Fri·Jan 23, 2015Friday·January 23, 2015

1. 01*

   Modern Studies of the Deuteron: from the Lab Frame to the Light Front

   Werner Boeglin🇺🇸 · Misak Sargsian🇺🇸

   We review the recent progress made in studies of deuteron structure at small internucleon distances. This progress is largely facilitated by the new generation of experiments in deuteron electrodisintegration carried out at unprecedentedly high momentum transfer. The theoretical analysis of these data confirms the onset of the high energy eikonal regime in the scattering process which allows one to separate long range nuclear effects from the effects genuinely related to the short distance structure of the deuteron. Our conclusion is that for the first time the deuteron is probed at relative momenta beyond 300 MeV/c without dominating long range effects. As a result, at these large nucleon momenta the cross section is sensitive to the nuclear dynamics at sub-fermi distances. Due to large internal momenta involved we are dealing with the relativistic bound state that is best described by the light-cone momentum distribution of nucleons in the deuteron. We present the first attempt of extracting the deuteron light-cone momentum distribution function from data and discuss the importance of this quantity for studies of QCD structure of the bound nucleon in deep inelastic scattering off the deuteron. We conclude the review giving an outlook of the next generation of high energy experiments which will extend our reach to much smaller distances in the deuteron.

   nucl-exhep-exhep-phnucl-thIJMPE(2015)·33 citations
2. 02*

   Measurement of the strong interaction induced shift and width of the 1s state of kaonic deuterium at J-PARC

   J. Zmeskal🇦🇹 · M. Sato🇯🇵 · S. Ajimura🇯🇵 · M. Bazzi🇮🇹 · G. Beer🇨🇦 · C. Berucci🇦🇹 · H. Bhang🇰🇷 · D. Bosnar🇭🇷 · M. Bragadireanu🇷🇴 · P. Buehler🇦🇹 · L. Busso🇮🇹 · M. Cargnelli🇦🇹 and 65 other authors

   The antikaon-nucleon interaction close to threshold provides crucial information on the interplay between spontaneous and explicit chiral symmetry breaking in low-energy QCD. In this context the importance of kaonic deuterium X-ray spectroscopy has been well recognized, but no experimental results have yet been obtained due to the difficulty of the measurement. We propose to measure the shift and width of the kaonic deuterium 1s state with an accuracy of 60 eV and 140 eV respectively at J-PARC. These results together with the kaonic hydrogen data (KpX at KEK, DEAR and SIDDHARTA at DAFNE) will then permit the determination of values of both the isospin I=0 and I=1 antikaon-nucleon scattering lengths and will provide the most stringent constraints on the antikaon-nucleon interaction, promising a breakthrough. Refined Monte Carlo studies were performed, including the investigation of background suppression factors for the described setup. These studies have demonstrated the feasibility of determining the shift and width of the kaonic deuterium atom 1s state with the desired accuracy of 60 eV and 140 eV.

   nucl-exphysics.ins-detActa Phys.Polon.B(2015)·18 citations
3. 03*

   Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}}=19.6$ and 200 GeV

   STAR Collaboration: L. Adamczyk🇵🇱 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · I. Alekseev🇷🇺 · J. Alford🇺🇸 · A. Aparin🇷🇺 · D. Arkhipkin🇺🇸 · E. C. Aschenauer🇺🇸 · G. S. Averichev🇷🇺 · A. Banerjee🇮🇳 and 324 other authors

   The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity $|y_{ee}|<1$ in minimum-bias Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened $\rho$ spectral function for $M_{ee}<1.1$ GeV/$c^2$. The integrated dielectron excess yield at $\sqrt{s_{NN}}$ = 19.6 GeV for $0.4<M_{ee}<0.75$ GeV/$c^2$, normalized to the charged particle multiplicity at mid-rapidity, has a value similar to that in In+In collisions at $\sqrt{s_{NN}}$ = 17.3 GeV. For $\sqrt{s_{NN}}$ = 200 GeV, the normalized excess yield in central collisions is higher than that at $\sqrt{s_{NN}}$ = 17.3 GeV and increases from peripheral to central collisions. These measurements indicate that the lifetime of the hot, dense medium created in central Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV is longer than those in peripheral collisions and at lower energies.

