Search

The goal of these proceedings is to review recent progress in studies of mesons with (hidden or open) charm or strangeness in nuclear matter. Particular focus is laid on the ϕ and D mesons which are particularly interesting in view of studying the effect of the partial restoration of chiral symmetry at finite density. Both effective theory approaches based on hadronic degrees of freedom and QCD methods involving quarks and gluons will be discussed.

The proposed Particle Factory detector at Turkish Accelerator Center (TAC-PF) aims to search for charm physics, CP violation and mixing of D0 mesons as well as new physics effects by investigating head-on collisions of 1 GeV electron from Energy Recovery Linac (ERL) with 3.56 GeV positrons from synchrotron storage ring. In this work, we constructed the TAC-PF detector design by using a recently developed framework namely Detector Description for High Energy Physics (DD4hep). The baseline TAC-PF detector design and its qualifications were summarized, followed by a general description.

We summarize the status of $|V_{cb}|$ and $|V_{ub}|$ determinations, including the long standing tension among exclusive and inclusive determinations. We also discuss $B$ meson semileptonic decays to excited states of the charm meson spectrum and leptonic and semileptonic $B$ decays into final states which include $\tau$ leptons., Comment: 12 pages, to be published in AIP Proceedings of the XI Quark Confinement and Hadron Spectrum Conference, Sep 8-12, 2014

The BESIII Experiment at the Beijing Electron Positron Collider (BEPC2) collected large data samples for electron-positron collisions with center-of-mass above 4 GeV during 2013 and 2014. In this mass region, there are several states that are yet to be understood. In this article we will discuss BESIII analyses of the exotic Zc states. We present the studies of their decays to hidden charm and open charm final states for both the charged and neutral Zc states.

In this paper we show the new set of parton distribution functions (PDFs) determined using new combined H1 and ZEUS data on neutral and charged current inclusive cross sections from all running periods (1994-2007). The combined data are used as the sole input to NLO and NNLO QCD analyses. The new set of PDFs is termed as HERAPDF2.0. Also we show an extended QCD analysis at NLO including the combined data on jet and charm production which enables the simultaneous determination of PDFs (HERAPDF2.0Jets) and the strong coupling constant from HERA data alone.

In this talk we present an approach to the Λb → J/ψK− p reaction, where we look at the invariant mass of K− p and also πΣ, with a view to determine the shape and production rate of the Λ(1405) resonance. We compare the results obtained with the analysis of the same reaction, made a posteriori by the LHCb collaboration, in which two pentaquark states were claimed. At the same time we show the results of another work, prompted by the findings of the LHCb collaboration, where we show that there is consistency with the results obtained in the study of the Λb → J/ψK− p reaction with other results previously reported about a hidden charm baryon state.

We discuss the effects of a strong magnetic field on B and D mesons, focusing on the changes of the energy levels and the masses of the bound states. Using the Color Evaporation Model we discuss the possible changes in the production of J/ψ and Υ. We briefly comment the recent experimental data.

We propose to investigate the gluon number fluctuations effects in deep inelastic electron-ion scattering at high energies. We estimate the nuclear structure function F2A(x,Q2), as well the longitudinal and charm contributions, using a generalization for nuclear targets of the Golec-Biernat-Wusthoff (GBW) model which describes the electron proton HERA data. Here we consider that the nucleus at high energies acts as an amplifier of the physics of high parton densities. For a first investigation we study the scattering with Ca and Pb nuclei. Our preliminary results predict that the effects of gluon number fluctuations are small in the region of the future electron ion collider.

The diffractive heavy quark cross sections are estimated considering photon-Pomeron interactions in hadron - hadron at RHIC, Tevatron, and CERN LHC energies. We assume the validity of the hard diffractive factorization and calculate the charm and bottom total cross sections and rapidity distributions using the diffractive parton distribution functions of the Pomeron obtained by the H1 Collaboration at DESY-HERA. Such processes are sensitive to the gluon content of the Pomeron at high energies and are a good place to constrain the behavior of this distribution. We also compare our predictions with those obtained using the dipole model, and verify that these processes are a good test of the different mechanisms for heavy quarks diffractive production at hadron colliders.

We report on charm production at LHC. The production of single cc pairs is calculated in the kt-factorization approachwith different unintegrated gluon distributions. Examples of transverse momentum distributions for charmed mesons are presented and compared to recent experimental results from LHC. Some missing strength is observed for most of UGDFs. Furthermore we discuss production of two cc pairs within double-parton scattering (DPS) and single-parton scattering (SPS) mechanisms. Surprisingly large cross sections, comparable to single cc pair production are predicted. We discuss first experimental results from LHCb collaboration on production of pairs of D mesons of the same flavour.

