The 7th International Workshop on Charm Physics (CHARM 2015)

18 May 2015, 08:00 → 22 May 2015, 19:00 US/Eastern

Wayne State University

The 7th International Workshop on Charm Physics (CHARM 2015) will be held on campus of Wayne State University in Detroit, Michigan on May 17-23, 2015.

The purpose of this workshop is to bring together particle and nuclear physicists working in the field related to physics of charm quark to discuss recent results in the field, including the impact on and from theory, as well as projections for results to be expected from upcoming facilities.

Workshop topics:
Charm Spectroscopy and Transitions
Production of Charm and Charmonia
Hidden and Open Charm in Media
Charm Meson and Baryon Spectroscopy
Light Hadronic Spectroscopy from Decays of Charm and Charmonia
Leptonic, Semileptonic and Rare Charm Decays
Advances in Theoretical Tools
D Oscillations and CP Violation
Tau lepton physics
New Physics Scenarios for Charm Decays
Experimental Charm Facilities - Status and Future

We invite you to attend CHARM 2015!

Monday, 18 May

Breakfast and Registration

Welcome

1 Welcome to Wayne State!

Speaker: Prof. Stephen Lanier (Vice President for Research, Wayne State University)

Spectroscopy I

Convener: Prof. David Cinabro (Wayne State University)

2 Charmonium and exotics on the continuum

Speaker: Dr Fulvio Piccinini (istituto nazionale di fisica nucleare, sezione di Pavia)

Slides piccinini.pdf

3 Lattice studies of charmonia and exotics

Speaker: Prof. Sasa Prelovsek (University of Ljubljana)

Slides prelovsek_charm15.pdf

4 Charmonium and exotics from Belle

Studies of many charmonium(-like) states including exotic candidates performed at Belle experiment are presented. Besides the candidates of conventional charmonium states, more and more charged charmonium-like states are found. The charged charmonium-like states look like forming a new spectroscopy.

Speaker: Dr Xiaolong Wang (Virginia Tech)

Slides Charm2015-wxl-v3.pdf

5 Charmonia and exotics from BES III

Speaker: Dr Mihajlo Kornicer (University of Hawaii)

Slides CHARM2015_Kornicer.pdf

6 Dalitz plot analysis of three-body charmonium decays in BaBar.

We study the reaction e+ e− -> gamma_ISR J/psi, where J/psi -> pi+ pi- pi0 and J/psi -> K+ K- pi0, using events obtained from the Initial State Radiation process. We measure the relative J/psi branching fraction and perform a Dalitz plot analysis of both J/psi decay modes using the isobar and Veneziano model. We study the process gamma gamma -> K anti-K pi. We observe the decays eta_c -> Ks K+- pi-+ and eta_c -> K+ K- pi0 and perform a Dalitz analysis of both eta_c decay modes. We also extract the mass dependent Kpi amplitude and phase using the model-independent partial wave analysis approach.

Speaker: Prof. Antimo Palano (INFN and University of Bari, Italy)

Slides Palano_babar_charm2015.pdf

12:00 Lunch

Lunch on your own, please see the list of nearby restaurants

Spectroscopy II

Convener: Prof. Sasa Prelovsek (University of Ljubljana)

7 Open-charm and exotics states from LHC

Speaker: Prof. Antimo Palano (INFN and University of Bari, Italy)

Slides Palano_lhcb_charm2015.pdf

8 Open charm and exotics on the lattice

Speaker: Dr Daniel Mohler (Fermilab)

Slides charm2015_mohler.pdf

9 A New Dynamical Picture for Production and Decay of the XYZ Mesons

I introduce an entirely new dynamical description for tetraquark mesons, based upon the competing effects of the strong attraction between quarks in a diquark, and the inability of the diquark to hadronize on its own due to being a color nonsinglet. This mechanism naturally explains, for example, the strong preference of the Z(4475) to decay to psi(2S) rather than the J/psi, the existence of a state Y(4630) that decays to Lambda_c baryon pairs, and why some but not all exotics lie near hadronic thresholds. Owing to high-energy constituent counting rules, the four-quark nature of the states produces major changes to both the high-s scaling of cross sections for producing such states and to the potency of the cusp effect of attracting resonances to pair-production thresholds.

Speaker: Prof. Richard Lebed (Arizona State University)

Slides Lebed.pdf

15:00 Coffee break

Production

Convener: Dr Abhijit Majumder (Wayne State University)

10 Theoretical aspects of quarkonia production in vacuum

Speaker: Dr Geoffrey Bodwin (Argonne National Laboratory)

Slides bodwin.pdf

11 Study of inclusive charmonium production in e+e- annihilation and B decays at BaBar

In a e+e- B factory charmonium states can be produced through different mechanisms, as in e+e- annihilation, with double charmonium production, and in B-meson decays. Prompt production of J/psi or psi(2S) in association with a second charmonium state has been observed by both the BaBar and Belle experiments in e+e- annihilation at a center-of-mass energy of 10.58 GeV. These processes provide an opportunity to study both perturbative and non-perturbative effects in QCD and to search for new charmonium states recoiling against the reconstructed J/psi or psi(2S). We present a study of such events using the full BaBar dataset. We also present measurements of absolute branching fractions of the two-body decays of B mesons B( B -> K Xcc), where Xcc is a charmonium state. In fact, in events where one B is fully reconstructed, the charmonium spectrum can be observed in an unbiased way, looking at the distribution of the K momentum in the recoiling B rest frame.

Speaker: Prof. Michael Sokoloff (University of Cincinnati)

Slides Charm2015_BaBar_Sokoloff.pdf

12 Studies of P-wave and S-wave quarkonium production with the CMS detector

Precise measurement of S-wave quarkonium cross-sections and polarizations performed at LHC helped clarifying the experimental scenario in the field of quarkonium production. From the theoretical point of view, the most promising framework to explain such phenomena has been, for almost 20 years, NRQCD. However, the interpretation of the latest results in this framework is not straight-forward, and might require the revision of some of the assumptions that were so far made. The scientific community has come to realize that a thorough understanding must encompass a broader view, and that the study of P-wave states plays a fundamental role. The CMS collaboration has provided some of the most precise P-wave charmonium and bottomonium measurements to date. In this contribution, such results will be presented and discussed. The studies of heavy quarkonium prompt-production and polarization at the LHC are becoming crucial to solve the puzzle of hadron formation. A dedicated dimuon trigger strategy combined with the energy and luminosity provided by the LHC allowed the CMS experiment to collect large samples of quarkonium states decaying in the dimuon channel. This contribution presents the most recent CMS quarkonium production results including rapidity-integrated production cross sections extended up to ~120GeV for J/Psi and ~100GeV for psi(2S) and Y(nS) with n=1,2,3.

