We report the status of the KOTO experiment at J-PARC to
search for the decay $K_L\to\pi^0\nu\overline{nu}$. The decay is sensitive to new
physics beyond the standard model because the standard model process is highly
suppressed in the decay. The branching ratio is $3\times 10^{-11}$ with small
theoretical uncertainty in the standard model. We set an upper limit of the
branching ratio at...
In this talk, I will discuss discrete Goldstone bosons
(dGB's), light particles arising from spontaneously broken exact discrete
symmetries. These dGB's are guaranteed to have nonzero masses, while the
associated discrete symmetry protects them from quadratically divergent mass
contributions. The nonzero masses of dGB's arise directly from the discrete
symmetry, without requiring an explicit...
An overview of the recent CP violation measurements in charm and beauty decays is presented, and an updated determination of CKM angle gamma, charm mixing, and CP-violation parameters using the LHCb measurements.
.Hints for the violation of lepton flavour universality (satisfied within the SM) have accumulated in recent years. In particular, deviations from the SM predictions were observed in semi-leptonic B decays (b->sll and b->ctau), in the anomalous magnetic moment of the muon (g-2), in leptonic tau decays and di-electron searches. Furthermore, also the deficit in first row CKM unitarity, known as...
There are many astrophysical observations and cosmological evidence for the existence of dark matter (DM), but little is known of its particle nature. The Standard Model (SM) does not predict its existence, however, numerous theories beyond the Standard Model (BSM) provide viable candidates for DM. Common candidates in many of these theoretical models are the weakly interacting massive...
I discuss the usefulness of symmetries in the study of Multi Higgs Doublet Models.
The KATRIN experiment aims to measure the neutrino mass by precision spectroscopy of tritium β-decay. Recently, KATRIN has improved the upper bound on the effective electron-neutrino mass to 0.8 eV/c² at 90% confidence level [1] and is continuing to take data for a target sensitivity of 0.2 eV/c².
In addition to the search for the neutrino mass, the ultra-precise measurement of the β-spectrum...
I discuss the application of modular invariance to the flavour problem from a (mostly) bottom-up perspective. In this framework, Yukawa couplings and mass matrices are obtained from modular forms, which are functions of a single complex number: the modulus VEV $\tau$. This VEV can be the only source of symmetry breaking, so no flavons need to be introduced. When $\tau$ is close to special...
The framework of compactified heterotic string theory offers consistent UV completions of the Standard Model of particle physics. In this approach, the existence of flavor symmetries beyond the Standard Model is imperative and the flavor symmetries can be derived from the top down. Such a derivation uncovers a unified origin of traditional discrete flavor symmetries, discrete modular flavor...
In this presentation, I will provide an overview on the current knowledge
on the unitarity of the CKM matrix and its constraining power on new
physics contributions. I will further review the current knowledge on the
determination of $V_{ub}$ and $V_{cb}$, whose values constrain together with the
CKM angle $\gamma / \phi_3$ constrain the apex of the unitary triangle. Several
new measurements...
In the Standard Model a Dark Matter candidate is missing, but it is relatively
simple to enlarge the model including one or more suitable particles.
We consider in this paper one such extension, inspired by simplicity and
by the goal to solve more than just the Dark Matter issue.
Indeed we consider a local $U(1) $ extension of the SM providing an
axion particle to solve the strong CP...
The first results from the Belle II collaboration related to the determination of CP violation in $B$ decays presented. Both time-dependent and direct CP violation measurements are possible at this next generation $e^+e^-$ $B$ factory. The first determinations of and constraints on all three CKM unitarity triangle angles are presented. Results using data sets equivalent to an integrated...
The large top quark samples in top quark pair and single top production have yielded measurements of the production cross section of unprecedented precision and in new kinematic regimes. They have also enabled new measurements of top quark properties that were previously inaccessible, enabled the observation of many rare top quark production processes predicted by the Standard Model and...
Future cosmological probes promise significant progress in probing the dark universe and the related fundamental particles. Their impact is most powerful when we combine cosmological data with astrophysical observations and laboratory experiments. While computational tools are available for such studies, the large number of model parameters and ensuring consistency between data sets can...
Many theories beyond the Standard Model (BSM) have been proposed to address several of the Standard Model shortcomings, such as the origin of dark matter and neutrino masses, the fine-tuning of the Higgs boson mass, or the observed pattern of masses and mixing angles in the quark and lepton sectors. Many of these BSM extensions predict new particles or interactions directly accessible at the...
