scholarly journals Exotic physics: search for scalar leptoquark pairs decaying to nu nu-bar qq-bar in p anti-p collisions at s**(1/2) = 1.96 tev

2004 ◽  
Author(s):  
D. Acosta
Keyword(s):  
Scalar Leptoquark ◽  
Exotic Physics

scholarly journals Interplay of New Physics effects in (g − 2)ℓ and h → ℓ+ℓ− — lessons from SMEFT

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Svjetlana Fajfer ◽  
Jernej F. Kamenik ◽  
M. Tammaro
Keyword(s):  
Closed Operator ◽  
Higgs Doublet ◽  
New Physics ◽  
Effective Field ◽  
Tree Level ◽  
Electroweak Symmetry ◽  
Scalar Leptoquark ◽  
Doublet Model ◽  
The One ◽  
Two Higgs Doublet Model

Abstract We explore the interplay of New Physics (NP) effects in (g− 2)ℓ and h→ℓ+ℓ− within the Standard Model Effective Field Theory (SMEFT) framework, including one-loop Renormalization Group (RG) evolution of the Wilson coefficients as well as matching to the observables below the electroweak symmetry breaking scale. We include both the leading dimension six chirality flipping operators including a Higgs and SU(2)L gauge bosons as well as four-fermion scalar and tensor operators, forming a closed operator set under the SMEFT RG equations. We compare present and future experimental sensitivity to different representative benchmark scenarios. We also consider two simple UV completions, a Two Higgs Doublet Model and a single scalar LeptoQuark extension of the SM, and show how tree level matching to SMEFT followed by the one-loop RG evolution down to the electroweak scale can reproduce with high accuracy the (g−2)ℓ and h→ℓ+ℓ− contributions obtained by the complete one- and even two-loop calculations in the full models.

scholarly journals Observation of anti-parity-time-symmetry, phase transitions and exceptional points in an optical fibre

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Arik Bergman ◽  
Robert Duggan ◽  
Kavita Sharma ◽  
Moshe Tur ◽  
Avi Zadok ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Brillouin Scattering ◽  
Optical Gain ◽  
Single Mode ◽  
Exceptional Point ◽  
Small Scale ◽  
Time Symmetry ◽  
Topological Features ◽  
Gain And Loss ◽  
Exotic Physics

AbstractThe exotic physics emerging in non-Hermitian systems with balanced distributions of gain and loss has recently drawn a great deal of attention. These systems exhibit phase transitions and exceptional point singularities in their spectra, at which eigen-values and eigen-modes coalesce and the overall dimensionality is reduced. So far, these principles have been implemented at the expense of precise fabrication and tuning requirements, involving tailored nano-structured devices with controlled optical gain and loss. In this work, anti-parity-time symmetric phase transitions and exceptional point singularities are demonstrated in a single strand of single-mode telecommunication fibre, using a setup consisting of off-the-shelf components. Two propagating signals are amplified and coupled through stimulated Brillouin scattering, enabling exquisite control over the interaction-governing non-Hermitian parameters. Singular response to small-scale variations and topological features arising around the exceptional point are experimentally demonstrated with large precision, enabling robustly enhanced response to changes in Brillouin frequency shift.

scholarly journals Non-standard interactions in SMEFT confronted with terrestrial neutrino experiments

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yong Du ◽  
Hao-Lin Li ◽  
Jian Tang ◽  
Sampsa Vihonen ◽  
Jiang-Hao Yu
Keyword(s):  
Neutrino Oscillation ◽  
New Physics ◽  
Effective Field ◽  
Scalar Leptoquark ◽  
Double Chooz ◽  
The Standard Model ◽  
Reactor Neutrino ◽  
Model Independent ◽  
Neutrino Experiments ◽  
Individual Dimension

Abstract The Standard Model Effective Field Theory (SMEFT) provides a systematic and model-independent framework to study neutrino non-standard interactions (NSIs). We study the constraining power of the on-going neutrino oscillation experiments T2K, NOνA, Daya Bay, Double Chooz and RENO in the SMEFT framework. A full consideration of matching is provided between different effective field theories and the renormalization group running at different scales, filling the gap between the low-energy neutrino oscillation experiments and SMEFT at the UV scale. We first illustrate our method with a top- down approach in a simplified scalar leptoquark model, showing more stringent constraints from the neutrino oscillation experiments compared to collider studies. We then provide a bottom-up study on individual dimension-6 SMEFT operators and find NSIs in neutrino experiments already sensitive to new physics at ∼20 TeV when the Wilson coefficients are fixed at unity. We also investigate the correlation among multiple operators at the UV scale and find it could change the constraints on SMEFT operators by several orders of magnitude compared with when only one operator is considered. Furthermore, we find that accelerator and reactor neutrino experiments are sensitive to different SMEFT operators, which highlights the complementarity of the two experiment types.

scholarly journals Progress in Measurements of 0.1–10 GeV Neutrino–Nucleus Scattering and Anticipated Results from Future Experiments

