Non-leptonic two-body weak decays of baryons are an important tool to probe the combined charge-conjugation--parity symmetry (CP) violation. We explain why the decays of strange baryons provide complementary information to the decays of kaons. A model-independent parameterization of the non-leptonic decays of the $Λ$- and $Ξ$-baryons is reviewed, and the amplitudes are updated according to the latest experimental input. We demonstrate the potential of performing precision tests in strange baryon decays at the next generation electron-positron $J/ψ$ factories with luminosity of $10^{35}$ cm$^{-2}$s$^{-1}$. The copious production of spin-entangled hyperon-antihyperon pairs via the $J/ψ$ resonance allows for a direct comparison of the baryon and antibaryon decay properties. Using analytic approximations and numerical calculations, we study the quantitative impact of spin correlations and polarization in such CP tests. We show that by using a longitudinally-polarized electron beam, the statistical precision of the CP tests can be significantly improved compared to the experiments without polarized beams. Furthermore, we map out further directions for possible improvements, like analysis of incompletely reconstructed events or a combination of the isospin related processes. Altogether, these methods are promising for the observation of a statistically significant CP-violation signal with a strength corresponding to the standard model predictions. Our conclusions should encourage more detailed feasibility studies, including optimisation of the measurement methods and studies of systematic effects. Finally, our results call for an update of the theory predictions with increased precision.
Neither Dark Matter nor scalar particles in the Higgs sector are ruled out at energies accessible to bottom and charm factories. In Dark Matter searches, the error on the mass of Dark Matter is $\sim 4$ GeV in the best LHC studies. For light Dark Matter this could represent a 100% (or more) error. In Higgs searches, the presence of a light singlet Higgs can make the LHC Higgs search difficult, if not impossible. If Dark Matter or a Higgs scalar is light, it will {\it require} a low-energy machine to precisely determine the couplings. We review the models, modes of discovery and rate expectatio…
CP violation (CPV) in the baryon sectors has not yet been established experimentally. In this work, we propose to search for the hyperon CPV through the Cabibbo-favored charm-baryon decaying processes involving a hyperon in the final states, such as $Λ_c^+\to Λ^0π^+, Λ^0\to pπ^-$. The CPV of the hyperon decays are purely revealed in these chain processes, since the CPV in the Cabibbo-favored charm decays are vanishing in the Standard Model (SM). The hyperons are polarized in the weak charm decays, so that we can measure the Lee-Yang asymmetric parameter $α$ by the angular distributions, and th…
Open charm hadrons are excellent probe to study the dynamics of quarks and gluons inside hadrons. Because the mass of a charm quark is heavier than $Λ_{QCD}$, the so called heavy quark symmetry emerges in the hadron containing a charm quark and plays a central role in the classification and constraining the interactions. Belle and BaBar, which are B-factory experiments, have made significant advances in the field of open charm hadron spectroscopy in these 15 years. In this article, experimental advances on both open charm mesons and baryons by B-factory experiments are reviewed. Finally, the p…
Fermilab operates the world's most intense antiproton source, now exclusively dedicated to serving the needs of the Tevatron Collider. The anticipated 2009 shutdown of the Tevatron presents the opportunity for world-leading low- and medium-energy antiproton programs. We summarize the status of the Fermilab antiproton facility and review physics topics for which a future experiment could make the world's best measurements.
$D^0-\bar{D}^0$ mixing leads to the mass and width differences in the mass eigenstates of $D^0$ and $\bar{D}^0$ mesons (measured by parameters $x^{~}_D$ and $y^{~}_D$ respectively), but their magnitudes cannot be reliably predicted by the standard model. We show that it is possible to separately determine $x^{~}_D$ and $y^{~}_D$ through {\it time-integrated} measurements of the dilepton events of coherent $D^0\bar{D}^0$ decays on the $ψ(4.14)$ resonance at a $τ$-charm factory.
The inclusive $J/ψ$ production in $e^+ e^- \to J/ψc\bar c$ at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double charm production process is larger than existing leading order (LO) QCD predictions by a factor of 5. In the nonrelativistic QCD (NRQCD) factorization formalism, we calculate the next-to-leading order (NLO) QCD virtual and real corrections to this process, and find that these corrections can substantially enhance the cross section with a $K$ factor of about 1.8. We further take into account the feeddown con…
To provide focus to my review of charm theory at the B-Physics and CP-Violation conference, I consider theoretical issues related to possible charm studies at B-factories. A few topics of interest to the author are stressed -- rare decays, CP-violating asymmetries and ${\bar D}^0 - D^0$ mixing.
