Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

Linear Collider Physics Resource Book for Snowmass 2001, 3: Studies of Exotic and Standard Model Physics

This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available.This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Muoproduction of J/psi(3100)

Interactions of 209-GeV muons within an instrumented magnetized-steel calorimeter have produced 4374 +- 87 ..mu../sup +/..mu../sup -/ pairs from J/psi decay, corresponding to the cross section sigma(..mu..N ..-->.. ..mu.. psi X) = 0.64 +- 0.10 nb. These interactions are classified as either elastic (sigma = 0.36 +- 0.07 nb) or inelastic (sigma = 0.28 +- 0.06 nb) based primarily on the calorimetric determination of E/sub X/. The cross section for elastic psi production by virtual photons, sigma/sub eff/(..gamma../sub V/N), rises with energy nu as log nu. Its dependence on Q/sup 2/ fits the vector-meson dominance form P(..lambda..) = (1 + Q/sup 2//..lambda../sup 2/)/sup -2/, with ..lambda.. = (2.0 - 2.4) +- 0.15 GeV, where the spread in values arises from considering the possibility of a Q/sup 2/ dependence in the decay angular distribution W (theta,phi) and in the nuclear shadowing factor. We find that W(theta,phi) is consistent with the form expected if the reaction ..gamma../sub V/N ..-->.. psiN conserves helicity in the s channel through natural-parity exchange in the t channel. After correction for nuclear effects, d sigma/sub eff//dt is described by the sum of two exponential terms in t, with average t slope b = 2.56 (+0.35 or - 0.32). The photon-gluon fusion (..gamma..g ..-->.. psi) perturbative quantum chromodynamic model for psi production provides an excellent description of the nu dependence of sigma/sub eff/, but cannot simultaneously explain the observed cross section and value of ..lambda... The differential cross section d/sup 2/sigma/sub eff//dzdp/sub perpindicular//sup 2/ for inelastically produced psi's rises approximately linearly with elasticity z identical with E/sub psi//nu. The p/sub perpendicular//sup 2/ dependence is flatter than that of d sigma/dt for elastic events, with average p/sub perpendicular//sup 2/ slope b = 1.46 +- 0.10. The Q/sup 2/ dependence of sigma/sub eff/ is that of P(..lambda..) with ..lambda.. = 3.0 +- 0.2 GeV, and the nu dependence is similar to that observed for elastic production. 101 references, 33 figures, 20 tables

Observation of deflection of a beam of multi-GeV electrons by a thin crystal

We report on an experiment performing channeling and volume reflection of a high-energy electron beam using a quasimosaic, bent silicon (111) crystal at the End Station A Test Beam at SLAC. The experiment uses beams of 3.35 and 6.3 GeV. In the channeling orientation, deflections of the beam of 400  μrad for both energies with about 22% efficiency are observed, while in the volume-reflection orientation, deflection of the beam by 120  μrad at 3.35 GeV and by 80  μrad at 6.3 GeV is observed with 86%–95% efficiency. Quantitative measurements of the channeling efficiency, surface transmission, and dechanneling length are taken. These are the first quantitative measurements of channeling and volume reflection using a primary beam of multi-GeV electrons