scholarly journals Systematic approach to B -physics anomalies and t -channel dark matter

2021 ◽  
Vol 104 (11) ◽  
Author(s):  
Giorgio Arcadi ◽  
Lorenzo Calibbi ◽  
Marco Fedele ◽  
Federico Mescia
Keyword(s):  
Dark Matter ◽  
B Physics ◽  
Systematic Approach

scholarly journals Collider signatures of coannihilating dark matter in light of the B-physics anomalies

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Michael J. Baker ◽  
Darius A. Faroughy ◽  
Sokratis Trifinopoulos
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Bound States ◽  
B Physics ◽  
Search Strategy ◽  
Dark Matter Candidate ◽  
Final States ◽  
Dark Sector ◽  
Decay Modes ◽  
The Standard Model

Abstract Motivated by UV explanations of the B-physics anomalies, we study a dark sector containing a Majorana dark matter candidate and a coloured coannihilation partner, connected to the Standard Model predominantly via a U1 vector leptoquark. A TeV scale U1 leptoquark, which couples mostly to third generation fermions, is the only successful single-mediator description of the B-physics anomalies. After calculating the dark matter relic surface, we focus on the most promising experimental avenue: LHC searches for the coloured coannihilation partner. We find that the coloured partner hadronizes and forms meson-like bound states leading to resonant signatures at colliders reminiscent of the quarkonia decay modes in the Standard Model. By recasting existing dilepton and monojet searches we exclude coannihilation partner masses less than 280 GeV and 400 GeV, respectively. Since other existing collider searches do not significantly probe the parameter space, we propose a new dedicated search strategy for pair production of the coloured partner decaying into bbττ final states and dark matter particles. This search is expected to probe the model up to dark matter masses around 600 GeV with current luminosity.

scholarly journals The THDMa Revisited

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2341
Author(s):  
Tania Robens
Keyword(s):  
Dark Matter ◽  
Parameter Space ◽  
B Physics ◽  
A Priori ◽  
New Physics ◽  
Dark Sector ◽  
The Standard Model ◽  
Future Collider ◽  
Physics Model ◽  
Scalar Sector

The THDMa is a new physics model that extends the scalar sector of the Standard Model by an additional doublet as well as a pseudoscalar singlet and allows for mixing between all possible scalar states. In the gauge-eigenbasis, the additional pseudoscalar serves as a portal to the dark sector, with a priori any dark matter spins states. The option where dark matter is fermionic is currently one of the standard benchmarks for the experimental collaborations, and several searches at the LHC constrain the corresponding parameter space. However, most current studies constrain regions in parameter space by setting all but 2 of the 12 free parameters to fixed values. In this work, we performed a generic scan on this model, allowing all parameters to float. We applied all current theoretical and experimental constraints, including bounds from current searches, recent results from B-physics, in particular Bs→Xsγ, as well as bounds from astroparticle physics. We identify regions in the parameter space which are still allowed after these were applied and which might be interesting for an investigation of current and future collider machines.

scholarly journals Constraints on light mediators: Confronting dark matter searches with B physics

2013 ◽  
Vol 727 (4-5) ◽  
pp. 506-510 ◽  
Author(s):  
Kai Schmidt-Hoberg ◽  
Florian Staub ◽  
Martin Wolfgang Winkler
Keyword(s):  
Dark Matter ◽  
B Physics

scholarly journals COLD DARK MATTER AND HIGGS MASS IN THE CONSTRAINED MINIMAL SUPERSYMMETRIC STANDARD MODEL WITH GENERALIZED YUKAWA QUASI-UNIFICATION

2013 ◽  
Vol 28 (30) ◽  
pp. 1330048 ◽  
Author(s):  
N. KARAGIANNAKIS ◽  
G. LAZARIDES ◽  
C. PALLIS
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
B Physics ◽  
Cold Dark Matter ◽  
Model Parameters ◽  
B Quark ◽  
The Universe

The construction of specific supersymmetric grand unified models based on the Pati–Salam gauge group and leading to a set of Yukawa quasi-unification conditions which can allow an acceptable b-quark mass within the constrained minimal supersymmetric standard model with μ > 0 is briefly reviewed. Imposing constraints from the cold dark matter abundance in the universe, B physics, and the mass mhof the lighter neutral CP-even Higgs boson, we find that there is an allowed parameter space with, approximately, 44 ≤ tan β ≤ 52, -3 ≤ A0/M1/2≤ 0.1, 122 ≤ mh/ GeV ≤ 127, and mass of the lightest sparticle in the range (0.75–1.43) TeV. Such heavy lightest sparticle masses can become consistent with the cold dark matter requirements on the lightest sparticle relic density thanks to neutralino–stau coannihilations which are enhanced due to stau–antistau coannihilation to down type fermions via a direct-channel exchange of the heavier neutral CP-even Higgs boson. Restrictions on the model parameters by the muon anomalous magnetic moment are also discussed.

scholarly journals Simple model for large CP violation in charm decays, B-physics anomalies, muon g − 2 and dark matter