Speaker: Dr Kai Yi (University of Iowa)

Slides charm2015.pdf

13 Conventional and exotic charmonium production at the ATLAS experiment

We present detailed precision measurements of the prompt and non-prompt differential production cross sections for the J/psi, psi2s, chi_c and X(3872) charmonium states at sqrt(s)=8 TeV, covering J/psi and psi2s --> mumu, psi2s-->J/psi pipi and chi_c. The results are compared with leading theoretical models.

Speaker: Dr Bruce Yabsley (University of Sydney)

Slides charm-20150518-production-yabsley.pdf

Welcome Reception

Tuesday, 19 May

08:00 Breakfast

Charm in media

Convener: Ramona Vogt (LLNL and UC Davis)

14 Experimental aspects of quarkonia production and suppression in cold and hot nuclear matter

Speaker: Dr Anthony Frawley (Florida State University)

Slides CHARM_2015_quarkonia.pdf

15 Theory aspects of quarkonia production and suppression in cold and hot nuclear matter

Speaker: Prof. Jianwei Qiu (Brookhaven National Laboratory)

Slides Qiu-Charm2015.pdf

16 Experimental aspects of open heavy flavor production and suppression in cold and hot nuclear matter

Speaker: Andrea Dainese (INFN - Padova, Italy)

Slides Dainese_CHARM2015.pdf

17 Theory aspects of open heavy flavor production and suppression in cold and hot nuclear matter

Speaker: Marlene Nahrgang (Duke University)

Slides CHARM2015_nahrgang.pdf

10:30 Coffee break

Rare and radiative decays and CP-violation

Convener: Prof. Gil Paz (Wayne State University)

18 Theoretical perspective on rare and radiative charm decays

Speaker: Prof. Svjetlana Fajfer (University of Ljubljana and J. Stefan Institute)

Slides CHARM15-Fajfer.pdf

19 Searches for rare and radiative charm decays

Speaker: Prof. Carla Göbel (PUC-Rio)

Slides CHARM2015_Gobel.pdf

20 Comments on CP-violation in charm

Speaker: Prof. Jure Zupan (University of Cincinnati)

Slides Charm2015_Zupan_print.pdf

12:30 Lunch break

Parallel Session 1

Convener: Prof. Joern Putschke (Wayne State University)

21 Shadowing Effects on Open and Hidden Heavy Flavor Production at the LHC

Speaker: Ramona Vogt (LLNL and UC Davis)

Slides Vogt_CHARM15.pdf

22 Open heavy-flavour measurements in pp and p-Pb collisions with ALICE

The ALICE detector is dedicated to the study of the high energy-density QCD matter produced in heavy-ion collisions. Important probes of this matter are heavy quarks (charm and beauty), as they are produced in the early stage of the collision via initial hard scatterings. Thus measurements of their production offer important information on the early stage of the collision and the parton-medium interaction. To quantify the measurements performed in Pb-Pb collisions it is necessary that the production in pp and p-Pb collisions is studied. In pp collisions, the measurement of heavy-flavour production cross sections not only provides the reference for heavy-ion studies, but also delivers critical tests of perturbative QCD. In p-Pb collisions, initial-state effects, due to the presence of a nucleus, can be accessed. Such effects include the modification of parton densities and k_T broadening, which can result from multiple soft scatterings of partons. In addition, the existence of possible final-state effects can also be investigated. In this contribution we present the results of open heavy-flavour production measurements in pp and p-Pb collisions with ALICE. These results will include the measurement of D-meson production as a function of charged-particle multiplicity. The D mesons are reconstructed via hadronic decay channels at mid-rapidity, and the yields are measured in specific transverse-momentum intervals for various multiplicity ranges. We compare the transverse-momentum dependent evolution of the per-event yield of D mesons in different multiplicity intervals in the two collision systems to gain an understanding of the interplay between hard and soft contributions to particle production and to possibly obtain insight into the role of multiple hard partonic interaction. In addition, we present the D-meson nuclear modification factor in different multiplicity ranges, which is defined as the ratio of the D-meson yield in p-Pb and pp collisions scaled by the number of binary nucleon-nucleon collisions. Finally, the azimuthal correlation of D mesons and charged hadrons, and electrons from heavy-flavor hadron decays and charged hadrons at mid-rapidity will be discussed as a function of transverse momentum.

Speaker: Sarah LaPointe (INFN Torino)

Slides Charm15-lapointe.pdf

23 J/ψ azimuthal anisotropy in Au+Au collisions at 200 GeV

In relativistic heavy-ion collisions, J/ψ can be produced via different mechanisms and the large mass of the charm quark makes it a valuable probe to the thermalization of the medium. The study of J/ψ azimuthal anisotropy can allow for the disentangling of a few interesting dynamic processes, e.g., J/ψ produced from direct pQCD processes, and J/ψ produced from recombination of charm quarks within the medium. J/ψ produced from direct pQCD processes have little azimuthal anisotropy due to the lack of collectivity and initial emitting azimuthal preference, while J/ψ produced from recombination of charm quarks are expected to inherit considerable azimuthal anisotropy if charm quarks have finite elliptic flow. In this talk, we will present J/ψ azimuthal anisotropy in Au+Au collisions at 200 GeV, from data taken by STAR during RHIC operation in year 2010 and 2011. The result will be presented as a function of centrality of Au+Au collisions and J/ψ transverse momentum.

Speaker: Mr Zhao Feng (Central China Normal University)

Slides jpsi_v2_Run_11_for_Charm_2015.pdf

24 Charmonium Production in Asymmetric Nuclear Collisions by the PHENIX Experiment at RHIC

The measurement of quarkonia production in relativistic heavy ion collisions provides a powerful tool for studying the properties of the hot and dense matter created in these collisions. To be really useful, however, such measurements must cover a wide range of quarkonia states and colliding species. The PHENIX experiment at RHIC has successfully measured J/psi, psi-prime, chi_c and Upsilon states in p+p, d+Au and Au+Au collisions. In this talk I will present recent results from the PHENIX collaboration on charmonium production in Cu+Au and U+U collisions at 200 GeV/c.