Atmospheric neutrino and muon fluxes come from cosmic ray interactions with air nuclei. Prompt leptons from charmed particle decays dominate the conventional leptonic flux from pion and kaon decays at sufficiently high energies. The IceCube Collaboration has published a measurement of the atmospheric neutrino energy spectrum up to neutrino energies of 400 TeV where the prompt neutrino flux is potentially important. They also set limits on the diffuse astrophysical flux of neutrinos for which the atmospheric neutrino flux is a background. A brief discussion of charm pair production in the atmosphere, including dipole models and the parton model with fixed-order plus next-to-leading log corrections (FONLL) is presented. Ultimately, a range of theory predictions consistent with current accelerator constraints on the cross section is needed.

We study the influence of possible molecular structures in the charmonium spectrum. We focus on the 0++, 1++ and 1−− sectors. In the first one we coupled the 23P0cc pair with DD, J/ψω, DsDs and J/ψφ channels and we obtain two states compatibles with the X(3945) and the Y(3940). In the second one we couple the 23P1cc state with the DD* channel and we obtain a dressed state compatible with the X(3940) and a new state that we assign to the X(3872). In the third one we include the 33S1 and 23D1 charmonium states coupled to DD, DD*, D*D*, DsDs, DsD*s and D*sD*s. In this calculation we obtain a new molecular state that could be the G(3900) or the controversial Y(4008) and two cc states dressed by the molecular components assigned to the ψ(4040) and the ψ(4160). Finally we perform a calculation in the five quark sector where we can describe the Λc(2940)+ as a ND* molecular state and predict a Λb(6248)+ state.

In the framework of the kT-factorization approach, the production of prompt photons in association with a heavy (charm or beauty) quarks at high energies is studied. The consideration is based on the O(αα2s) off-shell amplitudes of gluon-gluon fusion and quark-(anti)quark interaction subprocesses. The unintegrated parton densities in a proton are determined using the Kimber-Martin-Ryskin prescription. Our numerical predictions are compared with the D0 and CDF experimental data. Also we extend our results to LHC energies.

We investigate the production of a quark-antiquark pair in inclusive photon-proton scattering, considering distinct gluon distribution functions. The role played by the parton saturation effects is studied for the kinematic regime of the upcoming Large Hadron Electron Collider (LHeC). This proposed lepton-hadron (nucleus) collider will reach energies higher than the available at DESY HERA experiment. This fact will open a new regime to probe the gluon and sea quark distributions in nucleon and on nucleus. In deep inelastic scattering in lepton-hadron colliders, events with two jets and the scattered proton in the final state are predicted to be observable, with an important contribution from charm production. Thus, the contribution from heavy quarks should be investigated in details.

We present our new measurement of charm dimuon production in neutrino-iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15,340 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample (about 9 million events after all analysis cuts) to constrain the total systematic uncertainty to about 2%. The extraction of strange sea and charm production parameters is also discussed.

We report on a new determination of the MS charm quark mass from charmonium sum rules using perturbative QCD input at O(α3s). We establish two improvements over corresponding previous analyses: (i) all available experimental data for the hadronic R-ratio up to s = 10.538 GeV are included for the experimental moments and (ii) a detailed analysis of perturbative uncertainties (due to the truncation of the perturbative series) is carried out. Issue (i) avoids having to rely on theoretical model input in the data region 4.8 GeV

The Inner Tracking System of the ALICE experiment plays a crucial role in heavy flavour production measurements at central rapidity in Pb-Pb collisions thanks to its precise tracking and vertexing capabilities in a high-multiplicity environment. In view of the future luminosity increase at LHC, the ALICE experiment is developing an upgrade startegy where a new, more performant ITS is being proposed. Improving the tracking and particle identification performances, the resolution on the secondary vertices in the low momentum region as well as the read-out capabilities, the ITS will make new important measurements in the charm and beauty sector accessible in central heavy-ion collisions: the Λc baryon, B mesons and the total charm production cross section. In these proceeedings both the performances of a new ITS and some new accessible measurements of the heavy flavour physics in ALICE will be discussed.

Precision measurements of the masses and widths of the bottom baryon resonances Σb and Σ* and charm baryons Λc(2595), Λc(2625), Σc(2455), and Σc(2520) are reported. A new measurement of Λb production is described. The studies include the first measurement of the widths and isospin mass splittings of the members of the Σb family. The charm baryons are examined through their strong decays to the Λc ground state, and measurements of their mass differences relative to the ground state, and corresponding decay widths, are reported. The data were collected by the CDF and D0 detectors for 1.96 TeV proton-antiproton collisions during Run II at the Fermilab Tevatron.

