)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3

 %XPERIMENTS AT THE  'E6 0ROTON 3YNCHROTRON
4HE +%+  'E6 0ROTON 3YNCHROTRON 03 WASOPERATED IN SLOW BEAM EXTRACTION MODE IN !PRIL -AYAND *UNE !FTER THE SUMMER SHUTDOWN FAST BEAM
EXTRACTION MODE WAS STARTED AT THE END OF 3EPTEMBER AND
WAS SCHEDULED TO BE CONTINUED UNTIL THE END OF &9
$UE TO AN ELECTRICAL FAULT OF THE FIRST HORN OF THE NEUTRINOBEAM LINE IN .OVEMBER HOWEVER DATA ACQUISITION FROMTHE ++ EXPERIMENT % WAS HALTED AND THE INITIAL
PLAN WAS SWITCHED OVER TO ACCELERATOR STUDY AND 2$ OF
DETECTORS FOR * 0!2# AND THE NEXT GENERATION LONG BASELINE NEUTRINO OSCILLATION EXPERIMENT 4+ UNTIL THE END
OF $ECEMBER !CCELERATOR OPERATION WAS THEN CHANGEDTO THE SLOW BEAM EXTRACTION MODE IN *ANUARY &EBRUARYAND -ARCH $URING THE PERIOD IN SLOW BEAM EXTRACTIONMODE ABOUT  MONTHS IN TOTAL WORK WAS CARRIED OUT
ON THE %A EXPERIMENT AND  TESTS WERE PERFORMED%A IS SEARCHING FOR + , m PN@N DECAY WHICH ISTHE MOST ATTRACTIVE FLAVOR CHANGING NEUTRAL CURRENT&#.# PROCESS IN THE #0 VIOLATION STUDY 3INCE THEDECAY PROBABILITY IS WELL CALCULATED WITH A NEGLIGIBLEAMBIGUITY IN THE 3TANDARD -ODEL 3- IT PROVIDES THE
CLEANEST TEST OF THE 3- AND ANY DEVIATION FROM THEEXPECTATION WILL BE A CLEAR SIGNAL OF THE NEW PHYSICS
4HE EXPERIMENT PERFORMED DATA TAKING SUCCESSFULLY FOR
 DAYS FROM &EBRUARY TO *UNE  $URING THE DATATAKING IT WAS CONFIRMED THAT THE PENCIL + , BEAM ANDTHE DETECTOR SYSTEM INCLUDING THE VACUUM WORKED PROPERLY AS DESIGNED &IGURE    SHOWS A FINAL PLOT OFPROMPT ANALYSIS USING  OF THE OBTAINED DATA 7ITHSUCH A SMALL FRACTION OF DATA THE EXPERIMENT ALREADYREACHES A SENSITIVITY CLOSE TO THE CURRENT EXPERIMENTALLIMIT )N ADDITION TO A DETAILED ANALYSIS WITH HIGHER STATISTICS A SECOND DATA TAKING WAS PERFORMED AS AN EXTENSION FOR  DAYS FROM &EBRUARY TO -ARCH  WITH AFEW UPGRADES OF THE DETECTOR SYSTEM INDUCED BY THEPROMPT ANALYSIS4EST EXPERIMENTS WERE CARRIED OUT FOR CALIBRATIONSAND 2$ OF DETECTORS PREPARATIONS FOR 03 EXPERIMENTSOTHER LABORATORIES AND FUTURE FACILITIES 4HE 4 GROUPVERIFIED A NOVEL CONCEPT FOR SPACE BASED ANTIMATTERDETECTION THE 'ASEOUS !NTIPARTICLE 3PECTROMETER
'!03 EMPLOYED IN THE P BEAM LINE AS SHOWN IN &IG   4HE '!03 GAS TARGET IS DESIGNED SO THAT ANTIPROTONS WITH KINETIC ENERGY BELOW  -E6 WILL BE CAPTURED INTO EXOTIC ATOMS WITH NEARLY UNITY PROBABILITY )TSDETECTION RATES AND EFFICIENCIES AS INFERRED FROM AN&IG    $ECAY VERTEX VERSUS TRANSVERSE MOMENTUM
DISTRIBUTION OF RECONSTRUCTED P  FROM TWODETECTED GAMMAS 4HE RECTANGULAR BOX INDI
CATES THE SIGNAL REGION SEARCHED FOR +, m PN@NEVENTS 4HE EVENTS SURROUNDING THE SIGNAL BOXWERE IDENTIlED AFTER A PRELIMINARY BACKGROUNDANALYSIS AS +, m GG DECAYS AROUND 04  EVENTS DUE TO INTERACTION OF BEAM PARTICLES WITHUPSTREAM VERTEX   CM AND DOWNSTREAM
VERTEX   CM DETECTORS AND EVENTS FROMSEVERAL SOURCES INCLUDING +, DECAYS AT LOWER 04BELOW THE SIGNAL BOX&IG    0HOTOGRAPH OF THE '!03 DETECTOR WITH THEGAS TARGET IN THE P BEAM LINE)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3
EXPERIMENT WITH  ANTIPROTONS PER SPILL ARE CONSISTENTWITH SIMULATIONS 4HE 4 GROUP CHECKED /0%2!
