Top Quark Research Papers - Academia.edu (original) (raw)

2025, Physical Review D

We present a measurement of the mass dependence of the forward-backward charge asymmetry (AF B) for e + e -pairs produced via an intermediate Z/γ * with mass Mee > 40 GeV/c 2 . We study the constraints on the Z-quark couplings imposed by our measurement. We analyze an integrated luminosity of 72 pb -1 collected by the CDF II detector in pp collisions at √ s = 1.96 TeV at the Fermilab Tevatron. A comparison of the uncorrected AF B between data and Standard Model Monte Carlo gives good agreement with a χ 2 /DOF of 15.7/15. The couplings measurements are also consistent with Standard Model predictions.

2025, Higgs in Standard Models

The Standard Model of particle physics is our most successful theoretical framework, meticulously describing fundamental interactions like the electromagnetic, strong, and weak forces, as well as the building blocks of the universe. Within this model, the universe is assumed to be permeated by various quantum fields, and elementary particles are understood as quantized excitations or "ripples" in these fields. A profound and persistent challenge encountered in the early development of the Standard Model was explaining the observed masses of elementary particles. While some force carriers, like the photon (carrier of the electromagnetic force), were known to be massless, experimental measurements clearly showed that the W and Z bosons, the other fundamental force carriers of the weak interaction, possessed significant masses. Furthermore, all matter particles (fermions, including quarks and leptons) also exhibit mass; a property not naturally accounted for by the initial elegant formulations of gauge theories. After decades of intense theoretical development and challenging experimental research, a particle consistent with the properties of the Higgs boson was finally discovered in 2012 by the ATLAS and CMS collaborations at the Large Hadron Collider (LHC) at CERN. This monumental discovery represented a significant achievement, confirming a fundamental theory of mass generation in particle physics and completing the theoretical framework of the Standard Model. The Higgs boson itself is understood as the quantum excitation or the smallest ripple of the pervasive Higgs field, a fundamental field hypothesized to fill all space. The primary purpose of this report is to address the user's question regarding the theoretical proposal of the Higgs mechanism in 1964: "How did they come to the conclusion that the Higgs field would give mass to the universe (in 1964)?" This question aims to understand the intellectual and theoretical reasoning that led physicists at that time to conclude that this mechanism could impart mass to particles, rather than the later experimental discovery of the Higgs boson. The user's healthy skepticism, "What if mass is given by a completely different mechanism?", will also be directly addressed. This report will meticulously trace the theoretical problem that necessitated such a mechanism and elaborate on the elegant solution it offered. Understanding how this conclusion was reached in 1964 requires delving into the historical context and intellectual challenges of that era. The research materials consistently highlight that early particle physics theories, particularly gauge theories, predicted massless force carriers , yet experimental observations clearly showed that the W and Z bosons were massive. This was not a minor detail, but a "vexing problem" that threatened the consistency of the Standard Model. The Higgs mechanism thus emerged not as an arbitrary theoretical addition, but as a direct, targeted response to this glaring inconsistency. This exemplifies the functioning of the scientific method: empirical observation contradicting theoretical prediction, thereby

2025, arXiv (Cornell University)

We present a new approach for obtaining very precise integration results for infrared vertex and box diagrams, where the integration is carried out directly without performing any analytic integration of Feynman parameters. Using an appropriate numerical integration routine with an extrapolation method, together with a multi-precision library, we have obtained integration results which agree with the analytic results to 10 digits even for such a very small photon mass as 10 -150 GeV in the infrared vertex diagram.

2025, arXiv (Cornell University)

