109 research outputs found
Leptophilic dark matter from gauged lepton number: Phenomenology and gravitational wave signatures
New gauge symmetries often appear in theories beyond the Standard Model. Here
we study a model where lepton number is promoted to a gauge symmetry. Anomaly
cancellation requires the introduction of additional leptons, the lightest of
which is a natural leptophilic dark matter candidate. We perform a
comprehensive study of both collider and dark matter phenomenology. Furthermore
we find that the model exhibits a first order lepton number breaking phase
transition in large regions of parameter space. The corresponding gravitational
wave signal is computed, and its detectability at LISA and other future GW
detectors assessed. Finally we comment on the complementarity of dark matter,
collider and gravitational wave observables, and on the potential reach of
future colliders.Comment: 36 pages + appendix, 24 figures. Version accepted for publication in
JHE
Probing new physics through entanglement in diboson production
Pair production of heavy vector bosons is a key process at colliders: it
allows to test our understanding of the Standard Model and to explore the
existence of new physics through precision measurements of production rates and
differential distributions. New physics effects can be subtle and often require
observables specifically designed for their detection. In this study, we focus
on quantum information observables that characterise the spin states of the
final diboson system. We analyse concurrence bounds, purity, and Bell
inequalities for a bipartite qutrit system representing two massive gauge
bosons. Our findings show that quantum spin observables can serve as
complementary probes for heavy new physics as parametrised by higher
dimensional operators in the Standard Model effective field theory. In
particular, we find that these observables offer increased sensitivity to
operators whose contributions do not interfere with the Standard Model
amplitudes at the level of differential cross sections.Comment: 42 pages, 18 figures; v2: added ancillary file
Quantum SMEFT tomography: top quark pair production at the LHC
Quantum information observables, such as entanglement measures, provide a
powerful way to characterize the properties of quantum states. We propose to
use them to probe the structure of fundamental interactions and to search for
new physics at high energy. Inspired by recent proposals to measure
entanglement of top quark pairs produced at the LHC, we examine how
higher-dimensional operators in the framework of the SMEFT modify the Standard
Model expectations. We explore two regions of interest in the phase space where
the Standard Model produces maximally entangled states: at threshold and in the
high-energy limit. We unveil a non-trivial pattern of effects, which depend on
the initial state partons, or , on whether only linear or up to
quadratic SMEFT contributions are included, and on the phase space region. In
general, we find that higher-dimensional effects lower the entanglement
predicted in the Standard Model.Comment: 8 pages, 5 figures + appendix; v2: minor changes, published versio
Discovering the Decay in Associated Production
We explore the prospects to discover the decay in -associated production, featuring a signal-to-background ratio of . Performing a detailed analysis of the semi-leptonic -decay
channel, we demonstrate that the production mode could lead to a
discovery at the high-luminosity LHC, while the effective coupling could be extracted with a accuracy. Extending the
analysis to potential future colliders with 27 TeV and 100 TeV
center-of-mass energies, we also show that the latter would allow precision
measurements at the few percent level, rendering possible precise extractions
of the spin and CP properties of the Higgs boson.Comment: 7 pages, 4 figures, updated version matches the one published is
Phys. Rev.
