The Experts below are selected from a list of 54096 Experts worldwide ranked by ideXlab platform
Shaouly Barshalom - One of the best experts on this subject based on the ideXlab platform.
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scalar flavor changing neutral currents and rare top Quark decays in a two higgs doublet model for the top Quark
Physical Review D, 2008Co-Authors: Itzhak Baum, Gad Eilam, Shaouly BarshalomAbstract:In the so-called two Higgs doublet model for the top Quark (T2HDM), first suggested by Das and Kao, the top Quark receives a special status, which endows it with a naturally large mass, and also potentially gives rise to large flavor changing neutral currents only in the Up-Quark sector. In this paper, we calculate the branching ratio for the rare decays $t\ensuremath{\rightarrow}ch$ and $h\ensuremath{\rightarrow}\overline{t}c$ ($h$ is a neutral Higgs scalar) in the T2HDM, at tree level and at 1-loop when it exceeds the tree level. We compare our results to predictions from other versions of 2HDM's and find that the scalar flavor changing neutral currents in the T2HDM can play a significant role in these decays. In particular, the 1-loop mediated decays can be significantly enhanced in the T2HDM compared with the 2HDM of types I and II, in some instances reaching $\mathrm{BR}\ensuremath{\sim}{10}^{\ensuremath{-}4}$, which is within the detectable level at the LHC.
Jonathan L. Rosner - One of the best experts on this subject based on the ideXlab platform.
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Quark level analogue of nuclear fusion with doubly heavy baryons
Nature, 2017Co-Authors: Marek Karliner, Jonathan L. RosnerAbstract:Two singly charmed baryons can fuse into the recently discovered doubly charmed baryon and a neutron through an exothermic reaction analogous to the nuclear fusion between deuterium and tritium. The LHCb collaboration at CERN's Large Hadron Collider recently reported the discovery of a doubly charmed baryon with a large binding energy between the two charm Quarks inside it. Marek Karliner and Jonathan Rosner report that this strong binding energy allows for a rearrangement of the Quarks that releases energy in a Quark-level analogue of deuterium–tritium nuclear fusion. They point out that the even larger binding energy between two bottom Quarks can also enable such an exothermic rearrangement, with a considerably larger energy release. The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery1 of the first doubly charmed baryon , which contains two charm Quarks (c) and one Up Quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm Quarks. Here we report that this strong binding enables a Quark-rearrangement, exothermic reaction in which two heavy baryons (Λc) undergo fusion to produce the doubly charmed baryon and a neutron n ( ), resulting in an energy release of 12 MeV. This reaction is a Quark-level analogue of the deuterium–tritium nuclear fusion reaction (DT → 4He n). The much larger binding energy (approximately 280 MeV) between two bottom Quarks (b) causes the analogous reaction with bottom Quarks ( ) to have a much larger energy release of about 138 MeV. We suggest some experimental setUps in which the highly exothermic nature of the fusion of two heavy-Quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm Quarks preclude any practical applications of such reactions.
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Quark level analogue of nuclear fusion with doubly heavy baryons
Nature, 2017Co-Authors: Marek Karliner, Jonathan L. RosnerAbstract:The essence of nuclear fusion is that energy can be released by the rearrangement of nucleons between the initial- and final-state nuclei. The recent discovery of the first doubly charmed baryon , which contains two charm Quarks (c) and one Up Quark (u) and has a mass of about 3,621 megaelectronvolts (MeV) (the mass of the proton is 938 MeV) also revealed a large binding energy of about 130 MeV between the two charm Quarks. Here we report that this strong binding enables a Quark-rearrangement, exothermic reaction in which two heavy baryons (Λc) undergo fusion to produce the doubly charmed baryon and a neutron n (), resulting in an energy release of 12 MeV. This reaction is a Quark-level analogue of the deuterium-tritium nuclear fusion reaction (DT → 4He n). The much larger binding energy (approximately 280 MeV) between two bottom Quarks (b) causes the analogous reaction with bottom Quarks () to have a much larger energy release of about 138 MeV. We suggest some experimental setUps in which the highly exothermic nature of the fusion of two heavy-Quark baryons might manifest itself. At present, however, the very short lifetimes of the heavy bottom and charm Quarks preclude any practical applications of such reactions.
Lisa Randall - One of the best experts on this subject based on the ideXlab platform.
