scholarly journals New Physics Beryond the SM at BESIII

2019 ◽  
Vol 212 ◽  
pp. 06004
Author(s):  
Minggang Zhao
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
New Physics ◽  
Dark Sector ◽  
Decay Modes ◽  
The Standard Model ◽  
The Masses

Numerous astrophysical observations strongly suggest the existence of Dark Matter, which provides a hint of dark sector physics. There could exist many dark candidates predicted by theories BSM, such as dark photons and invisible things, that communicate with the Standard Model sector. The masses and decay modes of these particles are expected to be accessible at the BESIII experiment which is the only currently running tau-charm factory with the largest threshold charm samples and some other unique datasets. We have recently performed searches of dark photons and invisible things in several decay modes. Besides, FCNC processes, BNV/LNV processes are also investigated. This talk will summarize the recent results at BESIII on these searches for new physics BSM.

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.

THE FAMILY PROBLEM: EXTENSION OF STANDARD MODEL WITH A LOOSELY-COUPLED SU(3) FAMILY GAUGE THEORY

2011 ◽  
Vol 01 ◽  
pp. 5-9 ◽  
Author(s):  
W-Y. PAUCHY HWANG
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Dark Sector ◽  
Ordinary Matter ◽  
Loosely Coupled ◽  
Family Problem ◽  
Visible Matter ◽  
The Family ◽  
The Standard Model ◽  
The Masses

We all know that in our family of the basic particles we have three generations but still don't know why - the so-called "family problem". On other hand, in view of the masses and oscillations, the neutrinos now present some basic difficulty in the Standard Model. In this note, I propose that on top of the SUc(3) × SU(2) × U(1) standard model there is an SUf(3) extension - a simple SUc(3) × SU(2) × U(1) × SUf(3) extended standard model - neutrino masses are obtained in a "renormalizable" way in the dark sector. On the dark matter side, the family gauge bosons (familons) are massive through the so-called "colored" Higgs mechanism while the remaining Higgs particles are also massive. As the bridge between the dark matter and the ordinary matter, the three neutrinos, the electron-like, muon-like, and tao-like neutrinos, form the basic family triplets. Hopefully all the couplings to the "visible" ordinary matter are through the neutrinos, explaining why dark matter (25 %) is more than visible matter (5 %) in our Universe.

Extension of Standard Model in multi-spinor field formalism — Visible and dark sectors

2016 ◽  
Vol 31 (18) ◽  
pp. 1630027
Author(s):  
Ikuo S. Sogami
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Dark Sector ◽  
Quadratic Interaction ◽  
Inflationary Phase ◽  
The Standard Model ◽  
Visible Sector ◽  
Field Formalism ◽  
Main Component ◽  
Higgs Fields

With multi-spinor fields which behave as triple-tensor products of the Dirac spinors, the Standard Model is extended so as to embrace three families of ordinary quarks and leptons in the visible sector and an additional family of exotic quarks and leptons in the dark sector of our Universe. Apart from the gauge and Higgs fields of the Standard Model symmetry G, new gauge and Higgs fields of a symmetry isomorphic to G are postulated to exist in the dark sector. It is the bi-quadratic interaction between visible and dark Higgs fields that opens a main portal to the dark sector. Breakdowns of the visible and dark electroweak symmetries result in the Higgs boson with mass 125 GeV and a new boson which can be related to the diphoton excess around 750 GeV. Subsequent to a common inflationary phase and a reheating period, the visible and dark sectors follow weakly-interacting paths of thermal histories. We propose scenarios for dark matter in which no dark nuclear reaction takes place. A candidate for the main component of the dark matter is a stable dark hadron with spin 3/2, and the upper limit of its mass is estimated to be 15.1 GeV/c2.

CHARM MIXING AND CP VIOLATION AT B-FACTORIES

2014 ◽  
Vol 35 ◽  
pp. 1460413
Author(s):  
GIANLUIGI CIBINETTO ◽  
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
New Physics ◽  
Ratio Analysis ◽  
Charm Meson ◽  
Final State ◽  
Charm Decays ◽  
Decay Modes ◽  
The Standard Model ◽  
Model Predictions

CP violation in charm decays is expected to be very small in the Standard Model, at the level of 0.1% or less. A sizable excess of CP violation with respect to the Standard Model predictions could be a signature of new physics. We report on recent searches for CP violation in charm meson decays at BABAR and Belle experiments. In particular we report a lifetime ratio analysis of D0 → K+K−, π+π− with respect to D0 → K−π+ decays, which is sensitive to [Formula: see text] mixing and CP violation. We report also on searches for CPV in the 3-body D+ → K+K−π+ decay and for decay modes with a [Formula: see text] in the final state, such as [Formula: see text].

