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This will be the 31st meeting in this series of annual international multidisciplinary meetings, created in 1989 by Jean Trân Than Vân and which has in the past covered many topics in physics, astronomy and biology. All sessions take place in the Château of Blois, a beautiful renaissance castle which has housed many French kings, and notably François 1st. The 31st Rencontres de Blois on "Particle Physics and Cosmology" (Blois2019) will emphasize the increasing interplay between high energy accelerator based physics and cosmology. The conference will consist of plenary sessions for invited in-depth oral presentations (review talks) and contributed papers, in the form of relatively short oral papers. We will aim to achieve a balance between review talks, provocative talks given by recognized specialists, and shorter contributions. Special emphasis is being placed on active participation by younger researchers and post-docs. Parallel sessions are foreseen, and are being organised as the need arises.
Simple generalizations of well known BSM scenarios can lead to dramatic signals at colliders, providing interesting theoretical playgrounds and motivating new methods to isolate non-standard experimental signals. In this talk I will consider warped extra-dimensional models with multiple branes in the IR and discuss various possibilities and related collider signals. One generic feature of this scenario is the presence of three boson final state, with double resonant structure, and non-standard boosted fat jets in large parts of parameter space. These signals require dedicated strategies at LHC, with varying sophistication. I will present these methods, which are also relevant for many other BSM scenarios. This framework also motivates studying conformal dark sectors, with non-gravitational interactions to the SM. Motivating the minimal interaction to the conformal dark sector, I will discuss the collider and cosmological bounds on this scenario.
The high-precision measurement of the W-boson mass (MW) offers the possibility of a stringent test of the Standard Model of the electroweak and strong interactions. The uncertainty of the current world average for MW is 0.2 per mille and the ATLAS and CMS collaborations at CERN are planning to measure MW reaching a final error of 15 MeV or eventually 10 MeV: such a precision requires a careful assessment of the theoretical systematics affecting the W-boson mass measurement at hadron colliders. The main sources of theoretical uncertainties are discussed focusing in particular on the electroweak and mixed QCD-electroweak effects.
KM3NeT is a distributed research infrastructure in the Mediterranean Sea that will host a gigaton-scale neutrino telescope (ARCA) for high-energy neutrino astronomy, and a megaton-scale detector (ORCA) for neutrino oscillation studies with atmospheric neutrinos. ORCA is optimised for determining the neutrino mass ordering (NMO) by observing matter effects in atmospheric neutrino oscillations, providing a sensitivity to the NMO of approximately 3σ after 3 years of operation with the full detector. It will also measure the atmospheric mixing parameters Δm232 and θ23 using both the muon neutrino disappearance and tau neutrino appearance channels. Determining the tau neutrino appearance probability with unprecedented precision will provide for a powerful test of the unitarity of the 3-flavour mixing matrix. The observation of neutrino oscillations over a wide range of baselines and energies will provide broad sensitivity to new physics such as non-standard neutrino interactions (NSI) and sterile neutrinos.
In recent years, major milestones in neutrino physics were accomplished at nuclear reactors: the smallest neutrino mixing angle $\theta_{13}$ was determined with high precision and the emitted anti-neutrino spectrum was measured at unprecedented resolution. However, two anomalies, the first one related to the absolute flux and the second one to the spectral shape, have yet to be solved. The flux anomaly is known as the Reactor Antineutrino Anomaly (RAA) and could be caused by the existence of a light sterile neutrino eigenstate participating in the neutrino oscillation phenomenon. The RAA is best explained by an oscillation with parameters $\sin^{2}(2 \theta_{ee}) = 0.14$ and $\Delta m_{41}^{2} = 2.4~\textrm{eV}^{2}$.
The STEREO experiment was built to probe this parameter region. It is one of the first running experiments built to search for eV sterile neutrinos and takes data since end of 2016 at ILL Grenoble (France). At a short baseline of 10 metres, it measures the anti-neutrino flux and spectrum emitted by a compact research reactor. The segmentation of the detector in six cells allows for independent measurements of the neutrino spectrum at multiple baselines. An active-sterile flavour oscillation could be unambiguously detected, as it distorts the spectral shape of each cell's measurement differently. In 2018, STEREO was able to exclude significant part of the parameter space with its first data set of 66 (138) days reactor-on (off) data.
In this contribution, an overview on the STEREO experiment will be given. Furthermore, updated results with the new increased dataset of 185 (233) days of reactor-on (off) will be presented.
