183 research outputs found
SEARCH FOR CP VIOLATION IN RARE B-MESON DECAYS
No full textWe have studied in detail CP violation asymmetries of the B(d) --> K+ pi-, K+ rho-and K*+ pi-decays. We have found the asymmetries in all cases considered to be very sensitive to the gluon momentum transfer k. It is shown that supersymmetry leads to very small changes in the results of the standard model. From the results it follows that the considered decays have potentially large asymmetries which may be measured in future experiments
SINGLE PRODUCTION OF NEW GAUGE Z' BOSONS AND LEPTOQUARKS AT FUTURE E+E- COLLIDERS
No full textThe production of single scalar (fermionic) leptoquarks and new gauge Z' bosons in e+ e- collisions at square-root s = 2 TeV (the CLIC project) is studied in the Weizsacker-Williams approximation. It is shown that the cross section for these processes is large and completely detectable if the total luminosity is L = 10(33) cm-2.sec-1. Explicit analytic expressions are obtained for the visible electron spectrum in all cases. It follows from the analysis that study of the visible electron spectra is a very effective tool for determining the masses of leptoquarks and new Z' boson
LEPTOQUARK PRODUCTION WITH POLARIZED GAMMA-E BEAMS
No full textPossibilities of single production of the scalar leptoquark and also of its supersymmetric partner in polarized-gamma-e beams are studied in E6 superstring theories. Expressions for the differential and total cross sections are obtained and analyzed. It is shown that the scalar leptoquark of mass 300 GeV can be detected even for a very small interaction constant lambda-2/4-pi almost-equal-to 10(-3)alpha, and its supersymmetric partner can be detected for lambda-2/4-pi almost-equal-to 10(-2)alpha. The spin asymmetry due to the photon-beam polarization and the effect of this polarization on both the differential and the total cross sections are studied in detail. It is shown that study of the spin asymmetry and the effect of the photon-beam polarization can be used to extract information about the leptoquark masses
Polarization effects in exclusive semileptonic Lambda(b) -> Lambda l(+) l(-)
No full textThe independent helicity amplitudes in the Lambda(b) -> Lambda l(+)l(-) decay in the standard model and its minimal extension, i.e., with the new vector type interactions, are calculated. We calculate various asymmetry parameters characterizing the angular dependence of the differential decay width for the cascade decay Lambda(b) -> Lambda(-> a+b) V*(-> l(+)l(-)) with polarized and unpolarized heavy baryons. The sensitivity of the asymmetry parameters to the new Wilson coefficients are analyzed
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