Alexander L. Kagan
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Alexander L. Kagan has a total of 4 co-authors. Here are the top co-authors by number of shared publications:
- Yosef Nir
Weizmann Institute of Science
2 shared publications - Yuval Grossman
Department of Physics, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
2 shared publications - Matthias Neubert
Stanford Linear Accelerator Center Stanford University Stanford 94309 California U.S.A
1 shared publication - Yuval Grossman
Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309
1 shared publication
Latest Publications
- 28 February 2007
- Published by American Physical Society (APS) in Physical Review D
- Vol. 75 (3) , 036008
New physics andviolation in singly Cabibbo suppresseddecaysWe analyze various theoretical aspects of violation in singly Cabibbo suppressed (SCS) meson decays, such as . In particular, we explore the possibility that asymmetries will be measured close to the present level of experimental sensitivity of . Such measurements would signal new physics. We make the following points: (i) The mechanism at work in neutral decays could be indirect or direct violation (or both). (ii) One can experimentally distinguish between these possibilities. (iii) If the dominant violation is indirect, then there are clear predictions for other modes. (iv) Tree-level direct violation in various known models is constrained to be much smaller than . (v) SCS decays, unlike Cabibbo favored or doubly Cabibbo suppressed decays, are sensitive to new contributions from QCD penguin operators and especially from chromomagnetic dipole operators. This point is illustrated with supersymmetric gluino-squark loops, which can yield direct violating effects of .- 28 February 2007
- Published by American Physical Society (APS) in Physical Review D
- Vol. 75 (3) , 036008
New physics andviolation in singly Cabibbo suppresseddecaysWe analyze various theoretical aspects of violation in singly Cabibbo suppressed (SCS) meson decays, such as . In particular, we explore the possibility that asymmetries will be measured close to the present level of experimental sensitivity of . Such measurements would signal new physics. We make the following points: (i) The mechanism at work in neutral decays could be indirect or direct violation (or both). (ii) One can experimentally distinguish between these possibilities. (iii) If the dominant violation is indirect, then there are clear predictions for other modes. (iv) Tree-level direct violation in various known models is constrained to be much smaller than . (v) SCS decays, unlike Cabibbo favored or doubly Cabibbo suppressed decays, are sensitive to new contributions from QCD penguin operators and especially from chromomagnetic dipole operators. This point is illustrated with supersymmetric gluino-squark loops, which can yield direct violating effects of .- Open Access
New Physics and CP Violation in Singly Cabibbo Suppressed D Decays
We analyze various theoretical aspects of CP violation in singly Cabibbo suppressed (SCS) D-meson decays, such as $D \to K K,\pi \pi$. In particular, we explore the possibility that CP asymmetries will be measured close to the present level of experimental sensitivity of $O(10^{-2})$. Such measurements would signal new physics. We make the following points: (i) The mechanism at work in neutral D decays could be indirect or direct CP violation (or both). (ii) One can experimentally distinguish between these possibilities. (iii) If the dominant CP violation is indirect, then there are clear predictions for other modes. (iv) Tree-level direct CP violation in various known models is constrained to be much smaller than $10^{-2}$. (v) SCS decays, unlike Cabibbo favored or doubly Cabibbo suppressed decays, are sensitive to new contributions from QCD penguin operators and especially from chromomagnetic dipole operators. This point is illustrated with supersymmetric gluino-squark loops, which can yield direct CP violating effects of $O(10^{-2})$.Open AccessNew Physics and CP Violation in Singly Cabibbo Suppressed D Decays
We analyze various theoretical aspects of CP violation in singly Cabibbo suppressed (SCS) D-meson decays, such as $D \to K K,\pi \pi$. In particular, we explore the possibility that CP asymmetries will be measured close to the present level of experimental sensitivity of $O(10^{-2})$. Such measurements would signal new physics. We make the following points: (i) The mechanism at work in neutral D decays could be indirect or direct CP violation (or both). (ii) One can experimentally distinguish between these possibilities. (iii) If the dominant CP violation is indirect, then there are clear predictions for other modes. (iv) Tree-level direct CP violation in various known models is constrained to be much smaller than $10^{-2}$. (v) SCS decays, unlike Cabibbo favored or doubly Cabibbo suppressed decays, are sensitive to new contributions from QCD penguin operators and especially from chromomagnetic dipole operators. This point is illustrated with supersymmetric gluino-squark loops, which can yield direct CP violating effects of $O(10^{-2})$. - Open Access
Trojan Penguins and Isospin Violation in Hadronic B Decays
Some rare hadronic decays of B mesons, such as B->pi K, are sensitive to isospin-violating contributions from physics beyond the Standard Model. Although commonly referred to as electroweak penguins, such contributions can often arise through tree-level exchanges of heavy particles, or through strong-interaction loop diagrams. The Wilson coefficients of the corresponding electroweak penguin operators are calculated in a large class of New Physics models, and in many cases are found not to be suppressed with respect to the QCD penguin coefficients. Several tests for these effects using observables in B->pi K decays are discussed, and nontrivial bounds on the couplings of the various New Physics models are derived.
Open AccessTrojan Penguins and Isospin Violation in Hadronic B Decays
Some rare hadronic decays of B mesons, such as B->pi K, are sensitive to isospin-violating contributions from physics beyond the Standard Model. Although commonly referred to as electroweak penguins, such contributions can often arise through tree-level exchanges of heavy particles, or through strong-interaction loop diagrams. The Wilson coefficients of the corresponding electroweak penguin operators are calculated in a large class of New Physics models, and in many cases are found not to be suppressed with respect to the QCD penguin coefficients. Several tests for these effects using observables in B->pi K decays are discussed, and nontrivial bounds on the couplings of the various New Physics models are derived.