The vector leptoquark $U_{1}(3,1,2/3)$ is the only single mediator which can simultaneously address the anomalies in $B$-physics. Remarkably, such explanation of the $B$-anomalies requires a hierarchy in the $U_{1}$ couplings which may be connected with the well-known hierarchies in the masses of the SM fermions. In this direction, a twin Pati-Salam model was recently proposed, in which the...
The Weinberg model is a Z_2\times Z_2-symmetric
three-Higgs-doublet model (3HDM)} designed to accommodate CP violation in the
scalar sector within a gauge theory, while at the same time allowing for natural
flavour conservation. In this model the coefficients of the potential are taken to be
complex and therefore CP is explicitly violated. With coefficients chosen to be real,
CP can be...
Models with an extended scalar electroweak sector can have vanishing vacuum expectation values. Such behaviour is a result of an underlying symmetry. If a symmetry prevents couplings between fermions and additional scalars, such scalars could become viable dark matter candidates. We catalogue $S_3$-symmetric three-Higgs-doublet models, based on whether a specific model could possibly...
This talk presents recent Belle II results on lepton flavor universality and flavour violation tests using B meson and tau decay.
The low-background collision environment along with the possibility of partially or fully reconstructing one of the two B mesons in the event offer high precision measurements of B decays or rare decays with missing energy. Results from semileptonic and electroweak...
We consider a $U(1)_D$ extension of the Standard Model
that accounts for the neutrino masses and study in detail dark matter
phenomenology. The model under consideration includes a vector WIMP and a
fermion FIMP dark matter candidates and thus gives rise to two-component dark
matter scenarios. We discuss different regimes and mechanisms of production and
the interplay between neutrino masses...
Dark matter candidates can arise from a wide range of
extensions to the Standard Model. Simplified models with a small number of new
particles allow for the optimisation and interpretation of dark matter and collider
experiments, without the need for a UV-complete theory. In this talk, I will discuss
the results from a recent GAMBIT study of global constraints on vector-mediated
simplified...
In the context of a class of two Higgs doublet models where CP violation only arises spontaneously, a possible connection between CP violations in the quark and lepton sectors (described by the CKM and PMNS matrices) is analysed. The important role of scalar flavour changing couplings (SFCNC) in this type of scenario is also discussed in detail.
Dark matter interaction with the atomic electron is a
well-motivated problem in recent years. As the nature of DM and its
non-gravitational interactions with normal matter are still unknown, instead of
considering a specific, well-motivated method, we are using multi relativistic
random-phase approximation (MCRRPA) and Frozen core approximation (FCA) in
the present study. Recently, the...
B0– ̄B0 entanglement offers a conceptual alternative to the single charged B-decay asymmetry for the measurement of the direct CP-violating γ=φ3 phase. With f=J/ΨK_L ; J/ΨK_S and g=(ππ)0; (ρ_Lρ_L)0, the 16 time-ordered double-decay rate intensities to (f,g) depend on the relative phase between the f- and g-decay amplitudes given by γ at tree level. Several constraining consistencies appear....
We explore the discovery potential for long-lived particles at
the 250-GeV ILC. The goal is to investigate possible gains of a dedicated far
detector over the main detector ILD. For concreteness, we perform our study for
sub-GeV axion-like particles $a$ produced via $e^+e^- \to a \gamma$ or $e^+e^-
\to Z \gamma \to (a\gamma)\gamma$ and decaying into pairs of charged leptons.
In the ideal case...
Recent experimental advances now severely constrain electroweak-scale WIMPs produced via
thermal freeze-out, leading to a shift away from this standard paradigm. Here we consider
an axion-like particle (ALP), the pseudo-Goldstone boson of an approximate U(1) global
symmetry spontaneously broken at a high scale fa, as a mediator between the Standard
model (SM) particles and the dark matter (DM)...
A well known technique to determine the decay amplitudes
of non-leptonic B meson processes is QCD factorization. One of the main issues
faced by this procedure is the analytical determination of power suppressed terms,
for instance of annihilation topologies. In this talk we describe the extraction of the
annihilation contributions from data. Our method is based on establishing a set of
rules...
We investigate the potential of the model 'CP in the Dark'
for providing a strong first-order electroweak phase transition (SFOEWPT) by
taking into account all relevant theoretical and experimental constraints. For the
derivation of the strength of the phase transition we use the one-loop corrected,
daisy-resummed effective potential at finite temperature, implemented in the C++
code BSMPT, to...
The parameter ᵱᵃ is an important measure of the
imbalance between matter and antimatter in the neutral kaon (ᵃ0 and ᵃ¯0)
system. In particular, ᵱᵃ provides a highly sensitive probe of new physics and
plays a critical role in the global fit of the Cabibbo-Kobayashi-Maskawa matrix. As
one of the first discovered sources of ᵃᵄ violation, it has been extensively
measured in experiment to per-mil...