A Large Ion Collider Experiment (ALICE) is one of the four experiments at the Large Hadron Collider (LHC), and it is dedicated to the study of ultra-relativistic heavy-ion collisions, with the goal of investigating the properties of the high-density state of QCD matter produced in such events. The first Pb-Pb collisions at a centre of mass energy of S = 2.76 TeV per nucleon pair were delivered by LHC in November 2010. In Pb-Pb collisions heavy quarks are regarded as sensitive probes of the interaction dynamics between the parton and the medium produced in such collisions as they are produced on a very short time scale in the initial hard scattering processes and they follow all the evolution of the medium. At the energies available at the LHC charm is produced with large cross section and therefore it is possible to measure its production with good statistical precision. The study of open charm hadrons such as D+, D0, D*+, Ds and Λc in heavy ion collision is of particular interest because it can provide s...

We report recent BABAR charm physics results, including CP violation studies in D+ → Ksπ+0 and D+ → Ksh+h+h−0, a study of the Dalitz plot of Ds+ → K+K−π+, measurements of the mass and width of the Ds1(2536)+, and a search for the non-hadronic, rare D0 decay to two photons.

Studies performed by the LHCb experiment concerning decays of charmed mesons are presented, using data collected during 2010. Results are presented on: a search for CP violation in the Dalitz plot of the decay D+→K−K+π+ and its charge conjugate; measurement of the difference in the CP asymmetry (ΔACP) in the decays D0→K+K− and D0→π+π−; measurement of the CP asymmetry of the lifetime of the D0 (AΓ) in the decay D0→K+K−.

Based on a short review of the current experimental status, future perspectives for the spectroscopy of charmed hadrons at PANDA will be discussed. The main emphasis is on the sector of D mesons and charmonium systems. In contrast to other experiments, PANDA will render possible high-precision spectroscopy for bound states of any quantum number. The expected detector performance is highlighted by simulation results of selected physics benchmark channels.

In this paper we describe a new small-scale test, requiring small quantities of energetic material, designed using our CHARM ignition and growth routine in the DYNA2D hydrocode. The new test is a modified gap test and uses detonating nitromethane to provide dynamic confinement (instead of a thick metal case) whilst exposing the sample to a long duration shock wave. This arrangement allows less reactive materials that are below their critical diameter, more time to react. We present details of the modelling of the test together with some preliminary experiments to demonstrate the potential of the new test method.

The single and double diffractive cross sections for heavy quarks production are evaluated at NLO accuracy for hadronic and heavy ion collisions at the LHC. Diffractive charm and bottom production is the main subject of this work, providing predictions for CaCa, PbPb and pPb collisions. The hard diffraction formalism is considered using the Ingelman‐Schlein model where a recent parametrization for the Pomeron structure function (DPDF) is applied. Absorptive corrections are taken into account as well. The diffractive ratios are estimated and theoretical uncertainties are discussed. Comparison with competing production channels is also presented.

Properties of some open and hidden charm exotic states which have been studied using the composite model are summarized. It is found that, their decay properties are consistent with the data and further data are necessary to discriminate the hadronic molecular interpretation from other interpretations.

We present a theoretical update for the inclusive charm production in deep inelastic scattering. From the soft‐gluon resummation at the threshold we derive all the threshold‐enhanced contributions of the gluon coefficient function for the charm structure function F2c at the next‐to‐next‐to‐leading order. Some numerical results are presented.

We present experimental results from the BaBar experiment on charm baryon spectroscopy and production studies, including studies of excited cascades produced in charm baryon decays. We review the discovery of new decay modes of known states and searches for predicted states.

The energy loss of heavy quarks in the hot and dense matter created in high‐energy nuclear collisions at RHIC, can be used to probe the properties of the medium. Both charm and beauty quarks contribute to the non‐photonic electrons through their semi‐leptonic decays. It is essential to determine experimentally the relative contributions of charm and beauty quarks to understand the observed suppression of non‐photonic electrons at high pT in central Au+Au collisions. The azimuthal angular correlations of non‐photonic electrons with hadrons as well as with the reconstructed D0 allow to disentangle the contributions of charm and beauty to the electron spectrum. We discuss the STAR measurement of non‐photonic electron‐D0 and non‐photonic electron‐hadron azimuthal correlations in p+p collisions at 200 GeV and explore the consequences for the heavy flavour suppression in heavy ion collisions at RHIC.

