We propose a new technique for measuring the polarization of hadronically decaying boosted top qu... more We propose a new technique for measuring the polarization of hadronically decaying boosted top quarks. In particular, we apply a subjet-based technique to events where the decay products of the top are clustered within a single jet. The technique requires neither b-tagging nor W -reconstruction, and does not rely on assumptions about either the top production mechanism or the sources of missing energy in the event. We include results for various new physics scenarios made with different Monte Carlo generators to demonstrate the robustness of the technique.
We discuss how decays of Higgs bosons into light pseudoscalars A 1 reduce the required fine tunin... more We discuss how decays of Higgs bosons into light pseudoscalars A 1 reduce the required fine tuning in the parameter space of the constrained NMSSM as compared to the MSSM, notably for M A 1 ∼ 10 GeV where A 1 − η b mixing is relevant. Due to the induced dominant A 1 → gg decays, the search for jet substructures seems to be the only hope for Higgs discovery at the LHC in such a scenario.
We study the Higgs portal from the Standard-Model to a hidden sector and examine which elements o... more We study the Higgs portal from the Standard-Model to a hidden sector and examine which elements of the extended theory can be discovered and explored at the LHC. Our model includes two Higgs bosons covering parameter regions where the LHC will be sensitive to two, one or none of the particles at typical discovery luminosities for Standard Model Higgs production.
The present investigation uses information from computer simulations to train neural networks to ... more The present investigation uses information from computer simulations to train neural networks to identify decays of heavy Higgs particles (m, z=-mz>. Results are presented both for software and hardware analog neural networks. The hardware tests include the Intel ETANN and the CLNN32/CLNS64 (experimental, research prototype developed at Bellcore) chip-set implemented in VME-modules. The processing and learning times for the networks are discussed.
Searches for a heavy Standard Model Higgs boson focus on the 'gold plated mode' where the Higgs d... more Searches for a heavy Standard Model Higgs boson focus on the 'gold plated mode' where the Higgs decays to two leptonic Z bosons. This channel provides a clean signature, in spite of the small leptonic branching ratios. We show that using fat jets the semi-leptonic ZZ mode significantly increases the number of signal events with a similar statistical significance as the leptonic mode.
We consider the impact of new exotic colored and/or charged matter interacting through the Higgs ... more We consider the impact of new exotic colored and/or charged matter interacting through the Higgs portal on Standard Model Higgs boson searches at the LHC. Such Higgs portal couplings can induce shifts in the effective Higgs-gluon-gluon and Higgsphoton-photon couplings, thus modifying the Higgs production and decay patterns. We consider two possible interpretations of the current LHC Higgs searches based on ∼ 5 fb −1 of data at each detector: 1) a Higgs boson in the mass range (124 − 126) GeV and 2) a hidden heavy Higgs boson which is underproduced due to the suppression of its gluon fusion production cross section. We first perform a model independent analysis of the allowed sizes of such shifts in light of current LHC data. As a class of possible candidates for new physics which gives rise to such shifts, we investigate the effects of new scalar multiplets charged under the Standard Model gauge symmetries. We determine the scalar parameter space that is allowed by current LHC Higgs searches, and compare with complementary LHC searches that are sensitive to the direct production of colored scalar states.
In standard models of baryogenesis and of dark matter, the mechanisms which generate the densitie... more In standard models of baryogenesis and of dark matter, the mechanisms which generate the densities in both sectors are unrelated to each other. In this paper we explore models which generate the baryon asymmetry through the dark matter sector, simultaneously relating the baryon asymmetry to the dark matter density. In the class of models we explore, a dark matter asymmetry is generated in the hidden sector through a first order phase transition. Within the hidden sector, it is easy to achieve a sufficiently strong first order phase transition and large enough CP violation to generate the observed asymmetry. This can happen above or below the electroweak phase transition, but in both cases significantly before the dark matter becomes non-relativistic. We study examples where the Asymmetric Dark Matter density is then transferred to the baryons both through perturbative and non-perturbative communication mechanisms, and show that in both cases cosmological constraints are satisfied while a sufficient baryon asymmetry can be generated.
Many new physics models with strongly interacting sectors predict a mass hierarchy between the li... more Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.
2 This document proposes a collection of simplified models relevant to the design of new-physics ... more 2 This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ∼ 50 − 500 pb −1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.