In this talk I will present the latest developments on the minimal potentially realistic non-supersymmetric SO(10) GUT model with the scalar sector consisting of 45+126+10. This model is known to suffer from tachyonic instabilities in the spectrum at tree-level, but quantum corrections to the scalar potential may cure this problem - a route worth investigating, since this particular SO(10) GUT...
Scalar leptoquarks are popular mediators in new physics explanations of the experimental anomalies in $ b \to s \mu^+ \mu^-$ decays and the muon $g-2$; however, the non-observation of charged lepton flavor violation and proton decay impose severe constraints on their interactions. We present a novel protection mechanism in the form of a gauged, lepton-flavored U(1) symmetry, which is broken by...
Heisenberg’s uncertainty principle at the Planck scale leads
to extensions of Dirac equations. In this paper, the generalized uncertainty problem
(GUP) theory is used as an extension of the Dirac equation with the mass term
m_1+iγ^5 m_2 (tachyonic) in the Schwarzschild metric. Its eigenvalue problem for
a particle in a gravitational field created by a central mass is also solved....
Neutron to hidden neutron oscillation (n − n') experiments
are one of the several probes for testing the existence of hidden sector worlds [1,
2]. Although hidden states of matter were originally proposed to restore, on a
general picture, the breaking of P and CP symmetries [4], currently they also
correspond to candidates for dark matter [3]. In this work, we present a new
experimental...
The Pauli Exclusion Principle (PEP) is one of the main
cornerstones of the Quantum Theory. Violation of the PEP, albeit small, could be
motivated by physics beyond the Standard Model which entail extra space
dimensions, violation of the Lorentz invariance, non-commutative space-time.
These scenarios can be experimentally constrained with stat-of-the-art X-ray
spectroscopy, searching for...
Dark matter may be stable because of a conserved Z_p (cyclic) symmetry. Usually p is assumed to be 2, but it may also be larger than 2.
This Z_p is usually assumed to be in a direct product with some other symmetry group. The full symmetry group of the theory is then G = Z_p x G'. We suggest another possibility.
Many discrete subgroups of U(n), for any n > 2, have a non-trivial center Z_p,...
We use an unconventional diagrammatic approach to formulate CPT and unitarity constraints for higher-order CP asymmetries entering the source term in the Boltzmann equation. Usually, the reaction rate asymmetries in these constraints are computed within the classical kinetic theory, using zero-temperature quantum field theory to describe particles' interactions. We approximate the rates,...
The lepton sector of the Standard Model is at present haunted by several intriguing anomalies, including an emerging pattern of deviations in $b \to s \ell \ell$ processes, with hints of lepton flavor universality violation, and a discrepancy in the muon anomalous magnetic moment. More importantly, it cannot explain neutrino oscillation data, which necessarily imply the existence of non-zero...
The space-borne interferometer LISA will be sensitive to a variety of mechanisms sourcing gravitational waves in the late and early universe. In this talk we present the status of the LISA mission and summarize the science that LISA will achieve. We discuss in some detail the measurements that will allow LISA to probe BSM physics and cosmology. Particular attention will be dedicated to the...
After broad introduction on ultralight DM, I will briefly
discussed issues associated on quality problem and the interplay between
equivalence principle tests of ultralight DM and direct searches through the
oscillation of energy levels, and then I'll demonstrate the potentially surprising
result that oscillation of energy levels would provide us with possibly the best
bound on QCD-axion...
The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for tests of discrete symmetries as well as for medical imaging. The novelty of the system is based on usage of plastic scintillators for active detection material and trigger-less data acquisition system. The apparatus consists of 192 plastic scintillators read out from both ends with vacuum tube photomultipliers. Positronium...
Exact discrete symmetries, if non-linearly realized, can protect a given theory against ultraviolet sensitivity. Quadratic divergences can cancel exactly, while the lightest scalars stemming from spontaneous symmetry breaking are massive without breaking the symmetry. This is at variance with non-linearly realized continuous symmetries, for which the masses of pseudo-Goldstone bosons require...
The discovery of the Higgs boson with the mass of 125 GeV confirmed the mass generation mechanism via spontaneous electroweak symmetry breaking and completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many experimental measurements, it is not capable of solely explaining some observations. Many extensions of the Standard...
Extensions of the Standard Model (SM) with new Abelian
gauge groups allow for kinetic mixing between the new gauge bosons and the
hypercharge gauge boson, resulting in mixing with the photon. In many models the
mixing with the hypercharge gauge boson captures only part of the kinetic mixing
term with the photon, since the new gauge bosons can also mix with the neutral
component of the...