The GERDA experiment searches for the neutrinoless double beta decay ($0\nu\beta\beta$) of $^{76}$Ge. It uses HPGe detectors enriched in the isotope $^{76}$Ge, which are directly immersed into liquid argon (LAr). In Phase II, the radio-pure cryogenic liquid acts not only as cooling medium for the detectors and passive shielding but also as active shielding. Due to the active veto system detecting LAr scintillation light, the superior energy resolution and an improved background recognition, already the initial release of Phase II showed a background rate in the energy region of interest (ROI), after pulse shape discrimination and liquid argon veto cuts, in the range of a few counts/(ROI$\cdot$ton$\cdot$yr). This made GERDA the first $0\nu\beta\beta$ experiment being background free up to its design exposure of 100 kg$\cdot$yr.
With the latest data release in mid 2018, comprising a total exposure of 82.4 kg$\cdot$yr, GERDA remained in the background free regime. It is the first experiment to surpass a median sensitivity on the half-life of $10^{26}$ yr for $0\nu\beta\beta$ decay. No signal has been observed and a lower limit of $0.9\cdot10^{26}$ yr (90 % C.L.) has been derived. Meanwhile the experiment has been upgraded by deploying also a new type of germanium detector and by improving the LAr instrumentation. In this talk we will present the basic concept of the GERDA design and the present physics results. Moreover, we will focus on the background contributions at Q$_{\beta\beta}$. Results on the performance of the upgraded experimental setup will be discussed.
ABSTRACT: The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay (0νββ) that has been able to reach the one-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a compact cylindrical structure of 19 towers. The construction of the experiment was completed in August 2016 with the installation of all towers in the cryostat. Following a cooldown, diagnostic, and optimization campaign, routine data-taking began in spring 2017. In this talk, we present the 0νββ results of CUORE from examining a total TeO2 exposure of 86.3 kg∙yr, characterized by an average energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV∙kg∙yr). In this physics run, CUORE placed the current best lower limit on the 130Te 0νββ half-life of > 1.3 × 10^25 yr (90% C.L.). We then discuss the additional improvements in the detector performance achieved in 2018, the latest evaluation of the CUORE background budget, and we finally present the most precise measurement of the 130Te 2νββ half-life to date.
A convincing observation of neutrino-less double beta decay (0$\nu$DBD) relies on the possibility of operating high-energy resolution detectors in background-free conditions.
Scintillating cryogenic calorimeters are one of the most promising tools to fulfill the requirements for a next-generation experiment. Several steps have been taken to demonstrate the maturity of this technique, starting form the successful experience of CUPID-0.
The CUPID-0 experiment collected 10 kg*y of exposure, running 26 Zn$^{82}$Se crystals during two years of continuous detector operation. The complete rejection of the dominant alpha background was demonstrated, measuring the lowest counting rate in the region of interest for this technique. Furthermore, the most stringent limit on the Se-82 0$\nu$DBD was established.
In this contribution we present the final results of CUPID-0 Phase I, including a detailed model of the background and the measurement of the 2$\nu$DBD half-life.
The LUMINEU project has recently set up a technology for the development
of high-performance scintillating bolometers containing the nuclide
100Mo, in the framework of the R&D activities towards the proposed
tonne-scale neutrinoless double beta decay experiment CUPID. Using in
particular Li2100MoO4 detectors, high energy resolution (5-6 keV FWHM at
2615 keV), excellent alpha background rejection (>99.9%) and extreme
radiopurity (below 0.005 mBq/kg U/Th intrinsic activity) have been
demonstrated in multiple tests with remarkable reproducibility.
Moreover, with only 0.1 kg x y of 100Mo exposure, the measured
two-neutrino double beta decay half-life is one of the most precise
values ever reported. As a follow-up of this activity, a demonstrator
named CUPID-Mo is collecting data in the Modane underground laboratory
in France. CUPID-Mo consists of twenty 0.2-kg 100Mo-enriched Li2MoO4
scintillating bolometers (containing more than 2 kg of 100Mo) to be
operated for at least 0.5 yr, providing a sensitivity to 100Mo larger
than 10^24yr. CUPID-Mo is a very important demonstrator for the
implementation of CUPID, as the CUPID-Mo detectors follow closely the
configuration chosen for the baseline of CUPID.
Abstract:
We have continued discussions of neutrino electromagnetic properties [1,2] and have performed a detailed and accurate study [3] of the electromagnetic interactions of massive neutrinos in the theoretical formulation of low-energy elastic neutrino-electron scattering.
Using the derived new expression for a neutrino electromagnetic scattering cross section [3],
we obtained [4] a new bound on the neutrino charge radii from COHERENT elastic neutrino-nucleus scattering data. Worthy of note, our paper [4] has been included by the Editors Suggestion to the Phys.Rev.D “Highlights of 2018”.
