Abstract. The brief description of the Letter of Intent proposing primarily to perform measurements of asymmetries of the DY pair production in collisions of non-polarized, longitudinally and transversally polarized protons and deuterons which provide an access to all leading twist collinear and TMD PDFs of quarks and anti-quarks in nucleons.Main parts of the Letter of Intent (LoI) [1], devoted to development of spin program of NICA complex at JINR, are related to the studies of the nucleon structure. The beginning of the nucleon structure story refers to the early 50-ties of the 20th century when in the famous Hofstadter's experiments at SLAC the proton electromagnetic form factor was measured determining thus the proton radius.The naive quark-parton model (QPM) of nucleons, i.e. of the proton and neutron, has been born. Partons share between themselves fractions, x, of the total nucleon momentum. Parton Distribution Functions (PDFs) are universal characteristics of the internal nucleon structure. Now the quark-parton structure of nucleons and respectively the quark-parton model of nucleons are becoming more and more complicated and may even lose the universality property. Measurements of the collinear (integrated over k T ) and Transverse Momentum Dependent (TMD) PDFs, the most of which are not well measured or not discovered yet, are proposed in this LoI.1 The TMD PDFs.The new TMD PDFs can be measured only in the SIDIS or DY processes. In SIDIS, the TMD PDFs can be extracted from the data studying the azimuthal modulations of hadrons which are sensitive to convolution of PDF with the corresponding FF. They include transversity, Sivers, Boer-Mulders, pretzelosity and worm-gear functions. a Speaker; e-mail: teryaev@theor.jinr.ru Physics motivation The Drell-Yan mechanism as the second microscope of the nucleon structure studiesThe Drell-Yan (DY) process of the di-lepton production in high-energy hadron-hadron collisions is playing an important role in the hadron structure studies.Applying the Fourier analysis to the measured asymmetries, one can separate each of all ratios of angular modulations coefficients. This will be the ultimate task of the experiments proposed for SPD. The extraction of different TMD PDFs from those ratios is a task of the global theoretical analysis (a challenge for the theoretical community) since each of the angular coefficients is a result of convolutions of different TMD PDFs in the quark transverse momentum space. For this purpose one needs either to assume a factorization of the transverse momentum dependence for each TMD PDFs, having definite mathematic form (usually Gaussian) with some parameters to be fitted, or to transfer functions to impact parameter representation space and to use the Bessel weighted TMD PDFs.The full set of asymmetries gives the access to all eight leading twist TMD PDFs. However, sometimes one can work with integrated asymmetries. Integrated asymmetries are useful for the express analysis of data and checks of expected relations between asymmetries. They ...
Abstract. Status of the JINR polarized ion source development is described. The source is under tests at the test-bench of LHEP, JINR. A charge-exchange plasma ionizer has been tested initially without a storage cell in the ionization region. An unpolarized deuterium ion beam with peak current of 160 mA, 23 keV energy, pulse duration of 100 s and repetition rate of 1 Hz has been extracted from the ionizer. With a free polarized atomic hydrogen beam injected into the ionizer a polarized proton beam with peak current of 1.4 mA has been obtained. The nearest plans for the source development include tests of the ionizer with the storage cell and tuning of the high frequency transition units installed in their operating position with a Breit-Rabi polarimeter.
We propose to perform measurements of asymmetries of the DY pair"s production in collisions of non-polarized, longitudinally and transversally polarized protons and deuterons which provide an access to all leading twist collinear and TMD PDFs of quarks and anti-quarks in nucleons. The measurements of asymmetries in production of J/Ψ and direct photons will be performed as well simultaneously with DY using dedicated triggers. The set of these measurements will supply complete information for tests of the quark-parton model of nucleons at the QCD twisttwo level with minimal systematic errors. PAC Recommendations:….The PAC heard with interest a report on the preparation of the Letter of Intent "Spin physics experiments at NICA-SPD with polarized proton and deuteron beams" presented by I. Savin. The PAC is pleased to see the first steps toward formation of an international collaboration around the SPD experiment. The PAC regards the SPD experiment as an essential part of the NICA research program and encourages the authors of the Letter of Intent to prepare a full proposal and present it at one of the forthcoming meetings of the PAC. … --
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.