dataesr/scientific-paragraphs-categorization huggingface dataset:
08 x Bj = 0. 25 Fig. 7  The combined HERA data for the inclusive NC e -p reduced cross section as a function of Q 2 for four selected values of x Bj compared to the results from HERA I alone  [2]. The two measurements are displaced horizontally for better visibility. Error bars represent the total uncertainties The results of the combination of the data with lower proton beam energies are shown in Figs. 8  and 9  as a function of x Bj in selected bins of Q 2. These data augment the data with standard proton energy to provide increased sensitivity to the gluon density in the proton. The combined NC e + p data for very low Q 2 with proton beam energies of 920 and 820 GeV are shown in Figs. 10  and  11. These data were taken during the HERA I period, but due to the systematic shifts introduced by the combination with HERA II data, the numbers are not always the same as in the old HERA I combination.
The combined CC cross sections are shown in Figs. 12, 13, 14 and 15, together with the input data from H1 and ZEUS and the comparison to the HERA I combination results for e + p and e -p scattering. As for the NC data, the power of combination and the improved precision due to the high statistics data from HERA II are demonstrated. The high-precision DIS cross sections provided here form a coherent set spanning six orders of magnitude, both in Q 2 and x Bj. They are a major legacy of HERA.
QCD analysis In this section, the pQCD analysis of the combined data resulting in the PDF set HERAPDF2. 0 and its released variants is presented. The framework established for HERA-PDF1. 0 [2]  was followed in this analysis. A breakdown of pQCD is expected for Q 2 approaching 1 GeV 2. To safely remain in the kinematic region where pQCD is expected to be applicable, only cross sections for Q 2 starting from Q 2 min = 3. 5 GeV 2 were used in the analysis. In this kinematic region, target-mass corrections are expected to be negligible. Since the centre-of-mass energy at the γ p vertex W is above  15  GeV for all the data, large-x Bj higher-twist corrections are also expected to be negligible. The Q 2 range of the cross sections entering the fit is 3. 5 ≤ Q 2 ≤ 50,000 GeV 2. The corresponding x Bj range is 0.
It was chosen to be μ 2 f 0 = 1. 9 GeV 2 as for HERAPDF1. 0. The renormalisation and factorisation scales were chosen to be μ 2 r = μ 2 f = Q 2. The predictions for the structure functions  [1]  which appear in the calculation of the cross sections, see Eq. 1, were obtained by convoluting the parton distribution functions with coefficient functions appropriate to the order of the calculation. The light-quark coefficient functions were calculated using QCDNUM. The heavy-quark coefficient functions were calculated in the general-mass variableflavour-number scheme called RTOPT  [82] [83] [84]  for the NC structure functions. For the CC structure functions, the zeromass approximation was used, since all HERA CC data have Q 2 M 2 b , where M b is the beauty-quark mass parameter in the calculation.
Definition of χ 2 The pQCD predictions were fit to the data using a χ 2 method similar to that described in Sect. 4. 2. The definition of χ 2 is   H1 and ZEUS χ 2 exp (m, s) = i m i -j γ i j m i s j -μ i 2 δ 2 i,stat μ i m i + δ 2 i,uncor (m i ) 2 + j s 2 j + i ln δ 2 i,stat μ i m i +(δ i,uncor m i ) 2 (δ 2 i,stat +δ 2 i,uncor )(μ i ) 2 , ( 32 ) where the notation is equivalent to that in Eq. 22; here s is used to denote systematic shifts. The additional logarithmic term in Eq. 32 compared to Eq. 22 was introduced to minimise biases  [8]. Correlated systematic uncertainties were treated as for the combination of data, see Sect. 4. 2. For the combined inclusive data, the correlated systematic uncertainties are smaller or comparable to the statistical and uncorrelated uncertainties. Nevertheless, the remaining correlations are significant and thus the 162 systematic uncertainties present for the H1 and ZEUS data sets plus the seven sources of procedural uncertainty which resulted from the combination procedure, see Sect.
