arXiv subjects

U. Egede

Publications and source records attributed to U. Egede.

At least 19 recordsLinked to original sources

arXiv2025

HFLAV input to the 2026 update of the European Strategy for Particle Physics

Heavy-flavour physics is an essential component of the particle-physics programme, offering critical tests of the Standard Model and far-reaching sensitivity to physics beyond it. Experiments such as LHCb, Belle II, and BESIII drive progress in the field, along with contributions from ATLAS and CMS. The LHCb Upgrade II and upgraded Belle II experiments will provide unique and highly sensitive measurements for decades, playing a key role in the searches for new physics. Future facilities with significant heavy-flavour capabilities will further expand these opportunities. We advocate for a European Strategy that fully supports Upgrade II of LHCb and an upgrade of Belle II, along with their subsequent exploitation. Additionally, we support a long-term plan that fully integrates flavour physics in an $e^+e^-$ collider to run as a $Z$ factory.

hep-ex↗

arXiv2024

Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2023

This paper reports world averages of measurements of $b$-hadron, $c$-hadron, and $\tau$-lepton properties obtained by the Heavy Flavour Averaging Group using results available before October 2023. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays, and Cabibbo-Kobayashi-Maskawa matrix elements.

hep-ex↗

arXiv2023

Averages of $b$-hadron, $c$-hadron, and $τ$-lepton properties as of 2021

This paper reports world averages of measurements of $b$-hadron, $c$-hadron, and $τ$-lepton properties obtained by the Heavy Flavour Averaging Group using results available before April 2021. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays, and Cabibbo-Kobayashi-Maskawa matrix elements.

hep-ex↗

arXiv2022

Prospects for studies of $D^{0} \to μ^+μ^-$ and $B_{(s)}^{0} \to μ^+μ^-$ decays

Weak decays of the vector $D^{*0}$ and $B_{(s)}^{*0}$ mesons to the $\mumu$ final state provide novel potential to test the Standard Model of particle physics. Such processes have extremely small branching fractions as the vector mesons are able to decay through electromagnetic and (for the $D^{*0}$ meson) strong interactions. Nonetheless, the production of copious quantities of these particles in LHC collisions, and the ability to exploit experimental techniques that can suppress background to low levels, provides good potential to reach interesting sensitivity. The possibility to reconstruct these processes as part of the decay chain of $B^-$ or $B_c^+$ mesons appears particularly attractive due to the clean experimental signature of the displaced vertex. Indeed, published LHCb data on $\Bm \to \pim\mumu$ decays already implies a stringent limit on the branching fraction of $D^{*0} \to μ^+μ^-$. Estimates are made on the achievable sensitivity to $D^{*0} \to μ^+μ^-$ and $B_{(s)}^{*0} \to μ^+μ^-$ decays with the LHCb experiment.

hep-ex↗

arXiv2021

Averages of $b$-hadron, $c$-hadron, and $τ$-lepton properties as of 2018

This paper reports world averages of measurements of $b$-hadron, $c$-hadron, and $τ$-lepton properties obtained by the Heavy Flavor Averaging Group using results available through September 2018. In rare cases, significant results obtained several months later are also used. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays, and Cabibbo-Kobayashi-Maskawa matrix elements.

hep-ex↗

arXiv2020

Snowmass 2021 Letter of Interest: Decays of Heavy Flavors Beauty, Charm, and Tau

The Heavy Flavor Averaging Group provides this Letter of Interest (LOI) as input to the Snowmass 2021 Particle Physics Community Planning Exercise organized by the Division of Particles and Fields of the American Physical Society. Research in heavy flavor physics is an essential component of particle physics, both within and beyond the Standard Model. To fully realize the potential of this field, we advocate strong support within the U.S. high energy physics program for ongoing and future experimental and theory research in heavy flavor physics.

hep-ex↗

arXiv2018

HFLAV input to the update of the European Strategy for Particle Physics

The Heavy Flavor Averaging Group provides with this document input to the European Strategy for Particle Physics. Research in heavy-flavor physics is an essential component of the particle-physics program, both within and beyond the Standard Model. To fully realize the potential of the field, we believe the strategy should include strong support for the ongoing experimental and theoretical heavy-flavor research, future upgrades of existing facilities, and significant heavy-flavor capabilities at future colliders, including dedicated experiments.

hep-ex↗

arXiv2015

A facility to Search for Hidden Particles (SHiP) at the CERN SPS

A new general purpose fixed target facility is proposed at the CERN SPS accelerator which is aimed at exploring the domain of hidden particles and make measurements with tau neutrinos. Hidden particles are predicted by a large number of models beyond the Standard Model. The high intensity of the SPS 400~GeV beam allows probing a wide variety of models containing light long-lived exotic particles with masses below ${\cal O}$(10)~GeV/c$^2$, including very weakly interacting low-energy SUSY states. The experimental programme of the proposed facility is capable of being extended in the future, e.g. to include direct searches for Dark Matter and Lepton Flavour Violation.

