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Related papers: Transverse Spin Physics at HERMES

200 papers

We study single-spin asymmetries in semi-inclusive deep inelastic scattering with transversely polarized target. Based on the QCD factorization approach, we consider Sivers and Collins contributions to the asymmetries. We fit simple…

High Energy Physics - Phenomenology · Physics 2010-04-06 Werner Vogelsang , Feng Yuan

We study the process dependence of the Sivers function by considering the impact of color-gauge invariant initial and final state interactions on transverse spin asymmetries in proton-proton reactions within the framework of the transverse…

High Energy Physics - Phenomenology · Physics 2011-10-27 Umberto D'Alesio , Leonard Gamberg , Zhong-Bo Kang , Francesco Murgia , Cristian Pisano

We discuss various azimuthal asymmetries in semi-inclusive DIS and e^+e^- ==> h1 h2 X which involve chiral odd quantities like the transversity distribution h_1 and a fragmentation function H_1^\perp. For the fragmentation described by…

High Energy Physics - Phenomenology · Physics 2009-09-25 R. Jakob , D. Boer , P. J. Mulders

Preliminary measurements are reported on the azimuthal single-spin asymmetry of exclusive rho0 mesons for a transversely polarized hydrogen target at HERMES using the 27.6 GeV HERA positron beam. Within the generalized parton distribution…

High Energy Physics - Experiment · Physics 2007-07-18 Armine Rostomyan , Jeroen Dreschler

Sivers asymmetry, adopted to explain transverse single spin asymmetries (SSA) observed in inclusive pion production, p(transv. polarized) p --> pion + X and p-bar(transv. polarized) p --> pion + X is used here to compute SSA in Drell-Yan…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Anselmino , U. D'Alesio , F. Murgia

We study the single-spin (left-right) asymmetry in single-inclusive pion production in hadronic scattering. This asymmetry is power-suppressed in the transverse momentum of the produced pion and can be analyzed in terms of twist-three…

High Energy Physics - Phenomenology · Physics 2008-11-26 Chris Kouvaris , Jian-Wei Qiu , Werner Vogelsang , Feng Yuan

One of the important objectives of the COMPASS experiment (SPS, CERN) \cite{Abbon:2007pq} is the exploration of the transverse spin structure of the nucleon via spin dependent azimuthal asymmetries in single-hadron production in deep…

High Energy Physics - Experiment · Physics 2013-07-03 Bakur Parsamyan

We study the single transverse spin asymmetries in the single inclusive particle production within the framework of the generalized parton model (GPM). By carefully analyzing the initial- and final-state interactions, we include the…

High Energy Physics - Phenomenology · Physics 2011-04-28 Leonard Gamberg , Zhong-Bo Kang

We discuss transverse polarization distribution and fragmentation functions, in particular, T-odd functions with transverse momentum dependence, which might be relevant for the description of single transverse spin asymmetries. The role of…

High Energy Physics - Phenomenology · Physics 2011-04-15 Daniel Boer

A consistent phenomenological approach to the computation of transverse single spin asymmetries in inclusive hadron production is presented, based on the assumed generalization of the QCD factorization theorem to the case in which quark…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Anselmino , M. Boglione , F. Murgia

We study the Sivers effect in the transverse single spin asymmetries (SSA) for pion and kaon production in semi-inclusive deep inelastic scattering (SIDIS) processes. We perform a fit of A^sin(phi_h-phi_S)_UT which, by including recent high…

High Energy Physics - Phenomenology · Physics 2009-02-19 M. Anselmino , M. Boglione , U. D'Alesio , A. Kotzinian , S. Melis , F. Murgia , A. Prokudin , C. Turk

The transverse single-spin asymmetry for $\rho^0$ production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration. Using the Sivers functions extracted from pion and kaon productions, we perform a…

High Energy Physics - Phenomenology · Physics 2025-06-27 Yongjie Deng , Tianbo Liu , Ya-jin Zhou

We present the measurement of Single Beam-Spin Azimuthal Asymmetries in pion electroproduction off hydrogen in semi-inclusive deep inelastic scattering (SIDIS). The measurement was made using the HERMES spectrometer with an internal gas…

High Energy Physics - Experiment · Physics 2012-08-03 HERMES Collaboration , E. Avetisyan