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Tianjun Li ◽  
Ying Li ◽  
Bin Zhu
Keyword(s):  
Dark Matter ◽  
Cp Violation ◽  
B Physics ◽  
Scalar Fields ◽  
Electroweak Symmetry Breaking ◽  
Dark Matter Candidate ◽  
Minimal Extension ◽  
Electroweak Symmetry ◽  
Charm Decays ◽  
The Standard Model

Abstract We present a minimal extension of the Standard Model that can simultaneously account for the anomalies in semi-leptonic B meson decays and the muon g − 2, give large CP violation in charm decays (up to the value recently measured by LHCb), and provide thermal-relic dark matter, while evading all constraints set by other flavour observables, LHC searches, and dark matter experiments. This is achieved by introducing only four new fields: a vectorlike quark, a vectorlike lepton, and two scalar fields (a singlet and a doublet) that mix due to the electroweak symmetry breaking and provide the dark matter candidate. The singlet-doublet mixing induces chirally-enhanced dipole transitions, which are crucial for the explanation of the muon g − 2 discrepancy and the large charm CP violation, and allows to achieve the observed dark matter density in wide regions of the parameter space.

scholarly journals Gluino-SUGRA scenarios in light of FNAL muon g – 2 anomaly

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Zhuang Li ◽  
Guo-Li Liu ◽  
Fei Wang ◽  
Jin Min Yang ◽  
Yang Zhang
Keyword(s):  
Dark Matter ◽  
B Physics ◽  
Model Building ◽  
Mass Parameter ◽  
Boson Mass ◽  
Higgs Boson Mass ◽  
Gluino Mass ◽  
Null Results ◽  
Scalar Mass ◽  
Gut Scale

Abstract Gluino-SUGRA ($$ \overset{\sim }{g} $$ g ~ SUGRA), which is an economical extension of the predictive mSUGRA, adopts much heavier gluino mass parameter than other gauginos mass parameters and universal scalar mass parameter at the unification scale. It can elegantly reconcile the experimental results on the Higgs boson mass, the muon g − 2, the null results in search for supersymmetry at the LHC and the results from B-physics. In this work, we propose several new ways to generate large gaugino hierarchy (i.e. M3 » M1, M2) for $$ \overset{\sim }{g} $$ g ~ SUGRA model building and then discuss in detail the implications of the new muon g − 2 results with the updated LHC constraints on such $$ \overset{\sim }{g} $$ g ~ SUGRA scenarios. We obtain the following observations: (i) for the most interesting M1 = M2 case at the GUT scale with a viable bino-like dark matter, the $$ \overset{\sim }{g} $$ g ~ SUGRA can explain the muon g − 2 anomaly at 1σ level and be consistent with the updated LHC constraints for 6 ≤ M3/M1 ≤ 9 at the GUT scale; (ii) For M1 : M2 = 5 : 1 at the GUT scale with wino-like dark matter, the $$ \overset{\sim }{g} $$ g ~ SUGRA model can explain the muon g − 2 anomaly at 2σ level and be consistent with the updated LHC constraints for 3 ≤ M3/M1 ≤ 3.2 at the GUT scale; (iii) For M1 : M2 = 3 : 2 at the GUT scale with mixed bino-wino dark matter, the $$ \overset{\sim }{g} $$ g ~ SUGRA model can explain the muon g − 2 anomaly at 1σ level and be consistent with the updated LHC constraints for 6.9 ≤ M3/M1 ≤ 7.5 at the GUT scale. Although the choice of heavy gluino will always increase the FT involved, some of the 1σ/2σ survived points of $$ \Delta {a}_{\mu}^{\mathrm{combine}} $$ ∆ a μ combine can still allow low EWFT of order several hundreds and be fairly natural. Constraints from (dimension-five operator induced) proton decay are also discussed.

Reading Longer Words: Insights Into Multisyllabic Word Reading

2017 ◽  
Vol 2 (1) ◽  
pp. 86-94 ◽  
Author(s):  
Lindsay Heggie ◽  
Lesly Wade-Woolley
Keyword(s):  
Systematic Approach ◽  
Word Reading ◽  
Explicit Instruction ◽  
Working Memory Capacity ◽  
Reading Difficulties ◽  
Instructional Programs ◽  
Morphological Knowledge ◽  
Morphological Complexity ◽  
Reading Accuracy ◽  
Grade 3

Students with persistent reading difficulties are often especially challenged by multisyllabic words; they tend to have neither a systematic approach for reading these words nor the confidence to persevere (Archer, Gleason, & Vachon, 2003; Carlisle & Katz, 2006; Moats, 1998). This challenge is magnified by the fact that the vast majority of English words are multisyllabic and constitute an increasingly large proportion of the words in elementary school texts beginning as early as grade 3 (Hiebert, Martin, & Menon, 2005; Kerns et al., 2016). Multisyllabic words are more difficult to read simply because they are long, posing challenges for working memory capacity. In addition, syllable boundaries, word stress, vowel pronunciation ambiguities, less predictable grapheme-phoneme correspondences, and morphological complexity all contribute to long words' difficulty. Research suggests that explicit instruction in both syllabification and morphological knowledge improve poor readers' multisyllabic word reading accuracy; several examples of instructional programs involving one or both of these elements are provided.

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