EMULSION FILMS PREPARED IN THE 4ONO MINE 'IFU *APAN 
3OME OF THE FILMS WERE PICKED UP AND EXPOSED IN THE 4BEAM LINE TO MONITOR UNIFORMITY OF REFRESH PERFORMANCESENSITIVITY GRAIN DENSITY NOISE FOG ETC 4HE 44 GROUP TESTED THE TRACKER BASED ON SCINTILLATINGFIBERS FOR THE INTERNATIONAL -UON )ONIZATION #OOLING%XPERIMENT -)#% AT 2!, TO OPTIMIZE THE CONCENTRA
TION OF (& TO THE SENSITIVITY OF 6,0# 4HE 4 GROUPFOR E E+ , HYPERNUCLEI SPECTROSCOPY AT THE *EFFERSON,AB INVESTIGATED THE AMINO ' SALT CONCENTRATION OF
WATER #ERENKOV COUNTERS SO AS TO HAVE GOOD + SELECTION
AT THE TRIGGER LEVEL 4HE 4 GROUP EVALUATED THE PERFORMANCE OF A (ADRON "LIND $ETECTOR ("$ AND A
4IME 0ROJECTION #HAMBER 40# USING 'AS %LECTRON-ULTIPLIERS '%-S FOR THE 0(%.)8 DETECTOR TO REDUCETHE BACKGROUND 4HE 4 GROUP TESTED THE PERFORMANCE OF A SMALL PROTOTYPE 40#  CM DRIFT LENGTHWITH A -ULTI 7IRE 0ROPORTIONAL #HAMBER -70#READOUT ENDPLATE WHICH WAS BUILT BY -0) -UNICH AND$%39 AT THE P BEAM LINE WITH  TESLA IN THE SUPERCONDUCTIVE SOLENOIDAL MAGNET 4HE PURPOSE OF 4 WAS
2$ OF A NEW GASEOUS TIME OF FLIGHT DETECTOR THE-ULTI GAP 2ESISTIVE 0LATE #HAMBER FOR THE 0(%.)8EXPERIMENT AT 2()# 4HE 4 GROUP TESTED A PROXIMITY FOCUSING RING IMAGING #ERENKOV 2)#( DETECTORWITH A RADIATOR OF TWO OR MORE AEROGEL LAYERS OF DIFFERENTREFRACTIVE INDICES 4HE #ERENKOV ANGLE DISTRIBUTION

&IG    FOR THE DEFOCUSING DUAL RADIATOR 2)#( SHOWSTWO RINGS CLEARLY SEPARATED FROM EACH OTHER 4HE 4GROUP STUDIED THE READOUT OF A  BY  ARRAY OF LEAD TUNG
STATE %- CALORIMETERS USING AN AVALANCHE PHOTODIODE
4HE ENERGY RESOLUTION FOR  'E6 ELECTRONS WAS EVALUATEDTO BE S%   INCLUDING A CONSIDERABLE AMOUNT OFINTRINSIC BEAM MOMENTUM SPREAD OF AROUND  4HE4 GROUP HAS BEEN STUDYING A HIGH RESOLUTION TIME OFFLIGHT COUNTER CONSISTING OF A QUARTZ RADIATOR A MICROCHANNEL PLATE PHOTOMULTIPLIER TUBE -#0 0-4 AND&IG    $ISTRIBUTION OF THE #ERENKOV ANGLE FOR ACCUMULATED SINGLE PHOTONS FOR DEFOCUSING DUALRADIATOR 2)#( USING TWO LAYER AEROGEL&IG    ,EFT %FlCIENCY VERSUS LIGHT YIELD FOR ONE SEGMENT OF THE SEGMENTED SCINTILLATOR TRACKER 4HE HORIZONTAL LINESHOWS  EFlCIENCY WHICH WAS THE INITIAL GOAL OF THE DETECTOR 2IGHT ,IGHT YIELD OF THE ACRYLIC #ERENKOVDETECTOR AS A FUNCTION OF PARTICLE VELOCITY)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3
