PoS(Neutel 2013)013

, , 2 the e of 5eV . = (0 signal due to

new http://pos.sissa.it e )) ν θ → (2 µ 2 with probability 2 / ν 1 sin vents, which are about

≈ , 2

) events have been found, m ν

e ∆ ν L/E events, characterized by a fast

e ν = 36.5 m/MeV of the ICARUS reAlike Licence. ν new 2 clear m L/E ∆ ve signals of LSND and MiniBooNE ICARUS T600 detector located at the cess of 27 between the present ICARUS limit, the m m CERN at an average energy of about t t on the search for a . the (1 corresponding to oscillation probabilities 2 sence sence of a LSND anomaly. At 90% and 99% , are respectively set. The result strongly limits −2 6 events 6 events from conventional sources. Within the rang . 1×10 . 7±0 . 1

≤

〉 e ν the Creative Commons the Creative Attribution-NonCommercial-Sha → νµ P 〈 ). The present analysis is based on 1091 neutrino e new and θ −3 options for the LSND anomaly to a region around (

(2 2

4×10 1 . 2sin / 5 ≤

〉 e = 1 ν e ν → robert.sulej@cern.ch → νµ 005), where there is an overall agreement at 90% CL νµ . P window window of open We report an early result from the ICARUS experimen the the LSND anomaly. The search was performed with the Gran Sasso Laboratory, receiving CNGS neutrinos fro 20 GeV, at a distance to source of about 730 km. At compared thewith expectation of 3 P experiment the LSND anomaly would manifest as an ex observations, this result is compatible with the ab confidence levels the limits of 3.4 and 7.3 events, 〈 energy oscillation averaging approximately to sin 0 50% of the ICARUS data collected in 2010–2011. Two published limits of KARMEN and the published positi Collaborations. Copyright owned by the author(s) owned of the Copyrightby terms under

 1 on behalf the of Speaker, Collaboration ICARUS CNGS beam beam CNGS Robert Robert Sulej National Centre for Nuclear Research A. Soltana 7, 05-400 Otwock, Swierk, Poland E-mail: Sterile neutrino search with the ICARUS T600 in the within T600 ICARUS the searchneutrino Sterile

PoS(Neutel 2013)013

http://pos.sissa.it

reAlike Licence. the Creative Commons the Creative Attribution-NonCommercial-Sha

Copyright owned by the author(s) owned of the Copyrightby terms under

 XV Workshop on Neutrino Telescopes March 11-15, 2013 Venice, Italy

PoS(Neutel 2013)013

e

n n ν (1) and a ch is a 2 trinos. trinos. from from anti-

Robert Sulej protons on e for the three ν 13 peaked in the µ ν eutrino eutrino channels a t 2×10 may have a common 0.01 to 1.0 eV ≈

new 30 m. 30 m. The LSND signal 2 ≈ new m 2 L L ∆

m     ∆ ) of about 2% and an electron s “Gargamelle class” LAr-TPC . However, the possible presence . However, the presence possible 3 osed mainly of ν m ν neutrinos neutrinos from the 8 GeV FNAL- ( of the neutrino beam, about 2850 L ) Gran Sasso underground laboratory 2 al al search for an anomalous anti- 1 km long decay tunnel. Produced and GS). GS). interactions interactions but still introduce mixing 2 the LSND experiment [2] at the Los n anomalous excess of anti- ν ward the Gran Sasso laboratory (LNGS) re re of such a signal due to a LSND-like eV LNGS for a nominal beam intensity of 30 MeV and one or more sistent sistent picture, with the mixing of three ( , calibration calibration sources [5,6]. Also these effects ≈ 1 ide ide interval MeV

() ν n target followed by a magnetic horn and a 〉 2 new ν itude of the LSND anomaly. These anomalies ν E E m