Unraveling the Hyperon Puzzle in Neutron Stars via Novel, High-Precision Hyperon Factories
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；School of Physics and Astronomy, Tel Aviv University（特拉维夫大学物理与天文学学院）
Measurements by the Belle Collaboration of the exclusive J/psi + eta_c and inclusive J/psi +cc-bar+X productions in e^+ e^- annihilation differ substantially from theoretical predictions based on the nonrelativistic QCD factorization approach. In order to test if such a discrepancy is originated from the large perturbative corrections to the hard-scattering amplitude, we study inclusive production of four charm hadrons in e^+e^- annihilation at B factories.
In order to clarify the puzzling problems in double charm production, relativistic corrections at order $v^{2}$ to the processes $e^{+}e^{-}\to J/ψ+η_{c}$ and $e^{+}e^{-}\to J/ψ+c\bar{c}$ at B factories are studied in non-relativistic quantum chromodynamics. The short-distance parts of production cross sections are calculated perturbatively, while the long-distance matrix elements are estimated from $J/ψ$ and $η_c$ decays up to errors of order $v^4$. Our results show that the relativistic correction to the exclusive process $e^{+}e^{-}\to J/ψ+η_{c}$ is significant, which, when combined togethe…
In this concluding talk, the advances in the Flavour Problem studies are discussed, following the structure of the presentations in the Conference. The subjects touched are organized as follows: Baryons, K-physics, Charm and Beauty production, Charm and Beauty decays, B-Mixing and CP-Violation, Heavy Quarkonium.
A summary is given of the 5th International Conference on Hyperons, Charm and Beauty Hadrons held in Vancouver, Canada, June 25th to 29th, 2002. This series of conferences began in 1995 in Strasbourg, France, in large part through the efforts of A. Fridman, to whose memory this talk is dedicated. Topics reviewed include kaon and hyperon physics, charm and beauty production and decays, heavy baryons, the physics of the Cabibbo-Kobayashi-Maskawa matrix and CP violation, and precision electroweak analyses. An attempt is made to combine a review of the high points of the conference with a more gen…
A review is presented of the weak radiative decays of baryons.It includes an anlysis of the possible contributions of electromagnetic penguins to these decays,a survey of the difficulties still encountered in the sector of hyperon decays and a short account on some new developments on this topic. The theoretical treatments on charm and beauty baryon decays are summarized,with a good outlook for their detection.
The charm quark has unique properties that make it a very important probe of many facets of the Standard Model. New experimental information on charm decays is becoming available from dedicated experiments at charm factories, and through charm physics programs at the b-factories and hadron machines. In parallel, theorists are working on matrix element calculations based on unquenched lattice QCD, that can be validated by experimental measurements and affect our ultimate knowledge of the quark mixing parameters. Recent predictions are compared with corresponding experimental data and good agree…
Puzzles awaiting better experiments and better theory include: (1) the contradiction between good and bad SU(3) baryon wave functions in fitting Cabibbo theory for hyperon decays, strangeness suppression in the sea and the violation of the Gottfried Sum rule - no model fits all; (2) Anomalously enhanced Cabibbo-suppressed $D^+ \to K^{*+}(s\bar d)$ decays; (3) anomalously enhanced and suppressed $B \to η' X$ decays; (4) the OZI rule in weak decays; (5) Vector dominance ($W \to π, ρ, a_1, D_s, D^*_s $) in weak decays (6) Puzzles in doubly-cabibbo-suppressed charm decays.(7) Problems in obtaining…
We investigate production and decay of the $Λ_c^+ $ hyperon. The production considered is through the $e^+e^-$ annihilation channel, $e^+e^-\rightarrowΛ_c^+ \barΛ_c^-$, with summation over the $\barΛ_c^- $ anti-hyperon spin directions. It is in this situation that the $Λ_c^+ $ decay chain is identified. Two kinds of sequential decays are studied. The first one is the doubly weak decay $B_1\rightarrow B_2 M_2$, followed by $B_2 \rightarrow B_3 M_3$. The other one is the mixed weak-electromagnetic decay $B_1\rightarrow B_2 M_2$, followed by $B_2 \rightarrow B_3 γ$. In both schemes $B$ denotes ba…
Production of Hyperons, Charmed Baryons, and Hadronic Molecule Candidates in Neutrino-Proton Reaction
Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Tsinghua University（清华大学）；Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）
Belle Collaboration has recently observed a new state, the X(4160), in the process of double charm production $e^+e^-\to J/ψ+X(4160)$ followed by $X(4160)\to D^*\bar{D^*}$. We discuss possible interpretations for the X(4160) based on the NRQCD calculations and the potential model estimates for the charmonium spectrum. We first focus on the D-wave spin-singlet $2^{-+}$ charmonium $^1D_2(2D)$, which is estimated to have a small production rate of about 5% of that for $e^+e^-\to J/ψ+η_c(1S)$, and therefore is incompatible with the observed data for X(4160). We then discuss the possibility that th…
We present a concise overview on $CP$ violation in hyperon decays, including past, present, and future efforts to search for it. We highlight in particular the most recent results of the BESIII experiment using a quantum-entangled pair of hyperon and antihyperon produced by a charmonium resonance formed in $e^+e^-$ annihilation. The subsequent nonleptonic decays of these hyperon pairs allow for the simultaneous determination of various parameters pertaining to $CP$ violation in the decays. We compare the reported data with the corresponding current predictions for $CP$ asymmetries within the s…
We discuss the status of current dynamical lattice QCD simulations in connection to the emerging results on the strange and charmed baryon spectrum, excited states of the nucleon and the investigation of the structure of scalar mesons.