Speaker: Dr Alexandre Lebedev (Iowa State University)

Slides Study_of_charmonium_production_in_asymmetric_nuclear_collisions.pdf

25 Open heavy-flavour measurements in Pb-Pb collisions with ALICE at the LHC

The ALICE experiment at the LHC studies Pb-Pb, p-Pb, and pp collisions to investigate the properties of the high energy-density state of strongly-interacting matter, produced in Pb-Pb collisions, the so-called quark-gluon plasma (QGP). Heavy quarks (charm and beauty) are unique probes, since they are produced in the initial hard scattering processes in the earliest phase of the collisions and interact strongly with the medium carrying trace of its properties to the final state. In particular, heavy quarks lose less energy than light quarks and gluons and exhibit a harder fragmentation. The main results from LHC-Run 1 data related to open heavy-flavour production in Pb-Pb collisions will be discussed. Open heavy flavours are measured in ALICE via the full reconstruction of the charged decay particles of D mesons at mid-rapidity or via semi-electronic and semi-muonic decays of charm and beauty hadronsat mid-rapidity and forward rapidity, respectively. The measurements of the suppression of heavy-flavour particles with respect to pp collisions (nuclear modification factor) and of the elliptic flow bring insights into the energy loss mechanisms in the medium and the possible thermalization of charm quark. The perspectives on open heavy-flavour measurements will be also presented.

Speaker: Chiara Bianchin (Wayne State University)

Slides openHFinPbPb.pdf

15:40 Coffee Break

26 $J/\psi$ longitudinal double spin asymmetry measurement at forward rapidity in $p+p$ collisions at $\sqrt{s}=510$ GeV

The polarized gluon distribution, as described by the polarized parton distribution function $\Delta g(x)$, is an important part of the spin structure of the nucleon; however the current data have very limited constraints on $\Delta g(x)$ for $x < 0.01$. During the 2013 RHIC run, the PHENIX experiment collected 146 pb$^{-1}$ of longitudinally polarized $p+p$ data at $\sqrt{s} = 510$ GeV with an average beam polarization of 52\%. At this energy, $J/\psi$ particles are predominantly produced through gluon-gluon interactions and thus the longitudinal double spin asymmetry, $A_{LL}^{J/\psi}$, is sensitive to the gluon polarization inside the proton. We measure the $J/\psi$ $A_{LL}$ in the rapidity range $1.2 < |\eta| < 2.4$ by detecting the decay $\mu^+ \mu^-$ pairs using the PHENIX muon detector arms. In this kinematic range, $A_{LL}$ is sensitive to the polarized gluon distribution at small $x \sim 2\times 10^{-3}$ as well as at moderate $x \sim 0.05$ where recent RHIC data on jet and $\pi^0$ production show possible evidence for significant gluon polarization. Compared to previous measurements in 2005 and 2006, the Run 2013 data set has roughly twenty times more statistics and will allow us to measure $A_{LL}^{J/\psi}$ with a statistical uncertainty at $\sim1$\% level. The preliminary result of this analysis will be presented.

Speaker: Mr HAIWANG YU (Peking University)

Slides CHARM2015_Haiwang_v5.pdf

27 Resolving charm and bottom quark masses in precision Higgs boson analyses

Masses of the charm and bottom quarks are important inputs to precision calculations of Higgs boson observables, such as its partial widths and branching fractions. They constitute a major source of theory uncertainties that needs to be better understood and reduced in light of future high-precision measurements. Conventionally, Higgs boson observables are calculated in terms of $m_c$ and $m_b$, whose values are obtained by averaging over many extractions from low-energy data. This approach may ultimately be unsatisfactory, since $m_c$ and $m_b$ as single numbers hide various sources of uncertainties involved in their extractions some of which call for more careful estimations, and also hide correlations with additional inputs such as $\alpha_s$. Aiming at a more detailed understanding of the uncertainties from $m_c$ and $m_b$ in precision Higgs boson analyses, we present a calculation of Higgs boson observables in terms of low-energy observables, which reveals concrete sources of uncertainties that challenge sub-percent-level calculations of Higgs boson partial widths.

Speaker: Zhengkang Zhang (Michigan Center for Theoretical Physics, University of Michigan)

Slides charm15slides.pdf

28 New Physics Models Facing Lepton Flavor Violating Higgs Decays

We speculate about the possible interpretations of the recently observed excess in the h to tau mu decay. We derive a robust lower bound on the Higgs boson coupling strength to a tau and a muon, even in presence of the most general new physics affecting other Higgs properties. Then we reevaluate complementary indirect constraints coming from low energy observables as well as from theoretical considerations. In particular, the tentative signal should lead to tau to mu gamma at rates which could be observed at Belle II. In turn we show that, barring fine-tuned cancellations, the effect can only be accommodated within models with an extended scalar sector. These general conclusions are demonstrated using a number of explicit new physics models. Finally we show how, given the h to tau mu signal, the current and future searches for mu to e gamma and mu to e nuclear conversions unambiguously constrain the allowed rates for h to tau e.

Speaker: Nejc Košnik (Department of Physics, University of Ljubljana)

Slides HiggsLFV.pdf

29 Search for stop decays to charm + LSP at CMS

The supersymmetric partner of the top quark, the stop, is among the best candidates for stabilizing the Higgs mass against large radiative corrections. In the scenario where the dark matter candidate is close in mass to the stop, the decay stop -> charm, LSP is an important search channel. This talk describes the application of a monojet search topology to hunt for this decay with the CMS detector at the LHC.

Speaker: Dr Zhenbin Wu (Baylor University)

Slides Zhenbin_CHARM2015.pdf

30 Search for di-muon decays of a low-mass Higgs boson in the radiative decay of $J/\psi$

We search for di-muon decays a light Higgs boson ($A^0$) in the radiative decay of $J/\psi$: $J/\psi \rightarrow \gamma A^0$, $A^0 \rightarrow \mu^+\mu^-$. Here $A^0$ is the hypothetical CP-odd light Higgs boson predicted by many extensions of the Standard Model (SM), including Next-to-Minimal Sypersymmetric Standard Model (NMSSM). This study is based on 225 million $J/\psi$ events collected in 2009 by the BESIII experiment at the Institute of High Energy Physics, Beijing, China. We are studying the process and we will report the preliminary results of the work in this talk.