scholarly journals ANOMALOUS HIGGS COUPLINGS

1999 ◽  
Vol 14 (20) ◽  
pp. 3121-3156 ◽  
Author(s):  
M. C. GONZALEZ-GARCIA
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Boson Production ◽  
Gauge Bosons ◽  
Effective Interactions ◽  
Decay Modes ◽  
Effective Lagrangian ◽  
The Standard Model

We review the effects of new effective interactions on Higgs-boson phenomenology. New physics in the electroweak bosonic sector is expected to induce additional interactions between the Higgs doublet field and the electroweak gauge bosons, leading to anomalous Higgs couplings as well as anomalous gauge-boson self-interactions. Using a linearly realized SU (2)L× U (1)Y invariant effective Lagrangian to describe the bosonic sector of the Standard Model, we review the effects of the new effective interactions on the Higgs-boson production rates and decay modes. We summarize the results from searches for the new Higgs signatures induced by the anomalous interactions in order to constrain the scale of new physics, in particular at CERN LEP and Fermilab Tevatron colliders.

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 Electroweak symmetry non-restoration from dark matter

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Oleksii Matsedonskyi ◽  
James Unwin ◽  
Qingyun Wang
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Higgs Mass ◽  
Direct Detection ◽  
Higgs Doublet ◽  
New Physics ◽  
Electroweak Symmetry ◽  
The Standard Model ◽  
New States ◽  
Potential Remedy

Abstract Restoration of the electroweak symmetry at temperatures around the Higgs mass is linked to tight phenomenological constraints on many baryogenesis scenarios. A potential remedy can be found in mechanisms of electroweak symmetry non-restoration (SNR), in which symmetry breaking is extended to higher temperatures due to new states with couplings to the Standard Model. Here we show that, in the presence of a second Higgs doublet, SNR can be realized with only a handful of new fermions which can be identified as viable dark matter candidates consistent with all current observational constraints. The competing requirements on this class of models allow for SNR at temperatures up to ∼TeV, and imply the presence of sub-TeV new physics with sizable interactions with the Standard Model. As a result this scenario is highly testable with signals in reach of next-generation collider and dark matter direct detection experiments.

scholarly journals Observing the Dark Sector

Universe ◽  
2019 ◽  
Vol 5 (6) ◽  
pp. 137
Author(s):  
Valerio Marra ◽  
Rogerio Rosenfeld ◽  
Riccardo Sturani
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Standard Model ◽  
Dark Sector ◽  
The Standard Model

Despite the observational success of the standard model of cosmology, present-day observations do not tightly constrain the nature of dark matter and dark energy and modifications to the theory of general relativity. Here, we will discuss some of the ongoing and upcoming surveys that will revolutionize our understanding of the dark sector.

scholarly journals SEARCHING FOR A DARK MATTER COUPLING TO THE STANDARD MODEL WITH A STUECKELBERG EXTENSION

2012 ◽  
Vol 18 ◽  
pp. 10-12
Author(s):  
A. L. DOS SANTOS ◽  
D. HADJIMICHEF
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Z Boson ◽  
Dark Sector ◽  
Minimal Coupling ◽  
Matter Coupling ◽  
The Standard Model ◽  
Double Extension ◽  
Matter Sector

We investigate a double extension to the Standard Model (SM). A first extension introduces, via minimal coupling, a massive Z′ boson. This enlarged SM is coupled to a dark matter sector through the Stueckelberg mechanism by a A′ boson. However, the A′ boson does not interact directly with the SM fermions. In our study, we found that the A′ is a massless photon-like particle in dark sector. Constraints on the mass for Z′ and corrections to Z mass are obtained.

scholarly journals GAUGE THEORY AND MORE — ANOTHER SOLUTION FOR THE DARK MATTER

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3366-3371 ◽  
Author(s):  
W-Y. PAUCHY HWANG
Keyword(s):  
Dark Matter ◽  
Gauge Theory ◽  
Standard Model ◽  
Higgs Mechanism ◽  
Gauge Bosons ◽  
Basic Family ◽  
Visible Matter ◽  
The Family ◽  
The Standard Model ◽  
The Masses

These days we learn that, in our Universe, the dark matter occupies about 25% of the content, compared to only 5% of the "visible" ordinary matter. We propose that the description of the dark matter would be an extension of the Standard Model - a gauge theory. We all know that in the Standard Model we have three generations but still don't know why - the so-called "family problem". On other hand, in view of the masses and oscillations, the neutrinos now present some basic difficulty in the Standard Model. In this note, I propose that on top of the SUc(3)×, SU(2) × U(1) standard model there is an SUf(3) extension - a simple SUc(3) × SU(2) × U(1) × SUf(3) extended standard model. The family gauge bosons (familons) are massive through the so-called "colored" Higgs mechanism while the remaining Higgs particles are also massive. The three neutrinos, the electron-like, muon-like, and tao-like neutrinos, form the basic family triplets. Hopefully all the couplings to the "visible" matter are through the neutrinos, explaining why the dark matter is more than the visible matter in our Universe.

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