Production ofπ+,π−,

K. Abe¹,

Kenji Abe²,

T. Abe³

et al.

Abstract

We present improved measurements of the differential production rates of stable charged particles in hadronic Z 0 decays, and of charged pions, kaons, and protons identified over a wide momentum range using the SLD Cherenkov ring imaging detector. In addition to flavor-inclusive Z 0 decays, measurements are made for Z 0 decays into light ͑u, d, s͒, c, and b primary flavors, selected using the upgraded vertex detector. Large differences between the flavors are observed that are qualitatively consistent with expectations based upon previously measured production and decay properties of heavy hadrons. These results are used to test the predictions of QCD in the modified leading logarithm approximation, with the ansatz of local parton-hadron duality, and the predictions of three models of the hadronization process. The light-flavor results provide improved tests of these predictions; the heavy-flavor results provide complementary model tests. In addition we have compared hadron and antihadron production in light quark ͑as opposed to antiquark͒ jets. Differences are observed at high momentum for all three charged hadron species, providing direct probes of leading particle effects, and stringent constraints on models.

Logarithmic accuracy of angular-ordered parton showers

“…In order to tune the shower and light quark hadronization parameters we used data on jet rates and event shapes for centre-of-mass energies between 14 and 44 GeV [40][41][42][43], at LEP1 and SLD [42][43][44][45][46][47] and LEP2 [42,43,46,47], particle multiplicities [44,45] and spectra [44,45,[48][49][50][51][52][53][54][55][56][57][58][59][60] at LEP 1, identified particle spectra below the Υ(4S) from Babar [61], the charged particle multiplicity and distributions from [62][63][64][65][66][67] for centre-of-mass energies between 14 and 61 GeV, the charged particle multiplicity [68,69] and particle spectra [68,70,71] in light quark events at LEP1 and SLD, the charged particle multiplicity in light quark events at LEP2 [72,73], the cha...…”

“…The hadronization parameters for charm quarks were tuned using the charged multiplicity in charm events at HRS [64], SLD [69] and LEP2 [72,73], the light hadron spectra in charm events at LEP1 and SLD [68,70,71], the multiplicities of charm hadrons at the Z-pole [44,77], and charm hadron spectra below the Υ(4S) [80][81][82] and at LEP1 [83].…”

Measurement of Collins asymmetries in inclusive production of charged pion pairs ine+e−annihilation atBABAR

“…Fragmentation processes have been studied in leptonhadron and hadron-hadron scattering, as well as in e þ e − annihilation, which provides the cleanest environment since no hadrons are present in the initial state. Due to the large amount of experimental data collected at several e þ e − facilities, mainly LEP [1][2][3] and SLC [4][5][6] at high energies, and, recently, PEP-II [7] and KEKB [8] at the center-of-mass energy ffiffi ffi s p ∼ 10 GeV, the unpolarized functions are presently well known.…”

Charged hadron fragmentation functions from collider data

“…In this analysis we include all available SIA measurements from LEP (ALEPH [40], DELPHI [41, 42] and OPAL [43, 44]), PETRA (TASSO [45]), PEP (TPC [46]) and SLC (SLD [47]). These measurements consist of cross sections differential in the scaling variable , where is the four-momentum of the final-state hadron, q is the four-momentum of the exchanged virtual gauge boson and .…”

“…They are normalised to the total cross section for inclusive electron–positron annihilation into hadrons, . Besides measurements based on inclusive samples, which contain all quark flavours, we also include measurements based on flavour-enriched (or tagged) uds -, c - and b -quark samples from DELPHI [41, 42], OPAL [43] and SLD [47]. This data set is then equivalent to that of the identified charged pions, kaons and protons/antiprotons set used in NNFF1.0.…”