Experimental uncertainties Experimental uncertainties were determined using the Hessian method with the criterion χ 2 = 1. The use of a consistent input data set with common correlations justifies this approach. A cross check was performed using the Monte Carlo method  [87, 88]. It is based on analysing a large number of pseudo data sets called replicas. For this cross check, 1000 replicas were created by taking the combined data and fluctuating the values of the reduced cross sections randomly within their given statistical and systematic uncertainties taking into account correlations. All uncertainties were assumed to follow Gaussian distributions. The PDF central values and uncertainties were estimated using the mean and RMS values over the replicas. The uncertainties obtained by the Monte Carlo method and the Hessian method were consistent within the kinematic reach of HERA.
Model and parameterisation uncertainties For the NLO and NNLO PDFs, the uncertainties on HERA-PDF2. 0 due to the choice of model settings and the form of the parameterisation were evaluated by varying the assumptions. A summary of the variations on model parameters is given in Table  2. The variations of M c and M b were chosen in accordance with the χ 2 scans related to the heavyquark mass parameters as shown in Figs. 16  and 17. The data on heavy-quark production from HERA II led to a considerably reduced uncertainty on the heavy-quark mass parameters compared to the HERAPDF1. 0 and HERAPDF1. 5 analyses, see Appendix A. The variation of f s was chosen to span the ranges between a suppressed strange sea  [36, 85]  and an unsuppressed strange sea  [86]. In addition to this, two more variations of the assumptions about the strange sea were made.
Fiber positioning will be performed by a positioner consisting of two stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modules, each with three arms. The PFS project has passed several project-wide design reviews and is now in the construction phase.
INTRODUCTION The Prime Focus Spectrograph (PFS)  1  is an optical/near-infrared multifiber spectrograph with 2394 science fibers (Fig. 1 ), and is scheduled to be mounted on the Subaru 8. 2-m telescope. The position of each fiber is controlled by a fiber positioner, called "Cobra," consisting of two-staged piezoelectric rotary squiggle motors. Each fiber positioner unit samples a circular patrol region of 9. 5-mm diameter at the telescope focal plane, and these positioners are arrayed into a hexagonal pattern with 8-mm central distances between adjacent positioners. The whole array extends to a single hexagonal field of view (FOV) whose effective diameter is 1. 3 deg. The hexagonal FOV has an advantage for efficient tiling of survey areas, compared with e. g. , a circular FOV. The fibers are divided into four groups, each of which enters one of the four spectrograph modules in a slit comprising 600 or 597 science fibers in a single row.
2. 1, increases the F∕# of the beam to ease the design requirements on the spectrographs. The light then enters the multimode fibers, which are part of a fiber system described in Sec. 2. 2 that also includes connectors and fiber arrays. In the telescope focal plane, these fibers are mounted in a series of positioners, described in Sec. 2. 3, which connect the fibers to the celestial images. The fibers transmit the science light to one of the four spectrograph modules, described in Sec. 2. 4. The spectrograph modules also provide a means for back-illumination, which enables the metrology camera system, described in Sec. 2. 5, to measure the positions of the fibers. The relevant software and observational execution processes are described in Sec. 2. 6. PFS technical first light is scheduled on Subaru in early 2018 with the start of the associated Subaru strategic program survey expected in 2019.
5-mm diameter. Intensive tests using 29 engineering model fiber positioners have been completed and we are now in the phase of mass production (Fig. 6 ). The fiber positioners are built into a module containing 57 positioners each with a microlensed fiber and the Cobra drive electronics. The total positioner system consists of 42 of these modules mounted onto the fiber-positioner optical bench, which is attached to the PFI structure. As shown in Fig. 1 , the PFI is installed in Subaru's housing structure, called prime focus unit POpt2, whose rotator provides PFI with the rotating part and the nonrotating part with respect to the telescope structure. While the nonrotating part is fixed to the telescope, rotation enables tracking target objects in the sky. A structure called the positioner frame connects the POpt2 rotator and the fiber-positioner optical bench on which fiber positioners as well as six acquisition and guide (A&G) cameras are mounted.
