scholarly journals Searching in 2-Dimensional mass space for final states with 2 invisible particles

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
G. Anagnostou
Keyword(s):  
Dark Matter ◽  
Search Method ◽  
Final States ◽  
Missing Energy ◽  
Final State ◽  
True Nature ◽  
Mass Distributions ◽  
Bump Hunting ◽  
Related Distribution ◽  
Proof Of Principle

Abstract A method to search for particles of unknown masses in final states with two invisible particles is presented. Searching for final states with missing energy is a challenging task usually performed in the tail of a missing energy related distribution. The search method proposed is based on a 2-Dimensional mass reconstruction of the final state with two invisible particles. Thus, a bump hunting is possible, allowing a stronger signal versus background discrimination. Parameters of the new theory can be extracted from the mass distributions, a valuable step towards understanding its true nature. The proof of principle is based on the existing SM top pairs in their dilepton final state. The method is applicable in many interesting searches at the LHC, including dark matter candidates or heavy top partners.

GAMMA-RAY CONSTRAINTS ON DECAYING DARK MATTER

2010 ◽  
Vol 25 (11n12) ◽  
pp. 969-975
Author(s):  
CHUAN-REN CHEN ◽  
SOURAV K. MANDAL ◽  
FUMINOBU TAKAHASHI
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Hadronic Decay ◽  
Total Flux ◽  
Final States ◽  
Final State ◽  
Positron Fraction ◽  
Decaying Dark Matter

The anomalies in positron fraction observed in PAMELA and total flux of electrons and positron reported by Fermi can be explained by a decaying dark matter. The agreement between astrophysical background and observed data in anti-proton indicates a lep-tophilic dark matter and constrains the hadronic decay branching ratios. In this work, we study the constrains on decaying rates of a dark matter to various 2-body final states using the Fermi and HESS gamma-ray data. We find that µ+µ- or τ+τ- final state is preferred to simultaneously explain the excesses and meet the gamma-ray constrains.

scholarly journals Shining light on the scotogenic model: interplay of colliders and cosmology

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Sven Baumholzer ◽  
Vedran Brdar ◽  
Pedro Schwaller ◽  
Alexander Segner
Keyword(s):  
Dark Matter ◽  
Neutrino Masses ◽  
Production Mechanism ◽  
High Luminosity ◽  
Missing Energy ◽  
Final State ◽  
Lepton Colliders ◽  
Matter Component ◽  
Freeze Out

Abstract In the framework of the scotogenic model, which features radiative generation of neutrino masses, we explore light dark matter scenario. Throughout the paper we chiefly focus on keV-scale dark matter which can be produced either via freeze-in through the decays of the new scalars, or from the decays of next-to-lightest fermionic particle in the spectrum, which is produced through freeze-out. The latter mechanism is required to be suppressed as it typically produces a hot dark matter component. Constraints from BBN are also considered and in combination with the former production mechanism they impose the dark matter to be light. For this scenario we consider signatures at High Luminosity LHC and proposed future hadron and lepton colliders, namely FCC-hh and CLIC, focusing on searches with two leptons and missing energy as a final state. While a potential discovery at High Luminosity LHC is in tension with limits from cosmology, the situation greatly improves for future colliders.

scholarly journals RECENT τ LEPTON RESULTS FROM BABAR

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI
Keyword(s):  
Standard Model ◽  
Branching Fractions ◽  
Charged Particles ◽  
Babar Collaboration ◽  
Final States ◽  
Final State ◽  
Experimental Knowledge ◽  
Electron Positron ◽  
The Standard Model ◽  
Positron Collisions

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.

SEARCH FOR NEW PHYSICS IN eμX DATA AT THE TEVATRON USING SLEUTH: A QUASI-MODEL-INDEPENDENT SEARCH STRATEGY FOR NEW PHYSICS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON
Keyword(s):  
Standard Model ◽  
Search Strategy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Final State ◽  
The Standard Model ◽  
Model Independent

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.

scholarly journals Top squark searches using dilepton invariant mass distributions and bino-Higgsino dark matter at the LHC

2013 ◽  
Vol 87 (9) ◽  
Author(s):  
Bhaskar Dutta ◽  
Teruki Kamon ◽  
Nikolay Kolev ◽  
Kuver Sinha ◽  
Kechen Wang ◽  
...  
Keyword(s):  
Dark Matter ◽  
Invariant Mass ◽  
Top Squark ◽  
Dilepton Invariant Mass ◽  
Mass Distributions

scholarly journals Constraining the Inert Doublet Model using Vector Boson Fusion