This report describes a Negro family with the Gy p + type of hereditary persistence of fetal haem... more This report describes a Negro family with the Gy p + type of hereditary persistence of fetal haemoglobin. Family members with levels of haemoglobin F of 17 to 23 % had normal red cell indices, balanced globin chain synthesis, and a pancellular distribution of the fetal haemoglobin, showing that these subjects have a form of HPFH. The production of Hb A and C in addition to the large amount of Hb F in one family member showed that there was an active PA gene in cis to the HPFH determinant, while structural analysis of the Hb F revealed the presence of only Gy chains.
Page 1. HEMOGLOBIN, 13(4), 325-353 (1989) p-CLUSTER HAPLOTYPES, a-GENE STATUS, AND ... ABSTRACT T... more Page 1. HEMOGLOBIN, 13(4), 325-353 (1989) p-CLUSTER HAPLOTYPES, a-GENE STATUS, AND ... ABSTRACT The B-gene-cluster haplotype and a-gene status were determined for 221 patients with sickle cell anemia, 41 with SC disease, and 21 with SB-thalassemia. ...
In standard models of baryogenesis and of dark matter, the mechanisms which generate the densitie... more In standard models of baryogenesis and of dark matter, the mechanisms which generate the densities in both sectors are unrelated to each other. In this paper we explore models which generate the baryon asymmetry through the dark matter sector, simultaneously relating the baryon asymmetry to the dark matter density. In the class of models we explore, a dark matter asymmetry is generated in the hidden sector through a first order phase transition. Within the hidden sector, it is easy to achieve a sufficiently strong first order phase transition and large enough CP violation to generate the observed asymmetry. This can happen above or below the electroweak phase transition, but in both cases significantly before the dark matter becomes non-relativistic. We study examples where the Asymmetric Dark Matter density is then transferred to the baryons both through perturbative and non-perturbative communication mechanisms, and show that in both cases cosmological constraints are satisfied while a sufficient baryon asymmetry can be generated.
Theories of flavor violation beyond the Standard Model typically suppose that the new contributio... more Theories of flavor violation beyond the Standard Model typically suppose that the new contributions must be small, for example suppressed by Yukawa couplings, as in Minimal Flavor Violation. We show that this need not be true, presenting a case for flavor violation which maximally mixes the first and third generation flavors. As an example, we realize this scenario via new right-handed gauge bosons, which couple predominantly to the combinations (u, b)R and (t, d)R. We show that this new flavor violation could be responsible for several anomalies, focusing in particular on the B d , Bs systems, and the Tevatron top forward-backward asymmetry.
Many models of physics beyond the Standard Model yield exotic Higgs decays. Some of these, partic... more Many models of physics beyond the Standard Model yield exotic Higgs decays. Some of these, particularly those in which the Higgs decays to light quarks or gluons, can be very difficult to discover experimentally. Here we introduce a new set of jet substructure techniques designed to search for such a Higgs when its dominant decay is into gluons via light, uncolored resonances. We study this scenario in both V + h and tt + h production channels, and find both channels lead to discovery at the LHC with 5σ at L ∼ 100 fb −1 .
... Arun Thalapillil EFI and Department of Physics, University of Chicago, 5640 South Ellis Avenu... more ... Arun Thalapillil EFI and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA (Received 21 June 2010; published 14 October 2011) ... grows with pT: ffiffiffiffiffiffiffiffiffiffi hm2 Ji q $ "C s pTR, where "C ¼ 3ð4=3Þ for ...
DNA sequence analysis of a cloned partially deleted human alpha-thalassemia globin gene revealed ... more DNA sequence analysis of a cloned partially deleted human alpha-thalassemia globin gene revealed a novel 3' untranslated region displaying at least nineteen differences when compared with previously published alpha mRNA sequences. Restriction enzyme mapping established the origin of the alpha-thalassemia gene as the more 3' of the normal, duplicated alpha genes (alpha 1). DNA sequencing of a previously isolated alpha 1 gene revealed a 3' untranslated region identical to that of the alpha-thalassemia gene. The sequence of the corresponding region of the more 5' alpha gene (alpha 2) was consistent with published mRNA sequences except in three probably polymorphic positions. Therefore the 3' untranslated regions of the highly homologous alpha-globin genes differ significantly. The recognition that the duplicated alpha genes differ in a region expressed in mature mRNA should not permit direct assessment of relative gene output in various normal and pathologic states. The divergence of the alpha gene 3' untranslated regions in the face of minimal coding sequence differences must be reconciled with current models for matching homologous gene sequences by recombination events.
