1,492 research outputs found
Isospin-breaking effects on alpha extracted in B --> pi pi, rho rho, rho pi
Isospin-breaking in B --> pi pi caused by pi^0-eta-eta' mixing is studied in
a model-independent way using flavor SU(3). Measured branching ratios for B^+
--> pi^+ pi^0, B^+ --> pi^+ eta^(') and B^0 --> pi^0 eta^(') imply an
uncertainty in alpha smaller than 1.4 degree. We find a negligible effect of
pi^0-eta-eta' mixing on alpha in B --> rho pi. Characterizing the effect of
rho^0-omega mixing in B --> rho rho and in B --> rho pi by the two-pion
invariant mass dependence, we point out a way of constraining this effect
experimentally or eliminating it altogether. We show that a model-independent
shift in alpha caused by electroweak penguin amplitudes in B --> pi pi and B
--> rho rho, \Delta alpha_{EWP}=1.5+- 0.3 degree, may be slightly different in
B --> rho pi. Other sources of isospin-breaking in these processes are briefly
discussed.Comment: 21 pages, very slight changes, same version as in Physical Review
Upgrading to world class: The future of the New York region's Airport
This paper is intended to serve three purposes. First, it presents a slightly abbreviated version of the summary of the book published by Regional Plan Association (RPA) in January 2011 about the serious capacity and delay problems at the three major airports in New York and what might be done about it. Second, the paper provides information on the response by the Port Authority of New York and New Jersey, the owners and operators of the three airports and what has transpired in the two years since the book was published. Third, the paper discusses some relevant emerging issues that will likely further affect the ability to address the growing problem of capacity and delays at these airports
Semi-inclusive hadronic B decays as null tests of the Standard Model
We propose a new set of observables that can be used as experimental null
tests of the Standard Model in charged and neutral B decays. The CP asymmetries
in hadronic decays of charged B mesons into inclusive final states containing
at least one of the following mesons: K_{S,L}, eta', c\bar c bound states or
neutral K^* or D mesons, for all of which a U-spin rotation is equivalent to a
CP conjugation, are CKM suppressed and furthermore vanish in the exact U-spin
limit. We show how this reduces the theoretical error by using Soft Collinear
Effective Theory to calculate the CP asymmetries for K_{S,L} X_{s+d}, K^*
X_{s+d} and eta' X_{s+d} final states in the endpoint region. For these CP
asymmetries only the flavor and not the charge of the decaying B meson needs to
be tagged up to corrections of NLO in 1/m_b, making the measurements more
accessible experimentally.Comment: 8 pages, significantly expanded after the observation that both
neutral and charged B decays can be used, calculation for decays involving
eta' adde
Regio and Stereospecific 2 + 2 Photoaddition of Cyclopentene to Pentafluoro-alkoxybenzene
2 + 2 photoaddition of cyclopentene to pentafluoro-alkoxybenzene
in cyclohexane solution proceeds stereoselectively anti
and regiospecifically to the 3,4 position
Electronic Structure of Hydrazinium (2 + ) Ion. A Semiempirical MO Treatment
A simple semiempjrical MO treatment of the electronic structure
of hydrazinium (2 + ) ion was carried out on the basis of an
extended Htickel method. The electronic population analysis for
nitrogen and hydrogen atoms in this ion was calculated to b e (ls) 2
(2s)1 -121 (2px)1 ·3Go (2py)t·3Go (2p z)o .9BG and (ls)0o122, respectively
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