References - Bogoliubov Laboratory of Theoretical Physics - JINR

More documents

Recommendations

Info

Figure 3: The experimental results on Ay, Ayy, Axx and Axz analyzing powers of the 12 C( −→ d,p) 13 C ∗ reaction at energy Td = 270 MeV. to 18 ◦ in laboratory system have been also obtained. The Ayy data for 12 C( −→ d,p) 13 C(g.s.) andfor 12 C( −→ d,p) 13 C ∗ reactions are in accordance within achieved precision. The sign of tensor analyzing power for these reactions is positive, while the sign of the vector Ay analyzing power is different. Acknowledgments The work has been supported in part by the Russian Foundation for Fundamental Research (grant N o 07-02-00102a), by the Grant Agency for Science at the Ministry of Education of the Slovak Republic (grant N o 1/4010/07), by a Special program of the Ministry of Education and Science of the Russian Federation(grant RNP 2.1.1.2512). References [1] N. Keeley, N. Alamanos, and V. Lapoux Phys. Rev. C 69, 064604 (2004). [2] L. Trache, F. Carstoiu et al., Phys. Rev. Lett. 87, 271102 (2001). [3] F. Delaunay, F.M. Nunes et al.,Phys.Rev.C72, 014610 (2005). [4] M. Janek M. et al., Eur. Phys. J. A 33, 39 (2007). 220
OVERVIEW OF RECENT HERMES RESULTS V.A. Korotkov (on behalf of the HERMES Collaboration) Institite for High Energy Physics, Protvino, Russia E-mail: Vladislav.Korotkov@ihep.ru Abstract An overview of recent HERMES results is presented. The review topics include: the nucleon structure function F2(x), the polarized structure function g2(x), the search for a two-photon exchange effects in polarized DIS, the Collins and Sivers asymmetries, the azimuthal asymmetries in hadron electro-production off unpolarized target, and strange quark distributions, S(x) andΔS(x). 1 Introduction The HERMES experiment at DESY was designed to investigate the spin structure of the nucleon with a clear motivation to study/resolve the “Proton Spin Puzzle”. The “Puzzle” originated due to a measurement by the European Muon Collaboration of the quark spin contribution to the proton spin, which appeared to be surprisingly small [1]. Twelve years of running by the HERMES experiment, from 1995 to 2007, has led to many exciting, unexpected results. New fields of investigations gained importance, such as the study of the third twist-2 quark distribution function of the nucleon, so-called transversity, the study of Transverse Momentum Dependent distribution and fragmentation functions, the study of Generalized Parton Distributions. This paper presents part of the results obtained by the HERMES Collaboration in the past two years based on inclusive and semiinclusive DIS measurements only. Measurements of exclusive reactions are presented in other contributions of the HERMES Collaboration at this Workshop. The HERMES experiment studies the scattering of a longitudinally polarized lepton beam (e + or e − ) of 27.6 GeV off a transversely/longitudinally polarized or unpolarized gas target internal to the HERA storage ring. Scattered leptons and coincident hadrons were detected by the HERMES spectrometer [2]. Leptons were identified with an efficiency exceeding 98% and a hadron contamination of less than 1%. The HERMES dual-radiator ring-imaging Čerenkov detector allows full hadron identification in the momentum range 2 ÷ 15 GeV. 2 Inclusive DIS Structure function F2(x). During its data-taking, HERMES collected about 58 million DIS events with (un)polarized hydrogen and deuterium targets. This statistics is highly competitive with respect to other fixed target DIS experiments, and motivates a new extraction of structure function F2(x) performed by HERMES in the same kinematic domain explored by its polarized measurements. Extraction of such a function requires the experimental data are corrected for detector smearing and radiative effects with an unfolding procedure [3], and a precise knowledge of the luminosity [2]. To extend the 221
Page 1:
XIII Advanced Research Workshop on
Page 4 and 5:
ã�� [539.12.01 + 539.12 ... 14
Page 6 and 7:
Analytic perturbation theory and pr
Page 8 and 9:
Measurements of GEp/GMp to high Q 2
Page 11 and 12:
WELCOME ADDRESS Alexei Sissakian Di
Page 13 and 14:
he joined the group of prof. Przemy
Page 15 and 16:
proton. Dividing these 90 ◦ cm p-
Page 17 and 18:
p-p scattering angle fixed at exact
Page 19 and 20:
tuning for each ring. The Workshop
Page 21 and 22:
was only about 10 5 per second, but
Page 23:
[10] E.F. Parker et al., Phys. Rev.
