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arXiv2013

Experimental overview of charmonium spectroscopy

In this talk, I review the recent experimental results on charmonium spectroscopy from BESIII, Belle, BaBar and CLEOc. Below the open-charm threshold, the masses and widths of spin-singlet states eta_c, eta_c(2S), h_c are measured with high precision. Above the threshold, chi_{c2}(2P) is identified in the process gamma gamma -> chi_{c2}(2P) -> gamma D bar{D}; Evidence of X(3823) is found in the M(chi_{c1} gamma) invariant-mass distribution for B -> gamma chi_{c1} K decays, the measured properties are consistent with the missing psi_2(1^{2}D_2) state.

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arXiv2013

Status and prospects for the LHCb upgrade

High-precision measurements performed by the LHCb collaboration have opened a new era in charm physics. Several crucial measurements, particularly in spectroscopy, rare decays and CP violation, can benefit from the increased statistical power of an upgraded LHCb detector. The upgrade of LHCb detector, its software infrastructure, and the impact on charm physics are discussed in detail.

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arXiv2013

Performance of Irradiated Thin Edgeless N-on-P Planar Pixel Sensors for ATLAS Upgrades

In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. Because of its radiation hardness and cost effectiveness, the n-on-p silicon technology is a promising candidate for a large area pixel detector. The paper reports on the joint development, by LPNHE and FBK of novel n-on-p edgeless planar pixel sensors, making use of the active trench concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology, a complete overview of the electrical characterization of several irradiated samples will be discussed. Some comments about detector modules being assembled will be made and eventually some plans will be outlined.

physics.ins-det↗

arXiv2013

A comment on estimating sensitivity to neutrino mass hierarchy in neutrino experiments

Recently it has been proposed, in the context of experiments designed to resolve the neutrino mass hierarchy, to use the average posterior probability of one of the hypotheses as a measure of sensitivity of future experiments. This has led to sensitivity estimates that are drastically lower than common conventions. We point to the fact that such estimates can be severely misleading: the probability that an experiment would actually produce a result similar to the average value can be in fact negligibly small. We emphasize again the simple relation between median significance and the likelihood ratio evaluated with the ``Asimov'' data set, which can be used to express experimental sensitivity in Bayesian terms as well.

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arXiv2013

Snowmass 2013 Computing Frontier Storage and Data Management

The data storage and data management needs are summarized for the energy frontier, intensity frontier, cosmic frontier, lattice field theory, perturbative QCD and accelerator science. The outlook for data storage technologies and costs is then outlined, followed by a summary of the current state of data, software and physics analysis capability preservation. The HEP outlook is summarized, pointing out where future data volumes may strain against what is technologically and financially feasible. Finally recommendations for areas of particular attention and action are made.

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arXiv2013

CP Violation and Mixing in Multi-body $D$ decays

We present recent LHCb results and future prospects for CP violation and mixing measurements in multi-body charm decays. The complex amplitude structure of multi-body decays provides unique sensitivity to CP violation localised in certain phase space regions. A model-independent search in the phase space of D->pi+pi-pi+pi- and D->K+K-pi+pi- decays showed no evidence for localised CP violation. If one assumes the no CP violation hypothesis, the probability of getting the observed results is 9.1% and 41%, respectively. The model-independent determination of gamma from B->DK requires external input to account for the interference of D0 and D0bar amplitudes to the same final state. Previously this input could only be obtained at the charm threshold, but recently it has been proposed that D mixing can provide complimentary information. For the example of D->K+pi-pi+pi- decays, it is shown that charm mixing can be used to considerably improve current constraints on the coherence factor and average strong phase difference, with existing data.

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arXiv2013

Measurement of the $ν_μ$ flux and inclusive charged current cross section at T2K's near detector

We present the first measurement of the muon neutrino spectrum at the T2K near detector, ND280, using the data collected at the JPARC acc\ elerator facility in Tokai, Japan. ND280 is located 280 meters downstream from the target and 2.5$^\circ$ off-axis from the direction of the beam. The measured spectrum at ND280 constrains the flux and cross section uncertainties\ in the T2K oscillation analysis. We select inclusive charged-current (CC) events from muon \ neutrinos in ND280. These are separated into a charged current quasi-elastic (CCQE) enhanced sample and a CC non\ -QE sample. We then fit the muon spectrum for both samples to extract flux and cross section parameters, which are used as inputs into T2K's os\ cillation analysis. We separately produce a flux-averaged differential inclusive CC cross-se\ ction in the 2-dimensional plane of muon momentum and angle. For the cross-section measurement the flux is given by the MC and tuned to data from the NA61 experiment. We present the event selection, detector uncertainties, and final measurement result for both the spectrum and for the cross-section.