Dark, Cold, and Noisy: Constraining Secluded Hidden Sectors with Gravitational Waves
We explore gravitational wave signals arising from first-order phase
transitions occurring in a secluded hidden sector, allowing for the possibility
that the hidden sector may have a different temperature than the Standard Model
sector. We present the sensitivity to such scenarios for both current and
future gravitational wave detectors in a model-independent fashion. Since
secluded hidden sectors are of particular interest for dark matter models at
the MeV scale or below, we pay special attention to the reach of pulsar timing
arrays. Cosmological constraints on light degrees of freedom restrict the
number of sub-MeV particles in a hidden sector, as well as the hidden sector
temperature. Nevertheless, we find that observable first-order phase
transitions can occur. To illustrate our results, we consider two minimal
benchmark models: a model with two gauge singlet scalars and a model with a
spontaneously broken gauge symmetry in the hidden sector.Comment: 37 pages, 12 figures. Noise and PLI sensitivity curves are included
in the source director
An investigation in the correlation between Ayurvedic body-constitution and food-taste preference
Probing new physics through entanglement in diboson production
Abstract Pair production of heavy vector bosons is a key process at colliders: it allows to test our understanding of the Standard Model and to explore the existence of new physics through precision measurements of production rates and differential distributions. New physics effects can be subtle and often require observables specifically designed for their detection. In this study, we focus on quantum information observables that characterise the spin states of the final diboson system. We analyse concurrence bounds, purity, and Bell inequalities for a bipartite qutrit system representing two massive gauge bosons. Our findings show that quantum spin observables can serve as complementary probes for heavy new physics as parametrised by higher dimensional operators in the Standard Model effective field theory. In particular, we find that these observables offer increased sensitivity to operators whose contributions do not interfere with the Standard Model amplitudes at the level of differential cross sections
Probing Higgs-portal dark matter with vector-boson fusion
We constrain the Higgs-portal model employing the vector-boson fusion channel
at the LHC. In particular, we include the phenomenologically interesting
parameter region near the Higgs resonance, where the Higgs-boson mass is close
to the threshold for dark-matter production and a running-width prescription
has to be employed for the Higgs-boson propagator. Limits for the Higgs-portal
coupling as a function of the dark-matter mass are derived from the CMS search
for invisible Higgs-boson decays in vector-boson fusion at 13 TeV. Furthermore,
we perform projections for the 14 TeV HL-LHC and the 27 TeV HE-LHC taking into
account a realistic estimate of the systematic uncertainties. The respective
upper limits on the invisible branching ratio of the Higgs boson reach a level
of 2 % and constrain perturbative Higgs-portal couplings up to dark-matter
masses of about 110 GeV.Comment: 22 pages, 8 figures, minor revisions in introduction and appendix,
version published in JHE
Recommended from our members
Probing new physics through entanglement in diboson production
Acknowledgements: RA’s research was supported by the F.R.S.-FNRS project no. 40005600 and the FSR Program of UCLouvain. FM is partially supported by the F.R.S.- FNRS under the “Excellence of Science” EOS be.h project no. 30820817. LM is supported by the European Research Council under the European Union’s Horizon 2020 research and innovation Programme (grant agreement n.950246).Abstract
Pair production of heavy vector bosons is a key process at colliders: it allows to test our understanding of the Standard Model and to explore the existence of new physics through precision measurements of production rates and differential distributions. New physics effects can be subtle and often require observables specifically designed for their detection. In this study, we focus on quantum information observables that characterise the spin states of the final diboson system. We analyse concurrence bounds, purity, and Bell inequalities for a bipartite qutrit system representing two massive gauge bosons. Our findings show that quantum spin observables can serve as complementary probes for heavy new physics as parametrised by higher dimensional operators in the Standard Model effective field theory. In particular, we find that these observables offer increased sensitivity to operators whose contributions do not interfere with the Standard Model amplitudes at the level of differential cross sections.</jats:p
Primordial gravitational waves in the nano-Hertz regime and PTA data -- towards solving the GW inverse problem
In recent years, several pulsar timing array collaborations have reported
first hints for a stochastic gravitational wave background at nano-Hertz
frequencies. Here we elaborate on the possibility that this signal comes from
new physics that leads to the generation of a primordial stochastic
gravitational wave background. We propose a set of simple but concrete models
that can serve as benchmarks for gravitational waves sourced by cosmological
phase transitions, domain wall networks, cosmic strings, axion dynamics, or
large scalar fluctuations. These models are then confronted with pulsar timing
data and with cosmological constraints. With only a limited number of free
parameters per model, we are able to identify viable regions of parameter space
and also make predictions for future astrophysical and laboratory tests that
can help with model identification and discrimination.Comment: 26 pages + appendix, 17 figures; v2: updated author list to avoid
conflict with NANOGrav collaboration rule
- …