2018 ◽  
Vol 68 (1) ◽  
pp. 105-129 ◽  
Author(s):  
Kendall Mahn ◽  
Chris Marshall ◽  
Callum Wilkinson
Keyword(s):  
Cross Section ◽  
Neutrino Oscillation ◽  
Neutrino Interactions ◽  
Current State ◽  
Nucleus Scattering ◽  
The Subject ◽  
The Cross ◽  
Exotic Physics ◽  
Nuclear Targets

Neutrino interactions with nuclei have been the subject of intense interest during the last 15 years. Current and future measurements of neutrino oscillation and exotic physics use order 0.1–10 GeV neutrinos on a range of nuclear targets (12C,16O,40Ar). As the precision of these experiments has increased, information from their detectors and dedicated experiments has indicated deficiencies in the modeling of neutrino interactions on nuclear targets. Here, we present the current state of knowledge about neutrino–nucleus interactions, the challenge of extracting the cross section of these processes, and current experimental puzzles in the field. We also look forward to new and novel measurements and future efforts that seek to resolve these questions.

scholarly journals THE EXOTIC BARIUM BISMUTHATES

1996 ◽  
Vol 10 (08) ◽  
pp. 863-955 ◽  
Author(s):  
A. TARAPHDER ◽  
RAHUL PANDIT ◽  
H. R. KRISHNAMURTHY ◽  
T. V. RAMAKRISHNAN
Keyword(s):  
Bound States ◽  
Random Phase ◽  
Density Wave ◽  
Mean Field ◽  
Experimental Tests ◽  
Theoretical Work ◽  
Recent Theoretical Work ◽  
Effects Of Disorder ◽  
Exotic Physics ◽  
Transport Gaps

We review the remarkable properties, including superconductivity, charge-density-wave ordering and metal–insulator transitions, of lead- and potassium-doped barium bismuthate. We will discuss some of the early theoretical studies of these systems. Our recent theoretical work, on the negative-U, extended-Hubbard model for these systems, will also be described. Both the large- and intermediate-U regimes of this model were examined, using mean-field and random-phase approximations, particularly with a view to fitting various experimental properties of these bismuthates. On the basis of our studies, we point out possibilities for exotic physics in these systems. We also emphasize the different consequences of electronic and phonon-mediated mechanisms for the negative U. We show that, for an electronic mechanism, the semiconducting phases of these bismuthates must be unique, with their transport properties dominated by charge±2eCooperon bound states. This can explain the observed difference between the optical and transport gaps. We propose other experimental tests for this novel mechanism of charge transport and comment on the effects of disorder.

Scalar-leptoquark production at hadron colliders

1988 ◽  
Vol 37 (11) ◽  
pp. 3165-3171 ◽  
Author(s):  
J. L. Hewett ◽  
S. Pakvasa
Keyword(s):  
Hadron Colliders ◽  
Scalar Leptoquark

PROSPECTS FOR A GLOBAL NETWORK OF OPTICAL MAGNETOMETERS FOR EXOTIC PHYSICS (GNOME)

2014 ◽  
pp. 115-118
Author(s):  
D.F. JACKSON KIMBALL ◽  
S. PUSTELNY ◽  
M. POSPELOV ◽  
M.P. LEDBETTER ◽  
N. LEEFER ◽  
...  
Keyword(s):  
Global Network ◽  
Exotic Physics

scholarly journals On the contamination of the global 21 cm signal from polarized foregrounds

2019 ◽  
Author(s):  
Marta Spinelli ◽  
Gianni Bernardi ◽  
Mario G Santos
Keyword(s):  
Frequency Band ◽  
Low Frequency ◽  
Complex Frequency ◽  
Gaussian Profile ◽  
Reconstructed Signal ◽  
Linearly Polarized ◽  
Exotic Physics ◽  
Single Polarization ◽  
The Impact ◽  
The Universe

Abstract Global (i.e. sky-averaged) 21 cm signal experiments can measure the evolution of the universe from the Cosmic Dawn to the Epoch of Reionization. These measurements are challenged by the presence of bright foreground emission that can be separated from the cosmological signal if its spectrum is smooth. This assumption fails in the case of single polarization antennas as they measure linearly polarized foreground emission - which is inevitably Faraday rotated through the interstellar medium. We investigate the impact of Galactic polarized foregrounds on the extraction of the global 21 cm signal through realistic sky and dipole simulations both in a low frequency band from 50 to 100 MHz, where a 21 cm absorption profile is expected, and in a higher frequency band (100 − 200 MHz). We find that the presence of a polarized contaminant with complex frequency structure can bias the amplitude and the shape of the reconstructed signal parameters in both bands. We investigate if polarized foregrounds can explain the unexpected 21 cm Cosmic Dawn signal recently reported by the EDGES collaboration. We find that unaccounted polarized foreground contamination can produce an enhanced and distorted 21 cm absorption trough similar to the anomalous profile reported by Bowman et al. (2018), and whose amplitude is in mild tension with the assumed input Gaussian profile (at ∼1.5σ level). Moreover, we note that, under the hypothesis of contamination from polarized foreground, the amplitude of the reconstructed EDGES signal can be overestimated by around 30%, mitigating the requirement for an explanation based on exotic physics.

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