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arXiv2013

Baryon Number Violation

This report, prepared for the Community Planning Study - Snowmass 2013 - summarizes the theoretical motivations and the experimental efforts to search for baryon number violation, focussing on nucleon decay and neutron-antineutron oscillations. Present and future nucleon decay search experiments using large underground detectors, as well as planned neutron-antineutron oscillation search experiments with free neutron beams are highlighted.

hep-ph↗

arXiv2013

Atomic ionization of germanium due to neutrino magnetic moments

An ab initio calculation of atomic ionization of germanium (Ge) by neutrinos was carried out in the framework of multiconfiguration relativistic random phase approximation. The main goal is to provide a more accurate cross section formula than the conventional one, which is based on the free electron approximation, for searches of neutrino magnetic moments with Ge detectors whose threshold is reaching down to the sub-keV regime. Limits derived with both methods are compared, using reactor neutrino data taken with low threshold germanium detectors.

hep-ph↗

arXiv2013

The search for $D^0\to{}e^{\pm}μ^{\mp}$

An overview is presented of a method to search for $D^0\to{}e^{\pm}μ^{\mp}$ with LHCb data. In order to reduce combinatorial backgrounds, tagged $D^0$ candidates from the decay $D^{\ast+}\to{}D^0π^+$ are used. This measurement is performed with respect to $\mathcal{B}\left(D^0\to{}π^+π^-\right)$, which cancels uncertainties in the luminosity and $D^{\ast+}$ production cross-section. It is estimated that using $3\,\mathrm{fb}^{-1}$ of LHCb data an upper limit can be attained of $\mathcal{O}\left(10^{-7}\right)$ at a $90\%$ confidence level.

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arXiv2013

Studies of charmed baryons at LHCb

We report a search for the doubly charmed baryon $Ξ_{cc}^{+}$ through the decay $Ξ_{cc}^{+} \to Λ_{c}^{+} K^{-} π^{+}$, using a data sample corresponding to an integrated luminosity of $0.65~\mathrm{pb^{-1}}$ of $pp$ collisions at $\mathrm{\sqrt{s}} = 7~\mathrm{TeV}$. In the mass range 3300-3800$~\mathrm{MeV}/c^{2}$ no significant signal is observed. Upper limits at $95\%$ confidence level are set on $R$, the ratio of the production cross section of the $Ξ_{cc}^{+}$ times the relevant branching fraction over the $Λ_{c}^{+}$ cross section, as a function of the $Ξ_{cc}^{+}$ mass and lifetime. The largest upper limits on $R$ over the investigated mass range are $R<1.5\times10^{-2}$ for a lifetime of $100~\mathrm{fs}$ and $R<3.9\times10^{-4}$ for a lifetime of $400~\mathrm{fs}$.

hep-ex↗

arXiv2017

Measurement of D* Production in Diffractive Deep Inelastic Scattering at HERA

Measurements of $D^{*}(2010)$ meson production in diffractive deep inelastic scattering $(5<Q^{2}<100~{\rm GeV}^{2})$ are presented which are based on HERA data recorded at a centre-of-mass energy $\sqrt{s} = 319{\rm~GeV}$ with an integrated luminosity of $287$ pb$^{-1}$ collected by the H1 detector. The reaction $ep \rightarrow eXY$ is studied, where the system $X$, containing at least one $D^{*}(2010)$ meson, is separated from a leading low-mass proton dissociative system $Y$ by a large rapidity gap. The kinematics of $D^{*}$ candidates are reconstructed in the $D^{*}\rightarrow K ππ$ decay channel. The measured cross sections compare favourably with next-to-leading order QCD predictions, where charm quarks are produced via boson-gluon fusion and they are independently fragmented to the $D^{*}$ mesons. The calculations rely on the collinear factorisation theorem and are based on diffractive parton densities previously obtained by H1 from fits to inclusive diffractive cross sections. The data are further used to determine the diffractive to inclusive $D^{*}$ production ratio in deep inelastic scattering.

