A Higgs-like particle with a mass of about 125.5 GeV has been discovered at the LHC. Within the current experimental uncertainties, this new state is compatible with both the predictions for the ...Standard Model (SM) Higgs boson and with the Higgs sector in the Minimal Supersymmetric Standard Model (MSSM). We propose new low-energy MSSM benchmark scenarios that, over a wide parameter range, are compatible with the mass and production rates of the observed signal. These scenarios also exhibit interesting phenomenology for the MSSM Higgs sector. We propose a slightly updated version of the well-known
scenario, and a modified scenario (
), where the light
-even Higgs boson can be interpreted as the LHC signal in large parts of the
M
A
–tan
β
plane. Furthermore, we define a
light stop scenario
that leads to a suppression of the lightest
-even Higgs gluon fusion rate, and a
light stau scenario
with an enhanced decay rate of
h
→
γγ
at large tan
β
. We also suggest a
τ
-
phobic Higgs scenario
in which the lightest Higgs can have suppressed couplings to down-type fermions. We propose to supplement the specified value of the
μ
parameter in some of these scenarios with additional values of both signs. This has a significant impact on the interpretation of searches for the non-SM-like MSSM Higgs bosons. We also discuss the sensitivity of the searches to heavy Higgs decays into light charginos and neutralinos, and to decays of the form
H
→
hh
. Finally, in addition to all the other scenarios where the lightest
-even Higgs is interpreted as the LHC signal, we propose a
low
-
M
H
scenario, where instead the
heavy
-even Higgs boson corresponds to the new state around 125.5 GeV.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
Electroweak baryogenesis is an attractive scenario for the generation of the baryon asymmetry of the universe as its realization depends on the presence at the weak scale of new particles ...which may be searched for at high energy colliders. In the MSSM it may only be realized in the presence of light stops, and with moderate or small mixing between the left- and right-handed components. Consistency with the observed Higgs mass around 125 GeV demands the heavier stop mass to be much larger than the weak scale. Moreover the lighter stop leads to an increase of the gluon-gluon fusion Higgs production cross section which seems to be in contradiction with indications from current LHC data. We show that this tension may be considerably relaxed in the presence of a light neutralino with a mass lower than about 60 GeV, satisfying all present experimental constraints. In such a case the Higgs may have a significant invisible decay width and the stop decays through a three or four body decay channel, including a bottom quark and the lightest neutralino in the final state. All these properties make this scenario testable at a high luminosity LHC.
Higgs-mass predictions in the MSSM and beyond Slavich, P.; Heinemeyer, S.; Bagnaschi, E. ...
European physical journal. C, Particles and fields,
05/2021, Letnik:
81, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Predictions for the Higgs masses are a distinctive feature of supersymmetric extensions of the Standard Model, where they play a crucial role in constraining the parameter space. The discovery of a ...Higgs boson and the remarkably precise measurement of its mass at the LHC have spurred new efforts aimed at improving the accuracy of the theoretical predictions for the Higgs masses in supersymmetric models. The “
Precision SUSY Higgs Mass Calculation Initiative
” (KUTS) was launched in 2014 to provide a forum for discussions between the different groups involved in these efforts. This report aims to present a comprehensive overview of the current status of Higgs-mass calculations in supersymmetric models, to document the many advances that were achieved in recent years and were discussed during the KUTS meetings, and to outline the prospects for future improvements in these calculations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Understanding the genetic relationships among broad-based populations is a good starting point for breeding programs. These utilize introduction and adaptation of tropical and temperate populations ...to broaden the genetic resources for genetic improvement. A diallel of 16 maize populations adapted to the northern U.S. Corn Belt was used to estimate population genetic parameters. These were used to assess genetic diversity and assign the populations to heterotic groups. Using the general combining ability (g ᵢ) estimates, 19 agronomic and grain quality traits showed large contribution on the variability of the first two principal components. All traits were used to characterize the genetic similarities among the populations. The cluster analysis formed three groups and a singleton based on genetic distances (GD) of g ᵢ estimates. The specific heterosis (s ᵢⱼ) estimates for grain yield were used to assign the 16 populations to heterotic groups, since there was a positive correlation between GD and s ᵢⱼ . Four heterotic groups were established. These showed a good agreement with that formed using GD. The heterotic grouping agreed with genetic background information and heterotic group’s specific and general combining ability estimates. The EARLYGEM 21 populations with exotic background were assigned to a unique heterotic group. They showed high heterosis when crossed with a tropical population and populations belonging from other heterotic groups. The heterotic groupings among the 16 populations validated former heterotic groups, and new heterotic patterns were created. These results will increase breeding efficiency in developing new cultivars for the northern U.S. Corn Belt.