〈 en proposed by B. Pontecorvo [1]. Such “sterile” Such [1]. by B. Pontecorvo en “sterile” proposed ∆ 3 3 27.1 ). disappearance anomaly has been detected from nearby has been from detected anomaly disappearance new

    e for for different channels reflecting the so far unknow θ 2 ν

) (2 corresponds to a rate of events, 87.9±22.4±6.0 whi 2 representing the number of ordinary and sterile neu and sterile of ordinary number the representing −3 sin new θ j, k (2 or anti- new 2

e θ ν and mass eigenstates 2 τ () much higher than the experimentally measured ones ν 2 new range has confirmed in both the neutrino and antin 2 ν sin

and m µ = ∆ 0.5−1.0 m/MeV. m/MeV. 0.5−1.0 L/E ν matrix, with matrix,

e , ) ∼ e ν

j,k ν ν ( → search µ 30 GeV. The CERN-SPS 400 GeV proton beam with abou U ν LSND-like oscillation signal. With the formula formula the With signal. oscillation LSND-like ν ≤ L/E P

σ ν = (2.64±0.67±0.45)×10 e E ν ≤ pot/year with a spectral contamination from anti- anti- 19 According According to detailed Monte Carlo (MC) calculations A A recent result from MiniBooNE [3], performed with The CNGS facility [8] provides a neutrino beam comp In addition, apparent In an With the help of a novel development of a large mas effect at at effect νµ→ σ originated by muons from pions at rest with

anti- µ nuclear reactors [4] and from Mega-Curie k-capture seem to occur for a oscillations oscillations with ordinary neutrinos. An experiment of neutrino oscillations into of sterile has into states be oscillations neutrino states may not see fully the ordinary electro-weak Booster Booster in a similar production production at short distances has been performed Alamos 800 MeV by proton accelerator, which reported a located at a distance of 732 km. km. of 732 a distance atlocated target (pot) per spill is sent to a segmented carbo reflector, focusing charged secondary mesons neutrinos are into pointing down with a a 52 mrad slope to 2. The experimental setupThe experimental 2. these results correspond to a new signal within a w 1. Introduction 1. Introduction Neutrino oscillations have so far established a neutrino flavours con ICARUS: Sterile structure of theof structure neutrino oscillation scenario, in the order of magn may indeed represent an unified approach, in which 3.8 range range 10 origin, with the values of sin corresponding associated value of sin value associated corresponding combined 3.8 combined P charged charged current (CC) events/kt/year are expected at 4.5×10 ν imaging imaging detector, the ICARUS experiment (LNGS) [7] is at hereby visually the searching for the signatu anomaly in the CERN to Gran Sasso neutrino beam (CN beam neutrino Gran Sasso to in the CERN anomaly PoS(Neutel 2013)013

e ν ’s are e and ν µ ν ratio. The Robert Sulej µ , extending to to , extending ν 3 / e ν ducial ducial volume are ). This signal will have new θ are coming from decays of (2 µ 2 ν [7] offers a completely uniform s a function of the neutrino energy erent erent orientations. This provides a expectations are obtained with a % of stic events and with a less easy event, that allows for space point = 1/2sin rossing rossing LAr, is detected by a set of 〉 the first approximation, a hypothetical signal inside the SPS proton extraction e Charpak Charpak et al. [12]. The passage of the n model in the computed fluxes, can be The new method, proposed by C. Rubbia n allows detecting the entire signal of ay ay (37%) as well as by kaons (43%), the ngs ngs recorded with PMTs at the surface of the the systematics of the . The prompt scintillation light, produced al events of interest. These are important by a set of wires placed at the end of the observations of LSND and MiniBooNE of about 30 mrad of the beam optics. the of beam mrad of 30 about due to correlations between the LUKA LUKA MC code [9, 10]. Conservatively, a y y with equivalent Oxygen contents of the 36.5 m/MeV, a value much larger than the the LAr active volume, and 50 cm from the from and 50 cm volume, active LAr the icle icle tracks, by a uniform electric field over νµ→ν ns ns (6%) and tertiary decays (19%). ed by the drifting electrons. Non-destructive ≈ kgrounds kgrounds due to other and more conventional

ccuracy of the order of few mm ccuracy P nization electrons can be transported in high ν y y events rejection, based on deposition. charge 〈 from a gas to a liquid is not straightforward. A

L/E 4 4 1/2 and ≈ ) ν ratio is estimated to be better than 7%. 7%. than to be better estimated is ratio µ ν L/E / e new ν 2 m ∆

interactions per day with primary vertex in the fi ν (1.27 2 search ν LSND anomaly will produce very fast oscillations a e The LAr-TPC detector developed by the ICARUS group According According to the full neutrino beam calculation, 75 The ICARUS experiment is operated at A A few CNGS ν → , averaging to sin