4 μm in each of the x, y directions and a pin-diameter accuracy of 0. 4 μm. These pins allow accurate alignment of a pair of CCDs. For the NIR channel in each spectrograph module, a 4 K×4 K Teledyne H4RG-15 mercury-cadmium telluride device is used with the same pixel size of 15 μm × 15 μm to the optical CCD case. The special cutoff wavelength of 1. 7 μm, as short as is feasible, suppresses the thermal background. The expected location for installing the spectrograph modules is the fourth floor of the infrared side (IR4) in the Subaru enclosure. The four spectrograph modules will lie within a single light-weighted spectrograph clean room, with thermal insulator walls to improve both temperature control and cleanliness. The temperature inside of the spectrograph clean room will be kept within +/-1°C.
Software and execution processes of observations For science operations, the observation preparation software parses large surveys into a series of individual observations, matches fibers to designated targets, selects appropriate guide stars, predicts observing times, and provides sequence files in a Subaru format. The PFS observation control computer (OBCP) controls the entire instrument under the Subaru observation management software Gen2. Execution of an observation begins with moving the telescope to the desired field center. While the telescope is slewing, the fiber positioning system executes commands from the OBCP to simultaneously move all fibers to their required positions with the real positions verified by the metrology system. With several iterations, the position error of each science fiber can be effectively minimized.
In parallel with this process, the A&G system refines the pointing of the telescope and angle of the instrument rotator. The hexapod is commanded to move to the appropriate position to maintain the WFC alignment in the presence of flexure in the POpt2 structure. Once positioning is complete, autoguiding commences. The onsite data reduction system produces quick-look information on the completed observation so that data quality and survey progress can be monitored. The collected raw data will be transferred to and archived in the Subaru telescope archive system data archive system, which then provides data retrieval for further scientific data reduction and analysis.
SUMMARY Following the successful project conceptual design review and preliminary design review and further subsystem critical design reviews, PFS has now entered the construction phase. Mass production of the microlenses and fibers is complete. These two components are now being integrated, which includes gluing them in the fiber arm structure. Later, they will be integrated with each fiber positioner, shortly to enter the mass production phase, by gluing the fiber arm to the positioner motor shaft. The positioner modules will be integrated onto the positioner optical bench and then into the PFI structure. This integrated PFI system will be tested together with the metrology camera. For the spectrograph module side, all optical elements, including gratings, are in production. These optical components will be integrated with cryostats and dewars on four spectrograph optical benches.
ACKNOWLEDGEMENTS We gratefully acknowledge support from the  Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) program  " Subaru Measurements of Images and Redshifts (SuMIRe) ",  CSTP, Japan , and  Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) ,  Brasil. We appreciate staff members at  Subaru Telescope  for continuously supporting our activities. We thank  NAOJ ATC  staff members particularly  Tetsuo Nishino ,  Norio Okada , and  Yukiko Kamata  for preparing AlN pin bases, and  Durham University  staff members for their consultancy to IPMU on fiber system. We also acknowledge the WFMOS-B team whose accumulated efforts of many years have inspired us. This paper has been revised and updated, for the purpose of journal publication, from the  PFS  overview paper 28 presented in an SPIE conference.
Acknowledgements. The authors would like to thank  Walter Hochfellner  for performing simulations of rotor-router walks on Galton-Watson trees. We also thank the anonymous referees for carefully reading the first version and for suggesting various improvements. The research of Wilfried Huss was supported by the  Austrian Science Fund (FWF) :  P24028-N18  and by the  Erwin-Schrödinger scholarship  (FWF):  J3628-N26. The research of  Ecaterina Sava-Huss  was supported by the  Erwin-Schrödinger scholarship (FWF) :  J3575-N26. Moreover, all three authors were supported by the exchange program Amadeus between  Graz  and  Marseille , project number  FR 11/2014.