The spectrum of the C=1 hyperons is well described by the constituent quark model, if the fine structure interaction between the light and strange quarks is mediated by the $SU(3)_F$ octet of light pseudoscalar mesons, which are the Goldstone bosons of the hidden approximate chiral symmetry of QCD. With the addition of a phenomenological flavor exchange interaction of the same form between the light and the charm quarks to describe the $Σ_c-Σ_c^*$ and $Ξ_c^s-Ξ_c^*$ splittings, the splittings between the C=1 states fall within 10-30 MeV of the empirical values. Predictions are presented for the…
Measurements by the Belle Collaboration of the exclusive production of two charmonia in e^+ e^- annihilation differ substantially from theoretical predictions. Till now, no conclusive explanation for this remarkable discrepancy has been provided. Even the origin of the discrepancy is not identified, yet. We suggest that the measurement of four-charm events in Belle data must provide a strong constraint in identifying the origin of this large discrepancy. Our prediction of the cross section for e^+e^- -> c c-bar c c-bar, in lowest order in strong coupling constant, at sqrt{s}=10.6 GeV is about …
Following Rosner [hep-ph/0312269], we consider B-decay production channels for the exotic I=0 and $I=3/2$ pentaquarks that have been recently reported. We also discuss new search channels for isovector pentaquarks, such as the $Θ^{*++} (\bar s duuu)$, that are generically present in chiral soliton models but were not observed in recent experiments. Futhermore, we argue that weak decays of charmed baryons, such as the $Λ_c^+$ and $Ξ_c^0$, provide another clean way of detecting exotic baryons made of light quarks only. We also discuss discovery channels for charmed pentaquarks, such as the isosi…
The dependence of inclusive weak decay rates of heavy hadrons on the flavors of spectator light quarks is revisited with application to decays of charmed and b hyperons. It is pointed out that the differences in the semileptonic decay rates, the differences in the Cabibbo suppressed decay rates of the charmed hyperons, and the splitting of the total decay rates of the b hyperons are all related to the differences in the lifetimes of the charmed hyperons independently of poor knowledge of hadronic matrix elements. The approximations used in these relations are the applicability of the expansion…
We present results for the $σ$-terms and axial charges for various hyperons and charmed baryons using $N_f=2+1+1$ twisted mass fermions. For the computation of the three-point function we use the fixed current method. For one of the $N_f=2+1+1$ ensembles with pion mass of 373 MeV we compare the results of the fixed current method with those obtained with a stochastic method for computing the all-to-all propagator involved in the evaluation of the three point functions.
Leptonic and semileptonic decays in the charm sector have been well studied in recent years. With the largest data sample near $D\bar D$ threshold, precision measurements of leptonic and semileptonic decays of charm meson and baryon are perfromed at BESIII. Test for letpon flavor universality is also performed. Sensitivity for rare leptonic and semileptonic charm decays is significantly improved taking advantage of the huge statistics in LHCb and the $B$ factories.