Page 27 and 28:
MICROSCOPIC STERN-GERLACH EFFECT AN
Page 29 and 30:
DeGrand-Miettinen model predicted P
Page 31 and 32:
TOWARDS STUDY OF LIGHT SCALAR MESON
Page 33 and 34:
104xdBR(φ--> π η 0 -1 γ )/dm, G
Page 35 and 36:
RECURSIVE FRAGMENTATION MODEL WITH
Page 37 and 38:
Figure 2: String decaying into pseu
Page 39 and 40:
pT -distributions in the quark frag
Page 41 and 42:
4 Inclusion of spin-1 mesons For a
Page 43 and 44:
CONSTITUENT QUARK REST ENERGY AND W
Page 45 and 46:
〈r 2 ch 〉≈1fm2 . Now with Eqs
Page 47 and 48:
TOWARDS A MODEL INDEPENDENT DETERMI
Page 49 and 50:
Common for the difference cross sec
Page 51 and 52:
TRANSVERSITY GPDs FROM γN → πρ
Page 53 and 54:
The scattering amplitude of the pro
Page 55 and 56:
INFRARED PROPERTIES OF THE SPIN STR
Page 57 and 58:
5 Acknowledgement B.I. Ermolaev is
Page 59 and 60:
We shall call this model the “sec
Page 61 and 62:
y f ν V = f l V = f u V = f d gz V
Page 63 and 64:
2. We remind, that the celebrated G
Page 65 and 66:
of the resonance A, θV � 39 o .
Page 67 and 68:
• Right-handed EW currents. The c
Page 69 and 70:
pesum- (p Entries 0 + pe)-(p-pe) Me
Page 71 and 72:
CROSS SECTIONS AND SPIN ASYMMETRIES
Page 73 and 74:
R(ρ) 5 4 3 2 1 0 2 3 4 5 6 7 8 9 1
Page 75 and 76:
TWO-PHOTON EXCHANGE IN ELASTIC ELEC
Page 77 and 78:
and depend on three parameters : fN
Page 79 and 80:
O(αs) SPIN EFFECTS IN e + e −
Page 81 and 82:
3 Polarization results for mq → 0
Page 83 and 84:
Since one has (↑↓) pc Born =(
Page 85 and 86:
Figure 1: A typical lowest order Fe
Page 87 and 88:
sin φ S (π + ) A UT 1.0 0.8 0.6 0
Page 89 and 90:
form the agreement with these data
Page 91 and 92:
in settling this dynamical issue. G
Page 93 and 94:
SPIN CORRELATIONS OF THE ELECTRON A
Page 95 and 96:
the two-photon system equaling 1).