5. (θ s is the typical propagation angle of the soft primary gluons, and its above estimate will be discussed in Sect. 5. ) By progressively increasing the jet opening angle θ 0 within a rather wide range, say from θ 0 ∼ θ s up to θ 0 ∼ 1, we can recover part of the missing energy, but only very slowly : most of this energy lies at even larger angles, θ ∼ θ th θ s (see Fig. 1  and Sect. 5 for details). The above predictions -the numerical estimate for the energy loss at large angles ∆E flow and its extremely weak dependence upon the jet opening angle θ 0 -are in good agreement, qualitative and even semi-quantitative, with the phenomenology of di-jet asymmetry at the LHC  [2, 4, 5, 8]. Vice versa, we believe that these particular LHC data could not be understood in a scenario which neglects multiple branchings, nor in one which uses a vacuum-like model for the in-medium gluon fragmentation, that is, a model which ignores the quasi-democratic nature of the soft branchings and the associated turbulent flow.
Highlights of science results The Pierre Auger Observatory has made key measurements of the highest energy cosmic rays. Cosmic ray showers with zenith angle < 60 • are defined as vertical showers, while those with 60 • < zenith angle < 80 • are defined as horizontal showers. The energy spectrum is measured with unprecedented precision using four datasets: hybrid (events measured simultaneously by the SD and FD), SD 750 m array, SD baseline vertical, and SD baseline horizontal  [11, 12]. Thanks to the high statistics of the SD data, a first harmonic analysis was performed in different energy ranges starting from 2. 5 × 10 17 eV in a search for dipolar modulations in right ascension  [13, 14]. The upper limits in the dipole amplitude impose stringent constraints in astrophysical models  [13, 15, 16].
Using the observation of hybrid events, this energy calibration can then be transferred to the surface array with its 100% duty factor and large event gathering power. Moreover, independent measurements by the surface array and the fluorescence detectors alone have limitations that can be overcome by comparing their measurements in the set of showers measured by both. The hybrid dataset provides a thorough understanding of the capabilities and the systematic uncertainties of both components. The FD always operates in conjunction with the SD. Its primary purpose is to measure the longitudinal profile of showers recorded by the SD whenever it is dark and clear enough to make reliable measurements of atmospheric fluorescence from air showers. The integral of the longitudinal profile is used to determine the shower energy, and the rate of shower development is indicative of the primary particle's mass.
g. , Figure  8 ). The reflectivity of a few selected mirror segments is measured once or twice each year and it changes less than 1% per year. Alignment of individual mirror segments was cross-checked with a laser on site. Moreover, additional methods using data measured by telescopes were used, such as star tracking, Central Laser Facility (CLF) and eXtreme Laser Facility (XLF) shots (Section 4. 4. 2), or a comparison of FD and SD geometry reconstruction. Only in two cases were a realignment of a telescope and a readjustment of camera position needed.
This PC provides a connection between the communications network and the MPCs. The MPCs are diskless, thus they boot their Linux system through the network and store their data on the EyePCs hard drive. The events surviving all trigger levels are sent through the MPC to the EyePC, which builds an event from the coincident data in all telescopes at a given site and generates a hybrid trigger (FD-T3) for the surface array. The event rate is about 0. 012 Hz per site for the 24 baseline telescopes (see Sec. 12).
FD operation Beginning in 2005, the FD initially operated with 12 telescopes at two sites, Los Leones and Coihueco (see Figure  1 ). In the following years, two additional sites, Los Morados and Loma Amarilla, with six telescopes at each site, were brought into operation. All FD telescopes are operated remotely from the central campus by shift personnel. Their responsibilities include preparation of the FD for a run, making relative calibrations, starting and stopping runs and online checking of the quality of measured data  [46]. The Slow Control System (SCS) assures a secure remote operation of the FD system. The SCS works autonomously and continuously monitors detector and weather conditions. Commands from the remote operator are accepted only if they do not violate safety rules that depend on the actual experimental conditions: high voltage, wind speed, rain, light levels inside/outside the buildings, etc.
