Bulletin of the American Physical Society
4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan
Volume 59, Number 10
Tuesday–Saturday, October 7–11, 2014; Waikoloa, Hawaii
Session CF: Hadrons in Nuclei |
Hide Abstracts |
Chair: Emiko Hiyama, RIKEN Nishina Center Room: King's 2 |
Wednesday, October 8, 2014 7:00PM - 7:15PM |
CF.00001: ``Tagging'' the EMC effect with Short-Range Correlated protons Shalev Gilad, Barak Schmookler A linear correlation is observed between the slope of the typical EMC curve for 0.3 \textless x$_{\mathrm{B}}$ \textless 0.7 in deep-inelastic scattering (DIS), d[F$_{2}$(A)/F$_{2}$(d)]/dx$_{\mathrm{B}}$, and the per-nucleon cross section ratio of nucleus A to deuterium for 1.5 \textless x$_{\mathrm{B}}$ \textless 2, a$_{2}$(A/d), in inclusive electron scattering. a$_{2}$(A/d) is associated with the number of short-range correlated (SRC) nucleon pairs in nuclei. This correlation is surprising because of the vastly different energy and distance scales of EMC and SRC. A possible explanation is that the modification of the nucleon structure-functions F$_{2}$(A) in the nucleus depend on the virtuality of nucleons and is pronounced for SRC nucleons that are highly virtual. We are studying this hypothesis by tagging EMC events with high-momentum protons recoiling backward to the transferred-momentum direction, which have been shown to be spectators in scattering off their SRC partners. The DIS data off several nuclei were collected during the eg2 running period using the CLAS detector at JLab. These data are being analyzed now as part of the data mining project. We shall present preliminary results of ratios of inclusive DIS A(e,e')X/d(e,e')X, semi-exclusive DIS A(e,e'p$_{\mathrm{recoil}})$X/d(e,e'p$_{\mathrm{recoil}})$X and semi-exclusive to inclusive DIS A(e,e'p$_{\mathrm{recoil}})$X/d(e,e')X. We shall discuss these results with respect to our hypothesis that the EMC effect is related to DIS from highly virtual, SRC nucleons. [Preview Abstract] |
Wednesday, October 8, 2014 7:15PM - 7:30PM |
CF.00002: The phi meson in nuclear matter with finite momentum: a study based on QCD sum rules and the maximum entropy method Philipp Gubler, Keisuke Ohtani The behavior of the $\phi$ meson at finite density and finite momentum is studied, making use of a QCD sum rule approach in combination with the maximum entropy method. For the zero momentum case, it is demonstrated that, depending on the value of the strange sigma term $\sigma_{sN} = \langle N| \bar{s}s|N \rangle$, the $\phi$ meson could receive both a positive or negative mass shift at nuclear matter density. It will next be discussed how finite momentum effects could modify this behavior and whether they could have any consequences on physically measurable quantities. Our results are relevant for the E16 experiment to be performed at the J-PARC facility, where the behavior of the $\phi$ meson will be measured and which will hopefully provide precise information on the modification of the $\phi$ meson spectrum at finite density. [Preview Abstract] |
Wednesday, October 8, 2014 7:30PM - 7:45PM |
CF.00003: Search for $K^-pp$ deeply bound state via in-flight $^3$He($K^-,n$) reaction at J-PARC K1.8BR Shingo Kawasaki We acquired the first step data of the experimental search for deeply bound kaonic state at J-PARC beamline K1.8BR (J-PARC E15[1]) in May, 2013. We measure $K^-pp$ bound state by detecting forward scattered neutron from $^3$He($K^-,n$) reaction with the incident kaon momentum of 1 GeV/c. The neutron momentum is measured by TOF counter placed 15 m ahead in the forward direction. The decay charged particles from $K^- pp$ are tracked in the cylindrical detector system (CDS) surrounding the liquid $^3$He target. The invariant masses ($p\pi$) and ( $\Lambda p$) are reconstructed by the tracking for a search of $K^-pp\to\Lambda p \to p\pi^- p$. The in-flight reaction and CDS can distinguish all the background process such as kaon-nucleon absorption. $5.1\times10^9$ kaons hit on the target in the first E15 physics run data. Some structure below $\bar{K}NN$ or threshold was observed from the missing mass spectrum of $^3$He($K^-,n$). In this presentation, we will present an overview and the preliminary results of the first E15 physics run. [Preview Abstract] |