Very detailed measurements of Higgs boson properties can be performed with the Run 2 13 TeV pp collision dataset collected by the ATLAS experiment. This talk presents a review of the latest measurements of the Higgs boson properties, including its mass, CP, and differential cross-sections. Furthermore, couplings, including self-coupling measurement using Higgs pair production, combining...
The comparison of neutral K-meson transition rates between flavour and CP eigenstates is used to perform independent tests of time-reversal T, CP and CPT symmetries. The analysis of 1.7 fb$^{-1}$ of KLOE data acquired at the DA$\Phi$NE $e^+e^-$ collider, using ratios of rates of the two classes of processes, $K_S K_L \to \pi^\pm e^\mp \nu, 3 \pi^0$ and $K_S K_L \to \pi^+ \pi^-, \pi^\pm e^\mp...
The data collected by CMS during the LHC Run 2 allow measuring many properties of the Higgs boson. We will review in this talk the recent results from CMS. They include fiducial and differential cross-section measurements, also in the STXS framework, and measurements of di-Higgs production. They can be interpreted in terms of coupling and charge-parity measurements, or in the effective field...
We investigate the effect of quantum loops on the theory of
axionlike particles (ALPs) coupled to electrons. Contrary to some statements in the
recent literature, the effective ALP-photon coupling induced by an electron loop
can be sizeable in the plasma of a supernova. We define a general effective
coupling that depends on the kinematics of the specific process in which an ALP
scatters,...
The process $\phi \to K_S K_L \to\pi^+ \pi^- \pi^+ \pi^-$ exhibits the characteristic Einstein–Podolsky–Rosen correlation that prevents both kaons to decay into pairs of charged pions at the same time. This constitutes a formidable tool to test with high precision the quantum coherence of the entangled kaon state, and to search for tiny deviations from the quantum mechanical prediction that...
We explore a possible explanation for the hierarchy in scale between the atmospheric and solar neutrino mass differences ($|\Delta m^2_{31}|$ and $\Delta m^2_{21}$)
through the presence of two distinct neutrino mass mechanisms from tree-level and one-loop-level contributions. We demonstrate
that the ingredients needed to explain this hierarchy are present in the minimal discrete dark matter...
The experimental observations from the colliders
established the standard model (SM), is the most successful phenomenological
framework to explain the non-gravitational interactions of fundamental particles at
high energy. Non-zero neutrino mass and dark matter cast a shadow over its
success. This necessitates the extension of the SM. The most straightforward and
elegant extension of the SM to...
A search for charged Higgs may yield clear and direct sign
of new physics outside the realm of the Standard Model (SM). In the Two-Higgs
Doublet Model (2HDM), we investigate two of the main single charged Higgs
production channels at the Large Hadron Collider (LHC), assuming that either h or
H replicates the detected resonance at ∼ 125 GeV; we ponder the practicality of
the associated charged...
P2 is a precision experiment planned for the Mainz Energy recovering Superconducting Accelerator (MESA) currently under construction. The goal of P2 is to determine the electroweak mixing angle at a four-momentum transfer of Q^2 = 4.5e-3 GeV^2 with a precision of 0.14 %, comparable to existing measurements at the Z pole. The mixing angle is extracted by measuring the protons weak charge...
Supersymmetric Twin Higgs models allow for naturally low
electroweak scale without much fine-tuning. If the lightest supersymmetric particle
resides in the twin sector, it could be charged under the unbroken twin
electromagnetism. I will consider the twin stau as candidate for dark matter in
these class of models. All experimental constraints, including self-interaction
bounds, are satisfied...
The MUonE experiment aims to measure with extremely high precision the leading-order hadronic contribution to the muon anomalous magnetic moment g-2. This currently represents the largest uncertainty in the theoretical prediction. A first test has been performed in 2021, with prototypes of the silicon sensors and related electronics, the fundamental components of the detector. The collected...
The longstanding $(g-2)_\mu$ anomaly is one of the greatest puzzles in particle physics. If confirmed, it would be a clear indication for physics beyond the Standard Model. We discuss the implications of this anomaly on the flavor structure of its possible New Physics (NP) explanations. In particular, we investigate flavor alignment conditions that NP models need to satisfy in order to both...
Models of spontaneous CP violation can solve the Strong
CP problem without the need of an anomalous Peccei-Quinn symmetry. In this talk
we review the Nelson-Barr approach, quantifying a peculiar coincidence between
unrelated mass scales that these models must satisfy in order to correctly
reproduce the Standard Model quark masses and CP violation. We investigate the
compatibility between this...
