5,841 research outputs found
GEOS-C radar altimeter characteristics
The purpose of the GEOS-C mission and the operating characteristics of its special K-band altimeter are outlined. Special attention was given to the possible use of height measurements and other supporting GEOS-C data to evaluate the feasibility and value of altimetry on a global basis
Telephone or video? A review of telemedicine consultations during the COVID-19 pandemic in a spinal MSK service
A service evaluation of the move to virtual appointments during the COVID-19 pandemic
Drell-Yan Lepton Angular Distribution at Small Transverse Momentum
We investigate the dependence of the Drell-Yan cross section on lepton polar
and azimuthal angles, as generated by the lowest-order QCD annihilation and
Compton processes. We focus in particular on the azimuthal-angular
distributions, which are of the form cos(phi) and cos(2phi). At small
transverse momentum q_T of the lepton pair, q_T << Q, with Q the pair mass,
these terms are known to be suppressed relative to the phi-independent part of
the Drell-Yan cross section by one or two powers of the transverse momentum.
Nonetheless, as we show, like the phi-independent part they are subject to
large logarithmic corrections, whose precise form however depends on the
reference frame chosen. These logarithmic contributions ultimately require
resummation to all orders in the strong coupling. We discuss the potential
effects of resummation on the various angular terms in the cross section and on
the Lam-Tung relation.Comment: 13 pages, 2 figures; reference added, minor other changes, matches
version to be published in PR
Bs Mixing and Electric Dipole Moments in MFV
We analyze the general structure of four-fermion operators capable of
introducing CP-violation preferentially in Bs mixing within the framework of
Minimal Flavor Violation. The effect requires a minimum of O(Yu^4 Yd^4) Yukawa
insertions, and at this order we find a total of six operators with different
Lorentz, color, and flavor contractions that lead to enhanced Bs mixing. We
then estimate the impact of these operators and of their close relatives on the
possible sizes of electric dipole moments (EDMs) of neutrons and heavy atoms.
We identify two broad classes of such operators: those that give EDMs in the
limit of vanishing CKM angles, and those that require quark mixing for the
existence of non-zero EDMs. The natural value for EDMs from the operators in
the first category is up to an order of magnitude above the experimental upper
bounds, while the second group predicts EDMs well below the current sensitivity
level. Finally, we discuss plausible UV-completions for each type of operator.Comment: 11 pages; v2: references adde
Selective self-categorization: Meaningful categorization and the in-group persuasion effect
Research stemming from self-categorization theory (Turner et al., 1987) has demonstrated that individuals are typically more persuaded by messages from their in-group than by messages from the out-group. The present research investigated the role of issue relevance in moderating these effects. In particular, it was predicted that in-groups would only be more persuasive when the dimension on which group membership was defined was meaningful or relevant to the attitude issue. In two studies, participants were presented with persuasive arguments from either an in-group source or an out-group source, where the basis of the in-group/out-group distinction was either relevant or irrelevant to the attitude issue. Participants' attitudes toward the issue were then measured. The results supported the predictions: Participants were more persuaded by in-group sources than out-group sources when the basis for defining the group was relevant to the attitude issue. However, when the defining characteristic of the group was irrelevant to the attitude issue, participants were equally persuaded by in-group and out-group sources. These results support the hypothesis that the fit between group membership and domain is an important moderator of self-categorization effects
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