Page 97 and 98:
ANOTHER NEW TRACE FORMULA FOR THE C
Page 99 and 100:
Compare the gain of time and effort
Page 101 and 102:
where the triplet and octet axial c
Page 103 and 104:
[2] Y. Prok et al. [CLAS Collaborat
Page 105 and 106:
Melosh rotations which boost the re
Page 107 and 108:
ky �GeV� 0.4 0.2 0.0 �0.2 �
Page 109 and 110:
[2] B. Pasquini, and S. Boffi, Phys
Page 111 and 112:
The appearance of both |+〉 and |
Page 113 and 114:
2.2 Intrinsic Transverse Motion Qua
Page 115 and 116:
are still complex: for a given corr
Page 117 and 118:
This last is required to complete t
Page 119 and 120:
[16] P.G. Ratcliffe and O.V. Teryae
Page 121 and 122:
Figure 1: a)[left] μpG p E /Gp M (
Page 123 and 124:
4 Conclusion We introduced a simple
Page 125 and 126:
√ δΔq8 x for Δq8 and γΔGx fo
Page 127 and 128:
understanding of polarized light qu
Page 129 and 130:
They are inverse powers of Q 2 kine
Page 131 and 132:
accounts approximately for the TM a
Page 133 and 134:
POTENTIAL FOR A NEW MUON g-2 EXPERI
Page 135 and 136:
When the momentum increases (p >p0)
Page 137 and 138:
EVOLUTION EQUATIONS FOR TRUNCATED M
Page 139 and 140:
4 Perspectives Evolution equations
Page 141 and 142:
NEW DEVELOPMENTS IN THE QUANTUM STA
Page 143 and 144:
statistical approach compared to th
Page 145 and 146:
POLARIZED HADRON STRUCTURE IN THE V
Page 147 and 148:
g 3 A =Δuv(Q 2 ) − Δdv(Q 2 ), g
Page 149 and 150:
AXIAL ANOMALIES, NUCLEON SPIN STRUC
Page 151 and 152:
3. Vector current of strange quarks
Page 153 and 154:
ORBITAL MOMENTUM EFFECTS DUE TO A L
Page 155 and 156:
The elastic scattering S-matrix in
Page 157 and 158:
IDENTIFICATION OF EXTRA NEUTRAL GAU
Page 159 and 160:
for final l + l − events (l = μ,
Page 161 and 162:
QUARK INTRINSIC MOTION AND THE LINK
Page 163 and 164:
where wP = − m 2M 2 −p1 cos ω
Page 165 and 166:
where g q 2x − ξ 1(x, pT )= πM2
Page 167:
EXPERIMENTAL RESULTS
Page 170 and 171:
01 00 11 01 01 01 00 11 01 01 01 00
Page 172 and 173: where C1, C2 and A1 - signals from
Page 174 and 175: Figure 1: Layout of experiment targ
Page 176 and 177: According to requirements of the de
Page 178 and 179: Electron energy is measured at ATLA
Page 180 and 181: Fig. 2 shows the results of the lon
Page 182 and 183: e γ* e’ x+ ξ x− ξ A A’ e e
Page 184 and 185: cos 0φ C A φ cos C A cos 2φ C A
Page 186 and 187: 5 Summary HERMES has measured signi
Page 188 and 189: (1.205 ± 0.0012) GeV/c, 10 10 p/s,
Page 190 and 191: was done in the interval ”−t”
Page 192 and 193: If we admit a non-zero quark transv
Page 194 and 195: which is trivial in collinear LO ap
Page 196 and 197: In figure 3 the expected errors on
Page 198 and 199: [12] A. V. Efremov and O. V. Teryae
Page 200 and 201: Figure 1: The COMPASS spectrometer.
Page 202 and 203: Comparing this formula to the inclu
Page 204 and 205: Figure 5: Comparison of COMPASS inc
Page 206 and 207: [9] B. Adeva et al. (SMC Coll.), Ph
Page 208 and 209: q T sin( φ-φ ) M AUT 0.14 0.12 0.
Page 210 and 211: proton beam is planned. References
Page 212 and 213: Run Year √ s (GeV) Polarization R
Page 214 and 215: ackground fraction, and asymmetry i
Page 216 and 217: At √ s = 200 GeV, ALL(pp → π
Page 218 and 219: [6] D. de Florian, W. Vogelsang, an
Page 220 and 221: higher energies, where the cross se
Page 224 and 225: kinematic range to low values of Bj
Page 226 and 227: 3 Semi-Inclusive DIS Collins and Si
Page 228 and 229: Unpolarized target asymmetries. The
Page 230 and 231: 4 Summary Since the end of data-tak
Page 232 and 233: polarization as well as a construct
Page 234 and 235: Finally the COMPASS reconstruction
Page 236 and 237: tained in the NLO QCD approximation
Page 238 and 239: with only modern NN potential are r
Page 240 and 241: (a) (b) Figure 3: (a) T20 data take
Page 242 and 243: of electroproduction from polarized
Page 244 and 245: As is seen in Fig. 1 values of the
Page 246 and 247: SEMI-INCLUSIVE DIS AND TRANSVERSE M
Page 248 and 249: The yellow band in Fig. 1 is the re
Page 250 and 251: At leading twist, a third asymmetry
Page 252 and 253: THE COMPLETION OF SINGLE-SPIN ASYMM
Page 254 and 255: A N , % 30 20 10 0 0 0.2 0.4 0.6 0.