Wednesday, October 8, 2014 7:45PM - 8:00PM |
CF.00004: $Y_{c}NN$ 3-body charmed nuclei with channel coupling Saori Maeda, Akira Yokota, Emiko Hiyama, Makoto Oka, Yan-Rui Liu, Kenji Fukukawa Binding energies of $Y_{c}NN$ 3-body charmed nuclei are studied in a potential model. We take into account couplings of channels with $\Lambda_c$, $\Sigma_{c}$ and $\Sigma_{c}^{*}$ (spin 3/2). Since the mass difference between $\Sigma_{c}$ and $\Sigma_{c}^{*}$ is small, the effect of $\Sigma_{c}^{*}$ coupling is important. Between a charm baryon and a nucleon, we use $Y_{c}N$-CTNN potential, which consists of One Boson Exchange potential supplemented by the short-range repulsion from the Quark Cluster Model. Coupling constants and cut-off parameters are fixed so as to be consistent with the N-N interaction. Accordingly, the CTNN potential has four versions, two of which give a bound $\Lambda_c N$ ($^3 S_1$) state. We also include the Coulomb interaction for the charged charmed baryon and the proton. We find a bound state in the three-body system, when we use an effective one-body potential for $\Lambda_c N$, as a preliminary calculation. We will report the results of the full three-body calculation. [Preview Abstract] |
Wednesday, October 8, 2014 8:00PM - 8:15PM |
CF.00005: Exotic few-body systems with a heavy meson Yasuhiro Yamaguchi Hadron as an impurity bound in nuclei causes interesting phenomena which do not emerge in normal nuclei. These effects would give us the information not only on the internal structure of the nuclei, but also on the changing properties of the impurity in the nuclear medium. The hadron-nucleus systems have been studied in the light flavor sector, especially. However, a strong attraction between a heavy meson (Dbar and B) and a nucleon, provided by the one pion exchange potential (OPEP), was suggested recently. The OPEP is enhanced by the heavy quark spin symmetry which induces the mass degeneracy between the heavy pseudoscalar and vector mesons. The attraction motivates us to investigate the Dbar (B) nuclei having the exotic flavor structure. Hence, these bound states are stable against the strong decay. We discuss the possible existence of exotic few-body states realized as DbarNN and BNN. The OPEP between the Dbar (B) meson and the nucleon N is considered. By solving coupled channel equations for PNN and P$^\ast$ NN channels (P (P$^\ast$) is the heavy pseudoscalar (vector) meson), we obtain new three-body bound states and resonances. In these states, the tensor force of the OPEP plays an important role to yield the attraction. [Preview Abstract] |
Wednesday, October 8, 2014 8:15PM - 8:30PM |
CF.00006: Exploring hadronization mechanisms via neutral pion electroproduction off D, C, Fe and Pb Taisiya Mineeva Propagation of partons inside a nuclear medium and formation of hadrons is a topic of interest to multiple communities. New data available from Drell-Yan measurements at Fermilab, heavy ion collisions in RHIC and LHC, SIDIS measurements from HERMES at DESY and Jefferson Lab all bring different types of information on short distance processes. The most direct information comes from SIDIS measurements, which have a unique ability to investigate time-dependence of hadronization by embedding it in the nuclei of varying size. This talk presents results on a series of SIDIS measurements of neutral pion multiplicities on carbon, iron, and lead nuclei normalized to deuterium. The experiment was performed at Thomas Jefferson National Accelerator facility utilizing a 5 GeV electron beam and CEBAF Large Acceptance Spectrometer in Hall B. The high statistics accumulated during the experiment allowed for a three-dimensional analysis of neutral pion attenuation studied as a function of leptonic and hadronic variables. Combined with existing data on charged pions, these data provide new insights into hadronization mechanisms. [Preview Abstract] |
Wednesday, October 8, 2014 8:30PM - 8:45PM |
