Data on the production of antiprotons at an angle of 40° in the laboratory system in collisions of 50-GeV protons with C, Al, Cu, and W nuclear targets have been obtained in the SPIN experiment (IHEP, Protvino, Russia). Invariant cross sections have been measured at transverse momenta up to pT ≈ 2.6 GeV/c. The an-alysis of the momentum spectra has shown that multinucleon (multiquark) configurations inside a nucleus are involved in the production of antiprotons.

Data on the production of positively charged particles emitted at an angle of 40 $${}^{\circ}$$ (in the laboratory frame) with transverse momenta of up to 2.7 GeV $$/c$$ in the interaction of 50-GeV $$/c$$ protons with carbon, aluminum, copper, and tungsten nuclear targets are presented. Particular attention is given to studying the production of light nuclear fragments, such as deuterons ( $$d$$ ) and tritons ( $$t$$ ). An analysis of data on $$d$$ and $$t$$ particles gives grounds to state that these fragments arise via a local mechanism of their direct knockout from nuclei. The results were obtained in the SPIN experiment at the Institute for High Energy Physics (IHEP, Protvino).

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

The first data on the yield of the lightest nuclear fragments (protons p, deuterons d, and tritons t) with high transverse momenta pT at an angle of 40° in the laboratory reference frame from nuclear targets bombarded by 50-GeV/c protons and 20A-GeV/c carbon nuclei obtained in the SPIN experiment (IHEP, Protvino, Russia) have been reported. It has been shown that the pA and CA data can be described within a common scaling approach, which possibly indicates that the mechanism of formation of high-pT nuclear fragments is common for these reactions.

The yields of cumulative protons and π ± mesons emitted at a laboratory angle of 40° from carbon and heavier nuclear targets irradiated by a proton beam from the U70 accelerator (Institute for High Energy Physics, Protvino) have been studied in the SPIN experiment. It has been found that the effect of the target nucleus on the yield of particles with large transverse momenta is weakened.

Formation of the d and t cumulative light nuclear fragments emitted from the nucleus with large transverse momenta at an angle of 35° in the laboratory frame is investigated. The data on collisions of 50-GeV protons with the C, Al, Cu, and W nuclei are collected using the extracted proton beam of the IHEP accelerator and the SPIN detector. The results indicate that the dominant contribution to formation of nuclear fragments comes from the local process of direct knockout from the nucleus.

The first data on the production of cumulative π+, p, and light nuclear fragments d and t emitted from a nucleus with a high transverse momentum at an angle of 35° in the laboratory system have been reported. The data have been obtained at the SPIN setup at the interaction of a 50-GeV proton beam extracted from the U-70 accelerator (IHEP, Protvino) with C, Al, Cu, and W nuclei.

Momentum spectra of cumulative particles in the region of high transverse momenta (P T ) in pA → h + + X reactions were obtained for the first time. The experiment in which this was done was performed at the SPIN setup (Institute for High Energy Physics, Protvino) in a beam of 50-GeV protons interacting with C, Al, Cu, and W nuclei. Positively charged particles were detected at a laboratory angle of 35° and in the transverse-momentum range between 0.6 and 3.7 GeV/c. A strong dependence of the particle-production cross section on the atomic number was observed. A comparison with the results of calculations based on the HIJING and UrQMD models was performed in the subcumulative region.

Впервые получены импульсные спектры кумулятивных частиц в области больших в реакции . Эксперимент выполнен на установке СПИН (ИФВЭ, Протвино) на пучке протонов с энергией 50 ГэВ, взаимодействующих с ядрами C, Al, Cu и W. Положительно заряженные частицы регистрировались под углом 35 в л.с. и в диапазоне поперечных импульсов от 0.6 до 3.7 ГэВ/ . Наблюдена сильная зависимость сечения рождения частиц от атомного числа. В предкумулятивной области проведено сравнение с расчетами по моделям HIJING и UrQMD.

A program of polarization studies is presented; this program can enhance our understanding of the constituents from which the spin of hadrons and lightest nuclei is constructed. Beams of polarized lightest nuclei at Nuclotron are required to complete this program. Calculations of linear resonance strengths at Nuclotron, which may result in depolarization effects, are presented. The application of a new method for conserving particle beam polarization at crossing these resonances at Nuclotron is discussed.