We propose a new technique for measuring the polarization of hadronically decaying boosted top qu... more We propose a new technique for measuring the polarization of hadronically decaying boosted top quarks. In particular, we apply a subjet-based technique to events where the decay products of the top are clustered within a single jet. The technique requires neither b-tagging nor W -reconstruction, and does not rely on assumptions about either the top production mechanism or the sources of missing energy in the event. We include results for various new physics scenarios made with different Monte Carlo generators to demonstrate the robustness of the technique.
We discuss how decays of Higgs bosons into light pseudoscalars A 1 reduce the required fine tunin... more We discuss how decays of Higgs bosons into light pseudoscalars A 1 reduce the required fine tuning in the parameter space of the constrained NMSSM as compared to the MSSM, notably for M A 1 ∼ 10 GeV where A 1 − η b mixing is relevant. Due to the induced dominant A 1 → gg decays, the search for jet substructures seems to be the only hope for Higgs discovery at the LHC in such a scenario.
We study the Higgs portal from the Standard-Model to a hidden sector and examine which elements o... more We study the Higgs portal from the Standard-Model to a hidden sector and examine which elements of the extended theory can be discovered and explored at the LHC. Our model includes two Higgs bosons covering parameter regions where the LHC will be sensitive to two, one or none of the particles at typical discovery luminosities for Standard Model Higgs production.
The present investigation uses information from computer simulations to train neural networks to ... more The present investigation uses information from computer simulations to train neural networks to identify decays of heavy Higgs particles (m, z=-mz>. Results are presented both for software and hardware analog neural networks. The hardware tests include the Intel ETANN and the CLNN32/CLNS64 (experimental, research prototype developed at Bellcore) chip-set implemented in VME-modules. The processing and learning times for the networks are discussed.
Searches for a heavy Standard Model Higgs boson focus on the 'gold plated mode' where the Higgs d... more Searches for a heavy Standard Model Higgs boson focus on the 'gold plated mode' where the Higgs decays to two leptonic Z bosons. This channel provides a clean signature, in spite of the small leptonic branching ratios. We show that using fat jets the semi-leptonic ZZ mode significantly increases the number of signal events with a similar statistical significance as the leptonic mode.
We consider the impact of new exotic colored and/or charged matter interacting through the Higgs ... more We consider the impact of new exotic colored and/or charged matter interacting through the Higgs portal on Standard Model Higgs boson searches at the LHC. Such Higgs portal couplings can induce shifts in the effective Higgs-gluon-gluon and Higgsphoton-photon couplings, thus modifying the Higgs production and decay patterns. We consider two possible interpretations of the current LHC Higgs searches based on ∼ 5 fb −1 of data at each detector: 1) a Higgs boson in the mass range (124 − 126) GeV and 2) a hidden heavy Higgs boson which is underproduced due to the suppression of its gluon fusion production cross section. We first perform a model independent analysis of the allowed sizes of such shifts in light of current LHC data. As a class of possible candidates for new physics which gives rise to such shifts, we investigate the effects of new scalar multiplets charged under the Standard Model gauge symmetries. We determine the scalar parameter space that is allowed by current LHC Higgs searches, and compare with complementary LHC searches that are sensitive to the direct production of colored scalar states.
In standard models of baryogenesis and of dark matter, the mechanisms which generate the densitie... more In standard models of baryogenesis and of dark matter, the mechanisms which generate the densities in both sectors are unrelated to each other. In this paper we explore models which generate the baryon asymmetry through the dark matter sector, simultaneously relating the baryon asymmetry to the dark matter density. In the class of models we explore, a dark matter asymmetry is generated in the hidden sector through a first order phase transition. Within the hidden sector, it is easy to achieve a sufficiently strong first order phase transition and large enough CP violation to generate the observed asymmetry. This can happen above or below the electroweak phase transition, but in both cases significantly before the dark matter becomes non-relativistic. We study examples where the Asymmetric Dark Matter density is then transferred to the baryons both through perturbative and non-perturbative communication mechanisms, and show that in both cases cosmological constraints are satisfied while a sufficient baryon asymmetry can be generated.
Many new physics models with strongly interacting sectors predict a mass hierarchy between the li... more Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.
2 This document proposes a collection of simplified models relevant to the design of new-physics ... more 2 This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ∼ 50 − 500 pb −1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.