That massless dark photons could exist and have flavor-changing magnetic-dipole interactions with down-type light quarks is an attractive possibility which may be realized in various new-physics scenarios. It is potentially testable not only in kaon processes but also via two-body hyperon decays involving missing energy carried away by the massless dark photon. We explore the latter within a simplified model approach and take into account constraints from the kaon sector. We find that the branching fractions of some of these hyperon modes are allowed to be as high as a few times $10^{-4}$. Suc…
Electroweak Transitions of Hyperons and Charmed Baryons: Opportunities and Prospects
Uppsala University（乌普萨拉大学）；National Centre for Nuclear Research（国家核研究中心）；University of Cyprus（塞浦路斯大学）；The Cyprus Institute（塞浦路斯研究所）；Institute of High Energy Physics（高能物理研究所）；Lund University（隆德大学）；École Polytechnique Fédérale de Lausanne（洛桑联邦理工学院）；University of Graz（格拉茨大学）
In tau physics, we are at the frontier between the completion of the LEP program and the start of analyses from b-factories, which are expected to produce results in the coming years. Nice results from CLEO are steadily delivered in the meantime. For charm, impressive progress have been achieved by fixed target experiments in the search for CP violation and D^0 - \bar D^0 oscillations. First results from b-factories demonstrate the power of these facilities in such areas. The novel measurement of the D* width by CLEO happens to be rather different from current expectations. The absence of a ch…
We investigate the impact of charm mixing on the model-independent gamma measurement using Dalitz plot analysis of the three-body D decay from B+->DK+ process, and show that ignoring the mixing at all stages of the analysis is safe up to a sub-degree level of precision. We also find that in the coherent production of D0-D0* system in e+e- collisions, the effect of charm mixing is enhanced, and propose a model-independent method to measure charm mixing parameters in the time-integrated Dalitz analysis at charm factories.
Dark sector particles at the GeV scale carrying baryon number provide an attractive framework for understanding the origin of dark matter and the matter-antimatter asymmetry of the universe. We demonstrate that dark decays of hadronic states containing strange quarks -- hyperons -- offer excellent prospects for discovering such dark baryons. Building up on novel calculations of the matrix elements relevant for hyperon dark decays, and in view of various collider, flavor, and astrophysical constraints, we determine the expected rates at hyperon factories like BESIII and LHCb. We also highlight …
The highlights and conflicts at the B Factories are briefly reviewed. $CP$ violation was established in 2001 in $B^0 \to J/ψK_S$ and related modes, which has now become a precision measurement of CP violation in $B^0$-$\bar B^0$ mixing. However, the situation for the $B^0 \to π^+π^-$ and charmless $b\to s$ modes, which probe also CP violation in the {\it decay} amplitude, are not quite settled yet. They could be hinting at presence of both strong (CP conserving) and new physics (CP violating) phases. We critically assess the developments and discuss some related discrepancies and highlights, s…
The axial couplings of the low lying baryons are evaluated using a total of five ensembles of dynamical twisted mass fermion gauge configurations. The simulations are performed using the Iwasaki gauge action and two degenerate flavors of light quarks, and a strange and a charm quark fixed to approximately their physical values at two values of the coupling constant. The lattice spacings, determined using the nucleon mass, are $a=0.082$ fm and $a=0.065$ fm and the simulations cover a pion mass in the range of about 210 MeV to 430 MeV. We study the dependence of the axial couplings on the pion m…
Virtual fermionic N_f = 1 and N_f = 2 contributions to Bhabha scattering are combined with realistic real corrections at next-to-next-to-leading order in QED. The virtual corrections are determined by the package bha_nnlo_hf, and real corrections with the Monte Carlo generators Bhagen-1Ph, Helac-Phegas and Ekhara. Numerical results are discussed at the energies of and with realistic cuts used at the Phi factory DAFNE, at the B factories PEP-II and KEK, and at the charm/tau factory BEPC II. We compare these complete calculations with the approximate ones realized in the generator BabaYaga@NLO u…
We know that `our' Universe consists of `known' matter only $\sim$ 4.5\%: our understanding is incomplete seeing directly in neutrino oscillations (never mind about `other' Universes). Charm quarks had great impact on our understanding of known matter. QCD is the only local quantum field theory to describe strong forces. We can learn novel lessons about strong dynamics by measuring rates around the thresholds of $[\bar Q Q]$ states with $Q = b, c$. Furthermore they give us gateways for New Dynamics (ND), where we have to go from `accuracy' to `precision' eras. Finally we can connect with $τ$ t…
The recent progress in experiments at B-factories suggests an opportunity to search for missing charmonium states $η_{c}'(2^1S_0)$ and $h_c(1^1P_1)$. The feasibility of such a search in B-meson decays are discussed.
