相关论文: Signs, Spin, SMEFT: Sum Rules at Dimension Six
We demonstrate that fermion masses in the Standard Model (SM) can be constrained by the dispersion relations obeyed by hadronic and semileptonic decay widths of a fictitious heavy quark $Q$ with an arbitrary mass. These relations, imposing…
We show how sum rules for the weak decays of heavy flavor hadrons can be derived as the moments of spectral distributions in the small velocity (SV) limit. This systematic approach allows us to determine corrections to these sum rules, to…
The smallness and hierarchy of the fermion parameters could be explained in theories with extra dimensions where doublets and singlets are localized at slightly separated points. Scattering cross sections for collisions of such fermions…
We present the Standard Model Effective Field Theories (SMEFT) from purely on-shell arguments. Starting from a few basic assumptions such as Poincar\'e invariance and locality, we classify all the renormalisable and non-renormalisable…
We present the full analysis of the normal state of the spin-fermion model near the antiferromagnetic instability in two dimensions. This model describes low-energy fermions interacting with their own collective spin fluctuations, which…
The Standard Model Effective Field Theory (SMEFT) and the Low Energy Effective Field Theory (LEFT) can be extended by adding additional spin 0, 1/2 and 1 dark matter particles which are singlets under the Standard Model (SM) gauge group. We…
We analyze the constraints obtainable from present data using the Standard Model Effective Field Theory (SMEFT) on extensions of the Standard Model with additional electroweak singlet or triplet scalar fields. We compare results obtained…
The spin response functions measured in multi-component fermion gases by means of rf transitions between hyperfine states are strongly constrained by the symmetry of the interatomic interactions. Such constraints are reflected in the spin…
Recently the CDF collaboration at the Tevatron reported a significant discrepancy between the direct measurement of the $W$-boson mass and its Standard Model (SM) prediction based on electroweak precision tests (EWPTs). In this paper we…
Recently the RBC-UKQCD lattice collaboration presented new results for the hadronic matrix elements relevant for the ratio $\varepsilon'/\varepsilon$ in the Standard Model (SM). With the present knowledge of the Wilson coefficients and…
In this work, we investigate three typical new physics resonances which couple to the standard model (SM) quarks via direct top-quark flavor-changing interactions. We identify the possible SMEFT operators electroweak scale and analyze their…
I discuss recent progress on fits to dimension-six operators in the Standard Model Effective Theory (SMEFT). I focus on the top quark sector of the SMEFT, as well as the theoretical advances made in computing SMEFT effects through to…
New physics effects in $B$ decays are routinely modeled through operators invariant under the strong and electromagnetic gauge symmetries. Assuming the scale for new physics is well above the electro-weak scale, we further require…
New sources of charge-parity (CP) violation beyond those described in the Standard Model (SM) are required to explain the observed matter--antimatter asymmetry of the Universe. The Standard Model Effective Field Theory (SMEFT) provides a…
Current experimental information on the charm meson decay observables in which the $c\to s\ell\nu_\ell$ transitions occur is well compatible with the Standard Model predictions. Recent precise lattice calculations of the $D_s$ meson decay…
The Standard Model Effective Field Theory (SMEFT) provides a consistent framework for comparing precision measurements at the LHC to the Standard Model. The observation of statistically significant non-zero SMEFT coefficients would…
The ongoing Effective Field Theory (EFT) program at the LHC and elsewhere is motivated by streamlining the connection between experimental data and UV-complete scenarios of heavy new physics beyond the Standard Model (BSM). This connection…
Preliminary results of measurements of fermion-pair production at LEP2 are used to derive limits on new physics phenomena. Combinations of the cross sections and asymmetrie of the 4 LEP collaborations are interpreted in terms four-fermion…
We examine the contributions to rare processes that arise in models where the Standard Model fermions are localized at distinct points in compact extra dimensions. Tree-level flavor changing neutral current interactions for the Kaluza-Klein…
It is not only conceivable but likely that the spectrum of physics beyond the Standard Model (SM) is non-degenerate. The lightest non-SM particle may reside close enough to the electroweak scale that it can be kinematically probed at…