Leprosy (Hansen's disease) is an infectious, neglected tropical disease caused by the Mycobacterium Leprae (M. Leprae). Each year there are approximately 2, 02, 189 new cases are detected globally. In the year 2017 more than half million people were disabled due to leprosy and almost 50000 new cases are added every year world wide. In leprosy, lepra reactions are the major cause for nerve damage leading to disability. Early detection of lepra reactions through study of biomarkers have important role in prevention of subsequent disabilities. To our knowledge there seems to be very limited literature available on within-host modeling at cellular level involving the crucial biomarkers and the possible optimal drug regimen for leprosy disease and lepra reactions. Motivated by these observations, in this study, we have proposed and analyzed a three dimensional mathematical model to capture the dynamics of susceptible schwann cells, infected schwann cells and the bacterial load based on the pathogenesis of leprosy. We initially have established the existence of solution and later validated the model through the disease characteristics of leprosy. Further we dealt with the local and global stability of different equilibria about the reproduction number value R0 = 1. Later for numerical studies we estimated the parameters from various clinical papers to make the model more practical. The sensitivity of couple of parameters was evaluated through Partial Rank Correlation Coefficient (PRCC) method to find out the single most influential parameter and also combination of two most influential parameters was studied using Spearman's Rank Correlation Coefficient (SRCC) method. The sensitivity of other remaining parameters was evaluated using Sobol's index. We then have framed and studied an optimal control problem considering the different medication involved in the Multi Drug Therapy (MDT) as control variables. We further studied this optimal control problem along with both MDT and steroid interventions. Finally we did the comparative and effectiveness study of these different control interventions. The finding from this novel and comprehensive study will help the clinicians and public health researchers involved in the process of elimination and eradication of leprosy.

2025, Physics Letters B

We study possible anomalous top-quark couplings generated by SU(2) × U(1) gauge-invariant dimension-6 effective operators, using the final b-quark momentum distribution in γγ → t t → bX. Taking into account non-standard t tγ, tbW and γγH couplings, we perform an optimal-observable analysis in order to estimate the precision for the determination of all relevant non-standard couplings.

2025, Proceedings of The European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2017)

2025, Zeitschrift Fur Physik C-Particles and Fields

This paper presents an update of the measurement of the mean lifetime of the B 0 s meson. Combining D s `, D s h, `and inclusive D s nal states from the 3.2 million hadronic Z decays collected by DELPHI between 1991 and 1994, the B 0 s... more

2025

The Fractal-Hue Quantum Field Theory (FHQFT) introduces a recursive, multi-scale framework for modeling quantum fields as fractal-holographic entities embedded in hue-stratified manifolds. Unlike conventional field theories constrained by... more

2025, Journal of High Energy Physics

A search for resonant production of high-mass top-quark pairs is performed on 2.05 fb−1 of proton-proton collisions at $ \sqrt {s} = 7 $ TeV collected in 2011 with the ATLAS experiment at the Large Hadron Collider. This analysis of the lepton+jets final state is specifically designed for the particular topology that arises from the decay of highly boosted top quarks. The observed $ t\overline t $ invariant mass spectrum is found to be compatible with the Standard Model prediction and 95% credibility level upper limits are derived on the $ t\overline t $ production rate through new massive states. An upper limit of 0.7 pb is set on the production cross section times branching fraction of a narrow 1 TeV resonance. A Kaluza-Klein gluon with a mass smaller than 1.5 TeV is excluded.

2025, Physical Review D

We further develop the massive constructive theory of the Standard Model and use it to calculate the amplitude and squared amplitude for all 2-body decays, a collection of weak 3-body decays as well as Higgs decay to four neutrinos. We compare our results with those from Feynman diagrams and find complete agreement. We show that in all the cases considered here, the amplitudes of massive constructive theories are significantly simpler than those resulting from Feynman diagrams. In fact, a naive counting of the number of calculations required for a matrix-element generator to compute a phase-space point is orders-of-magnitude smaller for the result coming from the constructive method suggesting that these generators might benefit from this method in the future even in the case of massive weak amplitudes. We also anticipate that our simpler expressions will produce numerically more stable expressions.

2025, OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information)

2025, Nuclear Physics B

We present a new and more concise method for computing and organizing electroweak radiative corrections, based on an effective Lagrangian and incorporating a large class of diagrams into a few simple running couplings without use of truncated renormalization group approximations. We apply this technique to the case of four-fermion processes. Special emphasis is placed on the effects of heavy particles on low-energy physics and how such phenomena can be classified and measured in the new generation of precision electroweak experiments -in particular, experiments with polarized e-beams at the SLC and LEP. .