With an effective Lagrangian approach, we give a full analysis on the NN→NNππ and pp→pnπ+ reactions for proton beam energy from 1 to 1.5 GeV. The results are very consistent with the experiment data from CELSIUS, KEK, COSY, and so on. Based on these results, we consider the NN→NNππ and pp→pnπ+ for proton beam energy up to 4 GeV. Compare to the pp collisions, there are many benefits to study N* resonances in these two reactions. And for the high proton beam energy up to 15 GeV, we consider some new resonances with hidden charm which are definitely beyond three constituent quarks model in the pp→ppJ/ψ and pp→ppηc, where there are very nice places to find these new Ncc*. The predicted results about pp collisions can be looked for at the forthcoming PANDA/FAIR experiments.

The heavy quark‐antiquark potential is an important topic in QCD that involves perturbative as well as non‐perturbative methods. We construct the perturbative short‐distance part of the potential in coordinate space via a subtracted Fourier transform, covering the momentum region where perturbative QCD is applicable. This potential is matched at intermediate distances to the non‐perturbative long distance part from lattice QCD simulations. In addition to the static potential, quark mass dependent contributions and their effects on the quarkonium spectrum are discussed. Furthermore we derive charm and bottom quark masses in this approach.

We discuss new exotic nuclei which contain D and B mesons. As simplest systems, we consider D (B) bound systems with one nucleon and two nucleons. With respecting to the heavy quark symmetry, we derive the one pion exchange potential as a long range force as an interaction between D (B) meson and nucleon. We solve the Schrodinger equation with coupled channels, and investigate the DN (BN) bound states. We further discuss the possibility of existence of DNN (BNN). We discuss the possible observations of these exotic states in experiments in accelerator facilities.

The new FAIR facility in Darmstadt has a broad program in the field of hadron and nuclear physics utilizing ion beams with unprecedented intensity and accuracy. The hadron physics program centers around the the high‐energy storage ring HESR for antiprotons and the PANDA experiment that is integrated in it. The physics program includes among others topics like hadron spectroscopy in the charmonium mass region and below, hyperon physics, electromagnetic processes and charm in nuclei.

The possibility for a deeply bound D(*)DJ molecule to exist is discussed, and the example of a D*D1 isoscalar‐vector system bound by one‐pion exchange is considered. It is shown that, if the D1D*π coupling is strong enough to generate a bound D1D* state in the static limit then, with proper inclusion of dynamical pions (via three‐body D*D*π cuts) the bound state disappears, and the D*D*π strength is channelled into huge non‐resonant background.

The energy loss of heavy quarks in the hot and dense matter created at RHIC, can be used to probe the properties of the medium. Both charm and beauty quarks contribute to the non‐photonic electrons through their semi‐leptonic decays. It is essential to determine experimentally the relative contribution of charm and beauty quarks to understand the suppression of heavy flavors at high pT in central Au+Au collisions. The azimuthal angular correlations of non‐photonic electrons with the reconstructed D0 allow to disentangle the contribution of charm and beauty and to reduce the background below the D0 invariant mass as well. We discuss the STAR measurement of non‐photonic electron and D0→K−π+ azimuthal correlations in p+p collisions at 200 GeV. Furthermore, we show results from the application of microvertexing techniques for charm and beauty searches in Cu+Cu and Au+Au collisions at 200 GeV using the information of the Silicon tracker of STAR.

I present the summary of our recent work [1] on the long‐distance effect in B→K(*)l+l−, generated by the four‐quark operators with charmed quarks. In addition to the factorized cc loop, the soft‐gluon emission from the loop is calculated in the framework of light‐cone OPE, applying light‐cone QCD sum rules. The resulting contribution of this effect to the B→K(*)l+l−, decay amplitude is cast in a form of the correction to the leading Wilson coefficient C9.

We discuss the interpretation of the open charm mesons Ds0*(2317), Ds1(2460) and the hidden charm meson X(3872) as hadron molecules. Using a phenomenological Lagrangian approach we consider strong and radiative decays of the Ds0*(2317) and Ds1(2460) states. The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration. A potential model based on meson-exchange is able to generate weak binding of the molecular hadronic components. The observed radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decays are shown to be consistent with the molecular structure assumption of the X(3872).

In this contribution we address the subject from the perspective of saturation physcics and compute the heavy quark production cross section with the dipole model. We isolate shadowing and non‐linear effects, showing their effects on the tranverse momentum spectrum. The results showed here are based on reference [1].

In this invited presentation I review some recent developments in the theory of charmonium that appear likely to be of importance for future experimental studies in this field. The specific areas considered are double charmonium production, LQCD studies of charmonium, recent results for hadron loops, c-cbar production cross sections at PANDA, charm molecules, and two recent developments, "charmiscelleny"., 8 pp., 3 figures. Invited contribution to HADRON 2009 (XIIIth Internatl. Conf. on Hadron Spectroscopy, Tallahassee, FL, Nov.29 - Dec.4 2009).