Speaker: Dr Vindhyawasini Prasad (Post-doctoral Fellow)

Slides VPrasad_talk_lightHiggs_darkphotonsearch-CHARM-2015.pdf

31 LHCb High Level Trigger design issues for post Long Stop 1 running

The LHCb High Level Trigger uses two stages of software running on an Event Filter Farm (EFF) to select events for offline reconstruction and analysis. In LHC runs 1 & 2 the first stage (Hlt1) processes approximately 1 MHz of events accepted by a hardware trigger. In 2012, the second stage (Hlt2) wrote 5 kHz to permanent storage for later processing. Following the LHC's Long Stop 1, the machine energy will increase from 8 TeV in the center-of-mass to 13 TeV. The cross sections for beauty and charm are expected to grow proportionately. We plan to increase the Hlt2 output to 12.5 kHz, ~10 kHz for offline processing and ~ 2.5 kHz ready for immediate analysis. By increasing the absolute computing power of the EFF, buffering data for processing between machine fills, and improving algorithms, we should be able to significantly increase the efficiency for signal while improving signal-to-background ratios. Hlt1 will use a boosted decision tree to increase efficiency at that stage. We will determine calibration and alignment constants between Hlt1 and Hlt2, allowing Hlt2 to use reconstruction very close to that used offline, including RICH and calorimetric information. Post Long Stop 2 we will read out the front-end electronics at 40 MHz and move to a full software trigger while operating at higher luminosity. The implications for increasing charm yields are emphasized.

Speaker: Prof. Michael Sokoloff (University of Cincinnati)

Slides triggerTalk.pdf

32 Exotic meson studies at CMS

CMS has accumulated large amount of dimuon events at 7 and 8 TeV center-mass-energy. Fruitful results have been produced using these datasets. This talk will cover the observation of two structures in jpsi+phi mass spectrum via exclusive B+-> jpsi phi K+ decays, while the first one confirms a previous observation from CDF experiment, and the second one has been observed for the first time. A related decay channel B+-> psi2s phi K+ has been observed by CMS for the first time and will be reported.

Speaker: Jane Nachtman (University of Iowa)

Parallel Session 2

Convener: Prof. Klaus Peters (GSI Darmstadt)

33 Studies of Charmonium at BESIII

The BESIII Experiment at the Beijing Electron Positron Collider (BEPC2) has accumulated the world's largest samples of e+e- collisions in the tau-charm region. From these samples -- which include J/psi, psi(2S), and psi(3770) decays, among others -- BESIII has produced many new results in the spectroscopy, transitions, and decays of charmonium. This talk will review the current status of these analyses, which cover a wide range of topics from rare decays to radiative transitions to new precision measurements.

Speaker: Dr Rong-Gang Ping (Institute of High Energy Physics, CAS)

Slides pingrg.pdf

34 Hadronic Transitions above 4 GeV at BESIII

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. A number of hadronic transitions have been measured in these data samples, leading to a rather complex picture of the physics of charmonium above 4 GeV. In this talk we will present results for e+e- to pi0pi0J/psi (where the Y(4260) is seen in the cross section), as well as results for apparently more complex cross sections, such as e+e- to omega chic0 and eta J/psi, where structures are less apparent.

Speaker: Dr Xiao-Rui Lyu (UCAS)

Slides Xiaorui_HadTranXYZ_v1.pdf

35 Search for exotic charmonium at BaBar

One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. Over the years BaBar has extensively studied these states in B meson decays, initial state radiation processes and two photon reactions. We report on recent studies on some of these states performed using the entire data sample collected by BaBar in e+e- collisions at center of mass energies near 10.58 GeV/c^2. Among these, the study of the process B -> J/psi phi K with a search for the X(4140) and X(4270) in their decays to J/psi phi, and a search for charged charmonium-like state Zc(3900)^+ in the decay Y(4260) -> J/spi pi+pi-.

Speaker: Dr fabio anulli (INFN Sezione di Roma)

36 J/psi Upsilon production

The talk is devoted to theoretical description of J/psi Upsilon production at LHC. This process is interesting since at LO color-singlet approximation it is forbidden, so investigation of this reaction allows one to probe alternative mechanisms, such as color-octet production, double parton scattering, etc.

Speaker: Dr Alexey Luchinsky (IHEP, Protvino)

Paper http://arxiv.org/pdf/1503.00246.pdf

Slides Luchinsky.pdf

37 Factorized power expansion for high pT heavy quarkonium production

From the Tevatron and the LHC data, it is clear that current models for the heavy quarkonium production are not able to explain the polarization of heavy quarkonia produced at large transverse momentum pT in p-p collision. A new approach to evaluate the heavy quarkonium production, by expanding the cross section in powers of 1/pT before the expansion in powers of alpha_s, was proposed recently. In terms of the QCD factorization, it is proved that both the leading-power (LP) and next-to-leading power (NLP) terms in 1/pT for the cross sections can be systematically factorized to all orders of alpha_s. The predictive power of this new QCD factorization formalism depends on several unknown but universal fragmentation functions (FFs) at an input scale of the order of heavy quarkonium mass m_Q. Inspired by the fact that m_Q >> Lambda_QCD, we apply the NRQCD factorization formalism to further separate the perturbative and non-perturbative interactions. With our calculations, all the input polarization-summed FFs are expressed as complicated functions with a few unknown NRQCD long-distance matrix elements (LDMEs). In addition, by general symmetry arguments, we successfully generalize the polarized NRQCD four-fermion operators to d dimensions and calculate the polarized FFs with conventional dimensional regularization. In the first application, we find those non-relativistic QCD channels, which are expected to be important in the J/psi polarization, are actually dominated by the NLP term in the pT expansion at current collider energies. Therefore the QCD factorization is very promising to solve the long standing heavy quarkonium polarization puzzle.