2025

A summary of several recent studies of electroweak e+e-physics is provided. The significance of upcoming SLC/LEP measurements of 2 and W properties is discussed, with special emphasis placed on radiative corrections and polarization. New electroweak physics at a proposed TeV e+e-collider is presented as a natural outgrowth of the SLC/LEP programs. Precise tests of the trilinear gauge boson vertex through W pair production, searching for the disturbance of perturbative unitarity by radiative corrections, and of the gauge structure of a Z', through polarized e-beams, are presented.

2025, arXiv (Cornell University)

The electroweak Standard Model is summarized at the classical and quantum levels, including its gauge symmetry and symmetry-breaking aspects. The full implications of precise measurements of electroweak gauge forces are presented in terms of electroweak parameters and quantum corrections. The minimal Standard Model (SM) (including the top quark) satisfies the data well, up to oneloop accuracy. Possible non-Standard states subject to electroweak forces in quantum corrections is highly restricted by the present data. The status of exact and approximate symmetries of the electroweak Standard Model is summarized.

2025

We simulate the effective cross-sectional area of an electron using a Monte Carlo particle scattering model implemented in MATLAB. By throwing 10 5 virtual particles at a target representing the classical electron, with an assumed radius re = 2.8 × 10-15 m, we compute the proportion of particles that scatter versus those that miss. This hit-to-miss ratio provides an estimate of the effective area and, consequently, the inferred radius of the electron. The simulation presents a computational yet visually intuitive method to reinforce key concepts in classical particle physics. Such a model is especially valuable in pedagogical settings, where bridging theoretical quantities with interactive computational experiments can enhance conceptual clarity. Our results support the known classical radius and demonstrate the accessibility of physics simulations using standard programming tools.

2025, Journal of High Energy Physics

This paper reports the results of a search for strong production of supersymmetric particles in 20.1 fb -1 of proton-proton collisions at a centre-of-mass energy of 8 TeV using the ATLAS detector at the LHC. The search is performed separately in events with either zero or at least one high-p T lepton (electron or muon), large missing transverse momentum, high jet multiplicity and at least three jets identified as originated from the fragmentation of a b-quark. No excess is observed with respect to the Standard Model predictions. The results are interpreted in the context of several supersymmetric models involving gluinos and scalar top and bottom quarks, as well as a mSUGRA/CMSSM model. Gluino masses up to 1340 GeV are excluded, depending on the model, significantly extending the previous ATLAS limits.

2025, Journal of Instrumentation

During autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons.

2025, Journal of Physics G: Nuclear and Particle Physics

2025, Physical Review Letters

We have measured the W -boson mass MW using data corresponding to 2.2 fb -1 of integrated luminosity collected in pp collisions at √ s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470 126 W → eν candidates and 624 708 W → µν candidates yield the measurement MW = 80 387 ± 12stat ± 15syst = 80 387 ± 19 MeV/c 2 . This is the most precise measurement of the W -boson mass to date and significantly exceeds the precision of all previous measurements combined.

2025, Physical Review D

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 -5.4 fb -1 of pp collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 ± 0.081 [± 0.062 (stat.) ± 0.052 (syst.)] and f+ = -0.033 ± 0.046 [± 0.034 (stat.) ± 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682±0.057 [± 0.035 (stat.)±0.046 (syst.)] and f+ = -0.015±0.035 [± 0.018 (stat.)±0.030 (syst.)]. The results are consistent with standard model expectations.

2025, Physics Letters B

We present a search for the pair production of scalar top quarks ( t1), the lightest supersymmetric partners of the top quarks, in pp collisions at a center-of-mass energy of 1.96 TeV, using data corresponding to an integrated luminosity of 7.3 fb -1 collected with the D0 experiment at the Fermilab Tevatron Collider. Each scalar top quark is assumed to decay into a b quark, a charged lepton, and a scalar neutrino (ν). We investigate final states arising from t1 t1→ b bµτ ν ν and t1 t1→ b bτ τ ν ν. With no significant excess of events observed above the background expected from the standard model, we set exclusion limits on this production process in the (mt 1 ,mν ) plane.

2025, Physical Review Letters

We present a measurement of the ratio of top quark branching fractions R = B(t → W b)/B(t → W q), where q can be a d, s or b quark, in the lepton+jets and dilepton t t final states. The measurement uses data from 5.4 fb -1 of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R = 0.90 ± 0.04, and we extract the CKM matrix element |V tb | as |V tb | = 0.95 ± 0.02, assuming unitarity of the 3 × 3 CKM matrix.