TUNGSTEN PLATE 4HE PURPOSE OF 4 WAS IRRADIATIONTESTING OF A POLY SWITCH THAT IS EXPECTED TO HAVE RADIATION HARDNESS TO FAST NEUTRONS 4HERE WAS NO PROBLEM INTHE OPERATION OF THE POLY SWITCH AFTER  DAYS OF IRRADIATION  PRIMARY PROTONS AT THE TARGET STATION OF THENEUTRINO BEAM LINE 4HE PRIMARY PURPOSE OF THE 4EXPERIMENT WAS TO TEST A PROTOTYPE OF THE RANGE COUNTER
AND A DRIFT CHAMBER WITH A LARGE EFFECTIVE AREA FOR THE% EXPERIMENT WHICH WILL STUDY 1 PENTAQUARKS
THROUGH THE REACTION + P m 1 P  4HE STOP POSITIONS OFTHE INCIDENT PARTICLES INSIDE THE PROTOTYPE RANGE COUNTERWERE CONSISTENT WITH SIMULATIONS !LSO THE EFFICIENCIESOF THE DRIFT CHAMBER AND THE AEROGEL COUNTER WERE CONFIRMED TO BE HIGH ENOUGH 4HE PURPOSE OF EXPERIMENT4 IS TO EVALUATE PROTOTYPES FOR NEAR DETECTORS IN THE4+ EXPERIMENT AT * 0!2# 4WO TYPES OF DETECTORS FORTHE ON AXIS DETECTOR WHICH WILL MONITOR THE DIRECTION OFTHE NEUTRINO BEAM WERE TESTED ONE IS A TRACKER MADE OF
PLASTIC SCINTILLATOR BARS AND THE OTHER IS A #ERENKOVDETECTOR MADE FROM ACRYLIC PLATE 4HE RESULTS OF LIGHTYIELD MEASUREMENTS ARE SHOWN IN &IG   3EVERAL PHYSICS EXPERIMENTS ARE IN THE ANALYSISSTAGE 4HE BASIC EXPERIMENTAL CONCEPT OF % IS TOMEASURE THE MODIFICATION OF SPECTRAL FUNCTIONS OF VECTORMESONS WHICH ARE PRODUCED AND DECAY IN A NUCLEUS
THROUGH INVARIANT MASS SPECTROSCOPY IN THE ELECTRONPOSITRON PAIR CHANNEL $ETAILED ANALYSIS HAS ALREADYBEEN CARRIED OUT FOR THE F MESON 4HE PRELIMINARY DATASHOWN IN &IG    INDICATE MODIFICATION OF FS IN THECOPPER TARGET ESPECIALLY FOR THOSE THAT MOVE SLOWLY INTHE LABORATORY FRAME 4HE OBSERVED DIFFERENCE BETWEENCARBON AND COPPER TARGETS MIGHT BE DUE TO THE MUCH LONGER LIFETIME OF THE F MESON COMPARED TO THE NUCLEARRADII LEADING TO DIFFERENT IN MEDIUM DECAY RATES
%XPERIMENT % WAS PERFORMED AT + USING THEABSORPTION REACTION OF THE NEGATIVE KAON AT REST IN AHELIUM  TARGET ! TOTALLY NEW OBJECT OF THE + PNN SYSTEM NAMED THE STRANGE TRIBARYON 3 HAS BEEN DISCOVERED AS SHOWN IN &IG    4HE % GROUP HASINVESTIGATED THE PRECISE STRUCTURE OF , " HYPERNUCLEI BY A
