A
bstract
We consider a color octet scalar particle and its exotic decay in the channel gluon-
γ
using an effective Lagrangian description for its strong and electromagnetic interactions. Such a ...state is present in many extensions of the Standard Model, and in particular in composite Higgs models with top partial compositeness, where couplings to photons arise via the Wess-Zumino-Witten term. We find that final states with one or two photons allow for a better reach at the LHC, even for small branching ratios. Masses up to 1
.
2 TeV can be probed at the HL-LHC by use of all final states. Finally, we estimate the sensitivity of the hadronic FCC.
Review of fundamental composite dynamics Cacciapaglia, G.; Deandrea, A.; Sridhar, K.
The European physical journal. ST, Special topics,
2022/6, Letnik:
231, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This editorial provides a summary of the issues that our compendium,
Review of Fundamental Composite Dynamics
aims to address and an outline of the essays that appear in this collection.
A
bstract
The next generation electron-positron colliders are designed for precision studies of the Standard Model and its extensions, in particular in the Higgs sector. We consider the potential for ...discovery of composite Higgs models in Higgs pair production through photon collisions. This process is loop-generated, thus it provides access to all Higgs couplings and can show new physics effects in polarized and unpolarized cross-sections starting at relatively low collider energies. It is, therefore, relevant for all electron-positron colliders planned or in preparation. Sizeable deviations from the Standard Model predictions are present in a general class of composite Higgs models, as couplings of one or more Higgs bosons to fermions, or fermionic and scalar resonances, modify the destructive interference present in the Standard Model. In particular, large effects are due to the new quartic coupling of the Higgs to tops and to the presence of a light scalar resonance.
In the context of a simplified leptophilic dark matter (DM) scenario where the mediator is a new charged fermion carrying leptonic quantum number and the DM candidate is either scalar or vector, the ...complementarity of different bounds is analyzed. In this framework, the extra lepton and DM are odd under a Z2 symmetry, and hence the leptonic mediator can only interact with the DM state and Standard Model leptons of various flavors. We show that there is the possibility to characterize the DM spin (scalar or vector), as well as the nature of the mediator, through a combined analysis of cosmological, flavor and collider data. We present an explicit numerical analysis for a set of benchmarks points of the viable parameter space of our scenario.
We investigate the production of heavy colored scalars and vectors and their relevance at the LHC for the study of vectorlike quarks (T). These colored states (C) are present in a large number of ...extensions of the standard model, in particular, in composite models and in extradimensional models. Assuming that these bosonic states are heavier than the vectorlike quarks (VLQ), we consider their production through the process pp→C→tT. Large QCD production cross sections for C enable us to probe heavier masses for the VLQ, thereby allowing us to put stronger limits on the vectorlike quarks which are produced in their decay chain. We adopt a universal analysis strategy by including leptons under the classification of “jets,” thereby limiting the bias towards a specific combination of final state. We also study the possibility of disentangling these scenarios from supersymmetric extensions of the standard model by using simple discriminants based on jet multiplicity and missing energy. We demonstrate that a simple set of cuts is sufficient to disentangle the VLQ signal from the backgrounds. In models with a moderate B.R.(C→Tt), the analysis enables one to get a hint of VLQ masses as heavy as 3 TeV.
Theoretical and phenomenological implications of
R-parity violation in supersymmetric theories are discussed in the context of particle physics and cosmology. Fundamental aspects include the relation ...with continuous and discrete symmetries and the various allowed patterns of
R-parity breaking. Recent developments on the generation of neutrino masses and mixings within different scenarios of
R-parity violation are discussed. The possible contribution of
R-parity-violating Yukawa couplings in processes involving virtual supersymmetric particles and the resulting constraints are reviewed. Finally, direct production of supersymmetric particles and their decays in the presence of
R-parity-violating couplings is discussed together with a survey of existing constraints from collider experiments.