ν µ resulting integral error on the the error on integral resulting common common origins, significant cancellations occur in three orders of magnitude larger purity is necessar order of a few tens of ppt (parts per trillion). Io purity LAr, preserving practically undistorted part macroscopic distances (meters). Imaging is provided drift path continuously recording the signals induc electrons crossing subsequent wire planes with diff which were based on the observation of Cherenkov ri the detector volume and mostly limited to quasi-ela a liquid the TPC already described for a gas capability of by several meters of free electron drift G. read-out of ionization electrons by charge inductio simultaneously several projective views reconstruction of and precise calorimetric the measurement same photomultipliers (PMT’s) and used to trigger physic differences with respect to the previously reported and rays electrons. gamma between discrimination along along with the ionization by any charged particle c originated originated by pions through the subsequent muon dec remaining 20% is due to tertiary decays. Therefore, one of the experiments where anomalies appeared. In 3. Data selection3. Data and analysis ν ICARUS: Sterile component of about 1%. The neutrino flux and spectr simulation simulation of the beam line elements based on the F 10% systematics, introduced by the hadron productio acceptance the over angular averaging assessed when gate, gate, with application of automatic filter for empt eachof side from 5 cm cuts include volume Fiducial recorded, as expected. Events are triggered by PMT to be compared with the small, but significant, bac sources. neutrino imaging imaging with high accuracy of massive LAr volumes. [11] observes the true image of with the true image an[11] the a track observes E pion produced at the target, the rest is due to kao PoS(Neutel 2013)013

x /d

E stribution Robert Sulej n of a Landau alue of the energy l to noise ratio. Similar [16]. [16]. gnals gnals is shown in Fig. 1a for d uirement of a track exiting the primary primary the exiting of a track uirement events selection is essential in the e ift direction. The resulting charge is on the average value is at the level of etailed simulation of energy losses by iform iform vertex position within the T600 ν r to optimize the signal over background or or without secondary interactions except identification, but are not enough for the ding ding wire signal induction and electronics tor [13] includes quasi-elastic, resonant and and resonant quasi-elastic, includes [13] tor served recombination effects [14]. Energy b) CC vs NC discrimination. Events with a fully fully validated on MC simulation, using a reproduce reproduce the actual wire orientation and nd nd hadronic interactions. Ionisation charge lear reaction model of All FLUKA. reaction ig. ig. 1b shows the raw energy distribution for value agrees at 2% level with MC, and the CARUS CARUS T600 detector. Neutrino events are µ eal data. data. eal x ν /d

E and its RMS 10%.within 5 5

tracks recorded CC in events; b) rawthe energy di µ , for x /d for each track has been fitted with the convolutio E x CC CC interactions compared with the MC, the average v /d

µ E ν

and anti-

is about 10%, as expected for the hit charge signa µ search σ ν ν CC interactions compared with the MC expectations expectations MC the with compared interactions CC µ ν a) loss Energy density, d The agreement between the observed and predicted si Since Since the reliable estimation of efficiency of Muon neutrino CC events are identified with the reqthe with identified are events CC Muon neutrino a) agreement agreement is obtained for protons and pions [15]. F the observed the observed fitted fitted gaussian function with a gaussian. The most probable d of muon tracks recorded in CC events. The agreement 2.5%. The distribution of d response, and noise parameters extracted from the r from extracted parameters and noise response, along along the track is subject to the experimentally ob spacing, with a fine granularity convoluted with (0.2 the readout channel mm) response, inclu in the dr generated generated according to the expected spectra with un deep inelastic processes and is embedded in the nuc products are transported in the T600 volume, ionisation, with delta d ray production, electromagnetic a depositions are registered in grid structures that presented presented analysis, the overall procedures are care sophisticated simulation package dedicated to the I event neutrino The genera sensitive volume. adopted for the observed Figure 1. ICARUS: Sterile downstream wall. This initial cuts allow for shower reconstruction reconstruction of neutrino energies, nor for the vertex and travelling at least 250 cm in the detect electromagnetic activity. activity. electromagnetic deposited detectorthe in reproducedis 2.5% within deposited deposited energy above 30 GeV are rejected, in orde ratio. ratio. PoS(Neutel 2013)013