I will present our recent work (arXiv:2204.13605 [hep-ph]) based on a hybrid type-II seesaw/scotogenic model supplemented with a discrete flavour symmetry where CP is dynamically generated by the vacuum. Namely, we analyse compatibility with low-energy neutrino observables, review the charged lepton flavour violation implications and study the scalar and fermionic dark matter phenomenology of...
The NA62 experiment at CERN collected the world's largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio of the ultra-rare K+ --> pi+ nu nu decay, based on 20 candidates.
The radiative kaon decay K+ → pi0e+vg (Ke3g) was studied with a data sample of O(100k) Ke3g candidates with sub-percent background contaminations recorded in 2017-2018....
High statistics measurements of light-by-light scattering, made accessible using relativistic heavy-ion beams provide a precise and unique opportunity to investigate extensions of the Standard Model, such as the presence of axion-like particles. This talk presents a series of measurements of such processes performed by the ATLAS Collaboration. New measurements of exclusive dilepton production...
The NA62 experiment at CERN took data in 2016–2018 with the main goal of measuring the K+ -> pi+ nu nubar decay. The high-intensity setup and detector performance make NA62 particularly suited for searching new-physics effects from different scenarios involving feebly interacting particles in the MeV—GeV mass range.
Searches for K+→e+N, K+→μ +N and K+→μ+νX decays, where N and X are massive...
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for 0νββ decay that has been able to reach the one-tonne mass scale. The detector, located at the LNGS in Italy, consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data run in 2017 at a base temperature of...
The phenomenon of $B^0_q-\bar{B}^0_q$ mixing $(q=d,s)$ provides a sensitive probe for physics beyond the Standard Model. We have a careful look at the analyses of the determination of the Unitarity Triangle apex, which is needed for the Standard Model predictions of the $B_q$ mixing parameters, and we explore how much space for New Physics is left through the current data. We study the impact...
The heavy quark expansion (HQE) provides a well established framework to compute inclusive decay widths of heavy hadrons in terms of a systematic expansion in inverse powers of the constituent heavy quark mass. By including for the first time the contribution of the Darwin operator, SU(3)$_F$ breaking corrections to the matrix element of dimension-six four-quark operators and the so-called...
Permanent electric dipole moments probe the joint violation of parity and time-reversal symmetries, collecting many potential sources into a single low-energy observable. Although the Standard Model predicts finite values in many systems, these are too small for present-day experiments to detect.
Experimental results consistent with zero are thus interpreted, via the CPT theorem, as...
Scattering and decay processes of thermal bath particles in
the early universe can dump relativistic axions in the primordial plasma. If
produced with a significant abundance, their presence can leave observable
signatures in cosmological observables probing both the early and the late
universe. In this talk, I will focus on the QCD axion and I will present recent and
significant improvements...
We propose a novel mechanism for the production of dark matter (DM) from a thermal bath, based on the idea that DM particles $\chi$ can transform heat bath particles $\psi$: $\chi \psi \to \chi \chi$. For a small initial abundance of $\chi$ this leads to an exponential growth of the DM number density. We demonstrate that this mechanism complements freeze-in and freeze-out production in a...
The fundamental nature of dark or invisible matter remains
one of the great mysteries of our time. A leading hypothesis is that dark matter is
made of new elementary particles, with proposed masses and interaction cross
sections spanning an enormous range. Amongst the technologies developed to
search for dark matter particles, two-phase (liquid and gas) xenon time projection
chambers are...
This talk will give an overview over axions as dark matter and ways to detect them.
Any grand unified model is plagued with particles capable of inducing
proton decay. Identifying all potential scalar proton decay mediators
stemming from different irreducible representations of SO(10), we
will show their coupling with the Standard Model fermions, tree-level
contributions of the effective strength of $B-L$ conserving($d=6$),
and $B-L$ violating($d=7$) operators to proton...
Quantum correlations are the cornerstone of quantum information theories. Profiting from the non-classical behaviour of a system opens new possibilities but also requires dedicated algorithms, simulations, and even infrastructures to be used. In this talk, the application of such quantum correlations (including the entanglement) for various systems, which can and are used in different fields,...
We study the effect of Lorentz invariance violating(LIV) parameters on the discovery of the non-zero CP phase ($\delta_{13}$) and the octant of 2-3 mixing angle ($\theta_{23}$) in the neutrino sector in the context of the proposed T2HK/T2HKK experiments. We consider the CPT violating case and taking one LIV parameter at a time, investigate to what extent the CP discovery and octant...