At the leading twist, the transversity distribution function, $h^{q}_{1}(x)$, where $x$ is the longitudinal momentum fraction of the proton carried by quark $q$, encodes the transverse spin structure of the nucleon. Extraction of it is…

Nuclear Experiment · Physics 2023-02-01 Babu R. Pokhrel

COMPASS is a running fixed-target experiment at the CERN SPS with a rich physics program focused on nucleon spin structure and on hadron spectroscopy. One of the main goals of the spin program is the measurement of the transverse spin…

High Energy Physics - Experiment · Physics 2019-08-13 S. Levorato

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at $\sqrt{s} = 500~\text{GeV}$ by the STAR experiment at RHIC. The measured observable is…

Nuclear Experiment · Physics 2016-04-06 STAR Collaboration , L. Adamczyk , J. K. Adkins , G. Agakishiev , M. M. Aggarwal , Z. Ahammed , I. Alekseev , A. Aparin , D. Arkhipkin , E. C. Aschenauer , A. Attri , G. S. Averichev , X. Bai , V. Bairathi , A. Banerjee , R. Bellwied , A. Bhasin , A. K. Bhati , P. Bhattarai , J. Bielcik , J. Bielcikova , L. C. Bland , I. G. Bordyuzhin , J. Bouchet , J. D. Brandenburg , A. V. Brandin , I. Bunzarov , J. Butterworth , H. Caines , M. Calderón de la Barca Sánchez , J. M. Campbell , D. Cebra , I. Chakaberia , P. Chaloupka , Z. Chang , S. Chattopadhyay , J. H. Chen , X. Chen , J. Cheng , M. Cherney , W. Christie , G. Contin , H. J. Crawford , S. Das , L. C. De Silva , R. R. Debbe , T. G. Dedovich , J. Deng , A. A. Derevschikov , B. di Ruzza , L. Didenko , C. Dilks , X. Dong , J. L. Drachenberg , J. E. Draper , C. M. Du , L. E. Dunkelberger , J. C. Dunlop , L. G. Efimov , J. Engelage , G. Eppley , R. Esha , O. Evdokimov , O. Eyser , R. Fatemi , S. Fazio , P. Federic , J. Fedorisin , Z. Feng , P. Filip , Y. Fisyak , C. E. Flores , L. Fulek , C. A. Gagliardi , D. Garand , F. Geurts , A. Gibson , M. Girard , L. Greiner , D. Grosnick , D. S. Gunarathne , Y. Guo , S. Gupta , A. Gupta , W. Guryn , A. I. Hamad , A. Hamed , R. Haque , J. W. Harris , L. He , S. Heppelmann , S. Heppelmann , A. Hirsch , G. W. Hoffmann , S. Horvat , H. Z. Huang , X. Huang , B. Huang , T. Huang , P. Huck , T. J. Humanic , G. Igo , W. W. Jacobs , H. Jang , A. Jentsch , J. Jia , K. Jiang , E. G. Judd , S. Kabana , D. Kalinkin , K. Kang , K. Kauder , H. W. Ke , D. Keane , A. Kechechyan , Z. H. Khan , D. P. Kikoła , I. Kisel , A. Kisiel , L. Kochenda , D. D. Koetke , L. K. Kosarzewski , A. F. Kraishan , P. Kravtsov , K. Krueger , L. Kumar , M. A. C. Lamont , J. M. Landgraf , K. D. Landry , J. Lauret , A. Lebedev , R. Lednicky , J. H. Lee , X. Li , C. Li , W. Li , X. Li , Y. Li , T. Lin , M. A. Lisa , F. Liu , T. Ljubicic , W. J. Llope , M. Lomnitz , R. S. Longacre , X. Luo , G. L. Ma , L. Ma , R. Ma , Y. G. Ma , N. Magdy , R. Majka , A. Manion , S. Margetis , C. Markert , D. McDonald , K. Meehan , J. C. Mei , N. G. Minaev , S. Mioduszewski , D. Mishra , B. Mohanty , M. M. Mondal , D. A. Morozov , M. K. Mustafa , B. K. Nandi , Md. Nasim , T. K. Nayak , G. Nigmatkulov , T. Niida , L. V. Nogach , S. Y. Noh , J. Novak , S. B. Nurushev , G. Odyniec , A. Ogawa , K. Oh , V. A. Okorokov , D. Olvitt , B. S. Page , R. Pak , Y. X. Pan , Y. Pandit , Y. Panebratsev , B. Pawlik , H. Pei , C. Perkins , P. Pile , J. Pluta , K. Poniatowska , J. Porter , M. Posik , A. M. Poskanzer , N. K. Pruthi , J. Putschke , H. Qiu , A. Quintero , S. Ramachandran , S. Raniwala , R. Raniwala , R. L. Ray , H. G. Ritter , J. B. Roberts , O. V. Rogachevskiy , J. L. Romero , A. Roy , L. Ruan , J. Rusnak , O. Rusnakova , N. R. Sahoo , P. K. Sahu , I. Sakrejda , S. Salur , J. Sandweiss , A. Sarkar , J. Schambach , R. P. Scharenberg , A. M. Schmah , W. B. Schmidke , N. Schmitz , J. Seger , P. Seyboth , N. Shah , E. Shahaliev , P. V. Shanmuganathan , M. Shao , M. K. Sharma , B. Sharma , W. Q. Shen , Z. Shi , S. S. Shi , Q. Y. Shou , E. P. Sichtermann , R. Sikora , M. Simko , S. Singha , M. J. Skoby , D. Smirnov , N. Smirnov , W. Solyst , L. Song , P. Sorensen , H. M. Spinka , B. Srivastava , T. D. S. Stanislaus , M. Stepanov , R. Stock , M. Strikhanov , B. Stringfellow , M. Sumbera , B. Summa , X. M. Sun , Y. Sun , Z. Sun , B. Surrow , D. N. Svirida , Z. Tang , A. H. Tang , T. Tarnowsky , A. Tawfik , J. Thäder , J. H. Thomas , A. R. Timmins , D. Tlusty , T. Todoroki , M. Tokarev , S. Trentalange , R. E. Tribble , P. Tribedy , S. K. Tripathy , O. D. Tsai , T. Ullrich , D. G. Underwood , I. Upsal , G. Van Buren , G. van Nieuwenhuizen , M. Vandenbroucke , R. Varma , A. N. Vasiliev , R. Vertesi , F. Videbæk , S. Vokal , S. A. Voloshin , A. Vossen , H. Wang , G. Wang , F. Wang , Y. Wang , Y. Wang , J. S. Wang , J. C. Webb , G. Webb , L. Wen , G. D. Westfall , H. Wieman , S. W. Wissink , R. Witt , Y. Wu , Z. G. Xiao , W. Xie , G. Xie , K. Xin , J. Xu , Z. Xu , Y. F. Xu , Q. H. Xu , H. Xu , N. Xu , Q. Yang , Y. Yang , S. Yang , C. Yang , Y. Yang , Y. Yang , Z. Ye , Z. Ye , P. Yepes , L. Yi , K. Yip , I. -K. Yoo , N. Yu , H. Zbroszczyk , W. Zha , J. Zhang , Y. Zhang , J. Zhang , S. Zhang , S. Zhang , J. B. Zhang , Z. Zhang , X. P. Zhang , J. Zhao , C. Zhong , L. Zhou , X. Zhu , Y. Zoulkarneeva , M. Zyzak

The BRAHMS experiment at RHIC has the capability to measure the transverse spin asymmetries in polarized pp induced pion production at RHIC. The first results from the short run-4 show a signaificant asymmetry for pi-plus and pi-minus at…

Nuclear Experiment · Physics 2019-08-14 F. Videbaek

The BRAHMS experiment at RHIC has measured the transverse single spin asymmetries in polarized pp induced pion production at RHIC. The results from the RHIC run-5 shows a significant asymmetry for pi+ and pi- at moderate xF. The trend of…

Nuclear Experiment · Physics 2019-08-14 F. Videbaek

The $k_\perp$-moment of a quark's Sivers function is known to be related to the corresponding twist-three quark-gluon correlation function $T_{q,F}(x, x)$. The two functions have been extracted from data for single-spin asymmetries in…

High Energy Physics - Phenomenology · Physics 2011-05-12 Zhong-Bo Kang , Jian-Wei Qiu , Werner Vogelsang , Feng Yuan

Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the…

High Energy Physics - Experiment · Physics 2009-04-15 A. Airapetian