e ν he data ratio. ratio. Robert Sulej µ ν ’s in the T600 / 0 e pot), with the π ν 19 beam component e ν der to reduce the beam e prediction of theof e prediction nd nd simulations, including the low pairs. The 14 cm radiation length of eutrino eutrino events, including 168 events – neutrino interaction vertex is indicated

he initial cut on the energy deposit, the e tation, tation, except the he he MC expectation. To this sample, an dicate dicate a residual contamination of about

efficiency efficiency for electron showers is 10%. decays in CNGS events, rising to a few n the basis of the comparisons shown in from isolated secondary ation, examined wire by wire, is used to + e to beam direction. The rejection factor been defined as follows: as follows: defined been gible with respect to the pair production the the candidate electron track, before the e en en evaluated on MC samples of 104 events n energies, while the electron identification misidentification misidentification is due Compton scattering n assumed on the effect of the energy cut on ly 15% of the events it introduces a negligible a negligible 15% ofly introduces events it the have been applied, as earlier described. described. as earlier been applied, have ctions. ctions.

6 6

e 0 0 ν . → µ = 1 ν oscillated events has been performed as follows. T

e T ν p → µ pot) and 923 events collected in 2011 (2.7×10 ν 18

= 11 GeV and search

e ν E -conversion -conversion induced, double ionizing, γ background, that is to be added to the error on th error theto be added to that is background, background; background; e ν Typical MC generated In the present analysis, the electron signature has signature electron the the present analysis, In (a) fiducial volume; the inside event the vertex of (b) (b) visible event energy smaller than 30 GeV, in or The presence of an electron emitted in the primary In In order to estimate systematic errors induced by t The identification of overall overall event number in agreement within 6%, with t on the Since concerns cut flavor. for neutrino each systematic error on the signal and background expec initial cuts on fiducial volume and energy deposit and energy volume on fiducial cuts initial fraction of background and oscillated events has be CNGS CNGS data confirm the good agreement intera to Compton related of events tail ionisation between data a sample sample has been based on a total collected of in 2010 1091 (5.8×10 observed n Figure 2. ICARUS: Sterile of photons, however its cross section becomes negli above a few hundreds of MeV. Monte Carlo studies in efficiency efficiency is almost constant. The possible photon 0.18 % for the energy spectrum of photons from pion per cent in the sub-GeV energy region. The loss Results from an ongoing study on in low energy showers LAr LAr corresponds to about 45 readout wires in a clos based on ionisation increases with increasing photo the beam the beam whose energy spectrum extends to higher energies. O Fig. 1, a conservative 10% systematic error has bee GeV/c. event event from the program ICARUS with full simulation electromagnetic electromagnetic showering has occurred. This inform discriminate with the ionization density of the initial part of PoS(Neutel 2013)0132013)013

x n n 4: /d E 74. 74. ducial . events, e ν CC signal signal CC Robert Sulej 810 = e . → ν µ 0 / ν 6 . 30 GeV; C2: no < events have been

e ν dep CC CC , E µ η ν the background rejection rays, and subsequently building and rays, building subsequently cut is bound to be smaller than ence of apparent x ic particle, i.e. the average d the two transverse views (±60°), tracks tracks within 150 mrad in the /d interactions. interactions. ample ample with a fast simulation and tion cuts: C1: E NC NC ion ion efficiency conversion distance smaller than 1 cm ly from the vertex, fully consistent over fully the consistent ly over vertex, from scan, scan, the estimated background from imit imit of 0.3 events (including possibly responding responding to a selection efficiency d oscillated neutrino flavors have been in in different locations. An agreement has han 2.5% between the measured and the lectron” lectron” candidates if no muon-like track ta ta cuts have been applied to the simulated sample. sample. The average number of positively s cuts is summarized in Table 1.With this ial ial volume cuts (a). These events have been based on the specific ionization was applied s (C1 in Table 1), neutralbackground current r with initial point (conversion point in case of a ton ton (at least 100 MeV) to pointing the primary MC events, 146 events have a visible energy e

interaction vertex, separated from other tracks; C ν ν 7 7 CC categories are reduced to 0.93 after the cut on fi fiducial andfiducial cuts) energy results to be 0 → τ µ CC (see Fig. 1a). Fig. (see CC ν µ ν ν induced by the d η CC spectrum. An example of simulated event is show µ ν

