We introduce here a new method to measure the Higgs decay branching ratios at future $e^+e^-$ Higgs factories, by directly exploiting class numeration. Given the clean environment at a lepton collider, we build an event sample highly enriched in Higgs bosons and essentially unbiased for any decay mode. The sample can be partitioned into categories using event properties linked to the expected...
Many physics analyses in Higgs, top and electroweak physics improve the kinematic reconstruction of the final state by constrained fits. This is a particularly powerful tool at $e^+e^-$ colliders, where the initial state four-momentum is known and can be employed to constrain the final state. A crucial ingredient to kinematic fitting is an accurate estimate of the measurement uncertainties, in...
Among the high-energy physics community, there is a growing interest in replacing cut-based selections using different types of multivariate analysis. This transformation made it possible to use high-level variables produced by complex reconstruction algorithms.
Within this context, Deep Learning approaches are rapidly spreading to improve the selection performances by combining all the...
The Yukawa coupling of the Higgs boson to the top quark is a key parameter of the Standard Model. This coupling can be directly measured from the process of gg/qq -> ttH. And the multilepton channel is the most sensitive channel in this process. A search for ttH production in multilepton final states has been performed with an integrated luminosity of 80 fb-1 at a centre-of-mass energy of 13...
We evaluated CLAS Collaboration measurements for the 90-deg meson photoproduction off the nucleon using a tagged photon beam spanning the energy interval s = 3 – 11 GeV2. The results are compared with the “quark counting rules” predictions. The role of the Sudakov form-factor and Vector-Meson Dominance model is considered.
We analize the most general low-energy effective lagrangian including local parity violating terms parametrized by an axial chemical potential $\mu_5$. This result is obtained following the external source method, up to $\mathcal{O}(p^4)$ order in the chiral expansion for two light flavours. We show that the $\mathcal{O}(p^4)$ lagrangian includes new terms proportional to $\mu_5^2$ and new...
In this talk we show how to apply the SCET formalism to factorize Double Drell-Yan process involving a pion and a proton, with four leptons and the proton in the final state. We will show how the factorization of the cross-section leads to the appearance of a Double TMD and two GTMDs. Additionally, we will show how the subsequent zero-bin subtraction leads to the appearance of a new Soft...
LHCb is a spectrometer that covers the forward region of proton-proton collisions, corresponding to the pseudo-rapidity range 2<eta<5. In this unique phase space, LHCb can perform tests of perturbative and non-perturbative QCD models, by studying the production of heavy flavor quarks, like charm and top quarks. In this context the production of a Z boson in association with a c-jet can be...
Jets, clusters of collimated particles produced in high energy proton-proton ($pp$) collisions, are an excellent tool to study the internal structure of the proton. According to perturbative QCD calculations, for center of mass energies of $\sqrt{s} = $ 200 and 510 GeV at RHIC, jet production in the mid pseudo-rapidity, $|\eta| <$ 1, is dominated by quark-gluon and gluon-gluon scattering...
Kaonic atoms provide an ideal testing ground to precisely study QCD at very low energies. Theoretical models still show significant discrepancies in their descriptions of this regime, and fundamental experimental input to constrain these models is provided by X-ray spectroscopy of light kaonic atoms. This is the goal of the SIDDHARTA-2 experiment located at the DA$\Phi$NE collider at LNF,...
The striking discrepancy in the proton form factor ratio, $\mu_p G_E^p/G_M^p$, measured using unpolarized and polarized techniques is still not resolved. The leading explanation is hard two-photon exchange (TPE). Hard TPE is difficult to calculate without significant model dependence, and has generally not been included in radiative corrections. Three recent experiments found only a small...
The “muon-to-electron conversion” (Mu2e) experiment at Fermilab will search for the Charged Lepton Flavour Violating neutrino-less coherent conversion of a muon into an electron in the field of an aluminum nucleus. The observation of this process would be the unambiguous evidence of physics beyond the Standard Model. Mu2e detectors comprise a straw-tracker, an electromagnetic calorimeter and...
The cross-section in hadronic collisions is crucial information in any physics analysis of ALICE data at the LHC, as it not only provides the baseline for normalization but also is a source of substantial uncertainly by itself. The observable used to determine luminosity in ALICE is the visible cross-section ($\sigma_{vis}$), which is measured by using information from the LHC instrumentation...
The Phase-II upgrade of the LHC will increase its instantaneous luminosity by a factor of around 10 leading to the High Luminosity LHC (HL-LHC). At the HL-LHC, the number of proton-proton collisions in one bunch crossing (called pileup) increases significantly, putting more stringent requirements on the LHC detectors electronics and real-time data processing capabilities.
The ATLAS Liquid...
