45 research outputs found
Discovery prospects of a vectorlike top partner decaying to a singlet boson
The possibility of a vectorlike top partner decaying to a new colourless
weak-singlet scalar or pseudoscalar has attracted some attention in the
literature. We investigate the production of a weak-singlet charge-
quark that can decay to a spinless boson () and a top quark at the LHC.
Earlier, in 2203.13753, we have shown that in a large part of the parameter
space, the and the loop-induced decays become the
dominant decay modes for these particles. Here, we investigate the discovery
prospects of the quark in this region through the above decays. In
particular, we focus on the
channel. Separating this signal from the huge Standard Model background is a
challenging task, forcing us to employ a multivariate machine-learning
technique. We find that the above channel can be a discovery channel of the top
partner in the large part of the parameter space where the above decay chain
dominates. Our analysis is largely model-independent, and hence our results
would be useful in a broad class of new physics models.Comment: 12 pages, 10 figures, 3 table
On the BSM reach of four top production at the LHC
Many scenarios of beyond the Standard Model (BSM) physics give rise to new
top-philic interactions that can be probed at proton machines such as the Large
Hadron Collider through a variety of production and decay modes. On the one
hand, this will enable a detailed determination of the BSM model's parameters
when a discovery is made and additional sensitivity in non-dominant production
modes can be achieved. On the other hand, the naive narrow width approximation
in dominant production modes such as gluon fusion might be inadequate for some
BSM parameter regions due to interference effects, effectively making less
dominant production modes more relevant in such instances. In this work, we
consider both these questions in the context of four top quark final states at
the LHC. Firstly, we show that the SM potential can be enhanced through the
application of targeted Graph Neural Network techniques that exploit data
correlations beyond cut-and-count approaches. Secondly, we show that
destructive interference effects that can degrade BSM sensitivity of top-philic
states from gluon fusion are largely avoided by turning to four top final
states. This achieves considerable exclusion potential for, e.g., the two Higgs
doublet model. This further motivates four top final states as sensitive tools
for BSM discovery in the near future of the LHC.Comment: 21 pages, 9 figure
IRC-Safe Graph Autoencoder for Unsupervised Anomaly Detection
Anomaly detection through employing machine learning techniques has emerged as a novel powerful tool in the search for new physics beyond the Standard Model. Historically similar to the development of jet observables, theoretical consistency has not always assumed a central role in the fast development of algorithms and neural network architectures. In this work, we construct an infrared and collinear safe autoencoder based on graph neural networks by employing energy-weighted message passing. We demonstrate that whilst this approach has theoretically favorable properties, it also exhibits formidable sensitivity to non-QCD structures
Discovery prospects of a vectorlike top partner decaying to a singlet boson
The possibility of a vectorlike top partner decaying to a new colorless weak-singlet scalar or pseudoscalar has attracted some attention in the literature. We investigate the production of a weak-singlet charge-
2
/
3
T
quark that can decay to a spinless boson (
Φ
) and a top quark at the LHC. Earlier [A. Bhardwaj et al., Roadmap to explore vectorlike quarks decaying to a new scalar or pseudoscalar, arXiv:2203.13753.], we showed that in a large part of the parameter space, the
T
→
t
Φ
and the loop-induced
Φ
→
g
g
decays become the dominant decay modes for these particles. Here, we investigate the discovery prospects of the
T
quark in this region through the above decays. In particular, we focus on the
p
p
→
T
T
→
(
t
Φ
)
(
t
Φ
)
→
(
t
(
g
g
)
)
(
t
(
g
g
)
)
channel. Separating this signal from the huge Standard Model background is a challenging task, forcing us to employ a multivariate machine-learning technique. We find that the above channel can be a discovery channel of the top partner in the large part of the parameter space where the above decay chain dominates. Our analysis is largely model independent, and hence our results would be useful in a broad class of new physics models
Obesity-dependent changes in interstitial ECM mechanics promote breast tumorigenesis.
Obesity and extracellular matrix (ECM) density are considered independent risk and prognostic factors for breast cancer. Whether they are functionally linked is uncertain. We investigated the hypothesis that obesity enhances local myofibroblast content in mammary adipose tissue and that these stromal changes increase malignant potential by enhancing interstitial ECM stiffness. Indeed, mammary fat of both diet- and genetically induced mouse models of obesity were enriched for myofibroblasts and stiffness-promoting ECM components. These differences were related to varied adipose stromal cell (ASC) characteristics because ASCs isolated from obese mice contained more myofibroblasts and deposited denser and stiffer ECMs relative to ASCs from lean control mice. Accordingly, decellularized matrices from obese ASCs stimulated mechanosignaling and thereby the malignant potential of breast cancer cells. Finally, the clinical relevance and translational potential of our findings were supported by analysis of patient specimens and the observation that caloric restriction in a mouse model reduces myofibroblast content in mammary fat. Collectively, these findings suggest that obesity-induced interstitial fibrosis promotes breast tumorigenesis by altering mammary ECM mechanics with important potential implications for anticancer therapies
Obesity-dependent changes in interstitial ECM mechanics promote breast tumorigenesis
Obesity and extracellular matrix (ECM) density are considered independent risk and prognostic factors for breast cancer. Whether they are functionally linked is uncertain. We investigated the hypothesis that obesity enhances local myofibroblast content in mammary adipose tissue and that these stromal changes increase malignant potential by enhancing interstitial ECM stiffness. Indeed, mammary fat of both diet- and genetically induced mouse models of obesity were enriched for myofibroblasts and stiffness-promoting ECM components. These differences were related to varied adipose stromal cell (ASC) characteristics because ASCs isolated from obese mice contained more myofibroblasts and deposited denser and stiffer ECMs relative to ASCs from lean control mice. Accordingly, decellularized matrices from obese ASCs stimulated mechanosignaling and thereby the malignant potential of breast cancer cells. Finally, the clinical relevance and translational potential of our findings were supported by analysis of patient specimens and the observation that caloric restriction in a mouse model reduces myofibroblast content in mammary fat. Collectively, these findings suggest that obesity-induced interstitial fibrosis promotes breast tumorigenesis by altering mammary ECM mechanics with important potential implications for anticancer therapies
Implications of the muon anomalous magnetic moment for the LHC and MUonE
We consider the anomalous magnetic moment of the muon
a
μ
, which shows a significant deviation from the Standard Model expectation given the recent measurements at Fermilab and BNL. We focus on Standard Model Effective Field Theory (SMEFT) with the aim to identify avenues for the upcoming LHC runs and future experiments such as MUonE. To this end, we include radiative effects to
a
μ
in SMEFT to connect the muon anomaly to potentially interesting searches at the LHC, specifically Higgs decays into muon pairs and such decays with resolved photons. Our investigation shows that similar to results for concrete UV extensions of the Standard Model, the Fermilab/BNL result can indicate strong coupling within the EFT framework and
a
μ
is increasingly sensitive to a single operator direction for high scale UV completions. In such cases, there is some complementarity between expected future experimental improvements, yet with considerable statistical challenges to match the precision provided by the recent
a
μ
measurement
Towards efficient reconstruction of semi-invisible events from higgs at the LHC
by Akanksha Bhardwaj, Partha Konar and Abhaya Kumar Swai