13 θ CC CC e for muons in in for muons ν x /d

E search CC events). Moreover, an independent estimation of ν µ ν CC beam CC e ν at least 8 wires with a minimum ionising relativist lower than 3.1MeV/cm lower after than of removal 3.1MeV/cm delta visible shower; up a into except for short proton like recoils due to nuclear due recoils like proton short except for immediate immediate vicinity of the vertex in at least one of Fraction of MC events surviving the automatic selec A A scan of 800 simulated NC events has shown no pres The requirements for the shower isolation and for a (c) (c) the presence track starting of direct a charged In In order to determine the electron signature select (d) (d) visible spatial separation from other ionising C4 C4 0.30 0.71 0.13 0.0002 0.00005 0.60 C1 C1 C2 C3 0.47 0.47 0.33 0.92 0.92 0.79 0.93 0.17 0.14 0.89 0.66 0.10 0.89 0.19 0.03 0.81 0.81 0.66 = 0.74±0.05. = 0.74±0.05. The systematic error on Sel. cut Sel. cut volume. The signal selection efficiency (after the in Fig. 2. Out of an initial sample of 171 as an average factor (C4). The effect of the variou method, that is not fully equivalent to the visual were then applied (C3). Finally, the discrimination consistent for our sample with an estimated upper l misidentified misidentified Table 1. ICARUS: Sterile generated generated with MC according to the photon) at a distance smaller than 1 cm from the identified muon, at least one shower; C3: one showe single single ionisation in the first 8 samples. All event visually visually and independently scanned by three people been found with differences in less than 3% of the identified electron-like neutrino events is 90, cor smaller than 30 GeV, 122 of which satisfy the fiduc η could be identified, and at least one energetic pho (C2). present vertex was efficiency efficiency has been performed on reconstruction a algorithm. All much CNGS beam larger original an MC s and charged current events have been retained as “e taken taken into account. Automatic cuts mimicking the da events. After the fiducial and deposited energy cut predicted scale of the d the of scale predicted 1% from the already discussed agreement to better t PoS(Neutel 2013)013

e ν along along

dE/dx Robert Sulej ictions [18], [18], ictions events due to e d efficiency on ν

scale would modify x /d E ) = 0.0242±0.0026 [17]; [17]; ) = 0.0242±0.0026 13 θ e uncertainty on the NC and CC ( signature; (c): the actual cted cted number of 2 ts the single electron shower in the learly learly negligible w.r.t. its statistical signature have been identified, to be e nce of LSND anomaly, the estimated tainty tainty on the d 1.8 GeV taking into account a partially ν e event in Fig. 3b has 17 GeV of visible b) b) ound to be 74% in agreement with the ble background is then 3.7±0.6 events (syst. (syst. events 3.7±0.6 then is background ble ventional sources. The event in Fig. 3a has a 3a hasThe Fig. a in event sources. ventional al volumes defined in (a) and (b) are: are: (b) and(a) in defined volumes al

duction has duction been applied. smallness Given the of ). More detailed description event in the text. 8 8 oscillations with sin oscillations with 13 θ from the three neutrino mixing standard model pred model standard mixing three neutrino the from e → τ CC events amounts to 0.09 events, and the simulate µ

ν with τ events due to the estimated beam contamination; contamination; beam estimated the to due events the to due events e e ν search ν ν ν c) The two observed events (a) and (b) with electron 3.0±0.4 3.0±0.4 1.3±0.3 1.3±0.3 0.7±0.05 0.7±0.05 a)

