124 research outputs found
Non-minimally flavour violating dark matter
Flavour symmetries provide an appealing mechanism to stabilize the dark
matter particle. I present a simple model of quark flavoured dark matter that
goes beyond the framework of minimal flavour violation. I discuss the
phenomenological implications for direct and indirect dark matter detection
experiments, high energy collider searches as well as flavour violating
precision data.Comment: Proceedings for DISCRETE 2014: Fourth Symposium on Prospects in the
Physics of Discrete Symmetries, 2-6 December 2014, King's College Londo
Introduction to Flavour Physics and CP Violation
These lecture notes provide an introduction to the theoretical concepts of
flavour physics and CP violation, based on a series of lectures given at the
ESHEP 2016 summer school. In the first lecture we review the basics of flavour
and CP violation in the Standard Model. The second lecture is dedicated to the
phenomenology of K and B meson decays, where we focus on a few representative
observables. In the third lecture we give an introduction to flavour physics
beyond the Standard Model, both within the framework of Minimal Flavour
Violation and beyond.Comment: 30 pages, 10 figures. v2: Few references added. Lectures given at the
ESHEP 2016 summer school in Skeikampen, Norway, 15-28 June 2016. To be
published as CERN Yellow Repor
New Physics Signatures in Kaon Decays
Kaon physics provides a unique opportunity to identify new flavour and CP
violating interactions beyond the Standard Model (SM). In the SM, implied by
the hierarchical structure of the CKM matrix and the GIM mechanism, flavour
changing neutral current processes are most strongly suppressed in the kaon
sector while the suppression is much less effective in the B meson systems.
Thus their theoretical cleanness makes rare K decays, in particular the K -> pi
nu anti-nu system, extremely well suited to look for deviations from their tiny
SM values. Despite the increasingly stringent constraints on new physics from
direct search experiments as well as indirect searches in B meson decays, large
enhancements of both K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu are
still possible, and deviations from the SM could be observed even for a
multi-TeV new physics scale. In addition the correlation betweeen the charged
and neutral K -> pi nu anti-nu modes provides insight on the new physics
operator structure in K^0 - anti-K^0 mixing and its interplay with rare K
decays. Useful model-discriminating correlations exist also in the K_L -> pi^0
l^+ l^- system. Finally the K -> l nu decays provide a clean test of lepton
universality and place constraints on new physics complementary to the ones
obtained from the searches for charged lepton flavour violating decays.Comment: 10 pages, 7 figures. Proceedings for KAON13 - 2013 Kaon Physics
International Conference at the University of Michigan, Ann Arbor, April
29-May 1 201
Phenomenological aspects of flavoured dark matter
Flavour symmetries in the dark sector are a theoretically motivated and
phenomenologically appealing concept. The dark matter particle can be
stabilised with the help of flavour symmetries, without the need to introduce
an additional discrete symmetry by hand. Apart from the usual searches in
direct and indirect detection experiments and high energy colliders, flavoured
dark matter generally also gives rise to new flavour violating interactions
leading to interesting signatures in rare meson decays. This proceedings
article reviews a simplified model of flavoured dark matter in which the dark
matter coupling to quarks constitutes a new source of flavour violation, so
that the model goes beyond Minimal Flavour Violation. Particular emphasis is
put on the discussion of its phenomenological implications in flavour, collider
and direct detection experiments.Comment: 7 pages, proceedings of The European Physical Society Conference on
High Energy Physics, 22-29 July 2015, Vienna, Austri
Quo vadis flavour physics? - FPCP2017 theory summary and outlook
We review the recent highlights of theoretical flavour physics, based on the
theory summary talk given at FPCP2017. Over the past years, a number of
intriguing anomalies have emerged in flavour violating and meson
decays, constituting some of the most promising hints for the presence of
physics beyond the Standard Model. We discuss the theory status of these
anomalies and outline possible future directions to test the underlying New
Physics.Comment: 15 pages, 4 figures. Proceedings for FPCP2017, 5-9 June 2017, Prague.
v2: references added, final version to appear in Po
Top-Flavoured Dark Matter in Dark Minimal Flavour Violation
We study a simplified model of top-flavoured dark matter in the framework of
Dark Minimal Flavour Violation. In this setup the coupling of the dark matter
flavour triplet to right-handed up-type quarks constitutes the only new source
of flavour and CP violation. The parameter space of the model is restricted by
LHC searches with missing energy final states, by neutral meson mixing
data, by the observed dark matter relic abundance, and by the absence of signal
in direct detection experiments. We consider all of these constraints in turn,
studying their implications for the allowed parameter space. Imposing the mass
limits and coupling benchmarks from collider searches, we then conduct a
combined analysis of all the other constraints, revealing their non-trivial
interplay. Especially interesting is the combination of direct detection and
relic abundance constraints, having a severe impact on the structure of the
dark matter coupling matrix. We point out that future bounds from upcoming
direct detection experiments, such as XENON1T, XENONnT, LUX-ZEPLIN, and DARWIN,
will exclude a large part of the parameter space and push the DM mass to higher
values.Comment: 34 pages, 23 figures. v2: clarifying comments and few references
added, matches published versio
Emerging -Anomaly from Tree-Level Determinations of and the Angle
We point out that the recently increased value of the angle in the
Unitarity Triangle (UT), determined in tree-level decays to be
by the LHCb collaboration, combined with
the most recent value of implies an enhancement of
over the data in the ballpark of . This is roughly by a factor of two
larger than the enhancement of that is independent of .
This disparity of enhancements is problematic for models with Constrained
Minimal Flavour Violation (CMFV) and also for models. In view of the
prospects of measuring with the precision of by Belle II
and LHCb in the coming years, we propose to use the angles and
together with and as the fundamental parameters of the
CKM matrix until from tree-level decays will be known precisely.
Displaying as functions of clearly demonstrates the
tension between the value of from tree-level decays, free from new
physics (NP) contributions, and calculated in CMFV and
models and thus exhibits the presence of NP contributions to beyond these frameworks. We calculate the values of and
as functions of and and discuss the implications
of our results for and rare and decays. We also briefly
discuss a future strategy in which , possibly affected by NP, is
replaced by .Comment: 15 pages, 8 figures, 3 tables. v2: Clarifying comments and one figure
added, conclusions unchanged. Matches published versio
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