Using SU(3) Relations to bound the CP Asymmetries in B→KKKB \to KKK decays

We consider three body $\Delta s = 1$ $B \to f$ decays with $f=KKK$. The deviations of $-\eta_f S_f$ from $S_{\psi K_S}$ and of $C_f$ from zero can be bounded using the approximate SU(3) flavor symmetry of the strong interactions and branching ratios of various $\Delta s = 0$ modes. We present the most promising SU(3) amplitude relations that can be used to obtain these bounds.Comment: 14 pages, revtex

Relating leptogenesis parameters to light neutrino masses

We obtain model independent relations among neutrino masses and leptogenesis parameters. We find exact relations that involve the CP asymmetries $\epsilon_{N_\alpha}$, the washout parameters $\tilde m_\alpha$ and $\theta_{\alpha\beta}$, and the neutrino masses $m_i$ and $M_\alpha$, as well as powerful inequalities that involve just $\tilde m_\alpha$ and $m_i$. We prove that the Yukawa interactions of at least two of the heavy singlet neutrinos are in the strong washout region ($\tilde m_\alpha\gg10^{-3} eV$).Comment: 5 pages, 1 figur

The importance of N2 leptogenesis

We argue that fast interactions of the lightest singlet neutrino $N_1$ would project part of a preexisting lepton asymmetry $L_p$ onto a direction that is protected from $N_1$ washout effects, thus preventing it from being erased. In particular, we consider an asymmetry generated in $N_2$ decays, assuming that $N_1$ interactions are fast enough to bring $N_1$ into full thermal equilibrium. If $N_1$ decays occur at T\gsim 10^9 GeV, that is, before the muon Yukawa interactions enter into thermal equilibrium, then generically part of $L_p$ survives. In this case some of the constraints implied by the standard $N_1$ leptogenesis scenario hold only if $L_p \approx 0$. For T\lsim 10^9 GeV, $L_p$ is generally erased, unless special alignment/orthogonality conditions in flavor space are realized.Comment: 5 pages. A few clarifications added, conclusions unchanged. Version published in Phys. Rev. Lett. (Title changed in journal

SPICE: Simulation Package for Including Flavor in Collider Events

We describe SPICE: Simulation Package for Including Flavor in Collider Events. SPICE takes as input two ingredients: a standard flavor-conserving supersymmetric spectrum and a set of flavor-violating slepton mass parameters, both of which are specified at some high "mediation" scale. SPICE then combines these two ingredients to form a flavor-violating model, determines the resulting low-energy spectrum and branching ratios, and outputs HERWIG and SUSY LesHouches files, which may be used to generate collider events. The flavor-conserving model may be any of the standard supersymmetric models, including minimal supergravity, minimal gauge-mediated supersymmetry breaking, and anomaly-mediated supersymmetry breaking supplemented by a universal scalar mass. The flavor-violating contributions may be specified in a number of ways, from specifying charges of fields under horizontal symmetries to completely specifying all flavor-violating parameters. SPICE is fully documented and publicly available, and is intended to be a user-friendly aid in the study of flavor at the Large Hadron Collider and other future colliders.Comment: 31 pages, 3 figures, SPICE can be downloaded from http://hep.ps.uci.edu/~spice; v2: published versio

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival