922 research outputs found
Mesino - Antimesino Oscillations
The phenomenological implications of supersymmetric theories with low scale
supersymmetry breaking and a squark as the lightest standard model superpartner
are investigated. Such squarks hadronize with light quarks, forming sbaryons
and mesinos before decaying. Production of these supersymmetric bound states at
a high energy collider can lead to displaced jets with large negative impact
parameter. Neutral mesino - antimesino oscillations are not forbidden by any
symmetry and can occur at observable rates with distinctive signatures. Stop
mesino - antimesino oscillations would give a sensitive probe of up-type
sflavor violation in the squark sector, and can provide a discovery channel for
supersymmetry through events with a same-sign top-top topology.Comment: 4 pages, 1 figure, LaTe
CP parameters of the B systems from Tevatron
Recent results on CP parameters of the B systems obtained by the CDF and D0
collaborations using the data samples collected at the Tevatron Collider in the
period 2002 - 2007 were presented at the QCD 2008 conference (Montpellier,
France). These results include measurements of the mixing phase, decay width
difference, and CP violation parameters in the Bs and Bu decays.Comment: Presented at the QCD 2008 Conference (Montpellier, France); added
references; corrected RCP+ paramete
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
Time Vs. Goods: The Value of Measuring Household Production Technologies
We take U.S. and Israeli household data on expenditures of time and goods, generate an exhaustive set of commodities that households produce/consume using them, and calculate their relative goods intensities. Leisure activities are uniformly relatively time intensive, health, travel and lodging relatively goods intensive. We demonstrate how education and age alter the goods intensity of household production. The results of this accounting can be used as guides to: Understanding how goods and income taxation interact to affect welfare; expanding notions of the determinants of international flows of goods; generating models of business cycles and endogenous growth to include interactions of goods and time consumption; and obtaining better measures of the distribution of well being.
The Demand for Variety: A Household Production Perspective
Product diversity pervades every modern marketplace, and economists have devoted substantial attention to firms' decisions about the supply of variety. This study looks at the consumer's side by discussing the demand for variety. Using the framework of the home-production model, we trace differences in demand to differences in the opportunity costs of various activities. The cost differences are associated with investments in human capital; and the resulting differences in schooling attainment produce differences in time costs that in turn alter the kinds and variety of activities in which household members engage. Using time-budget surveys from Australia, Israel, the Netherlands, Sweden, the United States and West Germany from between 1985 and 1994, we find substantial differences among households in the extent of variety in the nonwork activities that they produce. More educated individuals generate more variety, engaging in both additional activities and the same ones as the less educated, with most of the effect of education on the variety of nonroutine activities. There is more variety on weekends; women engage in more different activities than men; young children add to variety in household consumption/production, especially among women; and income effects are clearly positive.
Framework for Identification of Neutral B Mesons
We introduce a method for the study of CP-violating asymmetries in tagged
states of neutral mesons with arbitrary coherence properties. A set of
time-dependent measurements is identified which completely specifies the
density matrix of the initial state in a two-component space with basis vectors
and , and permits a determination of phases in the
Cabibbo-Kobayashi-Maskawa matrix. For a given tagging configuration, the
measurement of decays both to flavor eigenstates and to CP eigenstates provides
the necessary information.Comment: Submitted to Phys. Rev. Letters. 8 pages, LaTeX, Technion-PH-93-31 /
EFI 93-3
Ratios of heavy hadron semileptonic decay rates
Ratios of charmed meson and baryon semileptonic decay rates appear to be
satisfactorily described by considering only the lowest-lying (S-wave) hadronic
final states and assuming the kinematic factor describing phase space
suppression is the same as that for free quarks. For example, the rate for
semileptonic decay is known to be lower than those for
or , and the model accounts for this difference. When applied to
hadrons containing quarks, this method implies that the semileptonic
decay rate is about 1% higher than that of the nonstrange mesons. This
small difference thus suggests surprisingly good local quark-hadron duality for
semileptonic decays, complementing the expectation based on inclusive
quark-hadron duality that these differences in rates should not exceed a few
tenths of a percent. For semileptonic decay, however, the inclusive
rate is predicted to be about 13% greater than that of the nonstrange
mesons. This value, representing a considerable departure from a calculation
using a heavy quark expansion, is close to the corresponding experimental ratio
of total decay rates.Comment: 12 pages, no figures. References adde
SU(3) Decomposition of Two-Body B Decay Amplitudes
We present the complete flavor SU(3) decomposition of decay amplitudes for
decays of the triplet (B^+_u, B^0_d, B^0_s) of B mesons nonleptonically into
two pseudoscalar mesons. This analysis holds for arbitrarily broken SU(3) and
can be used to generate amplitude relations when physical arguments permit one
to neglect or relate any of the reduced amplitudes.Comment: 31 pages, revtex, no figure
P and CP violation in B physics
While the Kobayashi--Maskawa single phase origin of CP violation passed its
first crucial precision test in , the chirality of weak
-quark couplings has not yet been carefully tested. We discuss recent
proposals for studying the chiral and CP-violating structure of these couplings
in radiative and in hadronic B decays.Comment: 15 pages, talk at PASCOS'03, Tata Inst., Mumbai, Jan. 200
Charmless decays using flavor SU(3) symmetry
The decays of mesons to a pair of charmless pseudoscalar () mesons are
analyzed within a framework of flavor SU(3). Symmetry breaking is taken into
account in tree () amplitudes through ratios of decay constants; exact SU(3)
is assumed elsewhere. Acceptable fits to and
branching ratios and CP asymmetries are obtained with tree, color-suppressed
(), penguin (), and electroweak penguin () amplitudes. Crucial
additional terms for describing processes involving and include
a large flavor-singlet penguin amplitude () as proposed earlier and a
penguin amplitude associated with intermediate and quarks. For
the mode a term associated with intermediate
and quarks also may be needed. Values of the weak phase are
obtained consistent with an earlier analysis of decays, where
denotes a vector meson, and with other analyses of CKM parameters.Comment: 26 pages, 1 figure. To be submitted to Phys. Rev. D. Reference
update
- …