– – In In the recorded sample, two events in which a giving giving a total of 5.0±0.6 expected events, where th – contaminations has been included. The expected visi Theexpected included. been has contaminations error after only), that there efficiency selection fluctuation. the number of electron like signal systematic expected uncertainty in on abse the predicted number is c CC CC events (after the fiducial and energy cuts) is f scanning scanning method. The contribution from a 2.5% uncer total total energy of 11.5±2.0 GeV and an electron of 10± missing component of the electromagnetic shower. Th energy and an electron of 7.5±0.3 GeV. In both even compared with the expectation of 3.7 events for of con 3.7 events with expectation compared the conventional sources in the energy range and range fiduci energy the in sources conventional this background estimate by less than 10%. The expe individual ofwires electronthe shower shown (a in Figure 3. ICARUS: Sterile misidentified NC and PoS(Neutel 2013)013 , , 2 = SD SD 〉 tron tron e , , the , but 2 ν m νµ→ν ∆ L/E P 〈 Robert Sulej , the longer = (0.11eV 30GeV. 30GeV. MiniBooNE and ≤ new

θ new 2 ν new )) and E m )) , 0.005) in which θ 2 −3 θ ∆ (2 1 m/MeV (Fig. 5), 2 (2 2 ≥

ν , sin 1 m/MeV region. The 2 , sin 2 ≤ L/E m

m = (0.5 eV ∆ ν = 5.4×10 〉 ∆ e new periment is shown in Fig. 4 in L/E )) . In most of the area covered by θ νµ→ν lation lation averages approximately to a number number of recorded events, the the ICARUS result now allows to P 2 (2 new 4.5 cm from primary vertex), where 〈 2 2 is shown in Fig. 6 [18]. Even if ≥ al contribution to the construction and 2 g tracks, are also displayed. displayed. also are tracks, g m ctively. ctively. e event, with the electron transverse the region m compatible with the absence of a LSND ∆ 1eV n the framework of the present neutrino ∆ collaborations. collaborations. , sin stance with ( . . The actual origin of the excess need may ena, between different pairs of neutrino ion ion of the ( articular, articular, by the LNGS Laboratory and its CARUS CARUS limit, (2) the limits of KARMEN 2 t explores much larger values of ity ity with respect to the one of the short ≤ are ion ion ( ν respectively respectively 3.4 and 7.1 events. According oNE oNE Collaboration. In the low mass peak

referred referred to a single effective m d 99% and taking into account the detection E

∆ new led led from 1 to 5. A detailed among comparison 1/2. For lower values of eavily ionising nuclear prongs. As a reference, a As reference, ionising nuclear prongs. eavily 2 ) and ≈

m ) new 9 9 ν ∆ θ there is already disagreement between the allowed 2 (2 2 L/E new events should have been observed with with been observed have should events misidentified background adding to the observed LN 2 along individual wires of the single ionising elec e µ x m ν ν >> 1eV /d ∆ → E µ new 2 ν m (1.27 2 ∆

search ν , respectively. The exclusion area of the ICARUS ex −2 distribution for single and double minimum ionisin minimum and double single for distribution Fig. Fig. 3c shows the actual d The oscillation probabilities from LSND are in the Within the range of our observations, the result is x /d E the track is well separated from other and h tracks isthe from well track separated d baseline baseline strongly enhances the oscillation probabil baseline experiments. In ICARUS, considering for in to the above described corresponding limits experimental on sample the oscillation and probability the efficiency, efficiency, the limits due to the LSND anomaly are anomaly. anomaly. At statistical confidence levels of 90% an MiniBooNE MiniBooNE result has extended the data to values in further further clarification, as pointed out by the MiniBo region the dominant signal is due to define a much narrower region centered around ( signal. As already mentioned, the present experimen 1.1×10 the ICARUS results exclude also a substantial fract curves shown in Fig. 5, in particular the ones labe the various results on different oscillation flavours, phenom each having specific mixing angles and developing developing into shower shown in Fig. 3a, in the reg terms terms of the two-dimensional plot of sin there is 90% CL agreement between (1) the present I MiniBooNE and of LSND signals positive and the (3) Acknowledgements The Collaboration ICARUS acknowledges the fundament operation operation of the experiment given by INFN and, in p 4. Results momentum of 1.8±0.4 GeV/c and 1.3±0.18 GeV/c, respe GeV/c, 1.3±0.18 and GeV/c of 1.8±0.4 momentum ICARUS: Sterile transverse plane is opposite to the remaining of th ICARUS ICARUS and allowed by LSND and MiniBooNE, the oscil half of its highest value, sin plot plot allows situating the residual “LSND anomaly” i oscillation oscillation results. While for regions from the published experiments, for disappearance disappearance and appearance results should not be 0.10), as many as 30 anomalous as many 0.10), corresponding corresponding to a signal peak at smaller values of PoS(Neutel 2013)013