Anomaly mediation models are well motivated supersymmetry breaking scenarios which appear as alternatives to the mSUGRA paradigm. These models are quite compelling from the theoretical point of view ...and it is therefore important to test if they are also viable models for phenomenology. We perform a study of these models in the light of all standard flavour, collider and dark matter constraints, including also the recent Higgs boson measurements for the mass and signal strengths in the different decay channels. The minimal AMSB scenario can satisfy in part of its parameter space the dark matter requirement but is only marginally consistent with the current Higgs boson mass value. The HyperCharge-AMSB and Mixed Moduli-AMSB scenarios can better describe present data from dark matter, flavour, low energy physics and are consistent with the measured mass of the Higgs boson. The inclusion of the preferred signal strengths for the Higgs boson decay channels shows that for tan(beta) > 5 the HC-AMSB and MM-AMSB models can be consistent with the present Higgs boson data. In contrast the minimal AMSB has a narrower allowed range in tan(beta). These different AMSB scenarios, while consistent with present Higgs boson measurements, can be further tested by future more precise data in the Higgs sector.
The approximate symmetries of Quantum ChromoDynamics in the infinite heavy quark (
Q =
c,
b) mass limit (
m
Q
→ ∞) and in the chiral limit for the light quarks (
m
q
→ 0,
q =
u,
d,
s) can be used ...together to build up an effective chiral lagrangian for heavy and light mesons describing strong interactions among effective meson fields as well as their couplings to electromagnetic and weak currents, including the relevant symmetry-breaking terms. The effective theory includes heavy (
Q
q
̄
) mesons of both negative and positive parity, light pseudoscalars, as well as light vector mesons. We summarize the estimates for the parameters entering the effective lagrangian and discuss in particular some phenomenologically important couplings, such as
g
B
∗Bπ
. The hyperfine splitting of heavy mesons is discussed in detail. The effective lagrangian allows for the possibility to describe consistently weak couplings of heavy (
B, D) to light (
π, ϱ, K
∗,
etc.
) mesons. The method has however its own limitations, due to the requirement that the light meson momenta should be small, and we discuss how such limitations can be circumvented through reasonable ansatz on the form factors. Flavour conserving (
e.g. B
∗ → Bγ
) and flavour changing (
e.g. B → K
∗γ
) radiative decays provide another field of applications of effective lagrangians; they are discussed together with their phenomenological implications. Finally, we analyze effective lagrangians describing heavy charmonium- like (Q̄Q) mesons and their strong and electromagnetic interactions. The role of approximate heavy quark symmetries for this case and the phenomenological tests of these models are also discussed.
A series of N-(2-amino-6-trifluoromethylpyridin-3-ylmethyl)-2-(3-fluoro-4-methylsulfonylaminophenyl)propanamides were designed combining previously identified pharmacophoric elements and evaluated as ...hTRPV1 antagonists. The SAR analysis indicated that specific hydrophobic interactions of the 2-amino substituents in the C-region of the ligand were critical for high hTRPV1 binding potency. In particular, compound 49 S was an excellent TRPV1 antagonist (K i(CAP) = 0.2 nM; IC50(pH) = 6.3 nM) and was thus approximately 100- and 20-fold more potent, respectively, than the parent compounds 2 and 3 for capsaicin antagonism. Furthermore, it demonstrated strong analgesic activity in the rat neuropathic model superior to 2 with almost no side effects. Compound 49 S antagonized capsaicin induced hypothermia in mice but showed TRPV1-related hyperthermia. The basis for the high potency of 49 S compared to 2 is suggested by docking analysis with our hTRPV1 homology model in which the 4-methylpiperidinyl group in the C-region of 49 S made additional hydrophobic interactions with the hydrophobic region.
We propose a model-independent and general framework to study the LHC phenomenology of top partners, i.e. vector-like quarks including particles with different electromagnetic charge. We consider ...vector-like quarks embedded in general representations of the weak SU(2)L, coupling to all Standard Model quarks via Yukawa mixing focusing on the case of a single multiplet. We show that, with very minimal and quite general assumptions, top partners may be studied in terms of few parameters in an effective Lagrangian description with a clear and simple connection with experimental observables. We also demonstrate that the parametrisation can be applied as well to cases with many vector-like multiplets, thus covering most realistic models of New Physics. We perform a numerical study to understand the conclusions which can be drawn within such a description and the expected potential for discovery or exclusion at the LHC. Our main results are a clear connection between branching ratios and single production channels, and the identification of novel interesting channels to be studied at the LHC.
PDF