2025, Physical Review Letters

We present a search for pair production of a fourth generation t quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3 fb -1 of proton-antiproton collisions at √ s = 1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the t t production cross section that exclude at the 95% C.L. a t quark that decays exclusively to W +jet with a mass below 285 GeV. We observe a small excess in the µ+jets channel which reduces the mass range excluded compared to the expected limit of 320 GeV in the absence of a signal.

2025, Physical Review D

We present a search for the standard model Higgs boson using events with two oppositely charged leptons and large missing transverse energy as expected in H → W W decays. The events are selected from data corresponding to 8.6 fb -1 of integrated luminosity in pp collisions at √ s = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. No significant excess above the standard model background expectation in the Higgs boson mass range this search is sensitive to is observed, and upper limits on the Higgs boson production cross section are derived.

2025, Physical Review D

This report describes a search for associated production of W and Higgs bosons based on data corresponding to an integrated luminosity of L ≈ 5.3 fb -1 collected with the D0 detector at the Fermilab Tevatron pp Collider. Events containing a W → ℓν candidate (with ℓ corresponding to e or µ) are selected in association with two or three reconstructed jets. One or two of the jets are required to be consistent with having evolved from a b quark. A multivariate discriminant technique is used to improve the separation of signal and backgrounds. Expected and observed upper limits are obtained for the product of the W H production cross section and branching ratios and reported in terms of ratios relative to the prediction of the standard model as a function of the mass of the Higgs boson (MH ). The observed and expected 95% C.L. upper limits obtained for an assumed MH = 115 GeV are, respectively, factors of 4.5 and 4.8 larger than the value predicted by the standard model.

2025, Physical Review D

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a W boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 collaborations have measured the top quark's mass in different final states for integrated luminosities of up to 5.8 fb -1 . This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes the treatment of the systematic uncertainties and their correlations. The mass value determined is 173.18 ± 0.56 (stat) ± 0.75 (syst) GeV or 173.18 ± 0.94 GeV, which has a precision of ±0.54%, making this the most precise determination of the top quark mass.

2025, International Journal of Modern Physics A

As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of Vtb. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits...

2025, Physical Review Letters

We have searched for heavy neutral gauge bosons ͑Z 0 ͒ in dielectron and dimuon decay modes using 110 pb 21 of pp collisions at p s 1.8 TeV collected with the Collider Detector at Fermilab. We present a limit on the production cross section times branching ratio of a Z 0 boson decaying into dileptons as a function of Z 0 mass. For mass M Z 0 . 600 GeV͞c 2 , the upper limit is 40 fb at 95% confidence level. We set the lower mass limits of 690, 590, 620, 595, 565, 630, and 600 GeV͞c 2 for Z 0 SM , Z c , Z h , Z x , Z I , Z LR , and Z ALRM , respectively. [S0031-9007(97)04021-0]

2025, Journal of High Energy Physics

Single top quark events produced in the t channel are used to set limits on anomalous Wtb couplings and to search for top quark flavour-changing neutral current (FCNC) interactions. The data taken with the CMS detector at the LHC in proton-proton collisions at √ s = 7 and 8 TeV correspond to integrated luminosities of 5.0 and 19.7 fb -1 , respectively. The analysis is performed using events with one muon and two or three jets. A Bayesian neural network technique is used to discriminate between the signal and backgrounds, which are observed to be consistent with the standard model prediction. The 95% confidence level (CL) exclusion limits on anomalous right-handed vector, and left-and righthanded tensor Wtb couplings are measured to be |f R V | < 0.16, |f L T | < 0.057, and -0.049 < f R T < 0.048, respectively. For the FCNC couplings κ tug and κ tcg , the 95% CL upper limits on coupling strengths are |κ tug |/Λ < 4.1 × 10 -3 TeV -1 and |κ tcg |/Λ < 1.8 × 10 -2 TeV -1 , where Λ is the scale for new physics, and correspond to upper limits on the branching fractions of 2.0 × 10 -5 and 4.1 × 10 -4 for the decays t → ug and t → cg, respectively.