CF.00007: SeaQuest (Fermilab E906) Potentials on the Study of the EMC Effect and Other Topics Donald Isenhower SeaQuest (Fermilab E906) started commissioning/data collection in November 2013. It is primarily known for its planned extension of the asymmetry measurement of the nucleon sea using the Drell-Yan (D-Y) process to higher Bjorken-x than in E866/NuSea. Also a number of important aspects of $J/\Psi$ production such as total cross section and nuclear dependence will be measured. Transverse momentum broadening is proportional to $\sqrt{s}$ and was a major correction required for E866 $J/\Psi$ nuclear dependence results. The use of the 120 GeV Fermilab Main Injector should reduce this correction in SeaQuest. Other aspects of the experiment involve questions that have avoided completely satisfactory solutions and explanations for many years, One of these is the well known, and extensively studied, EMC effect. SeaQuest will measure the EMC effect of antiquarks up to Bjorken-x of 0.45. The asymmetry measurement and EMC measurements are related, as it was the EMC effect that first indicated the light anti-quark sea could not be symmetric. While anti shadowing is observed in Deep Inelastic Scattering, in Fermilab E772 it was not observed in proton induced D-Y. SeaQuest will nearly double the x-range of E772. These topics will be discussed briefly, including errors and kinematics. [Preview Abstract] |
Wednesday, October 8, 2014 8:45PM - 9:00PM |
CF.00008: High precision systematic measurement of deeply bound pionic atoms Kenta Itahashi We report results from our recent precision measurement of pionic Sn atoms in RIBF. The presentation will include results from our pilot run in 2010 and our first production series of measurement in June 2014. We have just finished data taking of the experimental spectroscopy of pionic 1s and 2s states in 121Sn atom. We employed 250 MeV/u deuteron beam impinged on the 122Sn target, and measured 3He emitted in the 122Sn(d,3He) nuclear reaction. We measured Q-value of the reaction to measure the pionic atom spectra. The experiment is aiming at first simultaneous measurement of 1s and 2s pionic state in Sn atom by a high resolution spectroscopy, that will benefit in improving the systematic errors arising in the absolute energy scale. The results will set stringent constraints on the deduced quantities of chiral condensate at the normal nuclear density. [Preview Abstract] |
Wednesday, October 8, 2014 9:00PM - 9:15PM |
CF.00009: Near threshold $\Lambda $(1115) photo production on a deuteron Brian Beckford Experiments focused on the photo-production of K$^{0}$ and Lambda in the threshold energy region were performed at Research Center for Electron Photon Science, Tohoku University (ELPH). We carried out the study using tagged photons at energies between 0.8 - 1.08 GeV incident on a liquid deuterium target. Measurements of the decay products from the produced strange particles were accomplished utilizing the upgraded Neutral Kaon Spectrometer (NKS2). We present momentum and angle dependent differential cross sections, integrated and total cross sections as well as recoil polarizations in this report. Recent theoretical predictions were compared with our experimental findings and are discussed. [Preview Abstract] |
(Author Not Attending)
|
CF.00010: The Study of the D(e,e'p)n Reaction at High Four- Momentum Transfer Hari Khanal A study of the $D(e,e'p)$ reaction has been carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfers $Q^2$ = 2.1 and 0.8 (GeV/c)$^2$ and for missing momenta $p_{m}$ ranging from $p_{m}$ = 0.03 to $p_{m}$ = 0.65 GeV/c. The analysis resulted in the determination of absolute $D(e, e'p)n$ cross sections as a function of the recoiling neutron momentum and it's scattering angle with respect to the momentum transfer $\vec q$. The experimental momentum distribution of the bound proton inside the deuteron has been determined for the first time at a set of fixed neutron recoil angle. [Preview Abstract] |
Wednesday, October 8, 2014 9:30PM - 9:45PM |