C. Adler, Z. Ahammed, C. Allgower, J. Amonett, B.D. Anderson, M. Anderson, G.S. Averichev, J. Balewski, O. Barannikova, L.S. Barnby, J. Baudot, S. Bekele, V.V. Belaga, R. Bellwied, J. Berger, H. Bichsel, L.C. Bland, C.O. Blyth, B.E. Bonner, R. Bossingham, A. Boucham, A. Brandin, R.V. Cadman, H. Caines, M. Calderón de la Barca Sánchez, A. Cardenas, J. Carroll, J. Castillo, M. Castro, D. Cebra, S. Chattopadhyay, M.L. Chen, Y. Chen, S.P. Chernenko, M. Cherney, A. Chikanian, B. Choi, W. Christie, J.P. Coffin, L. Conin, T.M. Cormier, J.G. Cramer, H.J. Crawford, M. DeMello, W.S. Deng, A.A. Derevschikov, L. Didenko, J.E. Draper, V.B. Dunin, J.C. Dunlop, V. Eckardt, L.G. Efimov, V. Emelianov, J. Engelage, G. Eppley, B. Erazmus, P. Fachini, V. Faine,E. Finch, Y. Fisyak, D. Flierl, K.J. Foley, J. Fu, N. Gagunashvili, J. Gans, L. Gaudichet, M. Germain, F. Geurts, V. Ghazikhanian, J. Grabski, O. Grachov, D. Greiner, V. Grigoriev, M. Guedon, E. Gushin, T.J. Hallman, D. Hardtke, J.W. Harris, M. Heffner, S. Heppelmann, T. Herston, B. Hippolyte, A. Hirsch, E. Hjort, G.W. Hoffmann, M. Horsley, H.Z. Huang, T.J. Humanic, H. Hümmler, G. Igo, A. Ishihara, Yu.I. Ivanshin, P. Jacobs, W.W. Jacobs, M. Janik, I. Johnson, P.G. Jones, E. Judd, M. Kaneta, M. Kaplan, D. Keane, A. Kisiel, J. Klay, S.R. Klein, A. Klyachko, A.S. Konstantinov, L. Kotchenda, A.D. Kovalenko, M. Kramer, P. Kravtsov, K. Krueger, C. Kuhn, A.I. Kulikov, G.J. Kunde, C.L. Kunz, R.Kh. Kutuev, A.A. Kuznetsov, L. Lakehal-Ayat, J. Lamas-Valverde, M.A.C. Lamont, J.M. Landgraf, S. Lange, C.P. Lansdell, B. Lasiuk, F. Laue, A. Lebedev, T. LeCompte, R. Lednický, V.M. Leontiev, M.J. LeVine, Q. Li, Q. Li, S.J. Lindenbaum, M.A. Lisa, T. Ljubicic, W.J. Llope, G. LoCurto, H. Long, R.S. Longacre, M. Lopez-Noriega, W.A. Love, D. Lynn, R. Majka, S. Margetis, L. Martin, J. Marx, H.S. Matis, Yu.A. Matulenko, T.S. McShane, F. Meissner, Yu. Melnick, A. Meschanin, M. Messer, M.L. Miller, Z. Milosevich, N.G. Minaev, J. Mitchell, V.A. Moiseenko, D. Moltz, C.F. Moore, V. Morozov, M.M. de Moura, M.G. Munhoz, G.S. Mutchler, J.M. Nelson, P. Nevski, V.A. Nikitin, L.V. Nogach, B. Norman, S.B. Nurushev, G. Odyniec, A. Ogawa, V. Okorokov, M. Oldenburg, D. Olson, G. Paic, S.U. Pandey, Y. Panebratsev, S.Y. Panitkin, A.I. Pavlinov, T. Pawlak, V. Perevoztchikov, W. Peryt, V.A Petrov, W. Pinganaud, E. Platner, J. Pluta, N. Porile, J. Porter, A.M. Poskanzer, E. Potrebenikova, D. Prindle,C. Pruneau, S. Radomski, G. Rai, O. Ravel, R.L. Ray, S.V. Razin, D. Reichhold, J.G. Reid, F. Retiere, A. Ridiger, H.G. Ritter, J.B. Roberts, O.V. Rogachevski, J.L. Romero, C. Roy, D. Russ, V. Rykov, I. Sakrejda, J. Sandweiss, A.C. Saulys, I. Savin, J. Schambach, R.P. Scharenberg, K. Schweda, N. Schmitz, L.S. Schroeder, A. Schüttauf, J. Seger, D. Seliverstov, P. Seyboth, E. Shahaliev, K.E. Shestermanov, S.S. Shimanskii, V.S. Shvetcov, G. Skoro, N. Smirnov, R. Snellings, J. Sowinski, H.M. Spinka, B. Srivastava, E.J. Stephenson, R. Stock, A. Stolpovsky, M. Strikhanov, B. Stringfellow, H. Stroebele, C. Struck, A.A.P. Suaide, E. Sugarbaker, C. Suire, M. Šumbera, T.J.M. Symons, A. Szanto de Toledo, P. Szarwas, J. Takahashi, A.H. Tang, J.H. Thomas, V. Tikhomirov, T.A. Trainor, S. Trentalange, M. Tokarev, M.B. Tonjes, V. Trofimov, O. Tsai, K. Turner, T. Ullrich, D.G. Underwood, G. Van Buren, A.M. VanderMolen, A. Vanyashin, I.M. Vasilevski, A.N. Vasiliev, S.E. Vigdor, S.A. Voloshin, F. Wang, H. Ward, J.W. Watson, R. Wells, T. Wenaus, G.D. Westfall, C. Whitten Jr. , H. Wieman, R. Willson, S.W. Wissink, R. Witt, N. Xu, Z. Xu, A.E. Yakutin, E. Yamamoto, J. Yang, P. Yepes, A. Yokosawa, V.I. Yurevich, Y.V. Zanevski, I. Zborovský, W.M. Zhang, R. Zoulkarneev, A.N. Zubarev

We report the STAR measurement of ϕ meson production in Au+Au and p+p collisions at sNN=200GeV. Using the event mixing technique, the ϕ spectra and yields are obtained at mid-rapidity for five centrality bins in Au+Au collisions and for non-singly-diffractive p+p collisions. It is found that the ϕ transverse momentum distributions from Au+Au collisions are better fitted with a single-exponential while the p+p spectrum is better described by a double-exponential distribution. The measured nuclear modification factors indicate that ϕ production in central Au+Au collisions is suppressed relative to peripheral collisions when scaled by the number of binary collisions (〈Nbin〉). The systematics of 〈pt〉 versus centrality and the constant ϕ/K− ratio versus beam species, centrality, and collision energy rule out kaon coalescence as the dominant mechanism for ϕ production.