Thu·Nov 24, 2016Thursday·November 24, 2016

1. 01*

   Central Exclusive Production in the STAR Experiment at RHIC

   Rafal Sikora (for the STAR Collaboration)🇵🇱

   The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) performs studies of diffractive processes with the focus on the exclusive production of particles in central range of rapidity. In 2015 STAR collected 18 pb${}^{-1}$ of data in polarized proton+proton collisions at $\sqrt{s}$=200 GeV to measure Central Exclusive Production (CEP) process $pp\to pXp$ through Double Pomeron Exchange (DPE) mechanism. The intact protons moving inside the RHIC beampipe after the collision were measured in silicon strip detectors (SSD), which were placed in the Roman Pot vessels. This enables full control over interaction kinematics and verification of the exclusivity of the reaction by measuring the total (missing) transverse momenta of all final state particles: the central diffractive system in the Time Projection Chamber (TPC) and the forward protons in the Roman Pots. With the use of ionization energy loss in the TPC, d$E$/d$x$, it was possible to discriminate various production channels in $pp\to pXp$ reaction. This paper presents results on exclusive production of two charged particles (${\pi }^{+}{\pi }^{-}$ and $K^{+}{K}^{-}$) in mid-rapidity region, $-1<\eta <1$, with small squared four-momentum transfer of forward protons, $0.03<-t<0.3(\text{GeV}/c{)}^2$, obtained using 2.5% of full statistics.

   nucl-exhep-exAIP Conf.Proc.(2017)·10 citations
2. 02*

   Experimental Study of Boron-coated Straws with a Neutron Source

   Zhaoyang Xie · Jianrong Zhou · Yushou Song · Liang Sun · Zhijia Sun · Bitao Hu · Yuanbo Chen

   Multiple types of high quality neutron detectors are proposed for the first phase of the China Spallation Neutron Source (CSNS), which will be commissioned in 2018. Considering the shortage of 3He supply, a detector module composed of 49 boron-coated straws (BCS) was developed by Proportional Technologies Inc. (PTI). Each straw has a length of 1000 mm and a diameter of 7.5 mm. Seven straws are tightly packed in a tube, and seven tubes are organized in a row to form a detector module. The charge division method is used for longitudinal positioning. A specific readout system was utilized to output the signal and simultaneously encode each straw. The performance of this detector module was studied using a moderated 252Cf source at the Institute of High Energy Physics (IHEP). The signal amplitude spectrum indicates its n-gamma discrimination capability. Despite the complex readout method, a longitudinal resolution of 6.1-0.5 mm was obtained. The three-dimensional positioning ability qualifies this BCS detector module as a promising neutron scattering spectrometer detector.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2018)·2 citations
3. 03*

   Neutrino-Nucleus Cross Sections for Oscillation Experiments

   Teppei Katori🇬🇧 · Marco Martini🇧🇪

   Neutrino oscillations physics is entered in the precision era. In this context accelerator-based neutrino experiments need a reduction of systematic errors to the level of a few percent. Today one of the most important sources of systematic errors are neutrino-nucleus cross sections which in the hundreds-MeV to few-GeV energy region are known with a precision not exceeding 20%. In this article we review the present experimental and theoretical knowledge of the neutrino-nucleus interaction physics. After introducing neutrino oscillation physics and accelerator-based neutrino experiments, we overview general aspects of the neutrino-nucleus cross sections, both theoretical and experimental views. Then we focus on these quantities in different reaction channels. We start with the quasielastic and quasielastic-like cross section, putting a special emphasis on multinucleon emission channel which attracted a lot of attention in the last few years. We review the main aspects of the different microscopic models for this channel by discussing analogies and differences among them.The discussion is always driven by a comparison with the experimental data. We then consider the one pion production channel where data-theory agreement remains very unsatisfactory. We describe how to interpret pion data, then we analyze in particular the puzzle related to the impossibility of theoretical models and Monte Carlo to simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive cross sections are also discussed, as well as the comparison between the ${\nu }_{\mu }$ and ${\nu }_e$ cross sections, relevant for the CP violation experiments. The impact of the nuclear effects on the reconstruction of neutrino energy and on the determination of the neutrino oscillation parameters is reviewed. A window to the future is finally opened by discussing projects and efforts in future detectors, beams, and analysis.

   ↳ hep-phhep-exnucl-exnucl-thJ.Phys.G(2018)·206 citations
4. 04*

   DSSSD based Spectrometer of the Dubna Gas-Filled Recoil Separator

   Yu. S. Tsyganov🇷🇺

   Recently, in the DGFRS related experiments the discoveries of new superheavy elements 114 to 118 were successfully performed. As concerns to a background radical suppression in those experiments it was namely Active correlations method which was applied to this goal. Note, that application of DSSSD detector allows one to apply this method more effectively, although with some difficulties due to neighbor strips edge effects. Present version of the DGFRS spectrometer is presented. Shapes of ER registered energy spectra in the nat Yb+48Ca reaction are presented. First results of its application in the 240Pu+48Ca=Fl complete fusion nuclear reaction are presented too. Conclusion, that edge effects are to a first approximation explained by the role of inter strips area is drawn.

   ↳ physics.ins-detnucl-ex0 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.