Proton strangeness form factors in (4,1) clustering configurations

We reexamine a recent result within a nonrelativistic constituent quark model (NRCQM) which maintains that the uuds\bar s component in the proton has its uuds subsystem in P state, with its \bar s in S state (configuration I). When the result are corrected, contrary to the previous result, we find that all the empirical signs of the form factors data can be described by the lowest-lying uuds\bar s configuration with \bar s in P state that has its uuds subsystem in $S$ state (configuration II). Further, it is also found that the removal of the center-of-mass (CM) motion of the clusters will enhance the contributions of the transition current considerably. We also show that a reasonable description of the existing form factors data can be obtained with a very small probability P_{s\bar s}=0.025% for the uuds\bar s component. We further see that the agreement of our prediction with the data for G_A^s at low-q^2 region can be markedly improved by a small admixture of configuration I. It is also found that by not removing CM motion, P_{s\bar s} would be overestimated by about a factor of four in the case when transition dominates over direct currents. Then, we also study the consequence of a recent estimate reached from analyzing the existing data on quark distributions that P_{s\bar s} lies between 2.4-2.9% which would lead to a large size for the five-quark (5q) system, as well as a small bump in both G^s_E+\eta G^s_M and G^s_E in the region of q^2 =< 0.1 GeV^2.Comment: Prepared for The Fifth Asia-Pacific Conference on Few-Body Problems in Physics 2011 in Seoul, South Korea, 22-26 August 201

Strange Quark Contributions to Parity-Violating Asymmetries in the Backward Angle G0 Electron Scattering Experiment

We have measured parity-violating asymmetries in elastic electron-proton and quasi-elastic electron-deuteron scattering at Q^2 = 0.22 and 0.63 GeV^2. They are sensitive to strange quark contributions to currents in the nucleon, and to the nucleon axial current. The results indicate strange quark contributions of < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial current at these four-momentum transfers.Comment: 5 pages, 2 figures, changed references, typo, and conten

The Present and Future of QCD

This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming decades

Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering

We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from the proton, and performed the first measurement in quasi-elastic scattering on the deuteron, at backward angles (lab scattering angle of 108 degrees) for Q2 = 0.22 GeV^2/c^2 and 0.63 GeV^2/c^2 at beam energies of 362 MeV and 687 MeV, respectively. The asymmetry arises due to the imaginary part of the interference of the two-photon exchange amplitude with that of single photon exchange. Results for the proton are consistent with a model calculation which includes inelastic intermediate hadronic (piN) states. An estimate of the beam-normal single-spin asymmetry for the scattering from the neutron is made using a quasi-static deuterium approximation, and is also in agreement with theory

First Midwives in the Town of Bjelovar, Croatia 1756-1856

Prve izučene (aprobirane) primalje dolaze u novoosnovani Bjelovar, jako vojno središte Vojne krajine početkom druge polovice XVIII. stoljeća zajedno s vojnim liječnicima, kirurzima i ljekarnicima, a većina njih je germanskoga podrijetla. U do sada neistraženom arhivskom materijalu za razdoblje 1756.-1856. pronađeni su podaci o 23 izučene primalje, od kojih je 14 bilo pukovnijskih i 9 gradskih primalja. Visok perinatalni pomor djece i majki i kriminalni pobačaji karakteristike su toga razdoblja. Uz model domicilnoga primaljstva: skrb za trudnice, rodilje, babinjače, novorođenčad i dojenčad, primalje u teškim porodima obavljaju krštenje iz nužde ugroženoj novorođenčadi ili su pak krsne kume zdravoj dojenčadi. Premda je u samom gradu Bjelovaru ustrojeno stručno primaljstvo, u okolici grada i dalje se porodi obavljaju bez stručne pomoći. Za razliku od većine tadašnjih gradova kontinentalne Hrvatske, pa i Dalmacije, u Bjelovaru postoji kontinuirano izučeno primaljstvo i zaštita materinstva od polovice XVIII. stoljeća.The first trained (certified) midwives came to the newly founded town of Bjelovar, a strong military centre of Vojna Krajina (Croatian province bordering Ottoman Empire), at the beginning of the 1750s, along with army physicians, surgeons, and pharmacists. Most were of German origin. The archival material investigated for the period 1756-1856 speaks of 23 certified midwives, of whom 14 were regimental and nine municipal. This period was characterised by high neonatal and maternal mortality rates and criminal abortions. Within the scope of the domiciliary midwifery model that included care for pregnant women, parturient women, neonates, and infants, midwives used to act as godmothers to newborns at risk, in periculo, or to healthy newborns. Although Bjelovar had professional midwifery service, the practice of unassisted childbirths continued in the town surroundings. Unlike other inland and coastal (Dalmatian) towns of the time, Bjelovar has had a continuous tradition of training midwives and maternal health care since the 1750s

Pionska apsorpcija u 4He

This paper presents a large solid angle measurement of the positive pion absorption cross-section on 4He and its decomposition into partial channels. A large fraction of the absorption cross-section at incident pion kinetic energies of Tπ+ =70, 118, 162, 239, and 330 MeV is due to multinucleon channels.Daju se ishodi mjerenja pod velikim prostornim kutom udarnog presjeka za apsorpciju pozitivnih piona u He4 i razdjela na pojedine kanale. Velik dio apsorpcijskog udarnog presjeka za energije upadnih piona od Tπ+ =70, 118, 162, 239 i 330 MeV je posljedica višenukleonskih kanala

The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.Comment: Submitted to Nuclear Instruments and Method

Višenukleonska emisija nakon pionske apsorpcije u N, Ar i Xe

Positive pion absorption was studied in an almost 4π geometry allowing simultaneous measurements of various charge and neutral multiplicities. Total absorption cross sections and its decomposition into the most important channels is determined. The results are presented for N, Ar and Xe nuclei at incident pion energies of 118,162 and 239 MeV. The role of multinucleon emission in the absorption process is emphasized.Proučava se pionska apsorpcija s blizu 4π detekcijom koja dozvoljava istovremeno mjerenje raznih nabojskih i neutralnih višestrukosti. Određuju se ukupni udarni presjeci i njihovo razlaganje u najvažnije kanale. Predstavljaju se rezultati za jezgre N, Ar i Xe na energijama 118,162 i 239 MeV. Ističe se uloga višenukleonske emisije u procesu apsorpcije