References - Bogoliubov Laboratory of Theoretical Physics - JINR

More documents

Recommendations

Info

analysis was carried out reconstructing h + h − hadron pairs produced in invariant-mass windows below and above the Λ ( ¯ Λ) mass peak. As an additional check of a possible false polarization, the decay K0 s → π+ π− was studied. These analyzes resulted in Dh+ h− LL = −0.002 ± 0.011 and D K0 s LL = −0.016 ± 0.035. Λ 0.2 Λ 0.1 0 −0.1 1.0 − Λ Λ − The HERMES data for D 0.5 Λ LL [3] are presented in Fig. 2 as a function of xF together with data of the NOMAD experiment at CERN [4], the E665 experiment at Fermilab [5] and the COMPASS experiment at CERN [6]. As seen from Fig. 2, the NOMAD, COMPASS and HER- MES results are compatible in the kinematic region of overlap −0.1 < xF < 0.3. The HERMES results, averaged over kinematics are =0.102 ± 0.056(stat) ± 0.020(syst) forΛ P n (GeV) 0 0 0.1 0.2 0.3 0.4 0.5 0.6 ζ DΛ LL and D ¯ Λ LL =0.152 ± 0.139(stat) ± 0.030(syst) for ¯Λ, respectively. The spin transfer from the longitudinally polarized 1H and 2D targets to the hyperon, KΛ LL , Figure 4: Transverse polarizations PΛ and P¯Λ (upper panel) and mean 〈pT〉 (lower panel) was measured in the quasi-real photoproduction as functions of ζ =(EΛ + pzΛ)/(Ee + pe). regime. The KΛ LL extraction procedure is similar to the DΛ LL analysis [7]. The kinematical dependence of KΛ √ � LL as a function of t = −(pΛ − pp) 2 , where pΛ (pp) is the four-momentum of the Λ hyperon (target nucleon), is presented in Fig. 3 together with results obtained by the E704 (p↑p → � ΛX, pbeam = 200 GeV/c) [8] and STAR (�pp → � ΛX, √ s = 200 GeV) [9] collaborations. The HERMES data confirm the trend of KΛ LL increasing with decreasing √ t previously observed by the E704 collaboration. Averaged over kinematics the HERMES result for the =0.024 ± 0.008(stat) ± 0.003(syst) for the Λ hyperon, while for the spin transfer is KΛ LL ¯Λ hyperon it is compatible with zero: K ¯ Λ LL =0.002 ± 0.019(stat) ± 0.008(syst). P Λ 0.2 0.1 0 -0.1 1 H 2 D 0 < ζ < 1 HERMES PRELIMINARY 3 He 4 He 14 N 20 Ne 132 Xe 84 Kr 1 10 10 A 2 Figure 5: Transverse Λ polarization vs atomic number of nuclei. Transverse Λ polarization was observed and investigated in many high-energy scattering experiments, with a wide variety of hadron beams and kinematic settings [10, 11]. Because of the parity-conserving nature of the electromagnetic and the strong interaction, any final-state hadron (hyperon) polarization in an inclusive reaction with unpolarized beam and target can only point along the normal ˆn = �pe×�pΛ |�pe×�pΛ| of the production plane, where �pe is the (positron) beam momentum and �pΛ is the Λ momentum, respectively. Possible mechanisms for the origin of this polarization were discussed for example in Refs. [12], [13], [14] [15] [16], [17]. The formalism of the extraction of transverse Λ polarization is based upon the up/down symmetry of the HERMES detector and the moments method [2, 18]. Averaged over the experimental kinematics, the net Λ polarization extracted from the data collected in the years 1996-2005 with various targets was found to be signficantly positive while the net 264
¯Λ polarization was consistent with zero: PΛ = 0.078 ± 0.006(stat) ± 0.012(syst) and P¯ Λ = −0.025 ± 0.015(stat) ± 0.018(syst) [18]. The wide variety of target nuclei used until the end of data taking in 2007 allowed to study also the A-dependence of the transverse Λ polarization. The resulting A-dependence is presented in Fig. 5. There is a clear indication of an A-dependence of the spontaneous Λ polarization: the polarization for light nuclei ( 1 H, 2 D) is statistically significant positive, while for heavier nuclei ( 84 Kr, 132 Xe) the polarization is compatible with zero within the statistical uncertainties of the data. References [1] HERMES Collaboration, K.Ackerstaff et al., Nucl. Instr. Meth. A417 (1998) 230. [2] S. Belostotski, DESY-HERMES-06-57. Prepared for 58th Scottish Universities Summer School in Physics (SUSSP58): A NATO Advanced Study Institute and EU Hadron Physics 13 Summer Institute, St. Andrews, Scotland, 22-29 Aug (2004). [3] HERMES Collaboration, A. Airapetian et al., Phys. Rev. D74 (2006) 072004. [4] NOMAD Collaboration, P. Astier et al., Nucl. Phys. B588(2000) 3. [5] E665 Collaboration, M.R. Adams et al., Eur. Phys. J. C17(2000) 263. [6] COMPASS Collaboration, M. Alekseev et al., arXiv:0907.0388 [hep-ex]. [7] D. Veretennikov, in ”Proceedings of the XVI International Workshop on Deep- Inelastic Scattering and Related Topics”, London, England, April 7-11, (2008). [8] E704 collaboration, A. Bravar et al., Phys. Rev. Lett. 78 (1997) 4003. [9] Qinghua Xu for the STAR collaboration, hep-ex/0612035. [10] K. Heller, in “Proceedings of the 12 th International Symposium on High-Energy Spin Physics (SPIN 96)”, T.J. Ketel, P.J. Mulders, J.E.J. Oberski, M. Oskam-Tamboezer (World Scientific, Singapore, 1997), p.23. [11] J. Lach, Nucl. Phys. (Proc. Suppl.) 50 (1996) 216. [12] B. Andersson, G. Gustafson and G. Ingelman, Phys. Lett. B85, (1979) 417. [13] T. A. Degrand, J. Markkanen and H. I. Miettinen, Phys. Rev. D32, (1985) 2445-2448 [14] A.D. Panagiotou, Int. J. Mod. Phys. A5 (1990) 1197. [15] K. Kubo, Y. Yamamoto and H. Toki, Prog. Theor. Phys. 101 (1999) 615. [16] J. Soffer, Proceedings of Hyperon 99, hep-ph/9911373. [17] Homer A. Neal, Eduard De La Cruz Burelo in ”International Spin Physics Symposium (SPIN06)” AIP Conf.Proc.915, (2007) 449-453. [18] HERMES collaboration, A. Airapetian et al., Phys. Rev. D76(2007) 092008. 265
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 222 and 223: Figure 3: The experimental results
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 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

Create successful ePaper yourself

Delete template?

Save as template?