2025, Journal of High Energy Physics

A comparison of the differential cross sections for the processes Z/γ * +jets and photon (γ)+jets is presented. The measurements are based on data collected with the CMS detector at √ s = 8 TeV corresponding to an integrated luminosity of 19.7 fb -1 . The differential cross sections and their ratios are presented as functions of p T . The measurements are also shown as functions of the jet multiplicity. Differential cross sections are obtained as functions of the ratio of the Z/γ * p T to the sum of all jet transverse momenta and of the ratio of the Z/γ * p T to the leading jet transverse momentum. The data are corrected for detector effects and are compared to simulations based on several QCD calculations.

2025, Journal of High Energy Physics

A search for neutral Higgs bosons decaying into a b b quark pair and produced in association with at least one additional b quark is presented. This signature is sensitive to the Higgs sector of the minimal supersymmetric standard model (MSSM) with large values of the parameter tan β. The analysis is based on data from proton-proton collisions at a center-of-mass energy of 8 TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.7 fb -1 . The results are combined with a previous analysis based on 7 TeV data. No signal is observed. Stringent upper limits on the cross section times branching fraction are derived for Higgs bosons with masses up to 900 GeV, and the results are interpreted within different MSSM benchmark scenarios, m max h , m mod+ h , m mod- h , light-stau and light-stop. Observed 95% confidence level upper limits on tan β, ranging from 14 to 50, are obtained in the m mod+ h benchmark scenario.

2025, Journal of High Energy Physics

A measurement of the W boson helicity is presented, where the W boson originates from the decay of a top quark produced in pp collisions. The event selection, optimized for reconstructing a single top quark in the final state, requires exactly one isolated lepton (muon or electron) and exactly two jets, one of which is likely to originate from the hadronization of a bottom quark. The analysis is performed using data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the CERN LHC in 2012. The data sample corresponds to an integrated luminosity of 19.7 fb -1 . The measured helicity fractions are F L = 0.298 ± 0.028 (stat) ± 0.032(syst), F 0 = 0.720 ± 0.039 (stat) ± 0.037(syst), and F R = -0.018 ± 0.019 (stat) ± 0.011(syst). These results are used to set limits on the real part of the tWb anomalous couplings, g L and g R .

2025, Journal of High Energy Physics

Measurements of jet production rates in association with W and Z bosons for jet transverse momenta above 30 GeV are reported, using a sample of proton-proton collision events recorded by CMS at √ s = 7 TeV, corresponding to an integrated luminosity of 36 pb -1 . The study includes the measurement of the normalized inclusive rates of jets σ(V+ ≥ n jets)/σ(V), where V represents either a W or a Z. In addition, the ratio of W to Z cross sections and the W charge asymmetry as a function of the number of associated jets are measured. A test of scaling at √ s = 7 TeV is also presented. The measurements provide a stringent test of perturbative-QCD calculations and are sensitive to the possible presence of new physics. The results are in agreement with the predictions of a simulation that uses explicit matrix element calculations for final states with jets.

2025, Physical Review D

We present a measurement of the fraction f+ of right-handed W bosons produced in top quark decays, based on a candidate sample of t t events in the ℓ+jets and dilepton decay channels corresponding to an integrated luminosity of 370 pb -1 collected by the DØ detector at the Fermilab Tevatron pp Collider at √ s = 1.96 TeV. We reconstruct the decay angle θ * for each lepton. By comparing the cos θ * distribution from the data with those for the expected background and signal for various values of f+, we find f+ = 0.056±0.080 (stat)±0.057 (syst). (f+ < 0.23 at 95% C.L.), consistent with the standard model prediction of f+ = 3.6 × 10 -4 .

2025, Nuclear Physics B

We calculate the Drell-Yan cross section, resolving the full kinematics of the lepton pair, at high transverse momentum for hadron nucleus collisions. We use the general framework of Luo, Qiu and Sterman to calculate double scattering contributions that are of twist-4 and demonstrate their nuclear enhancement. By comparing single and double scattering at RHIC energies we find that double scattering gives contributions of comparable size. We also show that the angular dependence of the Drell-Yan pair discriminates between the various double scattering contributions.