   ↳ hep-exnucl-exPLB(2015)·75 citations
4. 04*

   Forward Compton Scattering with weak neutral current: constraints from sum rules

   Mikhail Gorchtein🇩🇪 · Xilin Zhang🇺🇸

   We generalize forward real Compton amplitude to the case of the interference of the electromagnetic and weak neutral current, formulate a low-energy theorem, relate the new amplitudes to the interference structure functions and obtain a new set of sum rules. We address a possible new sum rule that relates the product of the axial charge and magnetic moment of the nucleon to the 0th moment of the structure function $g_5(\nu ,0)$. We apply the GDH and the finite energy sum rule for constraining the dispersive $\gamma Z$-box correction to the proton's weak charge.

   ↳ nucl-thhep-phnucl-exPLB(2015)·8 citations
5. 05*

   Elimination of influence of neutron-skin size difference of initial colliding nuclei in Pb+Pb collisions

   Gao-Feng Wei🇨🇳

   Within an isospin- and momentum-dependent transport model using as an input nucleon density profiles from Hartree-Fock calculations based on a modified Skyrme-like (MSL) model, we study how to eliminate the influence of neutron-skin size difference of initial colliding nuclei in probing the nuclear symmetry energy. Within the current experimental uncertainty range of neutron-skin size of ${}^{208}$Pb, the Pb+Pb collisions are performed in semicentral and peripheral collisions with impact parameters of 5 and 9fm and at beam energies from 50 MeV/nucleon to 1000 MeV/nucleon, respectively. It is shown that combination of neutron and proton collective flows, i.e., neutron-proton differential elliptic flow, neutron-proton elliptic flow difference, neutron-proton differential transverse flow and neutron-proton transverse flow difference, can effectively eliminate the effects of neutron-skin size difference and thus can be as useful sensitive observables in probing nuclear matter symmetry energy in heavy-ion collisions. Moreover, the combined neutron-proton stopping power including the neutron-proton differential stopping power and neutron-proton stopping power difference can also eliminate the effects of neutron-skin size difference and shows some sensitivities to symmetry energy especially at the lower beam energy.

   ↳ nucl-thnucl-exPRC(2015)·6 citations
6. 06*

   Proton Structure and PHENIX Experiment

   Jian-Wei Qiu🇺🇸

   We briefly summarize the important and critical roles that PHENIX Experiment has played in determining the proton's internal structure in terms of quarks and gluons, and their dynamics. Some pioneering measurements by PHENIX Experiment on the motion and polarization of quarks and gluons, as well as their correlations inside a fast moving proton are presented. Some future opportunities and potentials of PHENIX Experiment are also discussed.

   ↳ nucl-thhep-phnucl-exPTEP(2015)·0 citations
7. 07*

   Multi-wavelength, Multi-Messenger Pulsar Science in the SKA Era

   John Antoniadis🇩🇪 · Lucas Guillemot🇩🇪 · Andrea Possenti🇮🇹 · Slavko Bogdanov🇺🇸 · Joseph D. Gelfand🇦🇪 · Michael Kramer🇩🇪 · Roberto Mignani🇬🇧 · Benjamin Stappers🇳🇱 · Pablo Torne🇩🇪

   The Square Kilometre Array (SKA) is an integral part of the next-generation observatories that will survey the Universe across the electromagnetic spectrum, and beyond, revolutionizing our view of fundamental physics, astrophysics and cosmology. Owing to their extreme nature and clock-like properties, pulsars discovered and monitored by SKA will enable a broad range of scientific endeavour and play a key role in this quest. This chapter summarizes the pulsar-related science goals that will be reached with coordinated efforts among SKA and other next-generation astronomical facilities.

   ↳ astro-ph.HEastro-ph.IMastro-ph.SRgr-qc+1PoS(2015)·4 citations
8. 08*

   Overview of ALICE results

   Antonio Ortiz (for the ALICE Collaboration)🇲🇽

   The ALICE detector was designed to study the physics of matter under extreme conditions of high energy density. Different results were reported by the experiment using data from the successful run I of the LHC. The goal of the present work is to present an overview of recent ALICE results. This comprises selected results from several analyses of pp, p-pb and Pb-Pb data at the LHC energies.

   ↳ hep-exnucl-exNucl.Part.Phys.Proc.(2015)·5 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.