, n n 2 are are are m ∆

values

ν lines lines th th ( L/E Robert Sulej ), are driven by the , are also compatible with the ed 3 + 1 model. All 9 dashed lines to ( 6 1–5 t of the Ministry of Science and Higher Finally, Finally, we thank CERN, in particular the trino beam facility. facility. beam trino 1 m/MeV, but they are entirely ruled out by the

cated by e oscillation probability at the large , ) −2 observed by LSND and MiniBooNE. The

, labeled from > ν new ν eters chosen within the MiniBoone allowed region. I θ 10 10 L/E (2 1×10 2 L/E . and −2 1 ≤ Solid lines vs sin 1×10 2 .

〉 m e 1 shows shows the “best value” including ICARUS results, wi ν ∆ ≤

→ ) νµ values.

P ν new 〈 θ (2 L/E Line 6 2

005). . 0 and , respectively at 90% and 99% 2 −3 −2 corresponds to the MiniBoone best fit in the combin search as a function of the distance 〉 ν e 5 eV 4×10 . ν . 2×10 → . νµ 2 5 P = (0 line 1 ≤ 〈

≤ Two-dimensional plot of

) new

anomaly and the present ICARUS result. The )) new 〉

e θ θ ν e ν → (2 (2 2 2 νµ → µ P consistent with data at low particular, present result because they would imply an excessiv for the main published experiments ν sensitive to the

Figure 5.

Figure 4. ICARUS: Sterile Directors. The Polish groups acknowledge the suppor Education, Education, and of National Science Centre, Poland. CNGS staff, for the successful operation of the neu the of operation the staff, successful for CNGS ICARUS limits to 〈 the oscillation probability are CL. CL. Limits correspond to 3.41 and to 7.13 events. sin present ICARUS result. Instead, parameter sets indi examples of oscillation patterns with sets of param additional signal recorded by MiniBooNE for sin investigated by ICARUS. corresponding to sin PoS(Neutel 2013)013 th th the

Robert Sulej , Varenna, , 47 (2010) , (1968)984 26 685 , 275(2004) 523 (1998) (2005) (2012) , 010001(2012) 86 13)260820 ., Sect. A en, en, Phys. BLett. (1970) (1970) . D , 31–49, (2007)

(2012) 896 Int. conf.onnuclear reaction mechanisms 11 11 , 015807 (2009) th , 1717 (1967), Sov. Phys. JETP 80 , 270, (2012) 12 53 , 073006 (2011) 711 1977 , 112007(2001) plane excluded by the ICARUS experiment compared wi 83

64 )) , P07011(2011) θ 6 ( 2 [hep-ex/1207.4809v1] tan , [CERN 98-02, INFN/AE-89-05] 2 m ∆ [hep-ph/1205.5254]

[CERN-2005-10, INFN/TC-05/11] [CERN-EP-77-08] search ν Regions in the ( G. Battistoni et al., proceedings in of F. Kaether,W. Hampel, G. Heusser, J.T. Kiko, Kirst J.N. Abdurashitov et al., Phys. C Rev. G. Mention et al., Phys. Rev. D A. FerrariA. et al., G. Charpak et al., Nucl. Instrum. and Meth. 80 13 C. C. Rubbia et al., J.Instrum. G. Aquistapace et al., C. C. Rubbia, G. Battistoni et al., proceedings in of AIP A. A. Aguilar-Arevalo et al., A. A. Aguilar et al., Phys. Rev. D B. Pontecorvo, Eksp. Zh. Teor. Fiz. S. Amoruso et al., Nucl. Instrum. Methods Phys. Res Italy, June 15–19 (2009) M. Antonello et al., Adv.High Phys. Energy 2013 (20 G.L. G.L. Fogli et al., M. Antonello et al., Phys. Lett. B J. Beringer et al. (Particle Data Group), Phys. Rev

[11] [13] [6] [5] [4] [9] [12] [7] [8] [10] [3] [2] [1] [14] [15] [17] [16] [18] published results [18]. Figure 6. References ICARUS: Sterile