2025, European Physical Journal C

We study the prospects of searches for exotic long-lived particles with the MoEDAL detector at the LHC, assuming the integrated luminosity of 30 fb -1 that is expected at the end of Run 3. MoEDAL incorporates nuclear track detectors deployed a few metres away from the interaction point, which are sensitive to any highly-ionizing particles. Hence MoEDAL is able to detect singly-or doublycharged particles with low velocities β < 0.15 or < 0.3, respectively, and lifetimes larger than O(1) m/c. We examine the MoEDAL sensitivity to various singly-charged supersymmetric particles with long lifetimes and to several types of doubly-charged long-lived particles with different spins and SU(2) charges. We compare the prospective MoEDAL mass reaches to current limits from ATLAS and CMS, which involve auxiliary analysis assumptions. MoEDAL searches for doubly-charged fermions are particularly competitive.

2025, Journal of High Energy Physics

We investigate the phenomenological aspects of non-perturbative baryon- and lepton-number-violating processes at hadron colliders. Such processes, induced by instan- ton/sphaleron configurations of the electroweak gauge fields, are believed to play a crucial role in the generation of baryon asymmetry in the early Universe at finite temperature. On the other hand, at colliders (that represent the zero-temperature high-energy regime) the rate and observability of such processes are still under debate. Motivated by current the- oretical considerations, we construct a modern event generator within the general-purpose Herwig Monte Carlo framework, that aims to capture the most relevant features of the dominant processes. We perform a detailed phenomenological analysis focussing on the Large Hadron Collider, at 13 TeV proton-proton centre-of-mass energy, a potential high- energy upgrade at 27 TeV and the proposed Future Circular Collider (FCC-hh) at 100 TeV. We derive constraints on the e...

2025, Journal of physics

We explore the flavor-changing parameters mediated by a Higgs boson within the THDM-III context. In particular, the h → t * c processes, and check the high suppression for the FC in the THDM-III context for the low t β parameters. Our exploration in the χ u ij -χ d ij -parameter space shows the allowed regions for different t β values. We explored different modes for Higgs decays, considered the experimental constraints to get scattering plots for the FC parameters and some relevant decay modes. We expect future results to figure out the FC and its implications in the scalar sector.

2025, Physical review

A recent determination of the mass of the b quark, based exclusively on quantum chromodynamics ͑by avoiding strictly to introduce any phenomenological interaction potential of nonperturbative origin͒, may be improved by allowing for a... more

2025, Journal of High Energy Physics

We compute the real and imaginary parts of the one-loop electroweak contributions to the left and right tensorial anomalous couplings of the tbW vertex in the Standard Model (SM). For both tensorial couplings we find that the real part of the electroweak SM correction is close to 10% of the leading contribution given by the QCD gluon exchange. We also find that the electroweak real and imaginary parts for the anomalous right coupling are almost of the same order of magnitude. The one loop SM prediction for the real part of the left coupling is close to the 3σ discovery limit derived from b → sγ. Besides, taking into account that the predictions of new physics interactions are also at the level of a few percents when compared with the one loop QCD gluon exchange, these electroweak corrections should be taken into account in order to disentangle new physics effects from the standard ones. These anomalous tensorial couplings of the top quark will be investigated at the LHC in the near future where sensitivity to these contributions may be achieved.

2025, arXiv (Cornell University)

We re-examine our former predictions of the top and Higgs masses via dynamical symmetry breaking in a 4-fermion theory which produces the Higgs as a bound state, and relates the top and Higgs masses to m W . The use of dynamical symmetry breaking was stongly motivated by the apparent equality, within a factor of two, of the known and expected masses of the W , Z, top and Higgs. In later work we evaluated the masses self-consistently at the mass-poles, which resulted in predictions of m t ∼ 175 GeV, and m H ∼ 125 GeV as central values within ranges produced by varying the measured strong coupling. Figures (1) and (2) result from evolution down to m W while the number quoted for the top quark mass, i.e. 175 GeV includes an evolution back up to the top and use of the determination of α s at LEP at that time. m H is less dependent on the value of the strong coupling. The variation of the predicted masses for a range of the strong and electro-weak couplings α s , α W at m W are exhibited in Figure (3) and Figure (4) reproduced from the last work , which was submitted to PRD well before the first FNAL publications suggesting evidence for the top.