scholarly journals Searching for Z′ bosons at the P2 experiment

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
P. S. Bhupal Dev ◽  
Werner Rodejohann ◽  
Xun-Jie Xu ◽  
Yongchao Zhang
Keyword(s):  
Parity Violation ◽  
Z Bosons ◽  
Gauge Coupling ◽  
New Physics ◽  
Polarized Electrons ◽  
Mixing Angles ◽  
Charge Assignment ◽  
Wide Range ◽  
Discovery Potential ◽  
Left And Right

Abstract The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-12C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to new physics mediated by an additional neutral gauge boson Z′ of a new U(1)′ gauge symmetry. If the charge assignment of the U(1)′ is chiral, i.e., left- and right-handed fermions have different charges under U(1)′, additional parity-violation is induced directly. On the other hand, if the U(1)′ has a non-chiral charge assignment, additional parity-violation can be induced via mass or kinetic Z-Z′ mixing. By comparing the P2 sensitivity to existing constraints, we show that in both cases P2 has discovery potential over a wide range of Z′ mass. In particular, for chiral models, the P2 experiment can probe gauge couplings at the order of 10−5 when the Z′ boson is light, and heavy Z′ bosons up to 79 (90) TeV in the proton (12C) mode. For non-chiral models with mass mixing, the P2 experiment is sensitive to mass mixing angles smaller than roughly 10−4, depending on model details and gauge coupling magnitude.

scholarly journals A search for charged lepton flavor violation in the Mu2e experiment

2020 ◽  
Vol 35 (19) ◽  
pp. 2030007
Author(s):  
Manolis Kargiantoulakis
Keyword(s):  
Charged Lepton ◽  
New Physics ◽  
Muon Beam ◽  
Integrated System ◽  
Beyond The Standard Model ◽  
Lepton Flavor Violation ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Wide Range ◽  
Discovery Potential

The Mu2e experiment will search for the neutrino-less conversion of a muon into an electron in the field of an aluminum nucleus. An observation would be the first signal of charged lepton flavor violation and de facto evidence for new physics beyond the Standard Model. The clean signature of the conversion process offers an opportunity for a powerful search: Mu2e will probe four orders of magnitude beyond current limits, with real discovery potential over a wide range of well-motivated new physics models. This goal requires an integrated system of solenoids that will create the most intense muon beam in the world, and suppression of all possible background sources. The Mu2e components are currently being constructed, with the experiment planned to begin operations in the Fermilab Muon Campus within the next few years.

LOOKING FOR Z′ BOSONS IN SUPERSYMMETRIC E6 Models THROUGH ELECTROWEAK PRECISION DATA

2000 ◽  
Vol 15 (05) ◽  
pp. 311-331 ◽  
Author(s):  
GI-CHOL CHO
Keyword(s):  
Parity Violation ◽  
Neutral Current ◽  
Z Bosons ◽  
Gauge Coupling ◽  
Precision Data ◽  
Mixing Angle ◽  
Mixing Parameter ◽  
Data Points ◽  
Electroweak Precision ◽  
Electroweak Precision Data

We review constraints on additional Z′ bosons predicted in supersymmetric (SUSY) E6 models from electroweak experiments — Z-pole experiments, mW measurements and the low-energy neutral current (LENC) experiments. Four representative models — χ, ψ, η and ν — are studied in some detail. We find that the improved data of parity violation in cesium atom, which is 2.2-σ away from the standard model (SM) prediction, could be explained by the exchange of the heavy mass eigenstate Z2 in the intermediate state. The improvement over the SM can be found in χ, η, ν models, where the total χ2 of the fit to the 26 data points decreases by about five units, owing to the better fit to the atomic parity violation. Impacts of the kinetic mixing between the U (1)Y and U (1)′ gauge bosons on the χ2-analysis are studied. We find that the Z′ model with (βE,δ)=(-π/4,0.2), where βE is the mixing angle between Zχ and Zψ bosons and δ denotes the kinetic mixing, shows the most excellent fit to the data: The total χ2 decreases by about seven units as compared to the SM. We introduce the effective mixing parameter ζ, a combination of the mass and the kinetic mixing parameters. The 95% CL lower mass bound of Z2 can be shown as a function of ζ. A theoretical prediction on ζ and the U (1)′ gauge coupling gE is studied for the χ, ψ, η and ν models by assuming the minimal particle content of the SUSY E6 models.