physics.ins-det↗

arXiv2013

Proposal to Search for Heavy Neutral Leptons at the SPS

A new fixed-target experiment at the CERN SPS accelerator is proposed that will use decays of charm mesons to search for Heavy Neutral Leptons (HNLs), which are right-handed partners of the Standard Model neutrinos. The existence of such particles is strongly motivated by theory, as they can simultaneously explain the baryon asymmetry of the Universe, account for the pattern of neutrino masses and oscillations and provide a Dark Matter candidate. Cosmological constraints on the properties of HNLs now indicate that the majority of the interesting parameter space for such particles was beyond the reach of the previous searches at the PS191, BEBC, CHARM, CCFR and NuTeV experiments. For HNLs with mass below 2 GeV, the proposed experiment will improve on the sensitivity of previous searches by four orders of magnitude and will cover a major fraction of the parameter space favoured by theoretical models. The experiment requires a 400 GeV proton beam from the SPS with a total of 2x10^20 protons on target, achievable within five years of data taking. The proposed detector will reconstruct exclusive HNL decays and measure the HNL mass. The apparatus is based on existing technologies and consists of a target, a hadron absorber, a muon shield, a decay volume and two magnetic spectrometers, each of which has a 0.5 Tm magnet, a calorimeter and a muon detector. The detector has a total length of about 100 m with a 5 m diameter. The complete experimental set-up could be accommodated in CERN's North Area. The discovery of a HNL would have a great impact on our understanding of nature and open a new area for future research.

hep-ex↗

arXiv2013

Performance of the LHCb RICH detector at the LHC

The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. This provides charged particle identification over a wide momentum range, from 2-100 GeV/c. The operation and control software, and online monitoring of the RICH system are described. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types (pion, kaon and proton) is achieved.

physics.ins-det↗

arXiv2010

The $\bar{B}_d \to \bar{K}^{*0} μ^+ μ^-$ decay

In this paper the potential for the discovery of new physics in the exclusive decay $\bar{B}_d \to \bar{K}^{*0} μ^+ μ^-$ is discussed. Attention is paid to constructing observables which are protected from uncertainties in QCD form factors and at the same time observe the symmetries of the angular distribution. We discuss the sensitivity to new physics in the observables including the effect of CP-violating phases.

hep-ph↗

arXiv2010

New physics reach of CP violating observables in the decay B to K* l+ l-

We discuss theoretical and experimental preparations for an indirect new physics search using the rare decay B to K*0 (to K pi) l+ l- focusing on CP violating observables. The separation of new physics effects and hadronic uncertainties is the key issue when using flavour observables in a new-physics search. Our analysis is based on QCD factorization and soft-collinear effective theory and critically examines the new physics reach of those observables via a detailed error analysis due to scale dependences, form factors, and other input parameters; we also explore the experimental sensitivities at LHCb using a full-angular fit method; finally, we make the impact of the unknown Lambda/mb corrections manifest in our theoretical predictions.

hep-ph↗

arXiv2010

Flavor Physics in the Quark Sector

One of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor and measurements and theoretical interpretations of their results have advanced tremendously: apart from masses and quantum numbers of flavor particles, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. Till early 1990s observations of CP violation were confined to neutral $K$ mesons, but since then a large number of CP-violating processes have been studied in detail in neutral $B$ mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of $K, D$, and $B$ mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field.

hep-ph↗

arXiv2009

The exclusive B to K*(to K pi) l+ l- decay: CP conserving observables

We study the K* polarization states in the exclusive 4-body B meson decay B to K* (to K pi) l+ l- in the low dilepton mass region working in the framework of QCDF. We review the construction of the CP conserving transverse and transverse/longitudinal observables AT2, AT3, and AT4. We focus here, on analyzing their behaviour at large recoil energy in presence of right-handed currents.

hep-ph↗

arXiv2009

Ganga: a tool for computational-task management and easy access to Grid resources

In this paper, we present the computational task-management tool Ganga, which allows for the specification, submission, bookkeeping and post-processing of computational tasks on a wide set of distributed resources. Ganga has been developed to solve a problem increasingly common in scientific projects, which is that researchers must regularly switch between different processing systems, each with its own command set, to complete their computational tasks. Ganga provides a homogeneous environment for processing data on heterogeneous resources. We give examples from High Energy Physics, demonstrating how an analysis can be developed on a local system and then transparently moved to a Grid system for processing of all available data. Ganga has an API that can be used via an interactive interface, in scripts, or through a GUI. Specific knowledge about types of tasks or computational resources is provided at run-time through a plugin system, making new developments easy to integrate. We give an overview of the Ganga architecture, give examples of current use, and demonstrate how Ganga can be used in many different areas of science.

cs.DC↗

arXiv2009

New observables in the decay mode anti-B --> anti-K*0 l+ l-

We discuss the large set of observables available from the angular distributions of the decay anti-B --> anti-K*0 l+ l-. We present a NLO analysis of all observables based on the QCD factorization approach in the low-dilepton mass region and an estimate of Λ/m_b corrections. Moreover, we discuss their sensitivity to new physics. We explore the experimental sensitivities at LHCb (10 fb^-1) and Super-LHCb (100 fb^-1) based on a full-angular fit method and explore the sensitivity to right handed currents. We also show that the previously discussed transversity amplitude A_T^(1) cannot be measured at the LHCb experiment or at future B factory experiments as it requires a measurement of the spin of the final state particles.

hep-ph↗

arXiv2008

B, D and K decays

With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavour physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavour physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-pT and flavour data.

hep-ph↗

arXiv2006

Towards the European strategy for particle physics: the Briefing Book

This document was prepared as part of the briefing material for the Workshop of the CERN Council Strategy Group, held in DESY Zeuthen from 2nd to 6th May 2006. It gives an overview of the physics issues and of the technological challenges that will shape the future of the field, and incorporates material presented and discussed during the Symposium on the European Strategy for Particle Physics, held in Orsay from 30th January to 2nd February 2006, reflecting the various opinions of the European community as recorded in written submissions to the Strategy Group and in the discussions at the Symposium.

hep-ph↗