HIGH RESOLUTION G SPECTROSCOPY TECHNIQUE USING A LARGEGERMANIUM DETECTOR ARRAY (YPERBALL 3IX G TRANSITIONS&IG    -ISSING MASS SPECTRA OF THE (ESTOPPED +P 3 REACTION OBTAINED BY TIME OF mIGHT ANALYSIS OF THE EMITTED PROTON&IG    0RELIMINARY INVARIANT MASS SPECTRA FOR F WHOSE BG IS LESS THAN  FOR CARBON LEFT AND COPPER RIGHT TARGETS
4HE GREEN HISTOGRAMS ARE THE EXPECTED MASS SHAPES DUE TO THE DETECTOR RESPONSE)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3&IG    4HE G RAY SPECTRA OF ," HYPERNUCLEI 3IX TRANSITIONS WERE OBSERVEDHAVE BEEN SUCCESSFULLY OBSERVED FROM , " AS SHOWN IN&IG    AND THEIR ENERGIES AND RELATIVE YIELDS HAVEBEEN MEASURED %XPERIMENT % FOR THE STUDY OF NEU
TRON RICH , HYPERNUCLEI USED THE IN FLIGHT P + $#8
REACTION ON A " TARGET IN ORDER TO PRODUCE A , ,I HYPER
NUCLEUS FOR THE FIRST TIME &ROM THE MISSING MASS SPEC
TRUM ON " AT  'E6C INCIDENT MOMENTUM THE , ,I
SIGNAL IS ESTIMATED AT    NBSR 4HE % GROUPOPTIONALLY TOOK P + DATA TO SEARCH FOR THE 1 VIA P P
m + 8 REACTION 3CINTILLATION FIBERS AND POLYETHYLENEWERE USED AS A TARGET 4HE MISSING MASS SPECTRUM AT0P   'E6C &IG    SHOWS A BUMP AT AROUND
 'E6C 3INCE THE STATISTICAL SIGNIFICANCE WAS NOTSO LARGE THE UPPER LIMIT OF THE DIFFERENTIAL CROSS SECTION
VIA THE P + REACTION WAS DERIVED AS DSD7   MB
SR PRELIMINARY AT THE  CONFIDENCE LEVEL 4HE %
GROUP STUDIED THE ELECTRON REARRANGEMENT AFTER FORMATION OF PIONIC ATOMS BY MEASURING THE ELECTRONIC 8 RAYSE8 RAYS AND PIONIC 8 RAYS EMITTED FROM PIONIC ATOMSIN VARIOUS ELEMENTS RANGING FROM ZINC TO LEAD 4HE DIF
FERENCES IN E8 RAY ENERGY BETWEEN THE :  ATOM ANDPIONIC ATOM FOR +A8 RAYS ARE SMALLER THAN THOSE FOR +B8RAYS IN THE LOW : REGION 4HE OBSERVED PHENOMENA SUG&IG    -ISSING MASS SPECTRUM OF THE P + REACTION
AT 0P   'E6C 4HE HATCHED HISTOGRAMSARE THE CARBON TARGET DATA NORMALIZED BY THETARGET AND BEAM COUNT THESE HISTOGRAMS REPRESENT THE CONTRIBUTION OF CARBON NUCLEI IN THESCINTILLATION lBER AND POLYETHYLENE TARGETGEST THAT PIONIC ATOMS ARE HIGHLY IONIZED BY THE !UGERPROCESS DURING THE PIONIC CASCADE IN THE RELATIVELY LOW :REGION)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3

 ++ %XPERIMENT++ +%+ 03 % IS THE FIRST ACCELERATOR BASEDLONG BASELINE NEUTRINO OSCILLATION EXPERIMENT FROM +%+TO +AMIOKA 4HE MAIN PHYSICS GOAL OF ++ IS TO CONFIRM