A reasonable part of the proposed talk is dedicated to results of our recently performed detailed studies of new effects in neutrino spin, spin-flavour and flavor oscillations under the influence of the transversal matter currents [5] and a constant magnetic field [6]. These two effects can be summarized as follows:
1) it is shown [5] that neutrino spin and spin-flavor oscillations can be engendered by weak interactions of neutrinos with the medium in the case when there are the transversal matter currents (for the appearance of neutrino spin oscillations in this case there is no need either for a neutrino nonzero magnetic moment or for an external magnetic field); different possibilities for the resonance amplification of oscillations are discussed, the neutrino Standard Model and non-standard interactions are accounted for;
2) within a new treatment [6] of the neutrino flavor, spin and spin-flavour oscillations in the presence of a constant magnetic field, that is based on the use of the exact neutrino stationary states in the magnetic field, it is shown that there is an interplay of neutrino oscillations on different frequencies; in particular: a) the amplitude of the flavour oscillations νLe↔ νLμ at the vacuum frequency is modulated by the magnetic field frequency, and b) the neutrino spin oscillation probability (without change of the neutrino flavour) exhibits the dependence on the neutrino mass square difference Δm2 .
The discovered new phenomena in neutrino oscillations should be accounted for reinterpretation of results of already performed experiments on detection of astrophysical neutrino fluxes produced in astrophysical environments with strong magnetic fields and dense matter. These new neutrino oscillation phenomena are also of interest [7,8] in view of future experiments on observations of supernova neutrino fluxes with large liquid-scintillator detectors like JUNO, for instance.
References:
[1] C. Guinti and A. Studenikin,
“Neutrino electromagnetic interactions: A window to new physics”,
Rev. Mod. Phys. 87 (2015) 531-591.
[2] A.Studenikin,
“Neutrino electromagnetic interactions: A window to new physics - II”,
PoS EPS-HEP2017 (2017) 137.
[3] K. Kouzakov, A. Studenikin,
“Electromagnetic properties of massive neutrinos in low-energy
elastic neutrino-electron scattering”, Phys. Rev. D 95 (2017) 055013.
[4] M. Cadeddu, C. Giunti, K. Kouzakov, Y.F. Li, A. Studenikin, Y.Y. Zhang,
“Neutrino charge radii from COHERENT elastic neutrino-nucleus scattering”,
Phys. Rev. D 98 (2018) no.11, 113010.
[5] P. Pustoshny, A. Studenikin,
"Neutrino spin and spin-flavour oscillations in transversal
matter currents with standard and non-standard
interactions", Phys.Rev. D98 (2018) no.11, 113009.
[6] A. Popov, A. Studenikin, "Neutrino eigenstates and flavour, spin and spin-flavour oscillations in a constant magnetic field ", Eur.Phys.J. C79 (2019) no.2, 144.
[7] C. Giunti, K. Kouzakov, Y. F. Li, A. Lokhov, A. Studenikin, S. Zhou,
Electromagnetic neutrinos in laboratory experiments and astrophysics,
Annalen Phys. 528 (2016) 198.
[8] J.S. Lu, Y.-F. Li and S. Zhou,
Getting the most from the detection of Galactic supernova neutrinos in future large liquid-scintillator detectors, Phys. Rev. D 94 (2016) 023006.
Just after inflation, due to the coupling between photons and baryons, sound waves were created and propagated in the primordial plasma until recombination. At that time, these so called Baryonic Acoustic Oscillations (BAO) left their imprint in the matter distribution. This feature is still measurable as a small excess (1%) in the matter 2-point correlation function.
This BAO peak can be measured both transversely and radially. The transverse measurement yields the ratio of the angular-diameter distance to the sound horizon scale at recombination (da(z)/rs), while the radial measurement gives access directly to the expansion rate through the quantity H(z)rs.
First detected in the Luminous red galaxy correlation function at redshifts between 0.16 and 0.47 (Einseinstein et al., 2005 and Cole et al., 2005), other matter tracers have since be used to access to other redshift ranges. The highest redshift measurement has been performed at z = 2.34, using the Lya forests seen in high redshift quasar spectra.
I will present the latest BAO measurement based on Lya forests at mean redshift 2.34 using the SDSS-IV – eBOSS data. This analysis yields 3.3 % and 4.4 % precision on the measurements of the H(z)rs and Da(z)/rs respectively.
