PUBLIKASI PENELITIAN

Berisi daftar Publikasi Penelitian LIPI

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2000 Isospin symmetry breaking and direct CP violation in B -> rho gamma within and beyond the standard model L.T. Handoko We discuss the isospin symmetry breaking quantity Delta^{pm 0} = Gamma(B^pm -> rho^pm gamma)/[2 Gamma(B^0 -> rho^0 gamma)] - 1, and the direct CP violation in B^pm -> rho^pm gamma within and beyond the standard model. After showing that the leading-order calculation would be a good approximation in such models, we argue that measurements of these quantities would be able to disentagle physics beyond the standard model. Lihat
2000 Supersymmetric effects on isospin symmetry breaking and direct CP violation in B -> rho gamma A. Ali, L. T. Handoko, D. London We argue that one can search for physics beyond the standard model through measurements of the isospin-violating quantity $Delta^{-0} equiv Gamma(B^- to rho^- gamma)/2Gamma(B^0 to rho^0 gamma)-1$, its charge conjugate $Delta^{+0}$, and direct CP violation in the partial decay rates of $B^pm to rho^pm gamma$. We illustrate this by working out theoretical profiles of the charge-conjugate averaged ratio $Delta equiv {1 over 2}(Delta^{+0} +Delta^{-0})$ and the CP asymmetry $A_{CP}(B^pm to rho^pm gamma)$ in the standard model and in some variants of the minimal supersymmetric standard model. We find that chargino contributions in the large $tan beta$ region may modify the… Lihat
2000 Neutrino mixing and flavour changing processes W. Buchmueller, D. Delepine, L. T. Handoko We study the implications of a large nu_mu - nu_tau mixing angle on flavour changing transitions of quarks and leptons in supersymmetric extensions of the standard model. Two patterns of supersymmetry breaking are considered, models with modular invariance and the standard scenario of universal soft breaking terms at the GUT scale. The analysis is performed for two symmetry groups G x U(1)_F, with G=SU(5) and G=SU(3)^3, where U(1)_F is a family symmetry. Models with modular invariance are in agreement with observations only for restricted scalar quark and gaugino masses, (M_squark^2)/(m_gluino^2) simeq 7/9 and m_bino > 350 GeV. A characteristic feature… Lihat
1999 A Comparison Study of the Decays B -> (K,K^) l^+ l^- in Standard Model and Supersymmetric Theories A. Ali, P. Ball, L. T. Handoko, G. Hiller Using improved theoretical calculations of the decay form factors in the Light Cone-QCD sum rule approach, we investigate the decay rates, dilepton invariant mass spectra and the forward-backward (FB) asymmetry in the decays B to (K,K^) ell^+ ell^- (ell^pm =e^pm,mu^pm,tau^pm) in the standard model (SM) and a number of popular variants of the supersymmetric (SUSY) models. Theoretical precision on the differential decay rates and FB-asymmetry is estimated in these theories taking into account various parametric uncertainties. We show that existing data on B to X_s gamma and the experimental upper limit on the branching ratio {cal B}(B to K^ mu^+… Lihat
1999 t -> c Upsilon within and beyond the standard model L. T. Handoko, C.-F. Qiao The top decay, tcups, is studied taking into account both color-singlet and color-octet mechanisms of ups configuration. In the numerical analysis, the results are applied to the standard model and the minimal supersymmetric standard model with conserved and violated R-parity. It is found that within the standard model the decay rate is near the border of reachable level of the next round of experiments, and is much larger than that of the rare top decays, while new contributions in the supersymmetric models could enhance the decay rate by few orders. It is also pointed out a possibility to establish a… Lihat
1999 Branching ratio and CP violation in semi-inclusive flavor-changing top decays L.T. Handoko Semi-inclusive top decays, t rightarrow q_i v, are examined in the framework of the standard model, with q_i = u ; {rm or} ; c, v : vector meson formed by q_j qb_j (q_j = d, s, b). By using a simple model of hadronization, that is < 0 l~~ qb_j gamma^mu q_j r~~ v > = mv fv evj^mu, the total branching ratio is expected to be br(tivj) < ( {l~~ vij^ast vtj r~~}/{l~~ vtb r~~})^2 times O({10}^{-3}) depends on the size of the coupling constant fv. On the other hand, the CP asymmetry should be induced only by… Lihat
1998 Manual maintainer P3FT LIPI Net L.T. Handoko Manual untuk para Pengelola Jaringan P2 Fisika LIPI. Lihat
1998 Manual singkat P3FT LIPI Net L.T. Handoko Manual singkat jaringan untuk sivitas P2 Fisika LIPI. Lihat
1998 Direct CP violation in semi-inclusive flavor-changing quark decays in the MSSM without R-parity L. T. Handoko, J. Hashida Semi-inclusive decays, hlx, are studied in the framework of the minimal supersymmetric standard model without R-parity, where qh (ql) are the second or third (first or second) generation quarks with the same charge and xi is a vector meson formed by q_j qb_j. The study is focused on the contributions of sfermions with m_{sf} < m_{rm top}. In this mass region, CP asymmetries in top decays can be induced by taking into account the decay-widths of the exchanged-bosons, while in light-quark decays it can be generated due to the long-distance effects. The contributions of sfermions also alter the branching-ratios destructively… Lihat
1998 Branching ratio and CP violation in semi-inclusive flavor-changing top decays L.T. Handoko Semi-inclusive top decays, t rightarrow q_i v, are examined in the framework of the standard model, with q_i = u ; {rm or} ; c, v : vector meson formed by q_j qb_j (q_j = d, s, b). By using a simple model of hadronization, that is < 0 l~~ qb_j gamma^mu q_j r~~ v > = mv fv evj^mu, the total branching ratio is expected to be br(tivj) < ( {l~~ vij^ast vtj r~~}/{l~~ vtb r~~})^2 times O({10}^{-3}) depends on the size of the coupling constant fv. On the other hand, the CP asymmetry should be induced only by… Lihat