Page 256 and 257: Unexpectedly large single spin asym
Page 258 and 259: THE GENERALIZED PARTON DISTRIBUTION
Page 260 and 261: , E) H ~ (H, I Im C 5 4 3 2 1 Q = 1
Page 262 and 263: Reducing to a common denominator (
Page 264 and 265: LAMBDA PHYSICS AT HERMES S. Belosto
Page 266 and 267: analysis was carried out reconstruc
Page 268 and 269: SPIN PHYSICS AT NICA A. Nagaytsev J
Page 270 and 271: original software packages (MC simu
Page 272 and 273:
MEASUREMENTS OF TRANSVERSE SPIN EFF
Page 274 and 275:
to “near-side” and “away-side
Page 276 and 277:
THE FIRST STAGE OF POLARIZATION PRO
Page 278 and 279:
In paper [12] the study was made of
Page 280 and 281:
emphasis to increase the statistics
Page 282 and 283:
Table 2: The parameters of the main
Page 284 and 285:
POLARIZATION MEASUREMENTS IN PHOTOP
Page 286 and 287:
With a polarized electron beam inci
Page 288 and 289:
Figure 3: Preliminary helicity asym
Page 290 and 291:
INVESTIGATION OF DP-ELASTIC SCATTER
Page 292 and 293:
framework with the use of deuteron
Page 294 and 295:
SPIN PHYSICS WITH CLAS Y. Prok 12,
Page 296 and 297:
1.3 Flavor Decomposition of the Hel
Page 298 and 299:
Γ p 1 0.15 0.125 0.1 0.075 0.05 0.
Page 300 and 301:
The upcoming energy upgrade of Jeff
Page 302 and 303:
y the nearly 1000 combined citation
Page 304 and 305:
� R = −Pt/Pl τ(1 + ε)/2ε; he
Page 306 and 307:
4 Results of GEp-III Experiment In
Page 308 and 309:
6 Theoretical Developments The earl
Page 310 and 311:
lz = 0 (along the direction of the
Page 312 and 313:
models have recently been challenge
Page 314 and 315:
[32] Chung P. L. and F. Coester, Ph
Page 316 and 317:
48 ± 3% for two beams. The proton
Page 318 and 319:
is constant with cos θ∗ , as exp
Page 320 and 321:
In summary, we made measurements on
Page 322 and 323:
angle between the direction of the
Page 324 and 325:
The sensitivity of the data to the
Page 326 and 327:
COMPASS could be converted into a f
Page 328 and 329:
3.1.2 Beam charge and spin asymmetr
Page 330 and 331:
contributions enter only beyond lea
Page 332 and 333:
References [1] D. Mueller et al, Fo
Page 334 and 335:
l’ l p q p h H (z) 1 h (x) 1 l l
Page 336 and 337:
3. Data selection. The data selecti
Page 338 and 339:
φ sin3 a 0.06 0.04 0.02 0 -0.02 -0
Page 340 and 341:
TRANSVERSE SPIN AND MOMENTUM EFFECT
Page 342 and 343:
model. Both the cos φh and the cos
Page 344 and 345:
D cos φ A 0 -0.1 -0.2 -0.3 + h -2
Page 346 and 347:
4.3 The Sivers asymmetry According
Page 348 and 349:
[3] A. Airapetian et al. [HERMES co
Page 350 and 351:
2. Delta-Sigma Experimental Set-up.
Page 352 and 353:
6. Estimate of the count rate in tr
Page 354 and 355:
2 Analysis Formalism Spin-dependent
Page 356 and 357:
The MC production comprises three s
Page 358 and 359:
6 High pT hadron pair analysis for
Page 360 and 361:
[2] V. Y. Alexakhin et al. [COMPASS
Page 362 and 363:
2 Towards polarized Antiprotons For
Page 364 and 365:
4 Spin-Filtering Experiments at COS
Page 366 and 367:
to test the theoretical models of t
Page 368 and 369:
C1 C2 π CH1,2 CH3,4 CH5,6 111 000
Page 370 and 371:
not even resemble the data behavior
Page 372 and 373:
to the slope of the Rosenbluth plot
Page 374 and 375:
The differential cross section of t
Page 376 and 377:
with zero for all mass ranges, with
Page 378 and 379:
more precise and dedicated measurem
Page 380 and 381:
oth types of experiment results are
Page 382 and 383:
is recorded, a good particle identi
Page 384 and 385:
error of the extracted asymmetries
Page 386 and 387:
2.6 Summary and Outlook The first d
Page 388 and 389:
386
Page 391 and 392:
PROTON BEAM POLARIZATION MEASUREMEN
Page 393:
N A 0.06 0.05 0.04 0.03 0.02 0.01 0
Page 396 and 397:
Intensity profile (arb. units) 1 0.
Page 398 and 399:
[4] H. Okada et al., Proc. of the 1
Page 400 and 401:
The amplitudes of the signals and t
Page 402 and 403:
The following results has been obta
Page 404 and 405:
interaction vanishes and a single Z
Page 406 and 407:
an amorphous NH3 for low and high,
Page 408 and 409:
and depends on a choice of � ℓ1
Page 410 and 411:
3 The conditions for transparent sp
Page 412 and 413:
where angles α and β are defined
Page 414 and 415:
forward angles, where vector Ay and
Page 416 and 417:
espectively. The open symbols repre
Page 418 and 419:
RF dipole (transverse B): εBdl = 1
Page 420 and 421:
i PV / PV i PV / PV 1 0.5 0 -0.5 -1
Page 422 and 423:
The energies of the states Ψ1 −
Page 424 and 425:
field P ≈ +1. If we add the trans
Page 426 and 427:
econstruction provide more accurate
Page 428 and 429:
y detector saturation from pC colli
Page 430 and 431:
2 �p+ 8 He analyzing power measur
Page 432 and 433:
3.3 Effect of valence neutrons on s
Page 434 and 435:
i.e. n0(θ +2π) =n0(θ) . There ar
Page 436 and 437:
w and ˙ɛ. For example, we use par
Page 438 and 439:
436
Page 441 and 442:
REGULARIZATION OF SOURCE OF THE KER
Page 443 and 444:
The corresponding phase transition
Page 445 and 446:
ABOUT SPIN PARTICLE SOLUTION IN BOR
Page 447 and 448:
where the functions fi(s, η) must
Page 449 and 450:
SPINDYNAMICS I.B. Pestov JINR, 1419
Page 451 and 452:
State of hadron matter is defined t
Page 453 and 454:
REMARK ON SPIN PRECESSION FORMULAE
Page 455 and 456:
It is easy to see that for a (massi
Page 457 and 458:
DYNAMICS OF SPIN IN NONSTATIC SPACE
Page 459 and 460:
Schwinger gauge. Probably for the f
Page 461 and 462:
DSPIN-09 WORKSHOP SUMMARY Jacques S
Page 463 and 464:
to some preliminary results reporte
Page 465 and 466:
A new measurement of the polarizati
Page 467 and 468:
new NLO QCD parametrization of the
Page 469:
Name (Institution, Town, Country) E
show all

References - Bogoliubov Laboratory of Theoretical Physics - JINR

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?