1,721,003 research outputs found
Electroweak corrections to Higgs boson decays to γγ and W+W- in standard model EFT
No full textHiggs decays to gauge boson pairs are a crucial ingredient in the study of Higgs properties, with the decay H→γγ being particularly sensitive to new physics effects. Assuming all potential new physics occurs at energies far above the weak scale, deviations from standard model predictions can be parametrized in terms of the coefficients of a standard model effective field theory (SMEFT). When experimental limits on the SMEFT coefficients reach an accuracy of a few percent, predictions must be done beyond the lowest order in the SMEFT in order to match theory and experimental accuracy. This paper completes a program of computing the one-loop electroweak SMEFT corrections to H→VV′, V=W±, Z, γ. The calculation of the real contribution to H→W+W-γ is performed by mapping two-loop amplitudes to the three-body phase space
Probing the top-quark width using the charge identification of b jets
No full textWe propose a new method for measuring the top-quark width based on the on-/off-shell ratio of b-charge asymmetry in pp→Wbj production at the LHC. The charge asymmetry removes virtually all backgrounds and related uncertainties, while remaining systematic and theoretical uncertainties can be taken under control by the ratio of cross sections. Limited only by statistical error, in an optimistic scenario, we find that our approach leads to good precision at high integrated luminosity, at a few hundred MeV assuming 300-3000 fb-1 at the LHC. The approach directly probes the total width, in such a way that model-dependence can be minimized. It is complementary to existing cross section measurements which always leave a degeneracy between the total rate and the branching ratio, and provides valuable information about the properties of the top quark. The proposal opens up new opportunities for precision top measurements using a b-charge identification algorithm
Higgs-like boson at 750 GeV and genesis of baryons HIGGS-LIKE BOSON at 750 GeV and GENESIS of ... HOOMAN DAVOUDIASL, PIER PAOLO GIARDINO, and CEN ZHANG
No full textWe propose that the diphoton excess at 750 GeV reported by ATLAS and CMS is due to the decay of an exo-Higgs scalar η associated with the breaking of a new SU(2)e symmetry, dubbed exo-spin. New fermions, exo-quarks and exo-leptons, get TeV-scale masses through Yukawa couplings with η and generate its couplings to gluons and photons at one loop. The matter content of our model yields a B-L anomaly under SU(2)e, whose breaking we assume entails a first-order phase transition. A nontrivial B-L asymmetry may therefore be generated in the early Universe, potentially providing a baryogenesis mechanism through the Standard Model (SM) sphaleron processes. The spontaneous breaking of SU(2)e can, in principle, directly lead to electroweak symmetry breaking, thereby accounting for the proximity of the mass scales of the SM Higgs and the exo-Higgs. Our model can be distinguished from those comprising a singlet scalar and vector fermions by the discovery of TeV scale exo-vector bosons, corresponding to the broken SU(2)e generators, at the LHC
Virtual corrections to gg→ZH via a transverse momentum expansion
Full text linkWe compute the next-to-leading virtual QCD corrections to the partonic cross section of the production of a Higgs boson in association with a Z boson in gluon fusion. The calculation is based on the recently introduced method of evaluating the amplitude via an expansion in terms of a small transverse momentum. We generalize the method to the case of different masses in the final state and of a process not symmetric in the forward-backward direction exchange. Our analytic approach gives a very good approximation (better than percent) of the partonic cross section in the center of mass energy region up to ∼ 750 GeV, where at the LHC ∼ 98% of the total hadronic cross section is concentrated
Gravitational waves from primordial black holes and new weak scale phenomena
No full textWe entertain the possibility that primordial black holes of mass ∼(1026–1029) g, with Schwarzschild radii of O(cm), constitute ∼10% or more of cosmic dark matter, as allowed by various constraints. These black holes would typically originate from cosmological eras corresponding to temperatures O(10–100) GeV, and may be associated with first order phase transitions in the visible or hidden sectors. In case these small primordial black holes get captured in orbits around neutron stars or astrophysical black holes in our galactic neighborhood, gravitational waves from the resulting “David and Goliath (D&G)” binaries could be detectable at Advanced LIGO or Advanced Virgo for hours or more, possibly over distances of O(10) Mpc encompassing the Local Supercluster of galaxies. The proposed Einstein Telescope would further expand the reach for these signals. A positive signal could be further corroborated by the discovery of new particles in the O(10–100) GeV mass range, and potentially also the detection of long wavelength gravitational waves originating from the first order phase transition era
Higgs Decays to and in the SMEFT: an NLO analysis
Full text linkWe calculate the complete one-loop electroweak corrections to the inclusive
and decays in the dimension-
extension of the Standard Model Effective Field Theory (SMEFT). The corrections
to are computed for on-shell bosons and are a precursor
to the physical calculation. We present
compact numerical formulas for our results and demonstrate that the logarithmic
contributions that result from the renormalization group evolution of the SMEFT
coefficients are larger than the finite NLO contributions to the decay widths.
As a by-product of our calculation, we obtain the first complete result for the
finite corrections to in the SMEFT.Comment: Published Version. The results for in the SMEFT are now
given in gauge; V3: corrected a typo in eq 38 and 39, updated eq. 41;
V4: corrected a typo in eq 39 (global minus sign
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Unlocking the sustainability of medium enterprises: A framework for reducing cognitive biases in sustainable performance management
No full textMedium Enterprises (MEs) are significant contributors to global economic development. Integrating sustainability practices in their business can support MEs worldwide to become more sustainable, improving companies’ performance and stakeholders’ expectations. Nevertheless, few MEs adopt sustainable practices. Following Behavioral Decision Theory and Behavioral Strategy literature, we argue that this can be associated with their managers’ decision-making processes – apart from not possessing considerable resources like large companies. Via a mixed-method research design involving 277 Italian ME managers, we investigate the cognitive biases that hinder the development of a sustainable performance management system (SPMS) in MEs. We found the most prominent biases influencing SPMS development. Then, we developed a ‘SPMS de-biasing funnel’ framework. We propose some corrective actions to reduce the impact of the most critical cognitive biases that influence SPMS development, allowing related beneficial potential outcomes
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