CF.00011: Development of a water Cherenkov counter for the spectroscopy of $\Xi$ hypernucleus Kohei Takenaka We plan to obtain the spectroscopic information of $\Xi$ hypernucleus through the $ ^{12}{\rm C}(K^-,K^+)$ reaction by using the high intensity $K^-$ beam at J-PARC. When $K^-$ hit the target, not only $K^+$ but also protons are scattered. The rate of protons is estimated three orders of magnitude higher than that of $K^+$. These protons are trigger backgrounds and make DAQ efficiency worse. Thus protons have to be suppressed by at least 10\% in the trigger level. In order to fulfill this requirement, we use a water ($n$ = 1.33) Cherenkov counter. The momentum region of $K^+$ and protons is around 1.3 GeV/$c$, both of which generate Cherenkov light. However, because high-velocity $K^+$ generate 2.5 times as many photons as protons, $K^+$ and protons can be discriminated by the number of photoelectrons. We estimated that at least 50 photoelectrons are required for $K^+$ at 1.3 GeV/$c$ in order to reject 90\% protons. We made and have developed a prototype of a water Cherenkov counter. We examined how proton rejection efficiency depends on reflective sheets and radiator by using cosmic ray. In addition, we investigated incident beam position and angle dependence of proton rejection efficiency at ELPH. I will report results of these experiments. [Preview Abstract] |
Wednesday, October 8, 2014 9:45PM - 10:00PM |
CF.00012: Double hypernuclei experiment with hybrid emulsion method (J-PARC E07) Hiroyuki Ekawa Double hypernuclei are important probes to study the system with strangeness -2. In order to search for double hypernuclei, an upgrade experiment is planned at J-PARC K1.8 beam line. In the experiment, the KURAMA spectrometer system will detect $\Xi^{\mathrm{-}}$ production in the ($K^{-}, K^{+})$ reaction on a diamond target. SSDs located the upstream and the downstream of emulsion plates will record $\Xi^{-}$ tracks which flight toward emulsion plates precisely. Tracks in SSDs and emulsion will be automatically connected by a hybrid method. Discoveries of more than 10 new double hypernuclear species are expected, which enable us to discuss binding energy in terms of mass number dependence. On the other hand, we will also observe $X$ rays from $\Xi ^{\mathrm{-}}$ atoms with a Germanium detector array installed close to the emulsion by tagging $\Xi^{-} $stopped events. This will be the first measurement in the world and give information on the $\Xi^{-} $potential shape at the nuclear surface region. Emulsion production has been completely done and a test experiment for some detectors of KURAMA spectrometer was carried out. In this talk, physics motivation and current status of the J-PARC E07 experiment will be reported. [Preview Abstract] |
Wednesday, October 8, 2014 10:00PM - 10:15PM |
CF.00013: Bose-Einstein correlations between two neutral pions from photoproduction below 1.2 GeV Qinghua He, Ryo Hashimoto, Takatsugu Ishikawa, Shinichi Masumoto, Manabu Miyabe, Norihito Muramatsu, Hajime Shimizu, Yasuhisa Tajima, Yusuke Tsuchikawa, Hirohito Yamazaki, Ryuji Yamazaki For the first time, we studied the space-time properties of the excited nucleons in the non-perturbative QCD region, via Bose-Einstein correlations (BEC) between two neutral pions from photoproduction off the proton/deuteron at incident photon energies below 1.2 GeV. In order to measure the Bose-Einstein correlations of two pions, an event mixing technique was developed and proved to be effective. The experiment was carried out at the Research Center for Electron Photon Science (ELPH) at Tohoku University. A 4$\pi$ electromagnetic calorimeter complex, named FOREST, was employed to detect neutral pions decaying into photons as well as some charged particles in the final state. In this work, we present the results of the spatial extension of the reaction region obtained from the BEC analysis. In addition, the BEC analysis provides useful information about the underlying mechanism of double neutral pion photoproduction. Preliminary results related to this study will be given. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700