NM m NT OSCILLATION DISCOVERED IN ATMOSPHERIC NEUTRINOS)N ADDITION ++ HAS RICH PHYSICS FOR THE STUDY OF OTHEROSCILLATION CHANNELS SUCH AS NM m NE APPEARANCE ANDNEUTRINO NUCLEUS INTERACTIONS IN THE FEW 'E6 REGION )N&9 EVIDENCE OF NEUTRINO OSCILLATION NAMELY THE
ENERGY DEPENDENT DISAPPEARANCE OF MUON NEUTRINOS WAS
PUBLISHED 4HIS RESULT IS ONE OF THE MOST IMPORTANT PHYSICS GOALS IN ++ AND IS DESCRIBED IN THIS REPORT!N INTENSE MUON NEUTRINO BEAM IS PRODUCED AT THE+%+ 0ROTON 3YNCHROTRON 03 AND THIS BEAM IS DETECTED
AT 3UPER +AMIOKANDE 3+ AFTER TRAVELING  KM ++STARTED DATA TAKING IN *UNE  AND FINISHED IN .OVEMBER WITH  §  PROTONS ON TARGET 0/4 ACCUMULATED FOR ANALYSIS 4HE RECORD OF DELIVERED 0/4 TO ++IS SUMMARIZED IN &IG   )N THE ANALYSIS WE USE PART OF THE DATA COLLECTED BEFORE&EBRUARY  CORRESPONDING TO  §  0/4 4HE
NEUTRINO FLUX AND SPECTRUM AT +%+ ARE MEASURED BY NEARNEUTRINO DETECTORS A ONE KILOTON WATER #HERENKOV DETECTOR +4 A SCINTILLATING FIBERWATER TARGET TRACKER
3CI&I A FULLY ACTIVE FINE SEGMENTED SCINTILLATOR TRACKER
3CI"AR AND A MUON RANGE DETECTOR -2$  4HE NUM
BER OF INTERACTED NEUTRINOS CORRESPONDING TO THE FLUX ISMEASURED BY +4 WITH COMPARABLY HIGH EFFICIENCY TO 3+
4HE NUMBER OF NEUTRINO EVENTS IN 3+ WITHOUT NEUTRINO
OSCILLATION IS ESTIMATED TO BE  n
BASED ON THE NEUTRINOEVENTS MEASURED BY +4 4HE NUMBER OF OBSERVED NEU
TRINO EVENTS IN 3+ IS  AS SUMMARIZED IN 4ABLE   
4HUS WE OBSERVE A SIGNIFICANT DEFICIT OF NEUTRINO EVENTS
IN 3+ AS ONE OF THE EVIDENCES OF NEUTRINO OSCILLATION
4ABLE    3UMMARY OF THE 3+ EVENTS -# IS A PREDICTIONBY -ONTE #ARLO SIMULATION WITHOUT NEUTRINOOSCILLATION$ATA-#

4OTAL

 n

4HE NEUTRINO ENERGY SPECTRUM AT +%+ IS MEASURED BY
+4 3CI&I AND 3CI"AR COMPLEMENTARILY 4HE MEASUREDNEUTRINO SPECTRUM WHICH IS A PRODUCT OF FLUX AND CROSSSECTION IS SHOWN IN &IG    4HE MEASURED SPECTRUM
AGREES WITH THE PREDICTION OF THE BEAM -ONTE #ARLO SIMULATION 4HE NEUTRINO SPECTRUM AT 3+ IS ESTIMATED BASEDON THE MEASUREMENT AT +%+ )N 3+ NEUTRINO ENERGY ISRECONSTRUCTED WITH AN ASSUMPTION OF THE CHARGED CURRENTQUASI ELASTIC ##1% INTERACTION )N ORDER TO ENHANCETHE FRACTION OF ##1% EVENTS THE SINGLE RING M LIKE EVENTSARE SELECTED IN 3+ &IFTY SEVEN EVENTS ARE SELECTED TO       

3INGLE RING M LIKE
3INGLE RING E LIKE-ULTI RING

       









