Physics Commons^™

Measurements Of The Absolute Branching Fractions Of B± → K±Xcc, J. P. Lees, V. Poireau, V. Tisserand, E. Grauges

Faculty Publications

A study of the two-body decays B^±→X_ccK^±, where Placeholder refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424 fb⁻¹. The absolute determination of branching fractions for these decays are significantly improved compared to previous BABARmeasurements. Evidence is found for the decay B⁺→ X ( 3872) K ⁺

at the Placeholder level. The absolute branching fraction Placeholder is measured for the first time. It follows that Placeholder, supporting the hypothesis of a molecular component for this resonance.

Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen

Physics Faculty Publications

Mechanisms of spin-flavor SU(6) symmetry breaking in quantum chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from A = 2 (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio Fⁿ₂/F^p₂ becomes constant for x_B ≥ 0.6, equaling 0.47 …

Intrinsic Transverse Momentum And Evolution In Weighted Spin Asymmetries, Jian-Wei Qiu, Ted C. Rogers, Bowen Wang

Physics Faculty Publications

The transverse momentum-dependent (TMD) and collinear higher twist theoretical factorization frameworks are the most frequently used approaches to describe spin-dependent hard cross sections weighted by and integrated over transverse momentum. Of particular interest is the contribution from small transverse momentum associated with the target bound state. In phenomenological applications, this contribution is often investigated using transverse momentum weighted integrals that sharply regulate the large transverse momentum contribution, for example, with Gaussian parametrizations. Since the result is a kind of hybrid of TMD and collinear (inclusive) treatments, it is important to establish if and how the formalisms are related in applications …

Measurement Of The ³He Spin-Structure Functions And Of Neutron (³He) Spin-Dependent Sum Rules At 0 .035≤Q²≤0 .24 Gev², V. Sulkosky, D. Hayes, C. E. Hyde, P. E. Ulmer, X. Zheng, L. Zhu, Et Al., Jefferson Lab E97-110 Collaboration

Physics Faculty Publications

The spin-structure functions g₁ and g₂, and the spin-dependent partial cross-section σπ have been extracted from the polarized cross-sections differences,

Δσ∥ (ν, Q²) and Δσ⊥ (ν,Q²) measured for the 3^→He(^→e, e')X reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404GeV were scattered at angles of 6^◦and 9^◦ from a longitudinally or transversely polarized ³He target. The data cover the kinematic regions of the quasi-elastic, …

Double Inclusive Small-X Gluon Production And Their Azimuthal Correlations In A Biased Ensemble, Gary Kapilevich

Publications and Research

We consider double gg → g production in the presence of a bias on the unintegrated gluon distribution of the colliding hadrons or nuclei. Such bias could be due to the selection of configurations with a greater number of gluons or higher mean transverse momentum squared or, more generally, due to a modified spectral shape of the gluon distribution in the hadrons. Hence, we consider reweighted functional averages over the stochastic ensemble of small-x gluons. We evaluate explicitly the double inclusive gluon transverse momentum spectrum in high-energy collisions, and their azimuthal correlations, for a few simple examples of biases.