Total and extractable starch, oil, protein, and amino acids of maize (
Zea mays
L.) are important to farmers and ranchers because of their various end uses including ethanol and feedstock nutrition. ...The objectives of this study were: (1) to evaluate grain quality traits in different water regimes and (2) to discuss the implications for breeding maize quality cultivars in water stressed (WS) environments. Ninety-four partial diallel crosses including 47 diverse maize inbreds and checks were tested in 12 WS, well watered (WW), and random drought (RDT) environments in 2013 and 2014. The changes in mean grain extractable (<1.33 %) and total starch (<0.74 %), oil (<2.2 %), cysteine (<2.91 %) and lysine (<2.81 %) contents in WS and RDT were small while the changes in grain protein (+6.58 % in WS and +3.46 % in RDT) and methionine (+4.41 % in WS and −1.86 % in RDT) content were large compared to WW environments. Additive genetic variance was most important across stresses and the largest variance was estimated in WS environments. The narrow-sense heritability (
h
2
) was found to be high (>0.40) for all traits in WW environments except for grain protein and amino acid contents. The mid-parent hybrid correlation was strong (>0.62) for all traits across stresses except for amino acid content (<0.55). The stress environments were largely associated for grain oil and total and extractable starch contents (>0.60). However, they were less associated with grain protein content and amino acid content (<0.49). Therefore, while breeding for better ethanol maize varieties could be based on multi-location testing in WS environments, breeding for healthier feedstock protein products could be conducted across environments.
A
bstract
Current Higgs data at the Large Hadron Collider is compatible with a SM signal at the 2σ level, but the central value of the signal strength in the diphoton channel is enhanced with respect ...to the SM expectation. If the enhancement resides in the diphoton partial decay width, the data could be accommodated in the Minimally Super-symmetric Standard Model (MSSM) with highly mixed light staus. We revisit the issue of vacuum instability induced by large mixing in the stau sector, including effects of a radiatively-corrected tau Yukawa coupling. Further, we emphasize the importance of taking into account the tan β dependence in the stability bound. While the metastability of the Universe constrains the possible enhancement in the Higgs to diphoton decay width in the light stau scenario, an increase of the order of 50% can be achieved in the region of large tan β. Larger enhancements may be obtained, but would require values of tan β associated with non-perturbative values of the tau Yukawa coupling at scales below the GUT scale, thereby implying the presence of new physics beyond the MSSM.
There is a need to develop the next generation of healthier crop products for an improved human and animal nutrition. Maize (
Zea mays
L.) cultivars with improved amino acid profiles are essential to ...diets focused on this crop. Breeders have added crop value with the development of quality protein maize (QPM). However, QPM cultivars have never been an option to farmer and ranchers in short-season environments. The objectives of this research were: (1) to adapt QPM genotypes to the northern U.S. through the North Dakota (ND) EarlyQPM Program, and (2) to develop new early generation SS and non-SS short-season QPM lines and populations for breeding purposes. Fifty-three inbred lines, including 47 QPM donor lines, five experimental North Dakota State University (NDSU) lines, and one ex-PVP line from industry, were selected to produce 94 early-QPM backcross populations. Considering earliness, protein content, and amino acid levels, 218 early generation lines were selected for producing testcrosses with industry testers. Experiments evaluating testcrosses were arranged in 10 × 10 and 12 × 12 partially balanced lattice designs across three ND locations in 2013 and 2014. A total of 48 lines were selected for further development, 17 representing the Stiff Stalk (SS) heterotic group and 31 representing the non-SS group. Selected lines showed, in hybrid combinations, not only above average grain yield, rate of dry down, and total protein content but also high levels of lysine, tryptophan, and methionine essential amino acids for feedstock nutrition. The results of this research show, for the first time, the successful adaptation of QPM genotypes to short-season environments. As a result, new ND EarlyQPM germplasms and lines have been developed for potential release.