Speaker: Dr Hong Zhang (The Ohio State University)

Slides Hong_Zhang.pdf

15:40 Coffee Break

38 Strategies for an accurate determination of the X(3872) energy from QCD lattice simulations

We develop a method to determine accurately the binding energy of the X(3872) from lattice data for the $D\bar{D}^*$ interaction. We show that, because of the small difference between the neutral and charged components of the X(3872), it is necessary to differentiate them in the energy levels of the lattice spectrum if one wishes to have a precise determination of the the binding energy of the X(3872). The analysis of the data requires the use of coupled channels. Depending on the number of levels available and the size of the box, we determine the precision needed in the lattice energies to finally obtain a desired accuracy in the binding energy.

Speaker: Dr Raquel Molina (The George Washington University)

Slides charm_x3872_volfin.pdf

39 XYZ radiative transitions

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 talk we will discuss BESIII analyses of radiative transitions among these states, which may improve our understanding of this important mass region. One example is the observation of the process e+e- to gamma X(3872).

Speaker: Dr Vindhyawasini Prasad (Post-doctoral Fellow)

Slides VPrasad_talk_XYZ-CHARM2015.pdf

40 Probing the nature of Z_c states via the eta_c rho decay

The nature of the so-called XYZ states is a long-standing problem. It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules. In the present work we analyze the Z_c^(') -> eta_c rho decay using both approaches. Such channel might provide useful insights on the nature of the Z_c^('), helping discriminating between the two different models.

Speaker: Mr Angelo Esposito (Columbia University)

Slides CHARM2015_etacrho_v2.pdf

41 A case for SU(3) in D to P P decays

The question of the validity of analyzing charmed meson decays to pairs of hadrons within the SU(3) framework has been long and often debated. While there are convincing arguments that small breaking of this symmetry can accommodate for the current experimental results, the inability to compute QCD effects in these modes render it quite impossible to justify with complete authority the physical interpretations of the parameters extracted from experimental data. In our work we explore the SU(3) framework for its strengths and weaknesses and cross-examine it with arguments derived from a diagrammatic approach. We show that isospin non-universality of QCD should be considered within this framework. We also consider η - η' mixing in our attempt to build a complete analysis of these modes.

Speaker: Mr Ayan Paul (INFN, Sezione di Roma)

Slides SU3_Charm2015.pdf

42 Measurements of time-integrated CP and other asymmetries

LHCb has collected the world's largest sample of charmed hadrons. This sample is used to search for direct CP violation in charm. New updated measurements from several decay modes, including DeltaACP from D0->hh decays, are presented. The talk also focuses on measurements of production and detection asymmetries.

Speaker: Dr Marco Gersabeck (The University of Manchester)

Slides TimeIntCPV_LHCb_Gersabeck.pdf

43 Measuring the CP content of D decays to multibody self-conjugate final states

Quantum-correlated psi(3770) to DDbar decays collected by the CLEO-c experiment are used to perform first measurements of F+, the fractional CP-even content of the self-conjugate decays D->pi+pi−pi0 and D->K+K−pi0. Values of 0.968±0.017±0.006 and 0.731±0.058±0.021 are obtained for pi+pi−pi0 and K+K−pi0, respectively. It is demonstrated how modes of this sort can be cleanly included in measurements of the unitarity triangle angle gamma/phi3 using B+->DK+ decays. The high CP-even content of D→pi+pi−pi0, in particular, makes this a promising mode for improving the precision on gamma/phi3. Prospects with other modes are also discussed.

Speaker: Prof. Jim Libby (Indian Institute of Technology Madras)

Slides LibbyCharm2015.pdf

44 A new method for measuring CPV in charm decays and the first measurement of F+ in D --> \pi^+\pi^+\pi^-\pi^- decays

A first measurement of F+, the CP-even content of the decay D--> 4pi using quantum correlated psi(3770) to DDbar decays collected by the CLEO-c experiment is presented. A high value is obtained, which makes the decay mode particularly suitable for both measurements of the CKM angle \gamma and charm CP violation in a model independent way. This novel approach to studying indirect CP violation in charm decays is based on the time-dependent inclusive analysis of multibody self-conjugate states. These final states can be used to determine the indirect $CP$-violating observable $A_\Gamma$ and the mixing observable $y_{CP}$, provided that $F_+$, is known. This approach can yield significantly improved sensitivity compared with the conventional method that relies on decays to $CP$ eigenstates. Extensions including direct CP violation are also presented.

Speaker: Dr Sneha Malde (University of Oxford)

Slides charm_malde.pdf

Wednesday, 20 May

08:00 Breakfast

Parallel Session 3

Convener: Dr Marco Gersabeck (The University of Manchester)

45 Semileptonic D-decays at BESIII

Speaker: Ms Fenfen An (Institute of High Energy Physics)

Slides semiD_charm2015.pdf

46 Measurement of the D -> pi- e+ nu partial branching fraction, form factor and implications for Vub.

Precision measurements of the D -> pi e+ nu form factor could shed new light on the persistent difference between inclusive and exclusive measurements of Vub. We report the measurement of the partial branching fraction of  D -> pi e+ nu in bins of the four-momentum transfer squared of the D to pi system using 347.2 /fb of integrated luminosity of the BaBar data. The D -> pi form factor is extracted with fits to the unfolded partial branching fraction using pole or generalized expansions and the value at zero recoil is determined. These form factors are compared to the current world average, the available lattice predictions, and interpreted with the expectation of a single dominant pole term. The measured form factor is then combined with previous BaBar B -> pi l nu information to determine a value of Vub.

Speaker: Arantza Oyanguren (IFIC-UV-CSIC)

Slides Arantza_Oyanguren_Charm15.pdf

47 Measurements of rare charm decays at LHCb

Following the intriguing hints of deviations from the Standard Model in rare B meson decays, searches for rare and forbidden decays of charm hadrons become a hot topic again. We present recent results on penguin D→μμhh' and lepton-flavour violating D→eμ decays. These results are presented on behalf of the LHCb collaboration.

Speaker: Ms Claudia Vacca (Università degli Studi di Cagliari-INFN Cagliari)

Slides CHARM2015_CVacca.pdf

48 Rare Semileptonic Charm Decays

We present a study of c → ull transitions. In the Standard Model these semileptonic charm decays are induced via Flavor Changing Neutral Currents and, thus are rare. This opens possibilities for potential Beyond Standard Model physics searches. We estimate phenomenological observables within the SM and effects due to BSM physics.