The LEGEND-200 experiment is under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Its main goal is a background-free search for neutrinoless double beta decay of Ge-76. Up to 200 kg of bare high purity germanium (HPGe) detectors with 76Ge enrichment beyond 86% will be deployed in liquid argon (LAr). The LAr will serve as a cooling medium for the detectors as well as a...
The ongoing search for dark matter continues to evolve, and the quest to reach lower cross-sections is leading to new technologies. One of the newer proposals involves the use of a bubble chamber which employs noble elements (such as argon and xenon) as the active mass. Combining recent developments of bubble chambers with liquid noble gases allows additional scintillation data to be...
Neutral bremsstrahlung emission in noble gases has been neglected in favor of excimer-based VUV emission. This alternative mechanism of secondary scintillation production was only recently unveiled in argon. We have found strong evidence of neutral bremsstrahlung emission in xenon, obtained using both the NEXT-White TPC, at present the largest optical Xe-TPC in operation, and a dedicated setup...
The design of detector concepts has been driven for a long time by requirements on transverse momentum, impact parameter and jet energy resolutions, as well as hermeticity. Only rather recently it has been realised that the ability to idenfity different types of charged hadrons, in particular kaons and protons, could have important applications at Higgs factories, ranging from improvements in...
The physics programme at ATLAS involves a variety of Standard Model and Beyond Standard Model resonances decaying to two b quarks, including the Higgs Boson. In order to identify these resonances at high momentum, ATLAS has developed the boosted X→bb tagger, a new NN-based tagging algorithm which combines the flavour information of up to three sub-jets associated to the large-R jet capturing...
New acceleration complex NICA (Nuclotron-based Ion Collider fAcility) as well as MultiPurpose Detector (MPD) for the study of heavy ion collisions is underway at Joint Institute for Nuclear Research (Dubna, Russia). Strangeness and hypernuclei production is presently under active experimental and theoretical investigation and is of particular interest of the NICA/MPD program. We combine...
In a few years the experiments with high luminosity (HL) beams will start at the Large Hadron Collider (LHC). Among the other opportunities for such experiments, there are plans to exploit the fixed target mode for HL beams [1]. Using this opportunity, here we suggest to perform the entirely new experiments by means of utilizing the scattering of the two colliding beams at the nuclei of a...
Lattice Quantum Chromodynamics predicts the existence of dense and hot nuclear matter at high temperature that behaves as a deconfined medium of quarks and gluons, known as Quark-Gluon-Plasma (QGP). Such conditions are created by colliding heavy-ions (Pb–Pb) at ultra-relativistic energies which are then studied by ALICE at LHC. The properties of QGP can be studied by measuring the production...
The advanced Hadron Resonance Gas Model (HRGM) which correctly accounts for the sequential strong and weak decays is developed. Our analysis of the STAR experiment data on hadronic multiplicities demonstrates that taking into account for the weak decays is extremely important to have a model that can describe the data with very high accuracy.
We report our results on fitting the particle...
The hot and dense QCD medium created in relativistic heavy ion collisions behaves like a fluid system and successfully studied by tools of relativistic hydrodynamics. A theory of relativistic hydrodynamics should be causal and stable. Causality is the restriction imposed by special theory relativity which doesn't allow any information to travel faster than the speed of light. The earliest...
In the past years, significant progress has happened in high-energy nuclear physics models. A more robust and quantitative picture has replaced the qualitative descriptions of heavy nuclei collisions in the earlier days, enabling us to have a clearer picture of different stages of a heavy-ion collision. These models typically have $O(10)$ free parameters that are tuned by Bayesian analysis in...
One of the main goals of the relativistic nuclear collisions is to investigate the behavior of nuclear matter under extreme conditions of temperature and energy density. The transverse momentum distributions of identified hadrons contain information about the collective expansion of the system and constrain the freeze-out properties of the matter created in these collisions. It is often...
The J/$\psi$ production is sensitive to the presence of the deconfined state of quarks and gluons, quark-gluon plasma (QGP), which is expected to form in the nuclear collisions. Measurements of J/$\psi$ meson originating from the weak decay of b-hadrons, non-prompt J/$\psi$, can provide an estimate of beauty quark production in the nuclear collisions. It is observed that production of...
Victor Feuillard, for the ALICE Collaboration
Physikalisches Institut, Heidelberg University
The ALICE experiment is optimized to the study of the quark-gluon plasma (QGP), a state of matter where, due to high temperature and density, chiral symmetry is restored, and quarks and gluons are deconfined. In order to obtain information on its properties, it is particularly valuable to study...
Di-Jet angular correlations serve as a sensitive probe of saturation physics in the Color Glass Condensate (CGC), an effective theory of QCD in which a heavy target nucleus can be modeled as a classical background field. The leading order cross section for di-jet production in Deep Inelastic Scattering (DIS) is well known, but experiments at the Electron Ion Collider will be sensitive to...