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arXiv2017

Search for Double Charged Particles as Direct Test for Dark Atom Constituents

The nonbaryonic dark matter of the Universe is assumed to consist of new stable particles. Stable particle candidates for cosmological dark matter are usually considered as neutral and weakly interacting. However stable charged leptons and quarks can also exist hidden in elusive dark atoms and can play a role of dark matter. Such possibility is strongly restricted by the constraints on anomalous isotopes of light elements that form positively charged heavy species with ordinary electrons. This problem might be avoided, if stable particles with charge -2 exist and there are no stable particles with charges +1 and -1. These conditions cannot be realized in supersymmetric models, but can be satisfied in several alternative scenarios, which are discussed in this paper. The excessive -2 charged particles are bound with primordial helium in O-helium atoms, maintaining specific nuclear-interacting form of the dark matter. O-helium dark matter can provide solution for the puzzles of dark matter searches. The successful development of composite dark matter scenarios appeals to experimental search for doubly charged constituents of dark atoms. Estimates of production cross section of such particles at LHC are presented and discussed. Signatures of double charged particles in the ATLAS experiment are outlined.

hep-ph↗

arXiv2017

The invariant and helicity amplitudes in the transitions $Λ_b\toΛ^\ast(\frac12^\pm,\frac32^\pm)+J/ψ$

We present results for the invariant and helicity amplitudes in the transitions $Λ_b\toΛ^{(\ast)}(J^P)+J/ψ$ where the $Λ^{(\ast)}(J^P)$ are $Λ(sud)$-type ground and excited states with $J^P$ quantum numbers $J^P=\frac12^{\pm},\frac32^{\pm}$. The calculations are performed in the framework of a covariant confined quark model. This analysis is important for the identification of the hidden charm pentaquark states $P_c^+(4380)$ and $P_c^+(4450)$ which were discovered by the LHCb Coll. We also discuss the possible New Physics effects in the exclusive decays $\bar{B}^0 \to D^{(\ast)} τ^- \barν_τ$. We extend the Standard Model by taking into account right-handed vector (axial), left- and right-handed (pseudo)scalar, and tensor current contributions. The $\bar{B}^0 \to D^{(\ast)}$ transition form factors are calculated in the full kinematic $q^2$ range by employing a covariant quark model.

hep-ph↗

arXiv2017

Study of double parton scattering processes with heavy quarks

Study of double parton scattering processes (DPS) involving heavy quarks provides the most precise probing of factorization hypothesis for DPS for gluon-mediated processes. The measurements are performed for the different final states, including open and hidden-flavour hadrons and for the different kinematic ranges of incoming gluons

hep-ex↗

arXiv2018

Exotics at Our Home

I. Light Scalars as Four-quark States II. Isotensor Tensor Tensor E(1500-1600) State III. X(3872) State as Charmonium χ_{c1}(2P) IV. Two-gluon Annihilation of Charmonium χ_{c2}(2P) There are considered problems of the exotic states, in which the author with his collaborators has made clear physical predictions, considerable part of wich is supported by experement already

hep-ph↗

arXiv2018

A Cylindrical GEM Inner Tracker for the BESIII experiment at IHEP

The Beijing Electron Spectrometer III (BESIII) is a multipurpose detector that collects data provided by the collision in the Beijing Electron Positron Collider II (BEPCII), hosted at the Institute of High Energy Physics of Beijing. Since the beginning of its operation, BESIII has collected the world largest sample of J/ψ and ψ(2s). Due to the increase of the luminosity up to its nominal value of 10^33 cm-2 s-1 and aging effect, the MDC decreases its efficiency in the first layers up to 35% with respect to the value in 2014. Since BESIII has to take data up to 2022 with the chance to continue up to 2027, the Italian collaboration proposed to replace the inner part of the MDC with three independent layers of Cylindrical triple-GEM (CGEM). The CGEM-IT project will deploy several new features and innovation with respect the other current GEM based detector: the μTPC and analog readout, with time and charge measurements will allow to reach the 130 μm spatial resolution in 1 T magnetic field requested by the BESIII collaboration. In this proceeding, an update of the status of the project will be presented, with a particular focus on the results with planar and cylindrical prototypes with test beams data. These results are beyond the state of the art for GEM technology in magnetic field.

physics.ins-det↗

arXiv2018

Indirect search for color octet electron at PWFA-LC

Indirect search for color octet electron at Plasma Wake Field Accelerator- Linear Collider (PWFA-LC) has been considered. It is shown that color octet electron masses can be probed up to 17.7 TeV at PWFA-LC with three years integrated luminosity. In addition, the compositeness scale can be probed up to 38.5 TeV.

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