Speaker: Stefan de Boer (TU Dortmund)

Slides deboer_charm2015.pdf

49 D rare/fobidden decays

Based on the sample taken at sqrt(s) = 3.773 GeV with 2.92/pb, which corresponds to the largest sample of e+e- -> psi(3770) in the world to date, we present our results of searches for flavor changing neutral curent and lepton number violation decays of the charged D meson in the final states of; D+ -> K+ e+ -, K- e+ e+, pi+ e+ e-, pi-e+ e+, as well as other searches such as for D0 -> gamma gamma.

Speaker: Dr Minggang Zhao (Nankai University)

Slides ZHAO_Talk5.pdf

10:10 Coffee Break

50 Search for CP violation in D0 -> pi0pi0 and pipi/KK decays at Belle

Speaker: Tara Nanut (Jozef Stefan Institute)

Slides tara_CPV.pdf

51 D0 to KsKK and D to omega pi

Based on 2.92 fb$^{-1}$ of $e^+e^-$ collision data taken at $\sqrt{s}$ = 3.773 GeV with the BESIII detector at BEPCII, we present preliminary results from the analysis of the decay $D^0 \to K_S^0 K^+ K^-$. We measure the branching fraction and investigate the rich substructure in the final state by performing a Dalitz plot analysis.

Speaker: Peter Weidenkaff (JGU)

Slides Talk_7_WEIDENKAFF.pdf

52 Mixing/coherence in D mesons

We report the measurement of the D0-D0bar mixing parameter, y_{CP} based on the sample taken at the DDbar mass threshold. Based on the events where we reconstruct one D decays to CP eigenstates while the other D decays semi-leptonially, we obtain y_{CP} = (-2.0+-1.3+-0.7)%. We also present results for model independent measurement of the strong phase difference between D0 and D0bar -> K0 pi+ pi-, through a binned dalitz analysis. These results represent a significant improvement in a previously statistically limited measurement, which will then allow for increased precision in the measurement of unitarity triangle angle gamma/phi3 using the decay B+- -> D (-> Ks pi+ pi-) K+- through the GGSZ method.

Speaker: Albayrak Onur (Carnegie Mellon University)

Slides charm2015_Albayrak_Dmixingcoherence.pdf

53 An exclusive approach on DDbar mixing

I will show an exclusive approach on calculating the DDbar mixing parameters y and x. We will sum up the contributions from the hadronic decays, based on the factorization-assisted topological-amplitude approach in which most SU(3) breaking effects are involved.

Speaker: Dr Fu-Sheng Yu (Lanzhou University)

Slides DDbarMixing_Yu.pdf

54 Measurements of mixing and indirect CP violation

LHCb has collected the world's largest sample of charmed hadrons. This sample is used to search for indirect CP violation in charm, and to measure D0 mixing parameters. New measurements from several decay modes are presented.

Speaker: Ms Stefanie Reichert (The University of Manchester)

Slides Charm_2015_Reichert.pdf

55 Measurements of T-odd observables

The study of T-odd observables using four-body hadronic final states of charm meson decays provides complementary insight to measuring CP asymmetries via decay rate asymmetries. New results based on the full LHCb dataset are presented.

Speaker: Dr Maurizio Martinelli (École Polytechnique Fédérale de Lausanne)

Slides Martinelli_ToddCorrelations_v2.pdf

Parallel Session 4

Convener: Prof. Robert Harr (Wayne State Universtiy)

56 Open charm spectroscopy

Excited charm states are studied at LHCb both in the pp collision and in decays of B hadrons. The latter method has the advantage of starting from a clean and well defined initial state with known quantum numbers. LHCb presents the observation of new spin-3 mesons decaying to D(*)K and Dπ, as well as many measurements of mass, width and spin of already known mesons.

Speaker: Dr Mark Whitehead (University of Warwick)

Slides mwhitehe_CHARM2015_Final.pdf

57 D± production asymmetry at the LHC from heavy quark recombination mechanism

The asymmetry in the forward region production cross section of D± is calculated using the heavy quark recombination mechanism for pp collisions at 7 TeV. By suitable choices of four nonperturbative parameters, our calculated results can reproduce those obtained at LHCb. We find A p ∼ −1% when integrated over 2.0 GeV < p T < 18 GeV and 2.2 < η < 4.75, which agrees with A p = −0.96 ± 0.26 ± 0.18% as measured by LHCb. Furthermore, the calculated distributions in η and p T agree reasonably well with those obtained at LHCb. Predictions on production asymmetry of heavy baryons are also made in the same formalism.

Speaker: Mr Wai Kin Lai (University of Pittsburgh)

Slides WKLai_talk_CHARM_2015.pdf

58 DD-bar shape

BESIII collected about 70 pb-1 e+e- annihilation data around the nominal mass of psi(3770), based on which we present preliminary results of study on the production line-shape of e+e- -> DDbar. In this study, we take into account the effect of interference due to the non-reconant DDbar production to describe the observed anomalous line-shape.

Speaker: Dr Yi Fang (IHEP)

Slides DDbarShape_Charm2015.pdf

59 τ physics at LHCb

The observation of neutrino oscillations has re-opened the case for searches of lepton-flavour violating decays. We report on recent results and prospects on lepton-flavour violating τ decays.

Speaker: Dr Jonathan Harrison (University of Manchester)

Slides TauPhysics_Charm_2015.pdf

60 Search for B decays to final states with the eta_c meson

We report a search for B decays to selected final states with the eta_c meson: B -> K eta_c pi+ pi-, B -> K eta_c omega, B -> K eta_c eta and B -> K eta_c pi0. The analysis is based on 772 millions of BB pairs collected at the Upsilon (4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We set 90% confidence level upper limits on the branching fractions of the studied B decay modes, independent of intermediate resonances, in the range (0.6 - 5.3)*10-4. We also search for molecular-state candidates for the D(*)0 combinations, neutral partners of the Z(3900)+- and Z(4020)+-, and a poorly understood state X(3915) as possible intermediate states in the decay chain, and set 90% confidence level upper limits on the product of branching fractions to X and decay branching fractions of X in the range (0.6 - 0.9)*10-5.