The medium-to-heavy mass ytterbium isotopes ($_{70}$Yb) in the rare-earth mass region are known to be well-deformed nuclei, which can be populated to very high spin. Spectroscopic information becomes scarcer as the neutron number increases, impeding the understanding of nuclear structure in this mass region, where interesting phenomena, such as shape coexistence, have been predicted. The lack...
A low mass straw tube tracker is at the heart of the Mu2e experiment, tasked with precisely measuring monochromatic electrons from μ$^-$ N→ e$^-$ N conversion as a signal for charged lepton flavor violation (CLFV). The goal of the Mu2e experiment is to discover CLFV and new physics through improving the current limit on the sensitivity of the neutrino-less muon to electron conversion rate by...
The Mu2e experiment at Fermilab will search for charged lepton flavor violation (CLFV) via muon to electron conversion, with a goal of improving the previous upper limit four orders of magnitude and reaching unprecedented single-event sensitivities. The signal of CLFV conversion is a ~105 MeV electron, which is detected using a high-precision straw tracker. Protons produced by muon capture can...
Based on the 225 million $J/\psi$ data set accumulated at the 3.097 GeV by the BESIII detector, we show searches for the extremely rare process of $J/\psi$ weak decays. We find no obvious signal event for the processes of $J/\psi\to \bar D^0\pi^0, \bar D^0 \eta, \bar D^0 \rho^0, D^-\pi^+$ and $J/\psi \to D^-\rho^+$ and present the most stringent constraints of $10^{-6}$ at 90\% confidence...
Ultracold neutrons (UCN) with kinetic energies below 300 neV can be confined for hundreds of seconds in storage volumes made from materials of high Fermi potential. The UCN source at the Paul Scherrer Institut (PSI) delivered UCNs for the measurement of the currently best limit on the permanent electric dipole moment of the neutron and will continue to do so for the follow-up experiment...
Discrete symmetry under the combined transformation of charge, parity, and time-reversal (CPT) can be tested in the decays of positronium atom, the lightest bound system built of charged leptons.
Jagiellonian Positron Emission Tomograph (J-PET) device constructed from plastic scintillators, detects the photons originating from electron-positron annihilation. This feature enables J-PET to...
Nuclear beta decay is a powerful tool to test the Standard Model (SM) in the electroweak sector. The wide variety of nuclei and beta transitions allows us to choose the perfect candidate for specific tests of the SM which are competitive with high energy physics experiments [1]. In particular, the beta-neutrino angular correlation coefficient $a_{\beta\nu}$ and the Fierz interference term $b$...
CP violation is a crucial ingredient in the understanding of the matter anti-matter asymmetry of the universe. A measured electric dipole moment of the neutron would signal breaking the CP symmetry and could hint towards new physics.
The n2EDM experiment is currently under construction by the international nEDM collaboration at PSI. It seeks to improve the sensitivity over the recently...
A neutron decays into a proton, an electron, and antineutrino in a lifetime of about 880 s. The neutron lifetime is one of the important parameters for particle physics and astrophysics. For instance, it dominates the uncertainty on 4He abundance in the Big Bang Nucleosynthesis and it also determines Vud term in the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Although the neutron lifetime...
The proton radius puzzle began in 2010 when the CREMA Collaboration released their measurement of the proton radius (Pohl et. al (2010)) from muonic hydrogen spectroscopy: rp=0.84184(67) fm, This was five standard deviations smaller that the accepted CODATA value at that time (0.8768(69) fm), and sparked an enduring and intriguing puzzle. This puzzle has been addressed in repeated electron...
40K is one of very few isotopes allowing comparison of a third-forbidden unique decay with first-forbidden unique decay. It is also a source of uncertainty in certain dark matter searches, and in K-based geochronology dating techniques. In particular, one decay branch of 40K has never been experimentally measured: the electron capture directly to the ground state of 40Ar, expected to be of the...
LUX-ZEPLIN (LZ) is a direct dark matter experiment, primarily designed to search for WIMPs, currently being commissioned 1.5 km underground at the Sanford Underground Research Facility in Lead, South Dakota. It features a 2-phase xenon time projection chamber with an active mass of 7 tonnes, surrounded by an instrumented xenon "skin" and a liquid scintillator outer detector which are used as...
Innovative experimental techniques are needed to further search for dark matter weakly interacting massive particles. The ultimate limit is represented by the ability to efficiently reconstruct and identify nuclear and electron recoil events at the experimental energy threshold. Gaseous Time Projection Chambers (TPC) with optical readout are very promising candidates thanks to the 3D event...
The NEWS-G (New Experiments With Spheres-Gas) collaboration is searching for light dark matter candidates using a novel detector concept, the spherical proportional counter. Access to the mass range from 0.05 to 10 GeV is enabled by the combination of a low energy threshold, light gaseous targets (H, He, Ne), and highly radio-pure detector construction. First NEWS-G results obtained with...