Data communications system The detector systems of the Observatory are deployed at widely dispersed positions over a very large area. To send commands and receive data from the four individual FD sites and from 1660 SD stations in the field, a bidirectional radio frequency telecommunication network has been designed and deployed. The reliability of the network is critical to the function of the Observatory, particularly in the context of controlling the experiment, identifying event triggers, and collecting data recorded at each detector for each air shower event. For Auger, a custom designed system based on a two-layer hierarchy has been implemented. Individual surface detector stations are connected by a custom WLAN which is sectorized and supported by four concentration nodes. The WLAN is serviced by a high capacity microwave backbone network which also supports communications between the four fluorescence detector sites and the main campus data acquisition and control center.
The microwave backbone network The top layer of the Auger data communications system is a 34 Mbps backbone network made from commercial, point-to-point, dish mounted equipment operating in the 7 GHz band. Receivers and transmitters are mounted on five communications towers located at the perimeter of the array as depicted in Figure  12. The microwave backbone provides high speed network communications to nodes at all four FD sites and with the main campus. The microwave backbone, depicted schematically in Figure  13 , consists of a set of paired links providing sufficient capacity to stream data to and from each of the FD sites as well as for collecting data from the individual surface stations.
These triggers combined with the T3 from FD sites (FD T3) are used to generate a request for the relevant data from SD stations for these events. The CDAS is then used to combine and store these data to form a shower event. The CDAS also contains configuration and control mechanisms, the means to monitor system performance, and the tools to access and download SD monitoring, calibration, control and configuration data. Except for triggering information (see Section 6. 3), the CDAS and the FD data acquisition systems are completely independent. The merging of FD and SD data is made offline during the daytime following an FD run. Data are synchronized on the central storage hardware after each night of observation. The newly acquired data within the central storage are mirrored at the primary data mirror located at the Lyon HEP Computer Center (France) every 3 hours; later these data can be transferred to secondary mirror sites.
The Post Master is used also to route data between the applications of the CDAS and the SD. Commands and configuration parameters can be transmitted, along with event requests, such as the level 3 trigger identified by the 'Central Trigger' processor. Software downloads over the communications link are also possible, thus enabling upgrades of the local DAQ software at the stations without the need to travel many kilometers to each one. Data received from each SD station belong to different data streams: 1. Local triggers, T2: the highest priority stream, with a list of time stamps and the type of trigger (threshold or time over threshold), is forwarded to the 'Central Trigger' application. 2. Shower data with its calibration data: data in this high priority stream are sent only when a request is received from the CDAS at an SD station.
Data acquisition must be monitored and failures of any station component (power system, PMT, communication device) must be detected. The data taking of the FD can only take place under specific environmental conditions and is organized in shifts. The sensitive cameras can only be operated on dark nights without strong winds or rain. This makes the operation a busy task for the shifters who have to judge the operating mode on the basis of the information given by the monitoring system. The technical description of the implementation is given separately for the services of the central server and the subcomponents. The subcomponents show the different ways the data flow to the central database are organized.
Server techniques The basis of the monitoring system is a database. We have chosen the widespread and publicly available MySQL database system. It includes all necessary features, e. g. , replication and stored functions/procedures. The front end is based on a web server running Apache. The web site uses mainly PHP, CSS and JavaScript. An interface has been developed for generating visualizations. Currently the usage of Gnuplot is implemented via an internal system call. The second option used for generation of visualizations is the JPGraph package which is implemented with direct PHP calls on an object oriented basis with the interface defined in the inherited classes. Alarms, occurrences of states that require immediate action, are first entered into a specified table of the database. The web front end checks this table for new entries and displays them on the web page.