Speaker: Ms Anna Vinokurova (Budker Institute of Nuclear Physics)

Slides Vinokurova.pdf

10:10 Coffee Break

61 Study of $B \to chi_{cJ} X$ at Belle

In spite of the fact that the two-body $B$ decays into $\chi_{c2}$ such as $B \to \chi_{c2} K^{(*)}$ are suppressed by the QCD factorization effect, the inclusive $B \to \chi_{c2} X$ branching fraction amounts to one third of the non-suppressed $B \to \chi_{c1} X$ decays because of the decay modes to the multi-body final states. Using a large statistics $\Upsilon(4S)$ data sample corresponding to 772 million $B$ meson pairs accumulated by the Belle detector at the KEKB $e^+e^-$ collider, precise measurements of inclusive $B \to \chi_{c1}$ and $\chi_{c2}$ branching fractions are carried out. The multi-body final states such as $\chi_{cJ} K \pi$, $\chi_{cJ} K \pi \pi$ and so on are also investigated to look for new charmonium-like resonance.

Speaker: Vishal Bhardwaj (University of South Carolina)

Slides Bhardwaj_Charm2015_final.pdf

62 Dalitz plot analysis of B -> D D K decays

We present Dalitz plot analyses for the decays of B mesons to D- D0 K+ and D0-bar D0 K+. We report the observation of the D_{s1}^* (2700)^+ resonance in these two channels and obtain measurements of the mass M(D^*_{s1}(2700)^+) = 2699^{+14}_{−} MeV/c^2 and of the width Γ(D^*_{s1}(2700)^+) = 127^{+24}_{−1} MeV, including statistical and systematic uncertainties. In addition, we observe an enhancement in the D0 K+ invariant mass around 2350–2500 MeV/c^2 in both decays B0 to D- D0 K+ and B+ to D0bar D0 K+, which we are not able to interpret. The results are based on 429 fb−1 ofdata containing 471×10^6 BB-bar pairs collected at the Υ(4S) resonance with the BaBar detector at the SLAC National Accelerator Laboratory.

Speaker: Prof. Milind Purohit (University of South Carolina)

Slides BDDK.pdf

63 Study of B -> X(3872) K pi at Belle

We report the first observation of $B^0 \to X(3872) (K^{+}\pi^{-})$ and evidence for $B^+ \to X(3872) (K^{0}\pi^{+})$. We measure the product of branching fractions for the former to be ${\cal B}(B^0 \to X(3872) (K^+ \pi^-)) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (7.9 \pm 1.3(\mbox{stat.})\pm 0.4(\mbox{syst.})) \times 10^{-6}$ and find that $B^{0}\to X(3872) K^{*}(892)^{0}$ does not dominate the $B^{0}\to X(3872)K^{+}\pi^{-}$ decay mode in contrast to other charmonium states like $\psi'$. We also measure ${\cal B}(B^+ \to X(3872) (K^0 \pi^+)) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (10.6 \pm 3.0(\mbox{stat.}) \pm 0.9(\mbox{syst.})) \times 10^{-6}$. This study is based on the full data sample of 711~fb$^{-1}$ ($772\times 10^6 B\bar B$ pairs) collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB collider.

Speaker: Mr Vishal Bhardwaj (University of South Carolina (Belle Collaboration))

Slides Bhardwaj_Charm2015_X3872_second.pdf

64 Charm contributions in B to K* l+l-

The rare semileptonic Bd → K∗l+i− decay has been extensively studied within the Standard Model and beyond. Significant efforts from Lattice QCD groups have reduced theoretical errors in the form-factors to tractable limits in the high q^2 regime while arguments from LCSR can be used for the same in the low q^2 regime. However, hadronic contributions coming primarily from charm loops still plague the predictions of many observables in this channel. While the intricacies of QCD prevent exact estimation of these hadronic contributions, experimental analysis will be reaching a point where these can be determined from data. We present in this work a Bayesian analysis of the decay in the full range of q2, in which we extract these charm loop hadronic contributions from available data. We also make well-motivated arguments about the size of the hadronic contributions and ultimately show the compatibility of the currently available experimental data with the Standard Model predictions.

Speaker: Mr Ayan Paul (INFN, Sezione di Roma)

Slides BKstll_CHARM_2015.pdf

65 B_c spectroscopy at ATLAS

We present latest results from the ATLAS experiment on B_c spectroscopy, including branching fraction measurements of Bc+-> J/psipi and Bc->J/psiDs(*) and observation of the B_c(2S) state.

Speaker: Rui Wang (Argonne national laboratory)

Slides charm2015_rwang.pdf

12:10 End of session

12:30 Lunch break

Conference excursion

Excursion to the Detroit Institute of Arts

Thursday, 21 May

08:00 Breakfast

Mixing and CP-violation I: Mixing and CP-violation

Convener: Prof. Chris Parkes (University of Manchester)

66 Charm mixing and CP-violation

Speaker: Prof. Alexander Kagan (University of Cincinnati)

Slides AKCharm2015fin.pdf

67 Implications of SU(3)F on Charm CP Violation

We present recent results on improved predictions for charm CP violation in nonleptonic decays. These are obtained from a fit of a diagrammatic parametrization to branching ratios including linear SU(3)F breaking. The predictions make possible future tests of the Standard Model once improved data is available.

Speaker: Dr Stefan Schacht (Karlsruhe Institute of Technology)

Slides charm-detroit-schacht.pdf

68 CDF results on CP-violation in charm

Speaker: Dr Sabato Leo (University of Illinois at Urbana Champaign)

Slides Charm_2015_SLeo.pdf

69 C, P, and CP asymmetry observables based on triple product asymmetries

Speaker: Dr Adrian Bevan (Queen Mary University of London)

Slides Bevan-Charm2015.pdf Bevan-Charm2015.ppt

10:30 Coffee break

70 LHCb results/serches for CP-violation in charm

Speaker: Dr Paras Naik (University of Bristol)

Slides Naik-CharmCPV-LHCb-Charm15-Final.pdf

71 Recent results on violation of discrete symmetries in charm decays at BaBar and Belle

The status of CP violations in charm sector is still unsettled. According to SM, the predicted asymmetries are small, but often affected by large uncertainties due to long-distance effects. However, it is possible to build observables which SM predicts to be CP conserving, so that any measured asymmetry is, with no doubts, a sign of New Physics.   We present recent results on charm CP violation at Belle and BaBar. We show the measurement of CP asymmetries in D+ -> K+ K- pi+, D+ -> KS K+, Ds+ -> KS K+, Ds+ -> KS pi+ at BABAR. Moreover, we show the Belle measurements of indirect CP violation parameters from D0 -> KS pi pi decay.

