and beam-charge azimuthal asymmetries in DVCS A. Airapetian et al, Phys. Rev. C 81 (2010) Eprint numbers: arXiv: (hep-ex) and DESY Transverse momentum broadening of hadrons produced in semi-inclusive deep-inelastic scattering on nuclei A. Airapetian et al, Phys. Lett. B 684 (2010) Eprint numbers: arXiv: (hep-ex) and DESY Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on an unpolarized deuterium target A. Airapetian et al, Nucl. Phys. B 829 (2010) 1-27 Eprint numbers: arXiv: (hep-ex) and DESY

Международные конференции (4-6 докладов от ПИЯФ в год) 2009 Ю.Г.Нарышкин "A-dependence of the transverse Lambda polarisation" European Nuclear Physics Conference (ENPC09) Mar , 2009 Bochum, Germany Ю.Г.Нарышкин "Lambda Physics at HERMES" XIII Workshop on High Energy Spin Physics (DSPIN09) Sep 1 - 5, 2009 Dubna, Russia П. Кравченко Hermes measurements of strange quark helicity distributions Europian Nuclear Physics Conference (EuNPC) March 16-20, 2009, Bochum С.И.Манаенков Exclusive Electroproduction of $\rho0$, $\phi$, and $\omega$ Mesons at HERMES XIII Workshop on High Energy Spin Physics (DSPIN09) Sep 1 - 5, 2009 Dubna, Russia 2008 Кравченко П. Measurement of Flavor Separated Quark Polarizations at HERMES International Conference DIFFRACTION 2008, La Londe-les-Maures, France September 9-14, 2008 Манаенков С. Exclusive Electroproduction of $\rho0$ and $\phi$ Mesons at HERMES International Workshop on Hadron Structure and QCD (HSQCD2008), Gatchina June 30 -July 04 Веретенников Д. Spin transfer coefficient K_LL in Lambda photoproduction in HERMES 16-th International Workshop DIS 2008, London, 7-11 April 2008 Белостоцкий С. Polarization in Lambda and Lambdabar production at HERMES. The 18th International Symposium on Spin Physics, Spin 2008October , 2008 in Charlottesville, Virginia, USA Белостоцкий С. Lambda physics at HERMES ECT 2008 International Workshop Strangeness polarization in semi-inclusive and exclusive Lambda production Trento, November С.И.Манаенков "Direct Extraction of Helicity Amplitude Ratios in Exclusive $\rho0$ Electroproduction".XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2010), April, Florence, Italy С.И.Манаенков "DIRECT EXTRACTION OF HELICITY AMPLITUDE RATIOS IN EXCLUSIVE $\rho0$ ELECTROPRODUCTION".International Workshop "Hadron Structure and QCD (HSQCD2010)", Gatchina 5-9 July, 2010, Russia Ю.Г.Нарышкин "Lambda polarization at HERMES" IX International Conference on Hyperons, Charm and Beauty Hadrons June 2010, AulaMagna, University of Perugia Perugia, Italy Ю.Г.Нарышкин "Measurement of the nuclear- mass dependence of spontaneous (transverse) Λ polarisation in quasi-real photoproduction at HERMES" SPIN2010 –19th International Spin Physics Symposium September 27 –October 2, 2010, Jülich, Germany Д.О.Веретенников "SPIN Transfer Coefficient DLL to Lambda Hyperon in SIDIS at HERMES". SPIN2010 –19th International Spin Physics Symposium September 27 –October 2, 2010, Jülich, Germany

Publication in progress Draft-84 "Ratios of Helicity Amplitudes for Exclusive ρ Electroproduction С.Манаенков Draft- 83 Study of nuclear medium effects on transverse Λ hyperon polarization С.Белостоцкий In quasi-real photoproduction Draft-88 Spin Transfer Coefficient DLL to and Hyperons in Semi-Inclusive DIS С.Белостоцкий at HERMES experiment Draft-85 An Exploration of kinematical dependences of longitudinal double-spin asymmetry at HERMES П.Кравченко Защищенные диссертации А. Жгун, Ю.Нарышкин, П.Кравченко Грядущие диссертации Д.Веретенников 2012 С.Манаенков Ю.Нарышкин

BACKUP SLIDES

Status and plans of Lambda analysis I.Recently completed or nearly completed analyses. A-dependence of Lambda polarization-> draft 83 Status: first circulation. Longitudinal spin transfer DLL in DIS->draft 88 Status: DLL for Λ released, DLL for analysis is finished and to be released early in S.Belostotski HERMES collaboration meeting November 2010

II. Analyses in progress. Longitudinal spin transfer DLL in photoproduction_>draft ?? Status:first run of analysis is finished, very preliminary results obtained. Draft ?? will include DLL (spin transfer from the beam) and KLL (spin transfer from longitudinally polarized target, already released). A-dependence of Λ,,Ks normalized yield in photoproduction. Pt and ζ dependences (Cronin effect ?). Reduced cross section per nuclear in heavy nuclei. Status: First very preliminary Pt dependences for Λ obtained. Jointly with Yerevan group. Tentative.

III.Analyses planned to be performed. Study of production of S0 (1193),X- (1321), S*+ (1393), S*- (1388) and their anti particles. Study of hyperon polarization. ( Preliminary results on hyperon yields detected by HERMES in table 1 below.) Study of Λ production in the target fragmentation region using RD. Using coincidences of K+ detected with HERMES spectrometer with Λ in RD. With a hope to detect exclusive Λ K+ reaction.Tentative. S.Belostotski HERMES collaboration meeting November 2010

VM production with polarized beam and target Сергей М Reaction mechanism ?? direct reconstruction of ρ0 production amplitudes С.Белостоцкий сессия ОФВЭ

Nuclear medium effect on transverse Λ polarization Data only, ( will double the statistics) New result unlike hadron and heavy ion collisions strong effect of target on P Λ Юрий Н

С.Белостоцкий сессия ОФВЭ Модернизация программы восстановления треков from HRC to HTC Александр К. 3D survey and alignment data Material distribution in the detector Magnetic field maps Beam line offset determination accuracy ~100 m Beam line slopes determination accuracy ~100 rad Существенное улучшение пространственного, углового и импульсного разрешения.

inclusively detected Phys Rev. D 2007 Transverse Λ polarizationData (RUN I only) С.Белостоцкий сессия ОФВЭ Включение данных RUN II даст фактор 3-5 в числе событий, что особенно важно для.

26 Longitudinal spin transfer DLL Belostotski Strangeness polarization… Trento, Oct.2008 Λ spin structure

27 Longitudinal spin transfer DLL Belostotski Strangeness polarization… Trento, Oct.2008 Λ spin structure Valid only for current fragmentation !!

ΔG final result compilation

Λ photoproduction mechanism by PYTHIA Belostotski spin 08 Λ to yield ratio target (ud) mechanism