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charming cp violation and dipole operators from rs flavor anarchy
Journal of High Energy Physics, 2013Co-Authors: Cédric Delaunay, Jernej Kamenik, Gilad Perez, Lisa RandallAbstract:avor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through avor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to . Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs prole, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs prole approaches the IR brane, implying small dependence on the precise details of the Higgs prole when it is quasi IR localized. We also explain why the calculation of the coecient of the lowest dimension 5D operator is guaranteed to be nite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b! s , 0 = K and ! e . We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative dierences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.
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Charming CP violation and dipole operators from RS flavor anarchy
The journal of high energy physics, 2013Co-Authors: Jernej Kamenik, Gilad Perez, Cédric Delaunay, Lisa RandallAbstract:Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to ??. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b ? s?, Ï? ?/Ï? K and ? ? e?. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario. © 2013 SISSA.
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charming cp violation and dipole operators from rs flavor anarchy
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: Cédric Delaunay, Jernej Kamenik, Gilad Perez, Lisa RandallAbstract:Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to e\gamma. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.
Jernej Kamenik - One of the best experts on this subject based on the ideXlab platform.
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charming cp violation and dipole operators from rs flavor anarchy
Journal of High Energy Physics, 2013Co-Authors: Cédric Delaunay, Jernej Kamenik, Gilad Perez, Lisa RandallAbstract:avor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through avor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to . Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs prole, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs prole approaches the IR brane, implying small dependence on the precise details of the Higgs prole when it is quasi IR localized. We also explain why the calculation of the coecient of the lowest dimension 5D operator is guaranteed to be nite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b! s , 0 = K and ! e . We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative dierences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.
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Charming CP violation and dipole operators from RS flavor anarchy
The journal of high energy physics, 2013Co-Authors: Jernej Kamenik, Gilad Perez, Cédric Delaunay, Lisa RandallAbstract:Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to ??. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b ? s?, Ï? ?/Ï? K and ? ? e?. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario. © 2013 SISSA.
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charming cp violation and dipole operators from rs flavor anarchy
arXiv: High Energy Physics - Phenomenology, 2012Co-Authors: Cédric Delaunay, Jernej Kamenik, Gilad Perez, Lisa RandallAbstract:Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the Quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the Up Quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to e\gamma. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.
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light colored scalar as messenger of Up Quark flavor dynamics in grand unified theories
Physical Review D, 2010Co-Authors: Ilja Dorsner, Jernej Kamenik, Svjetlana Fajfer, Nejc KosnikAbstract:The measured forward-backward asymmetry in the $t\overline{t}$ production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar. Such state appears in some of the grand unified theories, and its interactions with the Up-Quarks are purely antisymmetric in flavor space. We systematically investigate the resulting impact on charm and top Quark physics. The constraints on the relevant Yukawa coUplings come from the experimentally measured observables related to ${D}^{0}\mathrm{\text{\ensuremath{-}}}{\overline{D}}^{0}$ oscillations, as well as dijet and single-top production measurements at the Tevatron. After fully constraining the relevant Yukawa coUplings, we predict possible signatures of this model in rare top Quark decays. In a class of grand unified models we demonstrate how the obtained information enables to constrain the Yukawa coUplings of the Up-Quarks at very high energy scale.
Itzhak Baum - One of the best experts on this subject based on the ideXlab platform.
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scalar flavor changing neutral currents and rare top Quark decays in a two higgs doublet model for the top Quark
Physical Review D, 2008Co-Authors: Itzhak Baum, Gad Eilam, Shaouly BarshalomAbstract:In the so-called two Higgs doublet model for the top Quark (T2HDM), first suggested by Das and Kao, the top Quark receives a special status, which endows it with a naturally large mass, and also potentially gives rise to large flavor changing neutral currents only in the Up-Quark sector. In this paper, we calculate the branching ratio for the rare decays $t\ensuremath{\rightarrow}ch$ and $h\ensuremath{\rightarrow}\overline{t}c$ ($h$ is a neutral Higgs scalar) in the T2HDM, at tree level and at 1-loop when it exceeds the tree level. We compare our results to predictions from other versions of 2HDM's and find that the scalar flavor changing neutral currents in the T2HDM can play a significant role in these decays. In particular, the 1-loop mediated decays can be significantly enhanced in the T2HDM compared with the 2HDM of types I and II, in some instances reaching $\mathrm{BR}\ensuremath{\sim}{10}^{\ensuremath{-}4}$, which is within the detectable level at the LHC.