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Daniel Dercks ◽  
Tania Robens
Keyword(s):  
Dark Matter ◽  
Parameter Space ◽  
Vector Boson ◽  
Higgs Doublet ◽  
Dark Matter Candidate ◽  
Final States ◽  
Vector Boson Fusion ◽  
Doublet Model ◽  
Inert Doublet Model ◽  
Two Higgs Doublet Model

AbstractIn this work, we use a recast of the Run II search for invisible Higgs decays within Vector Boson Fusion to constrain the parameter space of the Inert Doublet model, a two Higgs doublet model with a dark matter candidate. When including all known theoretical as well as collider constraints, we find that the above can rule out a relatively large part in the $$m_H,\,\lambda _{345}$$mH,λ345 parameter space, for dark scalar masses $$m_H\,\le \,100\,{\mathrm{GeV}}$$mH≤100GeV. Including the latest dark matter constraints, a smaller part of parameter space remains which is solely excluded from the above analysis. We also discuss the sensitivity of monojet searches and multilepton final states from Run II.

scholarly journals Electron Momentum Spectroscopy

1986 ◽  
Vol 39 (5) ◽  
pp. 587 ◽  
Author(s):  
IE McCarthy
Keyword(s):  
Impulse Approximation ◽  
High Electron ◽  
Final States ◽  
Final State ◽  
Structure Information ◽  
Plane Wave Impulse Approximation ◽  
Ion Structure ◽  
Spectroscopic Factors ◽  
Electron Momentum Spectroscopy ◽  
Energy And Momentum

For sufficiently high electron energies (greater than a few hundred eV) and sufficiently low recoil momenta Oess than a few atomic units) the differential cross section for the non-coplanar symmetric (e,2e) reaction on an atom or molecule depends on the target and ion structure only through the target-ion overlap. Experimental criteria for the energy and momentum are that the apparent structure information does not change when the energy and momentum are varied. The plane-wave impulse approximation is a sufficient description of the reaction mechanism for determining spherically averaged squares of momentum-space orbitals for atoms and molecules and for coefficients describing initial- and final-state correlations. For mainly uncorrelated initial states, spectroscopic factors for final states belonging to the same manifold are uniquely determined. For molecules, summed spectroscopic factors can be compared for different ion manifolds. For atoms, summed spectroscopic factors and higher-momentum profiles require the dist~rted-wave impulse approximation.

scholarly journals Primordial black holes as dark matter: converting constraints from monochromatic to extended mass distributions

2018 ◽  
Vol 2018 (01) ◽  
pp. 004-004 ◽  
Author(s):  
Nicola Bellomo ◽  
José Luis Bernal ◽  
Alvise Raccanelli ◽  
Licia Verde
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Primordial Black Holes ◽  
Mass Distributions

The Dark Matter Enigma

2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Jean-Pierre Luminet
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
True Nature ◽  
The Many

Unveiling the true nature of dark matter is one of the most significant challenges in modern astrophysics. In an effort to explain this enigma, three categories of theories have been developed: Cold Dark Matter, Hot Dark Matter, and Warm Dark Matter. Jean-Pierre Luminet reviews these and other attempts to confront the many unresolved questions that obscure this perplexing aspect of our universe.

The Early and Final States of an Epidemic in a Large Heterogeneous Population by a Small Initial Number of Infectives

1994 ◽  
Vol 26 (03) ◽  
pp. 671-689
Author(s):  
Steven M. Butler
Keyword(s):  
Random Number ◽  
Death Process ◽  
Time Interval ◽  
Final States ◽  
Birth And Death Process ◽  
Initial Number ◽  
Threshold Behavior ◽  
Final State ◽  
Epidemic Process ◽  
Susceptibility To Infection

This paper describes the early and final properties of a general S–I–R epidemic process in which the infectives behave independently, each infective has a random number of contacts with the others in the population, and individuals vary in their susceptibility to infection. For the case of a large initial number of susceptibles and a small (finite) initial number of infectives, we derive the threshold behavior and the limiting distribution for the final state of the epidemic. Also, we show strong convergence of the epidemic process over any finite time interval to a birth and death process, extending the results of Ball (1983). These complement some results due to Butler (1994), who considers the case of a large initial number of infectives.

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