In this study, we investigate the discovery potential of double-charm tetraquarks $T^{\{cc\}}_{[\bar{q}\bar{q}']}$. We find that their production cross sections at the LHCb with $\sqrt{s} = 13$ TeV reach $\mathcal{O}(10^4)$ pb, which indicates that the LHCb has collected $\mathcal{O}(10^8)$ such particles. Through the decay channels of $T^{\{cc\}}_{[\bar{u}\bar{d}]}\to D^{+}K^{-}π^{+}$ or $D^0D^+γ$ (if stable) or $T^{\{cc\}}_{[\bar{u}\bar{d}]}\to D^0D^{*+}\to D^0D^0π^+$ (if unstable), it is highly expected that they get discovered at the LHCb in the near future. We also discuss the productions…
We discuss the determination of the CKM phase gamma through the decay B- -> K- D0 and related processes. In particular, we consider the use of this methods when the D0 subsequently decays to an inclusive state. We emphasize that strong phase information obtained at a psi(3770) charm factory can provide additional information which will be helpful in determining gamma.
The charm physics program accessible to a Tau-Charm Factory is summarized. Semileptonic, leptonic, hadronic, rare and forbidden charm decay modes are discussed, as well as \dmix\ mixing and CP violation in the charm sector. The theoretical expectations in the Standard Model and beyond as well as the experimental capabilities of a Tau-Charm Factory are examined for each of the above processes. {To appear in {\it The Tau-Charm Factory in the Era of B-Factories and CESR}, Stanford, CA, August 15-16, 1994}
I review several topics involving CP violation with heavy hadrons. In particular, I discuss (i) Hyperons: CP violation in the decay $Λ^0 \to p π^-$, (ii) Charm: indirect CP violation in the D^0 system, both within and beyond the SM, and (iii) Beauty: indirect CP violation in the neutral B-meson system beyond the SM. Talk presented at the 2nd International Conference on Hyperons, Charm and Beauty Hadrons, Montréal, Canada, August 1996.
We present results for the quasi-elastic weak production of $Λ$ and $Σ$ hyperons induced by $\barν$ scattering off nuclei, in the kinematical region of interest for accelerator neutrino experiments. We employ realistic hole spectral functions and we describe the propagation of the hyperons in the nuclear medium by means of a Monte Carlo cascade. The latter strongly modifies the kinematics and the relative production rates of the hyperons, leading to a non-vanishing $Σ^+$ cross section, to a sizable enhancement of the $Λ$ production and to a drastic reduction of the $Σ^0$ and $Σ^-$ distribution…
Rare charm decays offer the unique possibility to explore flavour-changing neutral-currents in the up-sector within the Standard Model and beyond. Due to the lack of effective methods to reliably describe its low energy dynamics, rare charm decays have been considered as less promising for long. However, this lack does not exclude the possibility to perform promising searches for New Physics per se, but a different philosophy of work is required. Exact or approximate symmetries of the Standard Model allow to construct clean null-test observables, yielding an excellent road to the discovery of …
It is argued that the results of recent precision measurements by LHCb of the lifetimes of charmed and bottom hyperons are very well consistent with the description within heavy quark expansion and allow to accurately determine matrix elements of light-flavor nonsinglet four-quark operators over the hyperons and to accurately reproduce the difference of lifemes of $Λ_b$ and $Ξ_b^-$. When combined with the recent LHCb results on the decay $Ξ_b^- \to Λ_b π^-$ this leads to prediction of a lower bound on the rate of the decays $Ξ_c \to Λ_c π$.
Beauty and charm e+e- factories running at resonance thresholds have unique capabilities for studies of the production of light Dark Matter particles in the decays of B_q (D) meson pairs. We provide a comprehensive study of light Dark Matter production in heavy meson decays with missing energy in the final state, such as B_q (D^0) -> "missing energy" and B_q (D^0) -> γ+ "missing energy". We argue that such transitions can be studied at the current flavor factories (and future super-flavor factories) by tagging the missing-energy decays with B_q (D^0) decays "on the other side".