The Migdal effect predicts the emission of an atomic electron when the respective nucleus is
perturbed. The experimental confirmation of this prediction would imply that current direct
detection experiments are sensitive to dark matter (DM) particles with mass well below the
thresholds typically assumed. In particular, it would have a great impact on the search for sub-GeV
DM...
The flavour problem of the Standard Model can be addressed through the Froggatt-Nielsen (FN) mechanism. In this work, we develop an approach to the study of FN textures building a direct link between FN-charge assignments and the measured masses and mixing angles via unitary transformations in flavour space. We specifically focus on the quark sector to identify the most economic FN models able...
The ENUBET experiment, included in the CERN Neutrino Platform effort as NP06/ENUBET, is developing a new neutrino beam based on conventional techniques in which the flux and the flavor composition are known with unprecedented precision ($\mathcal{O}$(1%)). Such a goal is accomplished monitoring the associated charged leptons produced in the decay region of the ENUBET facility. Positrons and...
The Deep Underground Neutrino Experiment Near Detector complex aims at constraining the systematic uncertainties and deconvolving the neutrino beam flux and cross-section models. The System for on-Axis Neutrino Detection (SAND) is the Near Detector component permanently on-axis. SAND is based on the 0.6 T superconducting magnet and electromagnetic calorimeter previously used in the KLOE...
DANSS detector is composed of plastic scintillator and takes full advantages
of its unique location directly below a commercial reactor core. The ability
to change the distance to the antineutrino source by means of a lifting
platform makes DANSS an ideal apparatus for sterile neutrino searches,
while the fine segmentation of the sensitive volume provides an exteremely
clean separation...
The Large Enriched Germanium Experiment for Neutrinoless double beta Decay (LEGEND)
Collaboration aims to develop an experimental program to search for neutrinoless
double-beta decay in $^{76}$Ge, with a half-life sensitivity of up to 10$^{28}$ years in the second
phase. Assuming a light neutrino exchange model, the sensitivity would cover the entire
parameter space for neutrinos in the...
Project 8 is a next-generation neutrino mass experiment that uses Cyclotron Radiation Emission Spectroscopy (CRES) to measure the neutrino mass. CRES is a novel technique for $\beta$-decay spectroscopy that measures the frequency of the cyclotron radiation produced by energetic electrons trapped in a magnetic field. The cyclotron frequency can be directly converted into the energy spectrum,...
Charged-current quasielastic scattering is the signal process in modern neutrino oscillation experiments and the main tool for the reconstruction of the incoming neutrino energy. Exploiting effective field theory, we factorize neutrino-nucleon quasielastic cross sections into soft, collinear, and hard contributions. We evaluate soft and collinear functions from QED and provide a model for the...
The Large Enriched Germanium Experiment for Neutrinoless 𝛽𝛽 Decay (LEGEND) is a program searching for neutrinoless double beta decay of $^{76}$Ge using high-purity germanium detectors operating in an active liquid argon veto. The first phase, LEGEND-200, is presently under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy and is scheduled to begin data taking in late...
Sterile neutrinos are a well motivated facet of the new physics landscape. From their role in the mechanism through which Standard Model (SM) neutrinos acquire mass, to their potential explanation of anomalies in oscillation experiments and even as Dark Matter candidates, these hypothetical particles are thought to play a central part in the near future of particle physics. Many models of...
The NEXT (Neutrino Experiment with a Xenon TPC) collaboration aims at the sensitive search of the neutrino-less double beta decay (ββ0ν) of 136Xe at the Laboratorio Subterraneo de Canfranc (LSC). The observation of such a lepton-number-violation process would prove the Majorana nature of neutrinos, providing also handles for an eventual measurement of the neutrino absolute mass. A first...
The ability to identify jets stemming from the hadronisation of b-quarks (b-jets) is crucial for the physics program of ATLAS.
The higher pileup conditions and the growing interest for measurements including c-jets and for searches in the high transverse momentum regime make the task more and more complex. The algorithms responsible for establishing the jet’s flavour are evolving quickly,...
The ATLAS experiment has performed measurements of B-meson rare decays proceeding via suppressed electroweak flavour changing neutral currents, and of mixing and CP violation in the neutral Bs meson system.
This talk will focus on the latest results from the ATLAS collaboration, such as rare processes B^0_s → mu mu and B^0 → mu mu, and CP violation in the B_s^0 —> J/psi phi decays. In the...
The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS experiment at the LHC. This sampling device uses steel plates as an absorber and scintillating tiles as the active medium and its response is calibrated to the electromagnetic scale by means of several dedicated calibration systems. The accurate time calibration is important for the energy...