scholarly journals Probing Anomalous Quartic Interactions at the LHC with proton tagging

2018 ◽  
Vol 172 ◽  
pp. 06002
Author(s):  
Cristian Baldenegro
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Gauge Coupling ◽  
New Physics ◽  
Interaction Point ◽  
The Standard Model ◽  
Discovery Potential

One of the main goals of the Large Hadron Collider is to find signatures of physics Beyond the Standard Model of particle physics. One way to do this is by studying with high precision the interactions of the Standard Model. In this talk, we address the discovery potential of New Physics in the exclusive channel pp → p X p which relies on the general purpose detectors at the Large Hadron Collider and their respective forward proton detector stations, located at about ~ 210 m w.r.t. the interaction point. These reactions are highly sensitive to quartic electroweak gauge interactions. As a proof of concept, we discuss the exclusive diphoton production at high diphoton invariant mass. We quote sensitivities on the anomalous γγγγ coupling for an integrated luminosity of 300 fb1 at the center-of-mass energy of 14 TeV.We also discuss the discovery potential of 3γZ anomalous quartic gauge coupling by measuring the pp → p(γγ → Zγ)p reaction.

LOW ENERGY TESTS OF THE STANDARD MODEL: THE 12 GeV PARITY VIOLATION PROGRAM AT JEFFERSON LABORATORY

2010 ◽  
Vol 19 (05n06) ◽  
pp. 927-937 ◽  
Author(s):  
KRISHNA S. KUMAR
Keyword(s):  
Parity Violation ◽  
New Physics ◽  
Low Energy ◽  
Current Status ◽  
Experimental Program ◽  
Target Species ◽  
Polarized Electrons ◽  
The Standard Model ◽  
Theoretical Predictions ◽  
Sufficient Precision

We discuss the current status and prospects of an experimental program of parity-violating asymmetry measurements in the scattering of longitudinally polarized electrons off unpolarized fixed targets. In particular, we focus on those measurements where judicious choices of target species and kinematics allows the theoretical predictions to be made purely in terms of fundamental electroweak couplings with little theoretical uncertainty. If such asymmetries are measured with sufficient precision, they are sensitive to new physics at the TeV scale. After reviewing recent results, two new experimental initiatives called MOLLER and SoLID being designed for the Jefferson Laboratory 12 GeV upgrade are discussed.

scholarly journals Syllabification of the Divine Comedy

2021 ◽  
Vol 14 (3) ◽  
pp. 1-26
Author(s):  
Andrea Asperti ◽  
Stefano Dal Bianco
Keyword(s):  
Text Processing ◽  
Solution Space ◽  
Generative Models ◽  
Divine Comedy ◽  
Point Of View ◽  
Computer Assisted ◽  
Wide Range ◽  
The Divine Comedy ◽  
Left And Right ◽  
Assisted Analysis

We provide a syllabification algorithm for the Divine Comedy using techniques from probabilistic and constraint programming. We particularly focus on the synalephe , addressed in terms of the "propensity" of a word to take part in a synalephe with adjacent words. We jointly provide an online vocabulary containing, for each word, information about its syllabification, the location of the tonic accent, and the aforementioned synalephe propensity, on the left and right sides. The algorithm is intrinsically nondeterministic, producing different possible syllabifications for each verse, with different likelihoods; metric constraints relative to accents on the 10th, 4th, and 6th syllables are used to further reduce the solution space. The most likely syllabification is hence returned as output. We believe that this work could be a major milestone for a lot of different investigations. From the point of view of digital humanities it opens new perspectives on computer-assisted analysis of digital sources, comprising automated detection of anomalous and problematic cases, metric clustering of verses and their categorization, or more foundational investigations addressing, e.g., the phonetic roles of consonants and vowels. From the point of view of text processing and deep learning, information about syllabification and the location of accents opens a wide range of exciting perspectives, from the possibility of automatic learning syllabification of words and verses to the improvement of generative models, aware of metric issues, and more respectful of the expected musicality.

scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.

scholarly journals Highly boosted Higgs bosons and unitarity in vector-boson fusion at future hadron colliders

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Wolfgang Kilian ◽  
Sichun Sun ◽  
Qi-Shu Yan ◽  
Xiaoran Zhao ◽  
Zhijie Zhao
Keyword(s):  
Pair Production ◽  
Vector Boson ◽  
New Physics ◽  
Higgs Bosons ◽  
Vector Boson Fusion ◽  
Final State ◽  
Proton Proton ◽  
Effective Lagrangian ◽  
Discovery Potential ◽  
New Interactions

Abstract We study the observability of new interactions which modify Higgs-pair production via vector-boson fusion processes at the LHC and at future proton-proton colliders. In an effective-Lagrangian approach, we explore in particular the effect of the operator $$ {h}^2{W}_{\mu \nu}^a{W}^{a,\mu \nu} $$ h 2 W μν a W a , μν , which describes the interaction of the Higgs boson with transverse vector-boson polarization modes. By tagging highly boosted Higgs bosons in the final state, we determine projected bounds for the coefficient of this operator at the LHC and at a future 27 TeV or 100 TeV collider. Taking into account unitarity constraints, we estimate the new-physics discovery potential of Higgs pair production in this channel.

scholarly journals FROM HADRONIC PARITY VIOLATION TO PARITY-VIOLATING ELECTRON SCATTERING AND TESTS OF THE STANDARD MODEL

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1266-1277 ◽  
Author(s):  
WILLEM T. H. VAN OERS
Keyword(s):  
Standard Model ◽  
Electron Scattering ◽  
Parity Violation ◽  
New Physics ◽  
Theoretical Interpretation ◽  
Weak Mixing Angle ◽  
Weak Mixing ◽  
Mixing Angle ◽  
The Standard Model ◽  
Analyzing Power

Searches for parity violation in hadronic systems started soon after the evidence for parity violation in β-decay of 60 Co was presented by Madame Chien-Shiung Wu and in π and μ decay by Leon Lederman in 1957. The early searches for parity violation in hadronic systems did not reach the sensitivity required and only after technological advances in later years was parity violation unambiguously established. Within the meson-exchange description of the strong interaction, theory and experiment meet in a set of seven weak meson-nucleon coupling constants. Even today, after almost five decades, the determination of the seven weak meson-nucleon couplings is incomplete. Parity violation in nuclear systems is rather complex due to the intricacies of QCD. More straight forward in terms of interpretation are measurements of the proton-proton parity-violating analyzing power (normalized differences in scattering yields for positive and negative helicity incident beams), for which there exist three precision experiments (at 13.6, at 45, and 221 MeV). To-date, there are better possibilities for theoretical interpretation using effective field theory approaches. The situation with regard to the measurement of the parity-violating analyzing power or asymmetry in polarized electron scattering is quite different. Although the original measurements were intended to determine the electro-weak mixing angle, with the current knowledge of the electro-weak interaction and the great precision with which electro-weak radiative corrections can be calculated, the emphasis has been to study the structure of the nucleon, and in particular the strangeness content of the nucleon. A whole series of experiments (the SAMPLE experiment at MIT-Bates, the G0 experiment and HAPPEX experiments at Jefferson Laboratory (JLab), and the PVA4 experiment at MAMI) have indicated that the strange quark contributions to the charge and magnetization distributions of the nucleon are tiny. These measurements if extrapolated to zero degrees and zero momentum transfer have also provided a factor five improvement in the knowledge of the neutral weak couplings to the quarks. Choosing appropriate kinematics in parity-violating electron-proton scattering permits nucleon structure effects on the measured analyzing power to be precisely controlled. Consequently, a precise measurement of the ‘running’ of sin 2θw or the electro-weak mixing angle has become within reach. The [Formula: see text] experiment at Jefferson Laboratory is to measure this quantity to a precision of about 4%. This will either establish conformity with the Standard Model of quarks and leptons or point to New Physics as the Standard Model must be encompassed in a more general theory required, for instance, by a convergence of the three couplings (strong, electromagnetic, and weak) to a common value at the GUT scale. The upgrade of CEBAF at Jefferson Laboratory to 12 GeV, will allow a new measurement of sin 2θW in parity-violating electron-electron scattering with an improved precision to the current better measurement (the SLAC E158 experiment) of the ‘running’ of sin 2θW away from the Z0 pole. Preliminary design studies of such an experiment show that a precision comparable to the most precise individual measurements at the Z0 pole (to about ±0.00025) can be reached. The result of this experiment will be rather complementary to the [Formula: see text] experiment in terms of sensitivity to New Physics.