&IG    $ELIVERED 0/4 AND BEAM INTENSITY PER PULSETO THE ++ EXPERIMENT FROM *UNE  TO.OVEMBER &IG    .EUTRINO ENERGY SPECTRUM MEASURED AT +%+4HE SPECTRUM IS A PRODUCT OF FLUX AND CROSSSECTION)NSTITUTE OF 0ARTICLE AND .UCLEAR 3TUDIES )0.3MEASURE THE NEUTRINO ENERGY 4HE DISTRIBUTION OF THERECONSTRUCTED NEUTRINO ENERGY IN 3+ IS SHOWN IN &IG   4HE OBSERVED SPECTRUM DOSE NOT MATCH THE EXPECTATION WITHOUT NEUTRINO OSCILLATION BUT MATCHES THAT WITHNEUTRINO OSCILLATION! TWO FLAVOR NEUTRINO OSCILLATION ANALYSIS IS PERFORMEDBY THE MAXIMUM LIKELIHOOD METHOD )N THE ANALYSISBOTH THE NUMBER OF NEUTRINO EVENTS AND THE ENERGY SPECTRUM SHAPE ARE USED 4HE BEST FIT POINT IN THE PHYSICALREGION IS FOUND AT SIN Q $M    s   E6 4HE ALLOWED REGIONS OF THE OSCILLATION PARAMETERS ARE
SHOWN IN &IG    WHERE THE LIKELIHOOD RATIO OF EACH
POINT TO THE BEST FIT POINT IS EVALUATED 7ITH NEUTRINO
OSCILLATION OF THE BEST FIT PARAMETERS THE EXPECTED NUM
BER OF EVENTS IS  WHICH AGREES WITH THE OBSERVATIONOF  EVENTS 4HE NEUTRINO ENERGY DISTRIBUTION WITH THEEXPECTED DISTRIBUTIONS OF THE BEST FIT PARAMETERS IS ALSOSHOWN IN &IG    4HE NO OSCILLATION PROBABILITY ISCALCULATED TO BE  S  7HEN ONLY NORMALIZATION SPECTRUM INFORMATION IS USED THE PROBABILITYIS    4HE  #, CONTOUR CROSSES THESIN Q   AXIS AT $M   AND  s   E6 WHICH ISCONSISTENT WITH THE RESULTS FROM ATMOSPHERIC NEUTRINOS)N &9 ++ ACHIEVED THE ORIGINAL GOAL AND
CONFIRMED NEUTRINO OSCILLATION &OR THE OSCILLATION ANALYSIS KNOWLEDGE OF THE NEUTRINO NUCLEUS CROSS SECTION ISIMPROVED BY THE NEAR NEUTRINO DETECTORS +4 3CI&I AND3CI"AR !S AN IMPROVEMENT THE ANALYSIS OF 3CI"AR DATAGIVES A MUCH SMALLER CROSS SECTION OF CHARGED CURRENTCOHERENT PION PRODUCTION THAN THE PREDICTION BY SEVERALMODELS WHICH RESOLVES THE LONG STANDING PROBLEM OF THEFORWARD MUON DEFICIT IN ++ -ORE RESULTS ARE EXPECTEDTO APPEAR IN &9&IG    2ECONSTRUCTED NEUTRINO ENERGY DISTRIBUTION OFSINGLE RING M LIKE EVENTS 0OINTS WITH ERRORBARS ARE DATA THE SOLID LINE IS THE BEST FITSPECTRUM WITH NEUTRINO OSCILLATION AND THEDASHED LINE IS THE EXPECTED SPECTRUM WITHOUTOSCILLATION 4HESE HISTOGRAMS ARE NORMALIZEDBY THE NUMBER OF OBSERVED EVENTS        &IG    !LLOWED REGIONS OF OSCILLATION PARAMETERS
4HE DASHED SOLID AND DOT DASHED LINES SHOWTHE   AND  #, CONTOURSRESPECTIVELY