Speaker: Mr Alessandro Pilloni (Sapienza U.)

Slides charm2015_pilloni.pdf

12:00 Lunch break

High energy charm

Convener: Prof. Michael Sokoloff (University of Cincinnati)

72 Higgs and EW decays to charm

Speaker: Prof. Frank Petriello (University of Wisconsin)

Slides petriello-CHARM2015.pdf

73 Studies of associated charmonium production at ATLAS

We present new measurements of the production of a charmonium state in association with a W boson, Z boson, or another charmonium state (covering diJpsi, Z+J/psi, W+J/psi). These rare production modes provide novel insight into the mechanisms of charmonium production and the impact of proton structure on these observables.

Speaker: Dr Bruce Yabsley (University of Sydney)

Slides charm-20150521-associated-yabsley.pdf

Mixing andf CP-violation II: Mixing and CP-violation 2

Convener: Prof. Michael Sokoloff (University of Cincinnati)

74 Hadronic decays of charmed mesons from BES

Speaker: Dr Hajime Muramatsu (U. of Minnesota)

Slides charm15.pdf

15:00 Coffee break

Charmed baryons

Convener: Dr Daniel Mohler (Fermilab)

75 Charmed baryons on the lattice

Speaker: Dr M Padmanath (Graz U.)

Slides Padmanath_Charm2015.pdf

76 Charmed baryons from LHCb

Speaker: Stephen Ogilvy (University of Glasgow)

Slides sogilvy_Charm2015.pdf

77 Lambda_c decays

Speaker: Dr Xiao-Rui Lyu (UCAS)

Slides Xiaorui_Lambdac_v2.pdf

17:30 Conference Banquet

Conference banquet at the Detroit Historical Museum

Friday, 22 May

08:00 Breakfast

Quark masses, leptonic and semileptonic and rare decays: Rare and semileptonic decays

Convener: Prof. Hai-Bo LI (Institute of High Energy Physics)

78 Charm and bottom quark masses on the lattice

Speaker: Dr Andrew Lytle (University of Glasgow)

Slides Lytle_Charm2015.pdf

79 Charm and bottom quark masses off the lattice

Speaker: Dr Vicent Mateu (University of Vienna)

Paper http://arxiv.org/pdf/1102.2264.pdf http://arxiv.org/pdf/1504.07638.pdf

Slides mateu.pdf

80 Lattice perspective on leptonic and semileptonic decays

Speaker: Dr Elvira Gamiz (Fermilab)

Slides gamiz_CHARM2015.pdf

81 Leptonic and semileptonic charm decays at Belle

We describe recent developments in experimental studies of D and Ds meson leptonic decays at the BaBar, Belle, BESIII and CLEO-c detectors and their implications for the determination of charm meson decay constants as well as searches for charged Higgs. Also discussed are semileptonic decays of D and Ds mesons and their relevance to hadronic form factors.

Speaker: Prof. Simon Eidelman (BINP)

Slides det151.pdf

82 D Leptonic and semi-leptonic decays from BESIII

The BESIII experiment has taken 2.92/fb of data at sqrt(s) = 3.773 GeV which contains the largest sample of e+e- -> psi(3770) -> DDbar in the world to date. We report the result of our branching fraction measurement of D+ -> mu+ nu based on this sample from which we extract its weak decay constant, f_D+, with the|Vcd| determined from a global Standard Model fit as an input. We also obtain |Vcd| from the measured branching fraction together with a Lattice QCD prediction for f_D+. In addition, we present measurements of D0 -> (K-/pi-) e+ nu, D+ -> KL e+v, and D+ to (omega/phi/K pi) e+ nu decays. Based on analysis of D0 -> (K-/pi-) e+ nu and D+ -> K_L e+ nu, we extract different parameterizations of the form factors together with the CKM matrix elements |Vcs(d)|. These will give a precision test on the LQCD calculation on these form factors and the unitarity of the CKM matrix. Based on analysis of D+ -> K- pi+ e+ nu, we perform a partial wave analysis and in return, we determine the S-wave contribution and its phase, the helicity basis form factors of D+ ->K*(892) e nu based on the SPD model, and we also measure them in a model-independent way. We also report searches for some rare semi-leptonic decays.

Speaker: Dr Hailong Ma (Institue of High Energy Physics, CAS, China)

Slides Talk-Charm2015-HailongMa-v1.pdf

11:00 Coffee break

Future experimental facilities I

83 Novosibirsk project

We present the concept design of Novosibirsk tau-charm factory: physics case, detector and machine. Status of its construction is discussed. Also briefly described is a similar project currently discussed at the University of Science and Technology of China (USTC) in Hefei.

Speaker: Prof. Simon Eidelman (BINP)

Slides d15.pdf

84 Future prospects for charm physics at BES III and beyond

Speaker: Prof. Yangheng Zheng (University of Chinese Academy of Sciences)

Slides BESIII-Prospects-Charm2015-zheng.pdf

12:30 Lunch break

Future experimental facilities

85 Future prospects at LHCb

Speaker: Prof. Chris Parkes (University of Manchester)

Slides LHCbFutureCharm_Parkes_vFinal.pptx LHCbFutureCharm_Parkes_vpdf.pdf

86 Future prospects at Belle II

Speaker: Prof. Marko Staric (J. Stefan Institute)

Slides staric_BelleIIcharm.pdf

Summary

Convener: Prof. Alexey Petrov (Wayne State University / MCTP)

87 Welcome to CHARM 2016

Speaker: Mr Angelo Carbone (INFN and University of Bologna)

Slides Charm2016@Bologna.pdf

88 Theory summary

Speaker: Prof. Luca Silvestrini (INFN, Rome)

Slides Silvestrini@Charm2015.pdf

89 Experimental summary

Speaker: Dr Alan Schwartz (University of Cincinnati)

Slides Exp_summary_schwartz.pdf