scholarly journals Searching for muon to electron conversion: The Mu2e experiment at Fermilab

2019 ◽  
Author(s):  
Richard Bonventre
Keyword(s):  
Charged Lepton ◽  
Conversion Rate ◽  
New Physics ◽  
Previous Measurement ◽  
Negative Muon ◽  
Lepton Flavor ◽  
Wide Range ◽  
Electron Conversion ◽  
Design And Construction

The Mu2e experiment will measure the charged-lepton flavor violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of a nucleus. Mu2e will improve the previous measurement by four orders of magnitude, reaching a 90% C.L. limit of 8\times10^{-17}8×10−17 on the conversion rate. The experiment will reach mass scales of nearly 10^4104 TeV, far beyond the direct reach of colliders. The experiment is sensitive to a wide range of new physics, complementing and extending other CLFV searches. Mu2e is under design and construction at the Muon Campus of Fermilab; we expect to start taking physics data in 2022 with 3 years of running to achieve our target sensitivity.

scholarly journals Effects of transverse relationships between maxillary arch, mouth, and face on smile esthetics

2015 ◽  
Vol 86 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Ke Zhang ◽  
Lan Huang ◽  
Lin Yang ◽  
Li Xu ◽  
Chaoran Xue ◽  
...  
Keyword(s):  
Young Female ◽  
Male And Female ◽  
Facial Region ◽  
Face Width ◽  
Wide Range ◽  
Left And Right ◽  
Smile Esthetics ◽  
Maxillary Arch ◽  
The Ideal

ABSTRACTObjective: To identify the ideal ratios between the widths of the maxillary arch, mouth, and face, respectively, and to determine the range of acceptable esthetic variations based on these ideal ratios.Materials and Methods: A photograph of a young female with a harmonious smile was selected and digitally altered to produce two sets of images. The first image showed an altered intercanine width, while the second one showed an altered oral fissure breadth. These alterations were independently rated by judges, including 23 orthodontists and 30 undergraduates. The Mann-Whitney U-test was used to compare the scores given by male and female judges and those given by professional and nonprofessional judges.Results: The following ideal transverse ratios were determined: intercanine width/oral fissure breadth, 0.638; oral fissure breadth/interparopia width: the distance between left and right paropia, 0.617; and intercanine width/face width at the level of the labial commissures, 0.300. A range of −10% to +10% was proposed as the thresholds of esthetic smile evaluations. It was shown that gender of the raters had no effect on the rating of photographs, nor were there any statistically significant differences between the professional and nonprofessional judges’ ratings.Conclusions: Balanced transverse relationships in the facial region are important for smile esthetics, and there is a wide range of esthetically acceptable variations in the transverse relationships between the maxillary arch, mouth, and face.

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