We discuss a ∼ 3 σ signal (local) in the light Higgs-boson search in the diphoton decay mode at ∼ 96 GeV as reported by CMS, together with a ∼ 2 σ excess (local) in the b ̄b final state at LEP in the same mass range. We interpret this possible signal as a Higgs boson in the 2 Higgs Doublet Model with an additional real Higgs singlet (N2HDM). We find that the lightest Higgs boson of the N2HDM can perfectly fit both excesses simultaneously, while the second lightest state is in full agreement with the Higgs-boson measurements at 125 GeV, and the full Higgs-boson sector is in agreement with all Higgs exclusion bounds from LEP, the Tevatron and the LHC as well as other theoretical and experimental constraints. We show that only the N2HDM type II and IV can fit both the LEP excess and the CMS excess with a large ggF production component at ∼ 96 GeV. We derive bounds on the N2HDM Higgs sector from a fit to both excesses and describe how this signal can be further analyzed at the LHC and at future e+e− colliders, such as the ILC.
I present the most general bounds one can make on the phenomenology of hidden sectors with conformal symmetry, which are weakly coupled to the SM. Without the need to specify their particle or symmetry content, we have derived a consistent description of final states in a generic CFT, and have applied it to current experimental runs. Our analysis covers a wide range of phenomena: we investigate collider searches (LEP, LHC run 2), a number of low-energy experiments, and effects on cosmology and astrophysical objects. The combined results form a guide to model building with conformal sectors.
Observations at astronomical and cosmological levels suggest the existence of a new form of non-luminous matter that interacts gravitationally with baryonic matter. The XENON1T detector, located at the underground National Laboratory of Gran Sasso in Italy, was designed and built to detect nuclear recoils from particles that may constitute the nature of this Dark Matter, their existence emerging in theories beyond the Standard Model under the generic name of Weakly Interacting Massive Particles (WIMPs). Using a 2t of ultra-pure liquid Xenon as target mass, this double phased TPC which was operational from late 2016 to 2018, after a 1 $\text{t}\times\text{yr}$ exposure, exhibiting an ultra-low electronic recoil background, did not observed a significant excess of the number of events over the expected background, thus achieving to provide the most stringent limit, to date, on the WIMP-nucleon spin-independent elastic scattering cross-section for WIMP masses above 6 $\text{GeV}/\text{c}^2$.
In this talk I will present an overview of the XENON1T experiment, its latest results, as well as the prospects for its immediate upgrading, the XENONnT detector that is expected to increase the sensitivity by more than one order of magnitude.
The EDELWEISS collaboration is performing direct searches for light Dark Matter particles using cryogenic germanium detectors equipped with a charge and thermal signal readout. This versatile and highly performing technology opens new possibilities for searches for signals involving either electrons or nuclear recoils. This is attested to by results on Axion-Like Particles in the keV range, and by the attainment of the first sub-GeV spin-independent dark matter limit based on a germanium target. The search has been extended to Strongly Interacting Particles (SIMP) down to 45 MeV by exploiting the Migdal effect. New results on SIMPs with spin-dependent interactions will also be presented.
The COSINE experiment aims at direct detection of Weakly Interacting Massive Particle (WIMP) using NaI(Tl) detectors, the same target material as the DAMA/LIBRA which claims to observe an annually modulated WIMP signal. The first phase of the experiment with ~106 kg of NaI(Tl) crystals consists of several shield structures including a liquid scintillator veto counter and installed at the Yangyang underground laboratory in Korea. The experiment started physics data taking in late September 2016 and several WIMP search analyses have been performed based on the 2 keV energy threshold with about 3 counts/day/kg/keV background rate in a region between 2 and 6 keV. In this talk, recent results and the prospect of the COSINE-100 experiment will be presented.
ANAIS (annual modulation with NaI Scintillators) is a dark matter direct detection experiment located at the Canfranc Underground Laboratory (LSC, Spain). Its main goal is to proof or refute in a model independent way the DAMA/LIBRA positive result: an annual modulation in the low-energy detection rate compatible with the expected signal induced by WIMPs in the galactic halo. This signal, observed during more than 20 years, is in strong tension with the negative results of other very sensitive experiments, but a direct comparison using the same target material (NaI(Tl)) is still lacking. ANAIS-112, consisting of 112.5 kg of NaI(Tl) scintillators, was installed at the LSC in August 2017 and to the date it has accumulated more than 1.5 y of data. In this talk we will present the annual modulation analysis corresponding to an exposure of 157.55 kgxy and the ANAIS-112 projected sensitivity for the scheduled 5 y of operation.
