“ F orbidden decays in 2014: material for discussion ”

“Forbiddendecays in 2014: material for discussion” Gianluca Lamanna & Tommaso Spadaro (Pisa & LNF) PhysSensy - NA62 Liverpool Meeting 28.08.2012

DISCLAIMER: PUT A BIG ~ IN FRONT ANY NUMBER

Figure of merit (according to Giuseppe) • 10% of nominal intensity: • On average, due to different reasons (technical, detectors, problems,…) • 60 days of data taking: • Very good data taking efficiency (good SPS, effective runs, …) • 10 KHz of data written on disk: • No limitation from the infrastructure 2014

Interestingforbiddendecays (1)

Interestingforbiddendecays (2)

NA62 prospects • * Roughestimation • ** SeeEvgueni

NA62 prospects • * assuming 20% trigger efficiency • ** assuming 1% trigger efficiency

The L0 Bandwidth 1 MHz • Main trigger pnn: • Q1*RICH*!MUV3*!LKR*!LAV 320 kHz • Q1*RICH*!LKR*!LAV*!MIP*ETOT380kHz • Let me assume that the total pnn trigger rate is 400 kHz. • Let me assume that at L1/L2 we will have additional 10/10 reduction factors. pnn • Assuming 1 MHz L0 readout bandwidth there are 600 kHz for: • Control triggers • Triggers to study detectors and background • Calibration & random • Other rare kaon decays (K->pp0g, K->pp0ee, Ke4n, …) • Forbiddens and exotics Kaon and p0 [All numbers from Spasimir]

Filling the L0: Q1/DW ppD: 4% 3p: 96% 3trk pp0: 21% Halo: 28% pnn 1trk Km2: 42% Other: 9% L0 : pnn .OR. Q1/DW (DW=13)

Very inefficient L0 for most of the decays • Big downscaling • 42% of Q1 coming from Halo+Km2 • Only the 70% of the Q1 from decays are in the decay region. • Change approach • Consider selective trigger for physics • Maintain a «quota» of generic (Q1) 1trk and 3trks decays for detector study In decayregion Halo+Km2 pnn

K->pg, p->ggg, p->gggg,p->nn, sgoldstino 1 trk Forbiddens and exotics LFV (pme), p0->me, dark photon, Axions, p0->ee, sgoldstino 3trks multi trks p->eeee

Forbidden 1 trk: F1TRK • L0: • the main trigger (pnn) has some efficiency for F1TRKdecays (ex: 40% for K->pg,100% for p0->nn) • DedicatedF1TRK: Q1*RICH32*!MUV3*!LAV is the startingpoint (500kHz). Tight !MIP*ETOT*NLKR? • RICHGPU: reconstruct the missing mass of the p+ (Elena) • L1/2: decayvertex+LKr • Some studiesalreadydone by Tommaso and Elisa: • p0->3g 4kHz (28%) • p0->4g 17 kHz (18%) Proposal: 7.2 MHz 1 kHz 50 kHz L1/L2 L0

Forbidden 3 trks: F3TRK • L0: • Starting point Q1*RICH>20*!LAV (>1 MHz) • Possibility to exploit the asymmetry on the RICH illumination to trigger on three tracks (P.Cooper – note (draft)) • Define triggers exploiting event topology and different detectors  dilepton triggers (Evgueni), Dark Photon (Bruno), … • Attempt to have a single strobe to L1 using GPU (next slide) • Higher efficiency (to be studied) • Smaller use of the L0 bandwidth • L1/L2: decay vertex+PID+Total Energy+… Proposal: 1 kHz 0.5 MHz 50 kHz L1/L2 L0

example For each 3 rings event build the following quantities: 1 2 • If for (mp,mp,mp) A is close to the transverse momentum of the kaon the event will be rejected • Simulation needed to understand resolution, rejection power and efficiency. 3 Where (m1, m2, m3) are the particles masses mp,mm,me

Twoscenarios • High intensity • Standard trigger configuration: pnn + F1TRK + F3TRK + FMTRK + OTHER/D1 + Q1/D2 + NHOD/D3 + CAL + RND • Low intensity (10%) • In principle it’s possible to think about an alternative trigger scheme (either changing D1,D2,D3 or changing cuts in order to increase the single trigger efficiency) Q1/50 Q1/50 pnn pnn F1/3TRK F1/3TRK

Conclusions • Assuming limited statistics in 2014, we will be competitive only on few forbidden decay modes. • Dedicatedtriggers to collectForbiddens and exotics: • Significantoverlap with othertriggers for physics and trigger for detector studies • In any case to study high efficiency low bandwidth dedicated parasitic triggers (for any channels), we could profit from the first phase of data collection. • It’s not a loss of time to collect data for all the decay modes.

“ F orbidden decays in 2014: material for discussion ”