We present recent results on the search for CP violation in charm decays and charmonium spectroscopy from BABAR experiment at SLAC.

The open charm mesons Ds0*(2317), Ds1(2460) and the hidden charm meson X(3872) are discussed as hadron molecules. Using a phenomenological Lagrangian approach we consider the strong and radiative decays of the Ds0*(2317) and Ds1(2460) states. The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration. Observed radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decays are shown to be consistent with the molecular structure assumption of the X(3872).

We calculate the form factors and the coupling constants in vertices with charm mesons, such as ρD*D*, in the framework of QCD sum rules. We first discuss the applications of these form factors in heavy ion collisions and in B decays. We then present an introduction to the method of QCD sum rules and describe how to work with the three-point function. We give special attention to the procedure employed to extrapolate results obtained in the deep euclidean region to the poles of the particles, located in the time-like region. Finally we present a table of ready-to-use parametrizations of all the form factors, which are relevant for the processes mentioned in the introduction. We also give the coupling constants.

We show that charm provides significant enhancement of the very high energy neutrino flux, when neutrinos originate in astrophysical sources with jets driven by central engines, such as gamma ray bursts or supernovae with jets. The neutrino flux from semi‐leptonic decays of charmed mesons is subject to much less hadronic and radiative cooling than the conventional flux from pion and kaon decays and therefore has a dominant contribution at higher energies, of relevance to future ultrahigh energy neutrino experiments.

Many precision tests of the Standard Model require input from Lattice QCD or other QCD techniques. Of particular importance are the semileptonic form factors used to extract Vub in semileptonic B decays. Similarities between the D and B sector make charm semileptonic decays an excellent testing ground for the increasingly precise predictions of Lattice QCD. CLEO‐c has recently used its entire data sample to produce a set of measurements involving the decays D0→π−e+νe, D0→K−e+νe, D+π0e+νe, and D+K0e+νe. These results, which include the world’s most precise measurements of D→π form factors, are in agreement with currently available theoretical results and are significantly more precise.

Overconstraining the CKM unitarity triangle with precision measurements of its angles continues to test the validity of the Standard Model. One of these angles, γ/φ3, has been measured by studying B±→DK± decays, where D = D0 or D0. I present recent results of hadronic D decays which will improve the sensitivity of γ/φ3, measurements.

Recent results on charm physics from the HERA ep collider experiments H1 and ZEUS are described. Cross section measurements are made in photoproduction and deep‐inelastic scattering (DIS) using a variety of techniques. The DIS results are used to extract the charm contribution to the proton structure function. The results are compared to QCD calculations.

The sum of charm and beauty in Au+Au collisions at 200 GeV measured through nonphotonic electrons, show similar suppression at high pT as light hadrons, in contrast to expectations based on the dead cone effect. To understand this observation, it is important to separate the charm and beauty components. Non-photonic electron-D0 and electron-hadron azimuthal angular correlations are used to disentangle the contributions from charm and beauty decays. The beauty contribution in p+p collisions at 200 GeV is found to be comparable to charm at pT 5.5 GeV, indicating that beauty may contribute significantly to the non photonic electrons from heavy flavour decays in Au+Au data at high pT. Furthermore, in Au+Au collisions we present the status of D0 meson reconstruction using microvertexing techniques made possible with the addition of the silicon detectors.

In the neutrino DIS diffraction the charged current non-conservation gives rise to sizable corrections to the longitudinal structure function, $F_L$. These corrections is a higher twist effect enhanced at small-$x$ by the rapidly growing gluon density. The phenomenon manifests itself in abundant production of charm and strangeness by longitudinally polarized W bosons of moderate virtualities $Q^2\lsim m_c^2$., Comment: Prepared for the Int. Workshop on Diffraction in High-Energy Physics, Diffraction 2008, La Londe-les-Maures, France, Sept. 9-14, 2008

We comment on aspects of electroweak phenomena involving D0 mesons, including D0−D−0 mixing, D0→???+???D− decays and D0 CP‐violations. A brief overview is given of some recent theoretical contributions to the literature.

Factorisation properties are a key subject in the field of diffraction. An important contribution to these studies comes from the analysis of ep scattering. In the recent years the H1 and ZEUS collaborations performed in‐depth analyses that improved the understanding of factorisation in diffraction and the factorisation breaking firstly observed in pp collisions. Recent updates of previously published results from H1 and ZEUS are presented.