The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. The current limits from the Tevatron and the prospective sensitivities at the LHC are often ...interpreted in specific MSSM scenarios. For heavy Higgs boson production and subsequent decay into or τ+τ–, the present Tevatron data allow one to set limits in the MA–tan β plane for small MA and large tan β values. Similar channels have been explored for the LHC, where the discovery reach extends to higher values of MA and smaller tan β. Searches for MSSM charged Higgs bosons, produced in top decays or in association with top quarks, have also been investigated at the Tevatron and the LHC. We analyze the current Tevatron limits and prospective LHC sensitivities. We discuss how robust they are with respect to variations of the other MSSM parameters and possible improvements of the theoretical predictions for Higgs boson production and decay. It is shown that the inclusion of supersymmetric radiative corrections to the production cross sections and decay widths leads to important modifications of the present limits on the MSSM parameter space. The impact on the region where only the lightest MSSM Higgs boson can be detected at the LHC is also analyzed. We propose to extend the existing benchmark scenarios by including additional values of the higgsino mass parameter μ. This affects only slightly the search channels for a SM-like Higgs boson, while having a major impact on the searches for non-standard MSSM Higgs bosons.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Maize (
Zea mays
L.) breeding programs integrating pre-breeding with cultivar development are needed. The objectives of the North Dakota corn breeding program are to adapt exotic and unique ...germplasm, maximize the genetic improvement of adapted germplasm, and develop unique short-season products for breeding and commercial use. This applied program has significant support from state maize grower organizations, farmers, food and fuel processors, and industry. As a result 25 inbred lines and 17 improved populations, carrying unique alleles not present in the B73 line and the Nested Association Mapping population (NAM) genomes, were released in the past 10 years and six hybrids were identified for commercial purposes. These included the first releases from our NDSU EarlyGEM program to increase the genetic diversity of U.S. northern hybrids and break environmental margins. These are not registered nationally due to exclusive agreements with industry. The strategic location of this research program allows the exploitation of challenging environmental conditions making evolution toward desirable goals faster, discarding unstable and weak maize varieties effectively. There are still several challenges to be addressed though. Retailer companies offer fewer products with more events making maize more vulnerable due to similar genetics. The confidential nature of the maize business limits breeding rights to develop better industry products, which currently reduces the breeding efficiency to identify the most outstanding hybrids for farmers across regions. Maize research, development, and production in marginal regions can be uniquely positioned to lead breeding research for climate changes and the development of the next generation of genetically broad-based elite products. Improvements in intellectual property and re-thinking of breeding rights access are encouraged.
Summary
Maize (
Zea mays
L.) average yields per hectare have significantly increased in the past 80 years. However, the variability of these yields across years has also significantly increased in ...the past 40 years making newer and genetically narrow-based hybrids, on average, less stable and more susceptible to climate changes. The objective of this research was to develop new sources of short-season inbred lines carrying unique alleles to grow maize hybrids under challenging environments. The North Dakota State University (NDSU) maize germplasm enhancement program has recently developed 10 new and unique exotic short-season populations partially derived from Argentina, Brazil, Chile, Cuba, Mexico, Saint Croix, and the USA. These germplasm sources were created recombining top early-generation NDSU EarlyGEM lines that were extensively tested in hybrid trials for general combining ability of several traits. Results have shown that germplasm carrying unique alleles can break environmental margins for maize production. Unfortunately, maize breeding programs tend to be located in ideal crop production areas instead of exploiting marginal environments for the development of more stable products. The NDSU EarlyGEM program is a successful example of tropical and late-temperate maize germplasm adaptation into short-season environments in order to increase the genetic diversity on farms. However, public sector applied maize breeding programs continue to disappear across the USA and abroad because of changes in research emphasis. Long-term germplasm adaptation and improvement programs carrying unique alleles will be essential in the development of the next generation of healthier cultivars tolerant to climate changes.
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