The evidence for the existence of Dark Matter is well supported by many cosmological observations. Separately, long standing problems within the Standard Model point to new weakly interacting particles to help explain away unnatural fine-tunings. The axion was originally proposed to explain the Strong-CP problem, but was subsequently shown to be a strong candidate for explaining the Dark Matter abundance of the Universe. ABRACADABRA is a proposed experiment to search for ultralight axion Dark Matter, with a focus on the mass range $10^{-14} < m_a < 10^{-6}$ eV. We search for these axions and other axion like particles (ALPs) through a modification to Maxwell's equations, which cause strong magnetic fields to source weak oscillating electrical currents parallel to the field. In this talk, I will describe the working principle behind the ABRACADABRA experiment, present the first results from a prototype experiment called ABRACADABRA-10 cm that we have built at MIT, and discuss prospects for future versions of ABRACADABRA.
The NEWSdm experiment, based on nuclear emulsions, is proposed to measure the direction of WIMP-induced nuclear recoils. We discuss the potentiality, both in terms of exclusion limits and potential discovery, of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution. We also report results of the test exposure conducted in Gran Sasso last year.
The DARWIN experiment is a proposed next-generation dual-phase time projection chamber which will operate 50 tonnes of natural xenon and whose primary goal will be to explore the entire experimentally accessible parameter space for WIMPs. Besides its unprecedented sensitivity to WIMPS above a mass of 5 GeV/c2, such a large detector, with its low-energy threshold and ultra low background level, will be sensitive to other rare interactions as well. DARWIN will measure low energy solar neutrinos with a high precision, observe the coherent neutrino-nucleus interaction and detect galactic supernovae. In addition it will search for axions, axion-like particles and the neutrinoless double beta decay of 136Xe. We discuss here the concept of DARWIN, the ongoing R&D and the sensitivity for the different physics channels.
With the goal of increasing the precision of NLO QCD prediction for pp -> ttA in the dilepton decay channel we study cross section ratios. Our analysis is based on fully realistic matrix elements including off-shell effects and interferences between resonance and continuum contributions. Focusing on the LHC at 13 TeV we present numerical results for inclusive and differential ratios and a detailed study of theoretical uncertainties stemming from renormalization/factorization scales as well as the impact of the parton distribution functions.
The LHC can be considered as a photon-photon collider with photons produced in ultraperipheral collisions of charged particles. Ultraperipheral collision is a kind of collision when the colliding particles pass at large distance from each other and collide with their electromagnetic fields. The particles remain intact after the collision. Electromagnetic field of an ultrarelativistic particle can be represented as a bunch of almost real (equivalent) photons distributed according to a known spectrum. Thus, ultraperipheral collisions at the LHC are a rich source of events to study $\gamma \gamma \to$ something reactions.
Photon flux in an ultraperipheral collision is proportional to $(Z_1 Z_2)^2$ where $Z_1$ and $Z_2$ are charges of the colliding particles. In this respect collisions of lead ions with $Z = 82$ look very promising for the search of New Physics in photon-photon collisions even though the $pp$ luminosity is a lot higher. However, the invariant mass of the produced system is limited by the maximum momentum of a virtual photon that the colliding particle can interact with in its reference frame without breaking apart. For the protons colliding with the energy of 13 TeV, the invariant mass can reach 2.8 TeV, while in the case of lead-lead collision with the energy of 5.02 TeV/(nucleon pair) production cross section falls rapidly after 100 GeV.
Production cross section of ultraperipheral collisions is very sensitive to electromagnetic form factors of the colliding particles. The data for $^{208}$Pb available in the literature is somewhat controversial. Nevertheless, the calculated production cross section for a pair of muons closely follows the experimental points. Production of muons in proton-proton collisions is described within the experimental uncertainty.
Ultraperipheral collisions at the LHC can be used to improve limits on supersymmetry in the region where chargino and neutralino masses are nearly equal. Final state protons can be registered by the forward detectors (ATLAS Forward Proton Detector or CMS-TOTEM Precision Spectrometer), and momenta of charginos produced in the collision are known. This information is used to greatly reduce the background from the Standard Model processes.
The talk is mostly based on the paper arXiv:1806.07238.
We summarize the most recent cosmological results from the Dark Energy Survey (DES). By combination of different probes (weak lensing, large scale structure, baryonic acoustic oscillations and supernovae Ia), DES has for the first time, for a galaxy survey, reached a precision in the cosmological parameters of the order of cosmic microwave background experiments. So far, no significant deviations from the LCDM model have been found. In the upcoming years, DES will improve over its current results, which will help to elucidate whether we are on the verge of a new revolution in cosmology, through a breakdown of the LCDM model, or if, on the contrary, the concordance model still holds as the best explanation for the nature of the Universe.