We investigate the in-medium masses of open charm mesons ($D$($D^0$, $D^+$), $\bar{D}$($\bar{D^0}$, $D^-$), $D_s$(${D_{s}}^+$, ${D_{s}}^-$)) and charmonium states ($J/ψ$, $ψ(3686)$, $ψ(3770)$, $χ_{c0}$, $χ_{c2}$) in strongly magnetized isospin asymmetric strange hadronic matter using a chiral effective model. In the presence of the magnetic field, the number density and scalar density of charged baryons have contributions from Landau energy levels. The mass modifications of open charm mesons arise due to their interactions with nucleons, hyperons, and the scalar fields (the non-strange field $…
After playing a pivotal role in the birth of the Standard Model in the 70's, the study of charm physics has undergone a revival during the last decade, triggered by a wealth of precision measurements from the charm and $B$ factories, and from the CDF and especially the LHCb experiments. In this article, we sum up how the unique phenomenology of charmed hadrons can be used to test the Standard Model and we review the latest measurements performed in this field by the LHCb experiment. These include the historic first observations of $CP$ violation and of a nonzero mass difference between the cha…
The processes of D^{(*)}-mesons and Λ_c-baryons production in e^+e^--annihilation at 10.58 GeV and 91.18 GeV energies are concerned. At the 10.58 GeV energy the production of charmed particles via the B-mesons decays is also concerned. Scaling violation of the fragmentation functions is calculated at the NLL-accuracy. Nonperturbative fragmentation functions are retrieved from the experimental data of B-factories and are approximated by simple analytic expressions. It is proved, that the difference between nonperturbative fragmentation functions of mesons and baryons can be easily explained by …
The importance of future studies of charm and $τ$ decays is emphasized as probes of New Physics: the most powerful tools are \cp asymmetries in charm and $τ$ decays both in partial widths and final state distributions. While these searches for \cp violation are instrumentalized in the search for and hopefully future analysis of New Physics, they might also shed light on the \cp breaking dynamics required to implement baryogenesis. $e^+e^-$ Super-Flavour Factories are optimally suited for the challenge, in many aspects even uniquely so.
We point out the physics opportunities of future high-luminosity B-factories at the Upsilon(5S) resonance and above. In this paper we discuss numerous interesting investigations, which can be performed in the e+e- centre-of-mass energy region from the Upsilon(5S) and up to 11.5 GeV, where an efficient data taking operation should be possible with the planned B-factories. These studies include abundant Bs production and decay properties; independent confirmation and if found, exhaustive exploration of Belle's claimed charged bottomonia; clarification of puzzles of interquarkonium dipion transit…
The classical quenched quark models with three constituent quarks provide a good description for the baryon spatial ground states, but fail to reproduce the spectrum of baryon excited states. More and more evidences suggest that unquenched effects with multi-quark dynamics are necessary ingredients to solve the problem. Several new hyperon resonances reported recently could fit in the picture of penta-quark states. Based on this picture, some new hyperon excited states were predicted to exist; meanwhile with extension from strangeness to charm and beauty, super-heavy narrow $N^*$ and $Λ^*$ res…
The coherence factor and average strong phase difference of D0 and D0bar decay amplitudes to the same final state play an important role in the precision determination of the CKM parameter gamma using B- -> DK- and related decay modes. So far, this important input from the charm sector could only be obtained from measurements based on quantum-correlated DDbar pairs produced at the charm threshold. We propose to constrain these parameters using charm mixing, using the large charm samples available at the B factories and LHCb. We demonstrate for the example of D0->Kpipipi that a substantial impr…
The recently obtained strong evidence for $D^0 - \bar D^0$ oscillations from the $B$ factories provides an important benchmark in our search for New Physics in charm transitions. While the theoretical verdict on the observed values of $x_D$ and $y_D$ is ambiguous -- they could be fully generated by SM dynamics, yet could contain also a sizable contribution from New Physics -- such oscillations provide a new stage for \cp violation driven by New Physics. After emphasizing the unique role of charm among up-type quarks, I describe in some detail the \cp phenomenology for charm decays.
In recent years charm physics has undergone a renaissance, one which has been catalysed by an unexpected and impressive set of experimental results from the $B$-factories, the Tevatron and LHCb. The existence of $D^0\bar{D}{}^0$ oscillations is now well established, and the recent discovery of $CP$ violation in $D^0$ decays has further renewed interest in the charm sector. In this article we review the current status of charm-mixing and $CP$-violation measurements, and assess their agreement with theoretical predictions within the Standard Model and beyond. We look forward to the great improve…
$Λ^+_c$ hypernuclei are expected to have binding energies and other properties similar to those of strange hypernuclei in view of the similarity between the quark structures of the strange and charmed hyperons, namely $Λ(uds)$ and $Λ^+_c (udc)$. One striking difference however occurs in their mesonic decays, as there is almost no Pauli blocking in the nucleonic decay of a charm hypernucleus because the final-state nucleons leave the nucleus at high energies. The nuclear medium nevertheless affects the mesonic decays of charm hypernucleus because the nuclear mean fields modify the masses of the…