This report describes a Negro family with the Gy p + type of hereditary persistence of fetal haem... more This report describes a Negro family with the Gy p + type of hereditary persistence of fetal haemoglobin. Family members with levels of haemoglobin F of 17 to 23 % had normal red cell indices, balanced globin chain synthesis, and a pancellular distribution of the fetal haemoglobin, showing that these subjects have a form of HPFH. The production of Hb A and C in addition to the large amount of Hb F in one family member showed that there was an active PA gene in cis to the HPFH determinant, while structural analysis of the Hb F revealed the presence of only Gy chains.
Page 1. HEMOGLOBIN, 13(4), 325-353 (1989) p-CLUSTER HAPLOTYPES, a-GENE STATUS, AND ... ABSTRACT T... more Page 1. HEMOGLOBIN, 13(4), 325-353 (1989) p-CLUSTER HAPLOTYPES, a-GENE STATUS, AND ... ABSTRACT The B-gene-cluster haplotype and a-gene status were determined for 221 patients with sickle cell anemia, 41 with SC disease, and 21 with SB-thalassemia. ...
In standard models of baryogenesis and of dark matter, the mechanisms which generate the densitie... more In standard models of baryogenesis and of dark matter, the mechanisms which generate the densities in both sectors are unrelated to each other. In this paper we explore models which generate the baryon asymmetry through the dark matter sector, simultaneously relating the baryon asymmetry to the dark matter density. In the class of models we explore, a dark matter asymmetry is generated in the hidden sector through a first order phase transition. Within the hidden sector, it is easy to achieve a sufficiently strong first order phase transition and large enough CP violation to generate the observed asymmetry. This can happen above or below the electroweak phase transition, but in both cases significantly before the dark matter becomes non-relativistic. We study examples where the Asymmetric Dark Matter density is then transferred to the baryons both through perturbative and non-perturbative communication mechanisms, and show that in both cases cosmological constraints are satisfied while a sufficient baryon asymmetry can be generated.
Theories of flavor violation beyond the Standard Model typically suppose that the new contributio... more Theories of flavor violation beyond the Standard Model typically suppose that the new contributions must be small, for example suppressed by Yukawa couplings, as in Minimal Flavor Violation. We show that this need not be true, presenting a case for flavor violation which maximally mixes the first and third generation flavors. As an example, we realize this scenario via new right-handed gauge bosons, which couple predominantly to the combinations (u, b)R and (t, d)R. We show that this new flavor violation could be responsible for several anomalies, focusing in particular on the B d , Bs systems, and the Tevatron top forward-backward asymmetry.
Many models of physics beyond the Standard Model yield exotic Higgs decays. Some of these, partic... more Many models of physics beyond the Standard Model yield exotic Higgs decays. Some of these, particularly those in which the Higgs decays to light quarks or gluons, can be very difficult to discover experimentally. Here we introduce a new set of jet substructure techniques designed to search for such a Higgs when its dominant decay is into gluons via light, uncolored resonances. We study this scenario in both V + h and tt + h production channels, and find both channels lead to discovery at the LHC with 5σ at L ∼ 100 fb −1 .
... Arun Thalapillil EFI and Department of Physics, University of Chicago, 5640 South Ellis Avenu... more ... Arun Thalapillil EFI and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, USA (Received 21 June 2010; published 14 October 2011) ... grows with pT: ffiffiffiffiffiffiffiffiffiffi hm2 Ji q $ "C s pTR, where "C ¼ 3ð4=3Þ for ...
DNA sequence analysis of a cloned partially deleted human alpha-thalassemia globin gene revealed ... more DNA sequence analysis of a cloned partially deleted human alpha-thalassemia globin gene revealed a novel 3' untranslated region displaying at least nineteen differences when compared with previously published alpha mRNA sequences. Restriction enzyme mapping established the origin of the alpha-thalassemia gene as the more 3' of the normal, duplicated alpha genes (alpha 1). DNA sequencing of a previously isolated alpha 1 gene revealed a 3' untranslated region identical to that of the alpha-thalassemia gene. The sequence of the corresponding region of the more 5' alpha gene (alpha 2) was consistent with published mRNA sequences except in three probably polymorphic positions. Therefore the 3' untranslated regions of the highly homologous alpha-globin genes differ significantly. The recognition that the duplicated alpha genes differ in a region expressed in mature mRNA should not permit direct assessment of relative gene output in various normal and pathologic states. The divergence of the alpha gene 3' untranslated regions in the face of minimal coding sequence differences must be reconciled with current models for matching homologous gene sequences by recombination events.
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